feat: init timeline zoom

4 files changed, 1855 insertions, 22 deletions

diff --git a/apps/web/src/components/editor/timeline-clean.tsx b/apps/web/src/components/editor/timeline-clean.tsx
new file mode 100644
index 00000000..cfb031a8
--- /dev/null
+++ b/apps/web/src/components/editor/timeline-clean.tsx
@@ -0,0 +1,665 @@
+"use client";
+
+import { Button } from "../ui/button";
+import {
+  Scissors,
+  ArrowLeftToLine,
+  ArrowRightToLine,
+  Trash2,
+  Snowflake,
+  Copy,
+  SplitSquareHorizontal,
+  Pause,
+  Play,
+  Video,
+  Music,
+  TypeIcon,
+  Lock,
+  LockOpen,
+  Link,
+} from "lucide-react";
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipTrigger,
+  TooltipProvider,
+} from "../ui/tooltip";
+import {
+  ContextMenu,
+  ContextMenuContent,
+  ContextMenuItem,
+  ContextMenuTrigger,
+} from "../ui/context-menu";
+import { useTimelineStore } from "@/stores/timeline-store";
+import { useMediaStore } from "@/stores/media-store";
+import { usePlaybackStore } from "@/stores/playback-store";
+import { useProjectStore } from "@/stores/project-store";
+import { useTimelineZoom } from "@/hooks/use-timeline-zoom";
+import { processMediaFiles } from "@/lib/media-processing";
+import { toast } from "sonner";
+import { useState, useRef, useEffect, useCallback } from "react";
+import { TimelineTrackContent } from "./timeline-track";
+import {
+  TimelinePlayhead,
+  useTimelinePlayheadRuler,
+} from "./timeline-playhead";
+import { SelectionBox } from "./selection-box";
+import { useSelectionBox } from "@/hooks/use-selection-box";
+import { SnapIndicator } from "./snap-indicator";
+import { SnapPoint } from "@/hooks/use-timeline-snapping";
+import type { DragData, TimelineTrack } from "@/types/timeline";
+import {
+  getTrackHeight,
+  getCumulativeHeightBefore,
+  getTotalTracksHeight,
+  TIMELINE_CONSTANTS,
+  snapTimeToFrame,
+} from "@/constants/timeline-constants";
+import { TimelineZoomControl } from "./timeline-zoom-control";
+import { useTimelineZoomActions } from "@/hooks/use-timeline-zoom-actions";
+
+export function Timeline() {
+  const {
+    tracks,
+    addTrack,
+    addElementToTrack,
+    removeElementFromTrack,
+    removeElementFromTrackWithRipple,
+    getTotalDuration,
+    calculateFitToWindowZoom,
+    selectedElements,
+    clearSelectedElements,
+    setSelectedElements,
+    splitElement,
+    splitAndKeepLeft,
+    splitAndKeepRight,
+    toggleTrackMute,
+    separateAudio,
+    snappingEnabled,
+    toggleSnapping,
+    rippleEditingEnabled,
+    toggleRippleEditing,
+    dragState,
+  } = useTimelineStore();
+  const { mediaItems, addMediaItem } = useMediaStore();
+  const { activeProject } = useProjectStore();
+  const { currentTime, duration, seek, setDuration, isPlaying, toggle } =
+    usePlaybackStore();
+  const [isDragOver, setIsDragOver] = useState(false);
+  const [isProcessing, setIsProcessing] = useState(false);
+  const [progress, setProgress] = useState(0);
+  const dragCounterRef = useRef(0);
+  const timelineRef = useRef<HTMLDivElement>(null);
+  const rulerRef = useRef<HTMLDivElement>(null);
+  const [isInTimeline, setIsInTimeline] = useState(false);
+
+  // Track mouse down/up for distinguishing clicks from drag/resize ends
+  const mouseTrackingRef = useRef({
+    isMouseDown: false,
+    downX: 0,
+    downY: 0,
+    downTime: 0,
+  });
+
+  // Fit to window function
+  const handleFitToWindow = useCallback(() => {
+    if (timelineRef.current) {
+      const containerWidth = timelineRef.current.clientWidth;
+      const optimalZoom = calculateFitToWindowZoom(containerWidth);
+      setZoomLevel(optimalZoom);
+    }
+  }, [calculateFitToWindowZoom]);
+
+  // Timeline zoom functionality
+  const { zoomLevel, setZoomLevel, handleWheel } = useTimelineZoom({
+    containerRef: timelineRef,
+    isInTimeline,
+    onFitToWindow: handleFitToWindow,
+  });
+
+  // Dynamic timeline width calculation based on playhead position and duration
+  const dynamicTimelineWidth = Math.max(
+    (duration || 0) * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel,
+    (currentTime + 30) * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel,
+    timelineRef.current?.clientWidth || 1000
+  );
+
+  // Scroll synchronization and auto-scroll to playhead
+  const rulerScrollRef = useRef<HTMLDivElement>(null);
+  const tracksScrollRef = useRef<HTMLDivElement>(null);
+  const trackLabelsRef = useRef<HTMLDivElement>(null);
+  const playheadRef = useRef<HTMLDivElement>(null);
+  const trackLabelsScrollRef = useRef<HTMLDivElement>(null);
+  const isUpdatingRef = useRef(false);
+  const lastRulerSync = useRef(0);
+  const lastTracksSync = useRef(0);
+  const lastVerticalSync = useRef(0);
+
+  // Timeline playhead ruler handlers
+  const { handleRulerMouseDown } = useTimelinePlayheadRuler({
+    currentTime,
+    duration,
+    zoomLevel,
+    seek,
+    rulerRef,
+    rulerScrollRef,
+    tracksScrollRef,
+    playheadRef,
+  });
+
+  // Zoom actions
+  useTimelineZoomActions({
+    zoomLevel,
+    setZoomLevel,
+    onFitToWindow: handleFitToWindow,
+  });
+
+  // Selection box functionality
+  const tracksContainerRef = useRef<HTMLDivElement>(null);
+  const {
+    selectionBox,
+    handleMouseDown: handleSelectionMouseDown,
+    isSelecting,
+    justFinishedSelecting,
+  } = useSelectionBox({
+    containerRef: tracksContainerRef,
+    playheadRef,
+    onSelectionComplete: (elements) => {
+      console.log(JSON.stringify({ onSelectionComplete: elements.length }));
+      setSelectedElements(elements);
+    },
+  });
+
+  // Calculate snap indicator state
+  const [currentSnapPoint, setCurrentSnapPoint] = useState<SnapPoint | null>(
+    null
+  );
+  const showSnapIndicator =
+    dragState.isDragging && snappingEnabled && currentSnapPoint !== null;
+
+  // Callback to handle snap point changes from TimelineTrackContent
+  const handleSnapPointChange = useCallback((snapPoint: SnapPoint | null) => {
+    setCurrentSnapPoint(snapPoint);
+  }, []);
+
+  // Track mouse down to distinguish real clicks from drag/resize ends
+  const handleTimelineMouseDown = useCallback((e: React.MouseEvent) => {
+    // Only track mouse down on timeline background areas (not elements)
+    const target = e.target as HTMLElement;
+    const isTimelineBackground =
+      !target.closest(".timeline-element") &&
+      !playheadRef.current?.contains(target) &&
+      !target.closest("[data-track-labels]");
+
+    if (isTimelineBackground) {
+      const now = Date.now();
+      mouseTrackingRef.current = {
+        isMouseDown: true,
+        downX: e.clientX,
+        downY: e.clientY,
+        downTime: now,
+      };
+    }
+  }, []);
+
+  // Track mouse up globally to reset mouse tracking
+  useEffect(() => {
+    const handleGlobalMouseUp = () => {
+      mouseTrackingRef.current.isMouseDown = false;
+    };
+
+    window.addEventListener("mouseup", handleGlobalMouseUp);
+    return () => window.removeEventListener("mouseup", handleGlobalMouseUp);
+  }, []);
+
+  // Handle clicks on timeline content (not playhead/ruler)
+  const handleTimelineContentClick = useCallback((e: React.MouseEvent) => {
+    // Only handle clicks if we didn't move much (distinguishing from drag end)
+    const { isMouseDown, downX, downY, downTime } = mouseTrackingRef.current;
+    const now = Date.now();
+    const distance = Math.sqrt(
+      Math.pow(e.clientX - downX, 2) + Math.pow(e.clientY - downY, 2)
+    );
+
+    // Not a real click if:
+    // - Mouse wasn't pressed down in timeline background
+    // - Too much movement (likely drag end)
+    // - Too much time passed (likely hold or slow drag)
+    if (!isMouseDown || distance > 5 || now - downTime > 300) {
+      return;
+    }
+
+    // Only proceed if we're not currently selecting and didn't just finish selecting
+    if (isSelecting || justFinishedSelecting) {
+      return;
+    }
+
+    // Get timeline content element and click position
+    const timelineContent = e.currentTarget as HTMLElement;
+    const rect = timelineContent.getBoundingClientRect();
+    const clickX = e.clientX - rect.left;
+
+    // Convert click position to time
+    const timeFromClick =
+      clickX / (TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel);
+
+    // Snap to frame boundary for accurate seeking
+    const snappedTime = snapTimeToFrame(timeFromClick, 30);
+
+    // Seek to the clicked time
+    seek(Math.max(0, snappedTime));
+  }, [zoomLevel, seek, isSelecting, justFinishedSelecting]);
+
+  // Scroll synchronization effect
+  useEffect(() => {
+    const rulerViewport = rulerScrollRef.current;
+    const tracksViewport = tracksScrollRef.current?.parentElement;
+    const trackLabelsViewport = trackLabelsScrollRef.current?.parentElement;
+
+    if (!rulerViewport || !tracksViewport) return;
+
+    // Horizontal scroll synchronization between ruler and tracks
+    const handleRulerScroll = () => {
+      const now = Date.now();
+      if (isUpdatingRef.current || now - lastRulerSync.current < 16) return;
+      lastRulerSync.current = now;
+      isUpdatingRef.current = true;
+      tracksViewport.scrollLeft = rulerViewport.scrollLeft;
+      isUpdatingRef.current = false;
+    };
+    const handleTracksScroll = () => {
+      const now = Date.now();
+      if (isUpdatingRef.current || now - lastTracksSync.current < 16) return;
+      lastTracksSync.current = now;
+      isUpdatingRef.current = true;
+      rulerViewport.scrollLeft = tracksViewport.scrollLeft;
+      isUpdatingRef.current = false;
+    };
+
+    rulerViewport.addEventListener("scroll", handleRulerScroll);
+    tracksViewport.addEventListener("scroll", handleTracksScroll);
+
+    // Vertical scroll synchronization between track labels and tracks content
+    if (trackLabelsViewport) {
+      const handleTrackLabelsScroll = () => {
+        const now = Date.now();
+        if (isUpdatingRef.current || now - lastVerticalSync.current < 16)
+          return;
+        lastVerticalSync.current = now;
+        isUpdatingRef.current = true;
+        tracksViewport.scrollTop = trackLabelsViewport.scrollTop;
+        isUpdatingRef.current = false;
+      };
+      const handleTracksVerticalScroll = () => {
+        const now = Date.now();
+        if (isUpdatingRef.current || now - lastVerticalSync.current < 16)
+          return;
+        lastVerticalSync.current = now;
+        isUpdatingRef.current = true;
+        trackLabelsViewport.scrollTop = tracksViewport.scrollTop;
+        isUpdatingRef.current = false;
+      };
+
+      trackLabelsViewport.addEventListener("scroll", handleTrackLabelsScroll);
+      tracksViewport.addEventListener("scroll", handleTracksVerticalScroll);
+
+      return () => {
+        rulerViewport.removeEventListener("scroll", handleRulerScroll);
+        tracksViewport.removeEventListener("scroll", handleTracksScroll);
+        trackLabelsViewport.removeEventListener("scroll", handleTrackLabelsScroll);
+        tracksViewport.removeEventListener("scroll", handleTracksVerticalScroll);
+      };
+    }
+
+    return () => {
+      rulerViewport.removeEventListener("scroll", handleRulerScroll);
+      tracksViewport.removeEventListener("scroll", handleTracksScroll);
+    };
+  }, []);
+
+  return (
+    <div
+      className="h-full flex flex-col transition-colors duration-200 relative bg-panel rounded-sm overflow-hidden"
+      onMouseEnter={() => setIsInTimeline(true)}
+      onMouseLeave={() => setIsInTimeline(false)}
+    >
+      {/* Toolbar */}
+      <div className="border-b flex items-center justify-between px-2 py-1">
+        <div className="flex items-center gap-1 w-full">
+          <TooltipProvider delayDuration={500}>
+            {/* Play/Pause Button */}
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant="text"
+                  size="icon"
+                  onClick={toggle}
+                  className="mr-2"
+                >
+                  {isPlaying ? (
+                    <Pause className="h-4 w-4" />
+                  ) : (
+                    <Play className="h-4 w-4" />
+                  )}
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>
+                {isPlaying ? "Pause (Space)" : "Play (Space)"}
+              </TooltipContent>
+            </Tooltip>
+            
+            <div className="w-px h-6 bg-border mx-1" />
+            
+            {/* Time Display */}
+            <div className="text-sm text-muted-foreground mr-2 font-mono">
+              {(() => {
+                const formatTime = (seconds: number) => {
+                  const h = Math.floor(seconds / 3600);
+                  const m = Math.floor((seconds % 3600) / 60);
+                  const s = Math.floor(seconds % 60);
+                  const ms = Math.floor((seconds % 1) * 100);
+                  return h > 0
+                    ? `${h}:${m.toString().padStart(2, "0")}:${s.toString().padStart(2, "0")}.${ms.toString().padStart(2, "0")}`
+                    : `${m}:${s.toString().padStart(2, "0")}.${ms.toString().padStart(2, "0")}`;
+                };
+                return `${formatTime(currentTime)} / ${formatTime(duration)}`;
+              })()}
+            </div>
+            
+            <div className="w-px h-6 bg-border mx-1" />
+            
+            {/* Timeline Settings */}
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant={snappingEnabled ? "default" : "text"}
+                  size="icon"
+                  onClick={toggleSnapping}
+                >
+                  <Snowflake className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>
+                {snappingEnabled ? "Disable Snapping" : "Enable Snapping"}
+              </TooltipContent>
+            </Tooltip>
+            
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant={rippleEditingEnabled ? "default" : "text"}
+                  size="icon"
+                  onClick={toggleRippleEditing}
+                >
+                  <Link className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>
+                {rippleEditingEnabled ? "Disable Ripple Editing" : "Enable Ripple Editing"}
+              </TooltipContent>
+            </Tooltip>
+          </TooltipProvider>
+          
+          {/* Timeline Zoom Control */}
+          <div className="w-px h-6 bg-border mx-2" />
+          <TimelineZoomControl
+            zoomLevel={zoomLevel}
+            onZoomChange={setZoomLevel}
+            onFitToWindow={handleFitToWindow}
+            className="mr-2"
+          />
+        </div>
+      </div>
+
+      {/* Timeline Container */}
+      <div
+        className="flex-1 flex flex-col overflow-hidden relative"
+        ref={timelineRef}
+      >
+        <TimelinePlayhead
+          currentTime={currentTime}
+          duration={duration}
+          zoomLevel={zoomLevel}
+          tracks={tracks}
+          seek={seek}
+          rulerRef={rulerRef}
+          rulerScrollRef={rulerScrollRef}
+          tracksScrollRef={tracksScrollRef}
+          trackLabelsRef={trackLabelsRef}
+          timelineRef={timelineRef}
+          playheadRef={playheadRef}
+          isSnappingToPlayhead={
+            showSnapIndicator && currentSnapPoint?.type === "playhead"
+          }
+        />
+        
+        <SnapIndicator
+          snapPoint={currentSnapPoint}
+          zoomLevel={zoomLevel}
+          tracks={tracks}
+          timelineRef={timelineRef}
+          trackLabelsRef={trackLabelsRef}
+          isVisible={showSnapIndicator}
+        />
+        
+        {/* Timeline Header with Ruler */}
+        <div className="flex bg-panel sticky top-0 z-10">
+          {/* Track Labels Header */}
+          <div className="w-48 flex-shrink-0 bg-muted/30 border-r flex items-center justify-between px-3 py-2">
+            <span className="text-sm font-medium text-muted-foreground opacity-0">.</span>
+          </div>
+
+          {/* Timeline Ruler */}
+          <div
+            className="flex-1 relative overflow-x-auto overflow-y-hidden h-4"
+            onWheel={handleWheel}
+            onMouseDown={handleSelectionMouseDown}
+            onClick={handleTimelineContentClick}
+            data-ruler-area
+            ref={rulerScrollRef}
+          >
+            <div
+              ref={rulerRef}
+              className="relative h-4 select-none cursor-default"
+              style={{
+                width: `${dynamicTimelineWidth}px`,
+              }}
+              onMouseDown={handleRulerMouseDown}
+            >
+              {/* Time markers */}
+              {(() => {
+                const getTimeInterval = (zoom: number) => {
+                  const pixelsPerSecond = TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoom;
+                  if (pixelsPerSecond >= 200) return 0.1;
+                  if (pixelsPerSecond >= 100) return 0.5;
+                  if (pixelsPerSecond >= 50) return 1;
+                  if (pixelsPerSecond >= 25) return 2;
+                  if (pixelsPerSecond >= 12) return 5;
+                  if (pixelsPerSecond >= 6) return 10;
+                  return 30;
+                };
+
+                const interval = getTimeInterval(zoomLevel);
+                const markerCount = Math.ceil(duration / interval) + 1;
+
+                return Array.from({ length: markerCount }, (_, i) => {
+                  const time = i * interval;
+                  if (time > duration) return null;
+
+                  const isMainMarker = time % (interval >= 1 ? Math.max(1, interval) : 1) === 0;
+
+                  return (
+                    <div
+                      key={i}
+                      className={`absolute top-0 bottom-0 ${
+                        isMainMarker
+                          ? "border-l border-muted-foreground/40"
+                          : "border-l border-muted-foreground/20"
+                      }`}
+                      style={{
+                        left: `${time * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel}px`,
+                      }}
+                    >
+                      <span
+                        className={`absolute top-1 left-1 text-[0.6rem] ${
+                          isMainMarker
+                            ? "text-muted-foreground font-medium"
+                            : "text-muted-foreground/70"
+                        }`}
+                      >
+                        {(() => {
+                          const formatTime = (seconds: number) => {
+                            const hours = Math.floor(seconds / 3600);
+                            const minutes = Math.floor((seconds % 3600) / 60);
+                            const secs = seconds % 60;
+
+                            if (hours > 0) {
+                              return `${hours}:${minutes.toString().padStart(2, "0")}:${Math.floor(secs).toString().padStart(2, "0")}`;
+                            } else if (minutes > 0) {
+                              return `${minutes}:${Math.floor(secs).toString().padStart(2, "0")}`;
+                            } else if (interval >= 1) {
+                              return `${Math.floor(secs)}s`;
+                            } else {
+                              return `${secs.toFixed(1)}s`;
+                            }
+                          };
+                          return formatTime(time);
+                        })()}
+                      </span>
+                    </div>
+                  );
+                }).filter(Boolean);
+              })()}
+            </div>
+          </div>
+        </div>
+
+        {/* Tracks Area */}
+        <div className="flex-1 flex overflow-hidden">
+          {/* Track Labels */}
+          {tracks.length > 0 && (
+            <div
+              ref={trackLabelsRef}
+              className="w-48 flex-shrink-0 border-r border-black overflow-y-auto"
+              data-track-labels
+            >
+              <div
+                ref={trackLabelsScrollRef}
+                className="w-full h-full"
+              >
+                <div className="flex flex-col gap-1">
+                  {tracks.map((track) => (
+                    <div
+                      key={track.id}
+                      className="flex items-center px-3 border-b border-muted/30 group bg-foreground/5"
+                      style={{ height: `${getTrackHeight(track.type)}px` }}
+                    >
+                      <div className="flex items-center flex-1 min-w-0">
+                        <TrackIcon track={track} />
+                      </div>
+                      {track.muted && (
+                        <span className="ml-2 text-xs text-red-500 font-semibold flex-shrink-0">
+                          Muted
+                        </span>
+                      )}
+                    </div>
+                  ))}
+                </div>
+              </div>
+            </div>
+          )}
+
+          {/* Timeline Tracks Content */}
+          <div
+            className="flex-1 relative overflow-auto"
+            onWheel={handleWheel}
+            onMouseDown={(e) => {
+              handleTimelineMouseDown(e);
+              handleSelectionMouseDown(e);
+            }}
+            onClick={handleTimelineContentClick}
+            ref={tracksContainerRef}
+          >
+            <div
+              ref={tracksScrollRef}
+              className="w-full h-full"
+            >
+              <SelectionBox
+                startPos={selectionBox?.startPos || null}
+                currentPos={selectionBox?.currentPos || null}
+                containerRef={tracksContainerRef}
+                isActive={selectionBox?.isActive || false}
+              />
+              <div
+                className="relative flex-1"
+                style={{
+                  height: `${Math.max(200, Math.min(800, getTotalTracksHeight(tracks)))}px`,
+                  width: `${dynamicTimelineWidth}px`,
+                }}
+              >
+                {tracks.length === 0 ? (
+                  <div></div>
+                ) : (
+                  <>
+                    {tracks.map((track, index) => (
+                      <ContextMenu key={track.id}>
+                        <ContextMenuTrigger asChild>
+                          <div
+                            className="absolute left-0 right-0 border-b border-muted/30 py-[0.05rem]"
+                            style={{
+                              top: `${getCumulativeHeightBefore(tracks, index)}px`,
+                              height: `${getTrackHeight(track.type)}px`,
+                            }}
+                            onClick={(e) => {
+                              if (
+                                !(e.target as HTMLElement).closest(".timeline-element")
+                              ) {
+                                clearSelectedElements();
+                              }
+                            }}
+                          >
+                            <TimelineTrackContent
+                              track={track}
+                              zoomLevel={zoomLevel}
+                              onSnapPointChange={handleSnapPointChange}
+                            />
+                          </div>
+                        </ContextMenuTrigger>
+                        <ContextMenuContent>
+                          <ContextMenuItem
+                            onClick={() => toggleTrackMute(track.id)}
+                          >
+                            {track.muted ? "Unmute Track" : "Mute Track"}
+                          </ContextMenuItem>
+                          <ContextMenuItem>
+                            Track settings (soon)
+                          </ContextMenuItem>
+                        </ContextMenuContent>
+                      </ContextMenu>
+                    ))}
+                  </>
+                )}
+              </div>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+function TrackIcon({ track }: { track: TimelineTrack }) {
+  return (
+    <>
+      {track.type === "media" && (
+        <Video className="w-4 h-4 flex-shrink-0 text-muted-foreground" />
+      )}
+      {track.type === "text" && (
+        <TypeIcon className="w-4 h-4 flex-shrink-0 text-muted-foreground" />
+      )}
+      {track.type === "audio" && (
+        <Music className="w-4 h-4 flex-shrink-0 text-muted-foreground" />
+      )}
+    </>
+  );
+}
diff --git a/apps/web/src/components/editor/timeline-fixed.tsx b/apps/web/src/components/editor/timeline-fixed.tsx
new file mode 100644
index 00000000..12b7012c
--- /dev/null
+++ b/apps/web/src/components/editor/timeline-fixed.tsx
@@ -0,0 +1,1008 @@
+"use client";
+
+import { Button } from "../ui/button";
+import {
+  Scissors,
+  ArrowLeftToLine,
+  ArrowRightToLine,
+  Trash2,
+  Snowflake,
+  Copy,
+  SplitSquareHorizontal,
+  Pause,
+  Play,
+  Video,
+  Music,
+  TypeIcon,
+  Lock,
+  LockOpen,
+  Link,
+} from "lucide-react";
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipTrigger,
+  TooltipProvider,
+} from "../ui/tooltip";
+import {
+  ContextMenu,
+  ContextMenuContent,
+  ContextMenuItem,
+  ContextMenuTrigger,
+} from "../ui/context-menu";
+import { useTimelineStore } from "@/stores/timeline-store";
+import { useMediaStore } from "@/stores/media-store";
+import { usePlaybackStore } from "@/stores/playback-store";
+import { useProjectStore } from "@/stores/project-store";
+import { useTimelineZoom } from "@/hooks/use-timeline-zoom";
+import { processMediaFiles } from "@/lib/media-processing";
+import { toast } from "sonner";
+import { useState, useRef, useEffect, useCallback } from "react";
+import { TimelineTrackContent } from "./timeline-track";
+import {
+  TimelinePlayhead,
+  useTimelinePlayheadRuler,
+} from "./timeline-playhead";
+import { SelectionBox } from "./selection-box";
+import { useSelectionBox } from "@/hooks/use-selection-box";
+import { SnapIndicator } from "./snap-indicator";
+import { SnapPoint } from "@/hooks/use-timeline-snapping";
+import type { DragData, TimelineTrack } from "@/types/timeline";
+import {
+  getTrackHeight,
+  getCumulativeHeightBefore,
+  getTotalTracksHeight,
+  TIMELINE_CONSTANTS,
+  snapTimeToFrame,
+} from "@/constants/timeline-constants";
+import { TimelineZoomControl } from "./timeline-zoom-control";
+import { useTimelineZoomActions } from "@/hooks/use-timeline-zoom-actions";
+
+export function Timeline() {
+  // Timeline shows all tracks (video, audio, effects) and their elements.
+  // You can drag media here to add it to your project.
+  // elements can be trimmed, deleted, and moved.
+
+  const {
+    tracks,
+    addTrack,
+    addElementToTrack,
+    removeElementFromTrack,
+    removeElementFromTrackWithRipple,
+    getTotalDuration,
+    calculateFitToWindowZoom,
+    selectedElements,
+    clearSelectedElements,
+    setSelectedElements,
+    splitElement,
+    splitAndKeepLeft,
+    splitAndKeepRight,
+    toggleTrackMute,
+    separateAudio,
+    snappingEnabled,
+    toggleSnapping,
+    rippleEditingEnabled,
+    toggleRippleEditing,
+    dragState,
+  } = useTimelineStore();
+  const { mediaItems, addMediaItem } = useMediaStore();
+  const { activeProject } = useProjectStore();
+  const { currentTime, duration, seek, setDuration, isPlaying, toggle } =
+    usePlaybackStore();
+  const [isDragOver, setIsDragOver] = useState(false);
+  const [isProcessing, setIsProcessing] = useState(false);
+  const [progress, setProgress] = useState(0);
+  const dragCounterRef = useRef(0);
+  const timelineRef = useRef<HTMLDivElement>(null);
+  const rulerRef = useRef<HTMLDivElement>(null);
+  const [isInTimeline, setIsInTimeline] = useState(false);
+
+  // Track mouse down/up for distinguishing clicks from drag/resize ends
+  const mouseTrackingRef = useRef({
+    isMouseDown: false,
+    downX: 0,
+    downY: 0,
+    downTime: 0,
+  });
+
+  // Fit to window function
+  const handleFitToWindow = useCallback(() => {
+    if (timelineRef.current) {
+      const containerWidth = timelineRef.current.clientWidth;
+      const optimalZoom = calculateFitToWindowZoom(containerWidth);
+      setZoomLevel(optimalZoom);
+    }
+  }, [calculateFitToWindowZoom]);
+
+  // Timeline zoom functionality
+  const { zoomLevel, setZoomLevel, handleWheel } = useTimelineZoom({
+    containerRef: timelineRef,
+    isInTimeline,
+    onFitToWindow: handleFitToWindow,
+  });
+
+  // Old marquee selection removed - using new SelectionBox component instead
+
+  // Dynamic timeline width calculation based on playhead position and duration
+  const dynamicTimelineWidth = Math.max(
+    (duration || 0) * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel, // Base width from duration
+    (currentTime + 30) * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel, // Width to show current time + 30 seconds buffer
+    timelineRef.current?.clientWidth || 1000 // Minimum width
+  );
+
+  // Scroll synchronization and auto-scroll to playhead
+  const rulerScrollRef = useRef<HTMLDivElement>(null);
+  const tracksScrollRef = useRef<HTMLDivElement>(null);
+  const trackLabelsRef = useRef<HTMLDivElement>(null);
+  const playheadRef = useRef<HTMLDivElement>(null);
+  const trackLabelsScrollRef = useRef<HTMLDivElement>(null);
+  const isUpdatingRef = useRef(false);
+  const lastRulerSync = useRef(0);
+  const lastTracksSync = useRef(0);
+  const lastVerticalSync = useRef(0);
+
+  // Timeline playhead ruler handlers
+  const { handleRulerMouseDown } = useTimelinePlayheadRuler({
+    currentTime,
+    duration,
+    zoomLevel,
+    seek,
+    rulerRef,
+    rulerScrollRef,
+    tracksScrollRef,
+    playheadRef,
+  });
+
+  // Zoom actions
+  useTimelineZoomActions({
+    zoomLevel,
+    setZoomLevel,
+    onFitToWindow: handleFitToWindow,
+  });
+
+  // Selection box functionality
+  const tracksContainerRef = useRef<HTMLDivElement>(null);
+  const {
+    selectionBox,
+    handleMouseDown: handleSelectionMouseDown,
+    isSelecting,
+    justFinishedSelecting,
+  } = useSelectionBox({
+    containerRef: tracksContainerRef,
+    playheadRef,
+    onSelectionComplete: (elements) => {
+      console.log(JSON.stringify({ onSelectionComplete: elements.length }));
+      setSelectedElements(elements);
+    },
+  });
+
+  // Calculate snap indicator state
+  const [currentSnapPoint, setCurrentSnapPoint] = useState<SnapPoint | null>(
+    null
+  );
+  const showSnapIndicator =
+    dragState.isDragging && snappingEnabled && currentSnapPoint !== null;
+
+  // Callback to handle snap point changes from TimelineTrackContent
+  const handleSnapPointChange = useCallback((snapPoint: SnapPoint | null) => {
+    setCurrentSnapPoint(snapPoint);
+  }, []);
+
+  // Track mouse down to distinguish real clicks from drag/resize ends
+  const handleTimelineMouseDown = useCallback((e: React.MouseEvent) => {
+    // Only track mouse down on timeline background areas (not elements)
+    const target = e.target as HTMLElement;
+    const isTimelineBackground =
+      !target.closest(".timeline-element") &&
+      !playheadRef.current?.contains(target) &&
+      !target.closest("[data-track-labels]");
+
+    if (isTimelineBackground) {
+      const now = Date.now();
+      mouseTrackingRef.current = {
+        isMouseDown: true,
+        downX: e.clientX,
+        downY: e.clientY,
+        downTime: now,
+      };
+    }
+  }, []);
+
+  // Track mouse up globally to reset mouse tracking
+  useEffect(() => {
+    const handleGlobalMouseUp = () => {
+      mouseTrackingRef.current.isMouseDown = false;
+    };
+
+    window.addEventListener("mouseup", handleGlobalMouseUp);
+    return () => window.removeEventListener("mouseup", handleGlobalMouseUp);
+  }, []);
+
+  // Handle clicks on timeline content (not playhead/ruler)
+  const handleTimelineContentClick = useCallback((e: React.MouseEvent) => {
+    // Only handle clicks if we didn't move much (distinguishing from drag end)
+    const { isMouseDown, downX, downY, downTime } = mouseTrackingRef.current;
+    const now = Date.now();
+    const distance = Math.sqrt(
+      Math.pow(e.clientX - downX, 2) + Math.pow(e.clientY - downY, 2)
+    );
+
+    // Not a real click if:
+    // - Mouse wasn't pressed down in timeline background
+    // - Too much movement (likely drag end)
+    // - Too much time passed (likely hold or slow drag)
+    if (!isMouseDown || distance > 5 || now - downTime > 300) {
+      return;
+    }
+
+    // Only proceed if we're not currently selecting and didn't just finish selecting
+    if (isSelecting || justFinishedSelecting) {
+      return;
+    }
+
+    // Get timeline content element and click position
+    const timelineContent = e.currentTarget as HTMLElement;
+    const rect = timelineContent.getBoundingClientRect();
+    const clickX = e.clientX - rect.left;
+
+    // Convert click position to time
+    const timeFromClick =
+      clickX / (TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel);
+
+    // Snap to frame boundary for accurate seeking
+    const snappedTime = snapTimeToFrame(timeFromClick);
+
+    // Seek to the clicked time
+    seek(Math.max(0, snappedTime));
+  }, [zoomLevel, seek, isSelecting, justFinishedSelecting]);
+
+  // Drag and drop handlers for adding media to timeline
+  const dragProps = {
+    onDragEnter: handleDragEnter,
+    onDragOver: handleDragOver,
+    onDragLeave: handleDragLeave,
+    onDrop: handleDrop,
+  };
+
+  function handleDragEnter(e: React.DragEvent) {
+    e.preventDefault();
+
+    // Don't update state for timeline elements - they're handled by tracks
+    if (e.dataTransfer.types.includes("application/x-timeline-element")) {
+      return;
+    }
+
+    dragCounterRef.current += 1;
+    if (dragCounterRef.current === 1) {
+      setIsDragOver(true);
+    }
+  }
+
+  const handleDragOver = (e: React.DragEvent) => {
+    e.preventDefault();
+  };
+
+  const handleDragLeave = (e: React.DragEvent) => {
+    e.preventDefault();
+
+    // Don't update state for timeline elements - they're handled by tracks
+    if (e.dataTransfer.types.includes("application/x-timeline-element")) {
+      return;
+    }
+
+    dragCounterRef.current -= 1;
+    if (dragCounterRef.current === 0) {
+      setIsDragOver(false);
+    }
+  };
+
+  const handleDrop = async (e: React.DragEvent) => {
+    // When media is dropped, add it as a new track/element
+    e.preventDefault();
+    setIsDragOver(false);
+    dragCounterRef.current = 0;
+
+    // Ignore timeline element drags - they're handled by track-specific handlers
+    const hasTimelineElement = e.dataTransfer.types.includes(
+      "application/x-timeline-element"
+    );
+    if (hasTimelineElement) {
+      return;
+    }
+
+    const itemData = e.dataTransfer.getData("application/x-media-item");
+    if (itemData) {
+      try {
+        const dragData: DragData = JSON.parse(itemData);
+
+        if (dragData.type === "text") {
+          // Always create new text track to avoid overlaps
+          useTimelineStore.getState().addTextToNewTrack(dragData);
+        } else {
+          // Handle media items
+          const mediaItem = mediaItems.find(
+            (item: any) => item.id === dragData.id
+          );
+          if (!mediaItem) {
+            toast.error("Media item not found");
+            return;
+          }
+
+          // Add to first available track or create new one
+          const targetTrack = tracks.find(
+            (track) => track.type === "media" && track.elements.length === 0
+          );
+
+          if (targetTrack) {
+            await addElementToTrack(targetTrack.id, {
+              id: crypto.randomUUID(),
+              type: "media",
+              mediaId: mediaItem.id,
+              startTime: 0,
+              duration: mediaItem.duration,
+              trimStart: 0,
+              trimEnd: 0,
+            });
+          } else {
+            const trackId = crypto.randomUUID();
+            addTrack({
+              id: trackId,
+              type: "media",
+              name: `Track ${tracks.length + 1}`,
+              elements: [],
+              muted: false,
+              volume: 1,
+            });
+            await addElementToTrack(trackId, {
+              id: crypto.randomUUID(),
+              type: "media",
+              mediaId: mediaItem.id,
+              startTime: 0,
+              duration: mediaItem.duration,
+              trimStart: 0,
+              trimEnd: 0,
+            });
+          }
+        }
+      } catch (error) {
+        console.error("Error parsing drag data:", error);
+        toast.error("Failed to add media to timeline");
+      }
+      return;
+    }
+
+    // Handle file drops (e.g., from desktop)
+    const files = Array.from(e.dataTransfer.files);
+    if (files.length > 0) {
+      setIsProcessing(true);
+      setProgress(0);
+      try {
+        const processedMedia = await processMediaFiles(files, (progress) => {
+          setProgress(progress);
+        });
+
+        for (const media of processedMedia) {
+          addMediaItem(media);
+
+          // Add to timeline automatically
+          const trackId = crypto.randomUUID();
+          addTrack({
+            id: trackId,
+            type: "media",
+            name: `Track ${tracks.length + 1}`,
+            elements: [],
+            muted: false,
+            volume: 1,
+          });
+          await addElementToTrack(trackId, {
+            id: crypto.randomUUID(),
+            type: "media",
+            mediaId: media.id,
+            startTime: 0,
+            duration: media.duration,
+            trimStart: 0,
+            trimEnd: 0,
+          });
+        }
+
+        toast.success(`Added ${processedMedia.length} media files to timeline`);
+      } catch (error) {
+        console.error("Error processing dropped files:", error);
+        toast.error("Failed to process some files");
+      } finally {
+        setIsProcessing(false);
+        setProgress(0);
+      }
+    }
+  };
+
+  // Keyboard shortcuts for timeline actions
+  useEffect(() => {
+    const handleKeyDown = (e: KeyboardEvent) => {
+      // Only handle shortcuts when timeline is focused or no input is focused
+      const isInputFocused = document.activeElement?.tagName.match(/INPUT|TEXTAREA|SELECT/);
+      if (isInputFocused) return;
+
+      if (e.key === 'Delete' || e.key === 'Backspace') {
+        e.preventDefault();
+        handleDeleteSelected();
+      }
+    };
+
+    window.addEventListener('keydown', handleKeyDown);
+    return () => window.removeEventListener('keydown', handleKeyDown);
+  }, [selectedElements, rippleEditingEnabled]);
+
+  // Context menu handlers
+  const handleSplitElement = () => {
+    if (selectedElements.length !== 1) {
+      toast.error("Select exactly one element to split");
+      return;
+    }
+    const { trackId, elementId } = selectedElements[0];
+    splitElement(trackId, elementId, currentTime);
+  };
+
+  const handleSplitAndKeepLeft = () => {
+    if (selectedElements.length !== 1) {
+      toast.error("Select exactly one element to split");
+      return;
+    }
+    const { trackId, elementId } = selectedElements[0];
+    const track = tracks.find((t) => t.id === trackId);
+    const element = track?.elements.find((e) => e.id === elementId);
+    if (!track || !element) return;
+
+    const effectiveStart = element.startTime + element.trimStart;
+    const effectiveEnd =
+      element.startTime +
+      (element.duration - element.trimStart - element.trimEnd);
+    if (currentTime <= effectiveStart || currentTime >= effectiveEnd) {
+      toast.error("Playhead must be within selected element");
+      return;
+    }
+    splitAndKeepLeft(trackId, elementId, currentTime);
+  };
+
+  const handleSplitAndKeepRight = () => {
+    if (selectedElements.length !== 1) {
+      toast.error("Select exactly one element to split");
+      return;
+    }
+    const { trackId, elementId } = selectedElements[0];
+    const track = tracks.find((t) => t.id === trackId);
+    const element = track?.elements.find((e) => e.id === elementId);
+    if (!track || !element) return;
+
+    const effectiveStart = element.startTime + element.trimStart;
+    const effectiveEnd =
+      element.startTime +
+      (element.duration - element.trimStart - element.trimEnd);
+    if (currentTime <= effectiveStart || currentTime >= effectiveEnd) {
+      toast.error("Playhead must be within selected element");
+      return;
+    }
+    splitAndKeepRight(trackId, elementId, currentTime);
+  };
+
+  const handleSeparateAudio = () => {
+    if (selectedElements.length !== 1) {
+      toast.error("Select exactly one media element to separate audio");
+      return;
+    }
+    const { trackId, elementId } = selectedElements[0];
+    const track = tracks.find((t) => t.id === trackId);
+    if (!track || track.type !== "media") {
+      toast.error("Select a media element to separate audio");
+      return;
+    }
+    separateAudio(trackId, elementId);
+  };
+
+  const handleDeleteSelected = () => {
+    if (selectedElements.length === 0) {
+      toast.error("No elements selected");
+      return;
+    }
+    selectedElements.forEach(({ trackId, elementId }) => {
+      if (rippleEditingEnabled) {
+        removeElementFromTrackWithRipple(trackId, elementId);
+      } else {
+        removeElementFromTrack(trackId, elementId);
+      }
+    });
+    clearSelectedElements();
+  };
+
+  // --- Scroll synchronization effect ---
+  useEffect(() => {
+    const rulerViewport = rulerScrollRef.current;
+    const tracksViewport = tracksScrollRef.current?.parentElement; // The container with overflow-auto
+    const trackLabelsViewport = trackLabelsScrollRef.current?.parentElement; // The container with overflow-y-auto
+
+    if (!rulerViewport || !tracksViewport) return;
+
+    // Horizontal scroll synchronization between ruler and tracks
+    const handleRulerScroll = () => {
+      const now = Date.now();
+      if (isUpdatingRef.current || now - lastRulerSync.current < 16) return;
+      lastRulerSync.current = now;
+      isUpdatingRef.current = true;
+      tracksViewport.scrollLeft = rulerViewport.scrollLeft;
+      isUpdatingRef.current = false;
+    };
+    const handleTracksScroll = () => {
+      const now = Date.now();
+      if (isUpdatingRef.current || now - lastTracksSync.current < 16) return;
+      lastTracksSync.current = now;
+      isUpdatingRef.current = true;
+      rulerViewport.scrollLeft = tracksViewport.scrollLeft;
+      isUpdatingRef.current = false;
+    };
+
+    rulerViewport.addEventListener("scroll", handleRulerScroll);
+    tracksViewport.addEventListener("scroll", handleTracksScroll);
+
+    // Vertical scroll synchronization between track labels and tracks content
+    if (trackLabelsViewport) {
+      const handleTrackLabelsScroll = () => {
+        const now = Date.now();
+        if (isUpdatingRef.current || now - lastVerticalSync.current < 16)
+          return;
+        lastVerticalSync.current = now;
+        isUpdatingRef.current = true;
+        tracksViewport.scrollTop = trackLabelsViewport.scrollTop;
+        isUpdatingRef.current = false;
+      };
+      const handleTracksVerticalScroll = () => {
+        const now = Date.now();
+        if (isUpdatingRef.current || now - lastVerticalSync.current < 16)
+          return;
+        lastVerticalSync.current = now;
+        isUpdatingRef.current = true;
+        trackLabelsViewport.scrollTop = tracksViewport.scrollTop;
+        isUpdatingRef.current = false;
+      };
+
+      trackLabelsViewport.addEventListener("scroll", handleTrackLabelsScroll);
+      tracksViewport.addEventListener("scroll", handleTracksVerticalScroll);
+
+      return () => {
+        rulerViewport.removeEventListener("scroll", handleRulerScroll);
+        tracksViewport.removeEventListener("scroll", handleTracksScroll);
+        trackLabelsViewport.removeEventListener("scroll", handleTrackLabelsScroll);
+        tracksViewport.removeEventListener("scroll", handleTracksVerticalScroll);
+      };
+    }
+
+    return () => {
+      rulerViewport.removeEventListener("scroll", handleRulerScroll);
+      tracksViewport.removeEventListener("scroll", handleTracksScroll);
+    };
+  }, []);
+
+  return (
+    <div
+      className={`h-full flex flex-col transition-colors duration-200 relative bg-panel rounded-sm overflow-hidden`}
+      {...dragProps}
+      onMouseEnter={() => setIsInTimeline(true)}
+      onMouseLeave={() => setIsInTimeline(false)}
+    >
+      {/* Toolbar */}
+      <div className="border-b flex items-center justify-between px-2 py-1">
+        <div className="flex items-center gap-1 w-full">
+          <TooltipProvider delayDuration={500}>
+            {/* Play/Pause Button */}
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant="text"
+                  size="icon"
+                  onClick={toggle}
+                  className="mr-2"
+                >
+                  {isPlaying ? (
+                    <Pause className="h-4 w-4" />
+                  ) : (
+                    <Play className="h-4 w-4" />
+                  )}
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>
+                {isPlaying ? "Pause (Space)" : "Play (Space)"}
+              </TooltipContent>
+            </Tooltip>
+            <div className="w-px h-6 bg-border mx-1" />
+            {/* Time Display */}
+            <div className="text-sm text-muted-foreground mr-2 font-mono">
+              {(() => {
+                const formatTime = (seconds: number) => {
+                  const h = Math.floor(seconds / 3600);
+                  const m = Math.floor((seconds % 3600) / 60);
+                  const s = Math.floor(seconds % 60);
+                  const ms = Math.floor((seconds % 1) * 100);
+                  return h > 0
+                    ? `${h}:${m.toString().padStart(2, "0")}:${s.toString().padStart(2, "0")}.${ms.toString().padStart(2, "0")}`
+                    : `${m}:${s.toString().padStart(2, "0")}.${ms.toString().padStart(2, "0")}`;
+                };
+                return `${formatTime(currentTime)} / ${formatTime(duration)}`;
+              })()}
+            </div>
+            <div className="w-px h-6 bg-border mx-1" />
+            {/* Element Actions */}
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant="text"
+                  size="icon"
+                  onClick={handleSplitElement}
+                  disabled={selectedElements.length !== 1}
+                >
+                  <Scissors className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>Split element at playhead (S)</TooltipContent>
+            </Tooltip>
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant="text"
+                  size="icon"
+                  onClick={handleSplitAndKeepLeft}
+                  disabled={selectedElements.length !== 1}
+                >
+                  <ArrowLeftToLine className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>Split and keep left part</TooltipContent>
+            </Tooltip>
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant="text"
+                  size="icon"
+                  onClick={handleSplitAndKeepRight}
+                  disabled={selectedElements.length !== 1}
+                >
+                  <ArrowRightToLine className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>Split and keep right part</TooltipContent>
+            </Tooltip>
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant="text"
+                  size="icon"
+                  onClick={handleDeleteSelected}
+                  disabled={selectedElements.length === 0}
+                >
+                  <Trash2 className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>Delete selected elements (Del)</TooltipContent>
+            </Tooltip>
+            <div className="w-px h-6 bg-border mx-1" />
+            {/* Media Actions */}
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant="text"
+                  size="icon"
+                  onClick={handleSeparateAudio}
+                  disabled={
+                    selectedElements.length !== 1 ||
+                    !tracks
+                      .find((t) => t.id === selectedElements[0]?.trackId)
+                      ?.elements.find((e) => e.id === selectedElements[0]?.elementId)
+                  }
+                >
+                  <SplitSquareHorizontal className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>Separate audio from video</TooltipContent>
+            </Tooltip>
+            <div className="w-px h-6 bg-border mx-1" />
+            {/* Timeline Settings */}
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant={snappingEnabled ? "accent" : "text"}
+                  size="icon"
+                  onClick={toggleSnapping}
+                >
+                  <Snowflake className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>
+                {snappingEnabled ? "Disable Snapping" : "Enable Snapping"}
+              </TooltipContent>
+            </Tooltip>
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  variant={rippleEditingEnabled ? "accent" : "text"}
+                  size="icon"
+                  onClick={toggleRippleEditing}
+                >
+                  <Link className="h-4 w-4" />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>
+                {rippleEditingEnabled
+                  ? "Disable Ripple Editing"
+                  : "Enable Ripple Editing"}
+              </TooltipContent>
+            </Tooltip>
+          </TooltipProvider>
+          
+          {/* Timeline Zoom Control */}
+          <div className="w-px h-6 bg-border mx-2" />
+          <TimelineZoomControl
+            zoomLevel={zoomLevel}
+            onZoomChange={setZoomLevel}
+            onFitToWindow={handleFitToWindow}
+            className="mr-2"
+          />
+        </div>
+      </div>
+
+      {/* Timeline Container */}
+      <div
+        className="flex-1 flex flex-col overflow-hidden relative"
+        ref={timelineRef}
+      >
+        <TimelinePlayhead
+          currentTime={currentTime}
+          duration={duration}
+          zoomLevel={zoomLevel}
+          tracks={tracks}
+          seek={seek}
+          rulerRef={rulerRef}
+          rulerScrollRef={rulerScrollRef}
+          tracksScrollRef={tracksScrollRef}
+          trackLabelsRef={trackLabelsRef}
+          timelineRef={timelineRef}
+          playheadRef={playheadRef}
+          isSnappingToPlayhead={
+            showSnapIndicator && currentSnapPoint?.type === "playhead"
+          }
+        />
+        <SnapIndicator
+          snapPoint={currentSnapPoint}
+          zoomLevel={zoomLevel}
+          tracks={tracks}
+          timelineRef={timelineRef}
+          trackLabelsRef={trackLabelsRef}
+          isVisible={showSnapIndicator}
+        />
+        {/* Timeline Header with Ruler */}
+        <div className="flex bg-panel sticky top-0 z-10">
+          {/* Track Labels Header */}
+          <div className="w-48 flex-shrink-0 bg-muted/30 border-r flex items-center justify-between px-3 py-2">
+            {/* Empty space */}
+            <span className="text-sm font-medium text-muted-foreground opacity-0">
+              .
+            </span>
+          </div>
+
+          {/* Timeline Ruler */}
+          <div
+            className="flex-1 relative overflow-x-auto overflow-y-hidden h-4"
+            onWheel={handleWheel}
+            onMouseDown={handleSelectionMouseDown}
+            onClick={handleTimelineContentClick}
+            data-ruler-area
+            ref={rulerScrollRef}
+          >
+            <div
+              ref={rulerRef}
+              className="relative h-4 select-none cursor-default"
+              style={{
+                width: `${dynamicTimelineWidth}px`,
+              }}
+              onMouseDown={handleRulerMouseDown}
+            >
+                {/* Time markers */}
+                {(() => {
+                  // Calculate appropriate time interval based on zoom level
+                  const getTimeInterval = (zoom: number) => {
+                    const pixelsPerSecond =
+                      TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoom;
+                    if (pixelsPerSecond >= 200) return 0.1; // Every 0.1s when very zoomed in
+                    if (pixelsPerSecond >= 100) return 0.5; // Every 0.5s when zoomed in
+                    if (pixelsPerSecond >= 50) return 1; // Every 1s at normal zoom
+                    if (pixelsPerSecond >= 25) return 2; // Every 2s when zoomed out
+                    if (pixelsPerSecond >= 12) return 5; // Every 5s when more zoomed out
+                    if (pixelsPerSecond >= 6) return 10; // Every 10s when very zoomed out
+                    return 30; // Every 30s when extremely zoomed out
+                  };
+
+                  const interval = getTimeInterval(zoomLevel);
+                  const markerCount = Math.ceil(duration / interval) + 1;
+
+                  return Array.from({ length: markerCount }, (_, i) => {
+                    const time = i * interval;
+                    if (time > duration) return null;
+
+                    const isMainMarker =
+                      time % (interval >= 1 ? Math.max(1, interval) : 1) === 0;
+
+                    return (
+                      <div
+                        key={i}
+                        className={`absolute top-0 bottom-0 ${
+                          isMainMarker
+                            ? "border-l border-muted-foreground/40"
+                            : "border-l border-muted-foreground/20"
+                        }`}
+                        style={{
+                          left: `${time * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel}px`,
+                        }}
+                      >
+                        <span
+                          className={`absolute top-1 left-1 text-[0.6rem] ${
+                            isMainMarker
+                              ? "text-muted-foreground font-medium"
+                              : "text-muted-foreground/70"
+                          }`}
+                        >
+                          {(() => {
+                            const formatTime = (seconds: number) => {
+                              const hours = Math.floor(seconds / 3600);
+                              const minutes = Math.floor((seconds % 3600) / 60);
+                              const secs = seconds % 60;
+
+                              if (hours > 0) {
+                                return `${hours}:${minutes.toString().padStart(2, "0")}:${Math.floor(secs).toString().padStart(2, "0")}`;
+                              } else if (minutes > 0) {
+                                return `${minutes}:${Math.floor(secs).toString().padStart(2, "0")}`;
+                              } else if (interval >= 1) {
+                                return `${Math.floor(secs)}s`;
+                              } else {
+                                return `${secs.toFixed(1)}s`;
+                              }
+                            };
+                            return formatTime(time);
+                          })()}
+                        </span>
+                      </div>
+                    );
+                  }).filter(Boolean);
+                })()}
+              </div>
+            </div>
+          </div>
+
+        {/* Tracks Area */}
+        <div className="flex-1 flex overflow-hidden">
+          {/* Track Labels */}
+          {tracks.length > 0 && (
+            <div
+              ref={trackLabelsRef}
+              className="w-48 flex-shrink-0 border-r border-black overflow-y-auto"
+              data-track-labels
+            >
+              <div
+                ref={trackLabelsScrollRef}
+                className="w-full h-full"
+              >
+                <div className="flex flex-col gap-1">
+                  {tracks.map((track) => (
+                    <div
+                      key={track.id}
+                      className="flex items-center px-3 border-b border-muted/30 group bg-foreground/5"
+                      style={{ height: `${getTrackHeight(track.type)}px` }}
+                    >
+                      <div className="flex items-center flex-1 min-w-0">
+                        <TrackIcon track={track} />
+                      </div>
+                      {track.muted && (
+                        <span className="ml-2 text-xs text-red-500 font-semibold flex-shrink-0">
+                          Muted
+                        </span>
+                      )}
+                    </div>
+                  ))}
+                </div>
+              </div>
+            </div>
+          )}
+
+          {/* Timeline Tracks Content */}
+          <div
+            className="flex-1 relative overflow-auto"
+            onWheel={handleWheel}
+            onMouseDown={(e) => {
+              handleTimelineMouseDown(e);
+              handleSelectionMouseDown(e);
+            }}
+            onClick={handleTimelineContentClick}
+            ref={tracksContainerRef}
+          >
+            <div
+              ref={tracksScrollRef}
+              className="w-full h-full"
+            >
+              <SelectionBox
+                startPos={selectionBox?.startPos || null}
+                currentPos={selectionBox?.currentPos || null}
+                containerRef={tracksContainerRef}
+                isActive={selectionBox?.isActive || false}
+              />
+              <div
+                className="relative flex-1"
+                style={{
+                  height: `${Math.max(200, Math.min(800, getTotalTracksHeight(tracks)))}px`,
+                  width: `${dynamicTimelineWidth}px`,
+                }}
+              >
+                {tracks.length === 0 ? (
+                  <div></div>
+                ) : (
+                  <>
+                    {tracks.map((track, index) => (
+                      <ContextMenu key={track.id}>
+                        <ContextMenuTrigger asChild>
+                          <div
+                            className="absolute left-0 right-0 border-b border-muted/30 py-[0.05rem]"
+                            style={{
+                              top: `${getCumulativeHeightBefore(tracks, index)}px`,
+                              height: `${getTrackHeight(track.type)}px`,
+                            }}
+                            onClick={(e) => {
+                              // If clicking empty area (not on a element), deselect all elements
+                              if (
+                                !(e.target as HTMLElement).closest(
+                                  ".timeline-element"
+                                )
+                              ) {
+                                clearSelectedElements();
+                              }
+                            }}
+                          >
+                            <TimelineTrackContent
+                              track={track}
+                              zoomLevel={zoomLevel}
+                              onSnapPointChange={handleSnapPointChange}
+                            />
+                          </div>
+                        </ContextMenuTrigger>
+                        <ContextMenuContent>
+                          <ContextMenuItem
+                            onClick={() => toggleTrackMute(track.id)}
+                          >
+                            {track.muted ? "Unmute Track" : "Mute Track"}
+                          </ContextMenuItem>
+                          <ContextMenuItem>
+                            Track settings (soon)
+                          </ContextMenuItem>
+                        </ContextMenuContent>
+                      </ContextMenu>
+                    ))}
+                  </>
+                )}
+              </div>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+function TrackIcon({ track }: { track: TimelineTrack }) {
+  return (
+    <>
+      {track.type === "media" && (
+        <Video className="w-4 h-4 flex-shrink-0 text-muted-foreground" />
+      )}
+      {track.type === "text" && (
+        <TypeIcon className="w-4 h-4 flex-shrink-0 text-muted-foreground" />
+      )}
+      {track.type === "audio" && (
+        <Music className="w-4 h-4 flex-shrink-0 text-muted-foreground" />
+      )}
+    </>
+  );
+}
diff --git a/apps/web/src/components/editor/timeline-zoom-control.tsx b/apps/web/src/components/editor/timeline-zoom-control.tsx
new file mode 100644
index 00000000..ab9c57a5
--- /dev/null
+++ b/apps/web/src/components/editor/timeline-zoom-control.tsx
@@ -0,0 +1,126 @@
+import { useState } from "react";
+import { Button } from "../ui/button";
+import { Slider } from "../ui/slider";
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipTrigger,
+} from "../ui/tooltip";
+import { ZoomIn, ZoomOut, Maximize2 } from "lucide-react";
+
+interface TimelineZoomControlProps {
+  zoomLevel: number;
+  onZoomChange: (zoom: number) => void;
+  onFitToWindow?: () => void;
+  className?: string;
+}
+
+export function TimelineZoomControl({
+  zoomLevel,
+  onZoomChange,
+  onFitToWindow,
+  className,
+}: TimelineZoomControlProps) {
+  // Convert zoom level to percentage for display
+  const zoomPercentage = Math.round(zoomLevel * 100);
+
+  const handleZoomIn = () => {
+    onZoomChange(Math.min(10, zoomLevel + 0.2));
+  };
+
+  const handleZoomOut = () => {
+    onZoomChange(Math.max(0.1, zoomLevel - 0.2));
+  };
+
+  const handleReset = () => {
+    if (onFitToWindow) {
+      onFitToWindow();
+    } else {
+      onZoomChange(1);
+    }
+  };
+
+  const handleSliderChange = (value: number[]) => {
+    onZoomChange(value[0]);
+  };
+
+  return (
+    <div className={`flex items-center gap-1 ${className || ""}`}>
+      {/* Zoom Out Button */}
+      <Tooltip>
+        <TooltipTrigger asChild>
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={handleZoomOut}
+            disabled={zoomLevel <= 0.1}
+            className="h-7 w-7 p-0"
+          >
+            <ZoomOut className="h-3 w-3" />
+          </Button>
+        </TooltipTrigger>
+        <TooltipContent>
+          <p>Zoom out</p>
+          <p className="text-xs text-muted-foreground">Ctrl + - / Ctrl + Wheel</p>
+        </TooltipContent>
+      </Tooltip>
+
+      {/* Zoom Slider */}
+      <div className="flex items-center gap-2 w-20">
+        <Slider
+          value={[zoomLevel]}
+          onValueChange={handleSliderChange}
+          min={0.1}
+          max={5}
+          step={0.1}
+          className="flex-1"
+        />
+      </div>
+
+      {/* Zoom In Button */}
+      <Tooltip>
+        <TooltipTrigger asChild>
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={handleZoomIn}
+            disabled={zoomLevel >= 5}
+            className="h-7 w-7 p-0"
+          >
+            <ZoomIn className="h-3 w-3" />
+          </Button>
+        </TooltipTrigger>
+        <TooltipContent>
+          <p>Zoom in</p>
+          <p className="text-xs text-muted-foreground">Ctrl + + / Ctrl + Wheel</p>
+        </TooltipContent>
+      </Tooltip>
+
+      {/* Fit to Window / Reset Button */}
+      <Tooltip>
+        <TooltipTrigger asChild>
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={handleReset}
+            className="h-7 px-2 min-w-[60px] flex items-center gap-1"
+          >
+            {onFitToWindow ? (
+              <>
+                <Maximize2 className="h-3 w-3" />
+              </>
+            ) : (
+              <span className="text-xs font-mono">{zoomPercentage}%</span>
+            )}
+          </Button>
+        </TooltipTrigger>
+        <TooltipContent>
+          <p>{onFitToWindow ? "Fit to Window" : "Reset Zoom"}</p>
+          <p className="text-xs text-muted-foreground">
+            {onFitToWindow ? "Show all track content" : "Ctrl + 0"}
+          </p>
+        </TooltipContent>
+      </Tooltip>
+    </div>
+  );
+}
diff --git a/apps/web/src/components/editor/timeline.tsx b/apps/web/src/components/editor/timeline.tsx
index 9e68fd4d..84c228f0 100644
--- a/apps/web/src/components/editor/timeline.tsx
+++ b/apps/web/src/components/editor/timeline.tsx
@@ -56,6 +56,8 @@ import {
   TIMELINE_CONSTANTS,
   snapTimeToFrame,
 } from "@/constants/timeline-constants";
+import { TimelineZoomControl } from "./timeline-zoom-control";
+import { useTimelineZoomActions } from "@/hooks/use-timeline-zoom-actions";
 
 export function Timeline() {
   // Timeline shows all tracks (video, audio, effects) and their elements.
@@ -69,6 +71,7 @@ export function Timeline() {
     removeElementFromTrack,
     removeElementFromTrackWithRipple,
     getTotalDuration,
+    calculateFitToWindowZoom,
     selectedElements,
     clearSelectedElements,
     setSelectedElements,
@@ -103,10 +106,20 @@ export function Timeline() {
     downTime: 0,
   });
 
+  // Fit to window function
+  const handleFitToWindow = useCallback(() => {
+    if (timelineRef.current) {
+      const containerWidth = timelineRef.current.clientWidth;
+      const optimalZoom = calculateFitToWindowZoom(containerWidth);
+      setZoomLevel(optimalZoom);
+    }
+  }, [calculateFitToWindowZoom]);
+
   // Timeline zoom functionality
   const { zoomLevel, setZoomLevel, handleWheel } = useTimelineZoom({
     containerRef: timelineRef,
     isInTimeline,
+    onFitToWindow: handleFitToWindow,
   });
 
   // Old marquee selection removed - using new SelectionBox component instead
@@ -141,6 +154,13 @@ export function Timeline() {
     playheadRef,
   });
 
+  // Zoom actions
+  useTimelineZoomActions({
+    zoomLevel,
+    setZoomLevel,
+    onFitToWindow: handleFitToWindow,
+  });
+
   // Selection box functionality
   const tracksContainerRef = useRef<HTMLDivElement>(null);
   const {
@@ -836,6 +856,15 @@ export function Timeline() {
               </TooltipContent>
             </Tooltip>
           </TooltipProvider>
+          
+          {/* Timeline Zoom Control */}
+          <div className="w-px h-6 bg-border mx-2" />
+          <TimelineZoomControl
+            zoomLevel={zoomLevel}
+            onZoomChange={setZoomLevel}
+            onFitToWindow={handleFitToWindow}
+            className="mr-2"
+          />
         </div>
       </div>
 
@@ -880,21 +909,21 @@ export function Timeline() {
 
           {/* Timeline Ruler */}
           <div
-            className="flex-1 relative overflow-hidden h-4"
+            className="flex-1 relative overflow-x-auto overflow-y-hidden h-4"
             onWheel={handleWheel}
             onMouseDown={handleSelectionMouseDown}
             onClick={handleTimelineContentClick}
             data-ruler-area
+            ref={rulerScrollRef}
           >
-            <ScrollArea className="w-full" ref={rulerScrollRef}>
-              <div
-                ref={rulerRef}
-                className="relative h-4 select-none cursor-default"
-                style={{
-                  width: `${dynamicTimelineWidth}px`,
-                }}
-                onMouseDown={handleRulerMouseDown}
-              >
+            <div
+              ref={rulerRef}
+              className="relative h-4 select-none cursor-default"
+              style={{
+                width: `${dynamicTimelineWidth}px`,
+              }}
+              onMouseDown={handleRulerMouseDown}
+            >
                 {/* Time markers */}
                 {(() => {
                   // Calculate appropriate time interval based on zoom level
@@ -962,8 +991,7 @@ export function Timeline() {
                     );
                   }).filter(Boolean);
                 })()}
-              </div>
-            </ScrollArea>
+            </div>
           </div>
         </div>
 
@@ -976,7 +1004,10 @@ export function Timeline() {
               className="w-48 flex-shrink-0 border-r border-black overflow-y-auto"
               data-track-labels
             >
-              <ScrollArea className="w-full h-full" ref={trackLabelsScrollRef}>
+              <ScrollArea
+                ref={trackLabelsScrollRef}
+                className="w-full h-full"
+              >
                 <div className="flex flex-col gap-1">
                   {tracks.map((track) => (
                     <div
@@ -1001,7 +1032,7 @@ export function Timeline() {
 
           {/* Timeline Tracks Content */}
           <div
-            className="flex-1 relative overflow-hidden"
+            className="flex-1 relative overflow-auto"
             onWheel={handleWheel}
             onMouseDown={(e) => {
               handleTimelineMouseDown(e);
@@ -1010,13 +1041,16 @@ export function Timeline() {
             onClick={handleTimelineContentClick}
             ref={tracksContainerRef}
           >
-            <SelectionBox
-              startPos={selectionBox?.startPos || null}
-              currentPos={selectionBox?.currentPos || null}
-              containerRef={tracksContainerRef}
-              isActive={selectionBox?.isActive || false}
-            />
-            <ScrollArea className="w-full h-full" ref={tracksScrollRef}>
+            <div
+              ref={tracksScrollRef}
+              className="w-full h-full"
+            >
+              <SelectionBox
+                startPos={selectionBox?.startPos || null}
+                currentPos={selectionBox?.currentPos || null}
+                containerRef={tracksContainerRef}
+                isActive={selectionBox?.isActive || false}
+              />
               <div
                 className="relative flex-1"
                 style={{
@@ -1070,7 +1104,7 @@ export function Timeline() {
                   </>
                 )}
               </div>
-            </ScrollArea>
+            </div>
           </div>
         </div>
       </div>