"use client";

import { ScrollArea } from "../ui/scroll-area";
import { Button } from "../ui/button";
import {
  Scissors,
  ArrowLeftToLine,
  ArrowRightToLine,
  Trash2,
  Snowflake,
  Copy,
  SplitSquareHorizontal,
} from "lucide-react";
import {
  Tooltip,
  TooltipContent,
  TooltipTrigger,
  TooltipProvider,
} from "../ui/tooltip";
import { DragOverlay } from "../ui/drag-overlay";
import { useTimelineStore, type TimelineTrack } from "@/stores/timeline-store";
import { useMediaStore } from "@/stores/media-store";
import { usePlaybackStore } from "@/stores/playback-store";
import { processMediaFiles } from "@/lib/media-processing";
import { ImageTimelineTreatment } from "@/components/ui/image-timeline-treatment";
import { toast } from "sonner";
import { useState, useRef, useEffect } from "react";

export function Timeline() {
  const { tracks, addTrack, addClipToTrack } = useTimelineStore();
  const { mediaItems, addMediaItem } = useMediaStore();
  const { currentTime, duration, seek } = usePlaybackStore();
  const [isDragOver, setIsDragOver] = useState(false);
  const [isProcessing, setIsProcessing] = useState(false);
  const [zoomLevel, setZoomLevel] = useState(1);
  const dragCounterRef = useRef(0);
  const timelineRef = useRef<HTMLDivElement>(null);

  const handleDragEnter = (e: React.DragEvent) => {
    e.preventDefault();

    // Don't show overlay for timeline clips or other internal drags
    if (e.dataTransfer.types.includes("application/x-timeline-clip")) {
      return;
    }

    dragCounterRef.current += 1;
    if (!isDragOver) {
      setIsDragOver(true);
    }
  };

  const handleDragOver = (e: React.DragEvent) => {
    e.preventDefault();
  };

  const handleDragLeave = (e: React.DragEvent) => {
    e.preventDefault();

    // Don't update state for timeline clips
    if (e.dataTransfer.types.includes("application/x-timeline-clip")) {
      return;
    }

    dragCounterRef.current -= 1;
    if (dragCounterRef.current === 0) {
      setIsDragOver(false);
    }
  };

  const handleDrop = async (e: React.DragEvent) => {
    e.preventDefault();
    setIsDragOver(false);
    dragCounterRef.current = 0;

    const timelineClipData = e.dataTransfer.getData("application/x-timeline-clip");
    if (timelineClipData) return;

    const mediaItemData = e.dataTransfer.getData("application/x-media-item");
    if (mediaItemData) {
      try {
        const { id, type } = JSON.parse(mediaItemData);
        const mediaItem = mediaItems.find((item) => item.id === id);

        if (!mediaItem) {
          toast.error("Media item not found");
          return;
        }

        const trackType = type === "audio" ? "audio" : "video";
        const newTrackId = addTrack(trackType);

        addClipToTrack(newTrackId, {
          mediaId: mediaItem.id,
          name: mediaItem.name,
          duration: mediaItem.duration || 5,
          startTime: 0,
          trimStart: 0,
          trimEnd: 0,
        });
      } catch (error) {
        console.error("Error parsing media item data:", error);
        toast.error("Failed to add media to timeline");
      }
    } else if (e.dataTransfer.files?.length > 0) {
      setIsProcessing(true);

      try {
        const processedItems = await processMediaFiles(e.dataTransfer.files);

        for (const processedItem of processedItems) {
          addMediaItem(processedItem);

          const currentMediaItems = useMediaStore.getState().mediaItems;
          const addedItem = currentMediaItems.find(
            (item) => item.name === processedItem.name && item.url === processedItem.url
          );

          if (addedItem) {
            const trackType = processedItem.type === "audio" ? "audio" : "video";
            const newTrackId = addTrack(trackType);

            addClipToTrack(newTrackId, {
              mediaId: addedItem.id,
              name: addedItem.name,
              duration: addedItem.duration || 5,
              startTime: 0,
              trimStart: 0,
              trimEnd: 0,
            });
          }
        }
      } catch (error) {
        console.error("Error processing external files:", error);
        toast.error("Failed to process dropped files");
      } finally {
        setIsProcessing(false);
      }
    }
  };

  const handleTimelineClick = (e: React.MouseEvent) => {
    const timeline = timelineRef.current;
    if (!timeline || duration === 0) return;

    const rect = timeline.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const timelineWidth = rect.width;
    const visibleDuration = duration / zoomLevel;
    const clickedTime = (x / timelineWidth) * visibleDuration;

    seek(Math.max(0, Math.min(duration, clickedTime)));
  };

  const handleWheel = (e: React.WheelEvent) => {
    e.preventDefault();
    const delta = e.deltaY > 0 ? -0.05 : 0.05;
    setZoomLevel(prev => Math.max(0.1, Math.min(10, prev + delta)));
  };

  const dragProps = {
    onDragEnter: handleDragEnter,
    onDragOver: handleDragOver,
    onDragLeave: handleDragLeave,
    onDrop: handleDrop,
  };

  return (
    <div
      className={`h-full flex flex-col transition-colors duration-200 relative ${isDragOver ? "bg-accent/30 border-accent" : ""
        }`}
      {...dragProps}
    >
      <DragOverlay
        isVisible={isDragOver}
        title={isProcessing ? "Processing files..." : "Drop media here"}
        description={
          isProcessing
            ? "Please wait while files are being processed"
            : "Add media to timeline tracks"
        }
      />

      {/* Toolbar */}
      <div className="border-b flex items-center px-2 py-1 gap-1">
        <TooltipProvider delayDuration={500}>
          <Tooltip>
            <TooltipTrigger asChild>
              <Button variant="ghost" size="icon">
                <Scissors className="h-4 w-4" />
              </Button>
            </TooltipTrigger>
            <TooltipContent>Split clip (S)</TooltipContent>
          </Tooltip>

          <Tooltip>
            <TooltipTrigger asChild>
              <Button variant="ghost" size="icon">
                <ArrowLeftToLine className="h-4 w-4" />
              </Button>
            </TooltipTrigger>
            <TooltipContent>Split and keep left (A)</TooltipContent>
          </Tooltip>

          <Tooltip>
            <TooltipTrigger asChild>
              <Button variant="ghost" size="icon">
                <ArrowRightToLine className="h-4 w-4" />
              </Button>
            </TooltipTrigger>
            <TooltipContent>Split and keep right (D)</TooltipContent>
          </Tooltip>

          <Tooltip>
            <TooltipTrigger asChild>
              <Button variant="ghost" size="icon">
                <SplitSquareHorizontal className="h-4 w-4" />
              </Button>
            </TooltipTrigger>
            <TooltipContent>Separate audio (E)</TooltipContent>
          </Tooltip>

          <Tooltip>
            <TooltipTrigger asChild>
              <Button variant="ghost" size="icon">
                <Copy className="h-4 w-4" />
              </Button>
            </TooltipTrigger>
            <TooltipContent>Duplicate clip (Ctrl+D)</TooltipContent>
          </Tooltip>

          <Tooltip>
            <TooltipTrigger asChild>
              <Button variant="ghost" size="icon">
                <Snowflake className="h-4 w-4" />
              </Button>
            </TooltipTrigger>
            <TooltipContent>Freeze frame (F)</TooltipContent>
          </Tooltip>

          <Tooltip>
            <TooltipTrigger asChild>
              <Button variant="ghost" size="icon">
                <Trash2 className="h-4 w-4" />
              </Button>
            </TooltipTrigger>
            <TooltipContent>Delete clip (Delete)</TooltipContent>
          </Tooltip>
        </TooltipProvider>
      </div>

      {/* Tracks Area */}
      <ScrollArea className="flex-1">
        <div
          ref={timelineRef}
          className="min-w-[800px] relative cursor-pointer select-none"
          onClick={handleTimelineClick}
          onWheel={handleWheel}
        >
          {/* Timeline Header */}
          <div className="py-3 relative bg-muted/30 border-b">
            {/* Zoom indicator */}
            <div className="absolute top-1 right-2 text-xs text-muted-foreground">
              {zoomLevel.toFixed(1)}x
            </div>
          </div>

          {/* Timeline Tracks */}
          <div className="relative">
            {tracks.length === 0 ? (
              <div className="flex flex-col items-center justify-center py-12 text-center">
                <div className="w-16 h-16 rounded-full bg-muted/30 flex items-center justify-center mb-4">
                  <SplitSquareHorizontal className="h-8 w-8 text-muted-foreground" />
                </div>
                <p className="text-sm text-muted-foreground">
                  No tracks in timeline
                </p>
                <p className="text-xs text-muted-foreground/70 mt-1">
                  Add a video or audio track to get started
                </p>
              </div>
            ) : (
              <div className="flex flex-col gap-2.5">
                {tracks.map((track) => (
                  <TimelineTrackComponent key={track.id} track={track} zoomLevel={zoomLevel} />
                ))}
              </div>
            )}

            {/* Playhead for tracks area */}
            {tracks.length > 0 && (
              <div
                className="absolute top-0 bottom-0 w-0.5 bg-red-500 pointer-events-none z-20"
                style={{
                  left: `${currentTime * 50 * zoomLevel + 128}px`,
                }}
              >
                <div className="absolute -top-8 left-1/2 transform -translate-x-1/2 w-3 h-3 bg-red-500 rounded-full border-2 border-white shadow-sm" />
              </div>
            )}
          </div>
        </div>
      </ScrollArea>
    </div>
  );
}

function TimelineTrackComponent({ track, zoomLevel }: { track: TimelineTrack, zoomLevel: number }) {
  const { mediaItems } = useMediaStore();
  const { moveClipToTrack, updateClipTrim, updateClipStartTime } = useTimelineStore();
  const [isDropping, setIsDropping] = useState(false);
  const [dropPosition, setDropPosition] = useState<number | null>(null);
  const [isDraggedOver, setIsDraggedOver] = useState(false);
  const [resizing, setResizing] = useState<{
    clipId: string;
    side: 'left' | 'right';
    startX: number;
    initialTrimStart: number;
    initialTrimEnd: number;
  } | null>(null);
  const dragCounterRef = useRef(0);

  const handleResizeStart = (e: React.MouseEvent, clipId: string, side: 'left' | 'right') => {
    e.stopPropagation();
    e.preventDefault();

    const clip = track.clips.find(c => c.id === clipId);
    if (!clip) return;

    setResizing({
      clipId,
      side,
      startX: e.clientX,
      initialTrimStart: clip.trimStart,
      initialTrimEnd: clip.trimEnd
    });
  };

  const updateTrimFromMouseMove = (e: { clientX: number }) => {
    if (!resizing) return;

    const clip = track.clips.find(c => c.id === resizing.clipId);
    if (!clip) return;

    const deltaX = e.clientX - resizing.startX;
    const deltaTime = deltaX / (50 * zoomLevel);

    if (resizing.side === 'left') {
      const newTrimStart = Math.max(0, Math.min(
        clip.duration - clip.trimEnd - 0.1,
        resizing.initialTrimStart + deltaTime
      ));
      updateClipTrim(track.id, clip.id, newTrimStart, clip.trimEnd);
    } else {
      const newTrimEnd = Math.max(0, Math.min(
        clip.duration - clip.trimStart - 0.1,
        resizing.initialTrimEnd - deltaTime
      ));
      updateClipTrim(track.id, clip.id, clip.trimStart, newTrimEnd);
    }
  };

  const handleResizeMove = (e: React.MouseEvent) => {
    updateTrimFromMouseMove(e);
  };

  const handleResizeEnd = () => {
    setResizing(null);
  };

  useEffect(() => {
    if (!resizing) return;

    const handleGlobalMouseMove = (e: MouseEvent) => {
      updateTrimFromMouseMove(e);
    };

    const handleGlobalMouseUp = () => {
      setResizing(null);
    };

    document.addEventListener('mousemove', handleGlobalMouseMove);
    document.addEventListener('mouseup', handleGlobalMouseUp);

    return () => {
      document.removeEventListener('mousemove', handleGlobalMouseMove);
      document.removeEventListener('mouseup', handleGlobalMouseUp);
    };
  }, [resizing, track.id, zoomLevel, updateClipTrim]);

  const handleClipDragStart = (e: React.DragEvent, clip: any) => {
    const dragData = { clipId: clip.id, trackId: track.id, name: clip.name };

    e.dataTransfer.setData("application/x-timeline-clip", JSON.stringify(dragData));
    e.dataTransfer.effectAllowed = "move";

    // Add visual feedback to the dragged element
    const target = e.currentTarget.parentElement as HTMLElement;
    target.style.opacity = "0.5";
    target.style.transform = "scale(0.95)";
  };

  const handleClipDragEnd = (e: React.DragEvent) => {
    // Reset visual feedback
    const target = e.currentTarget.parentElement as HTMLElement;
    target.style.opacity = "";
    target.style.transform = "";
  };

  const handleTrackDragOver = (e: React.DragEvent) => {
    e.preventDefault();
    if (!e.dataTransfer.types.includes("application/x-timeline-clip")) return;
    e.dataTransfer.dropEffect = "move";

    setIsDraggedOver(true);

    // Calculate and show drop position with better precision
    const trackContainer = e.currentTarget.querySelector(".track-clips-container") as HTMLElement;
    if (trackContainer) {
      const rect = trackContainer.getBoundingClientRect();
      const mouseX = Math.max(0, e.clientX - rect.left);
      const dropTime = mouseX / (50 * zoomLevel);
      setDropPosition(dropTime);
    }
  };

  const handleTrackDragEnter = (e: React.DragEvent) => {
    e.preventDefault();
    if (!e.dataTransfer.types.includes("application/x-timeline-clip")) return;

    dragCounterRef.current++;
    setIsDropping(true);
    setIsDraggedOver(true);
  };

  const handleTrackDragLeave = (e: React.DragEvent) => {
    e.preventDefault();
    if (!e.dataTransfer.types.includes("application/x-timeline-clip")) return;

    dragCounterRef.current--;

    if (dragCounterRef.current === 0) {
      setIsDropping(false);
      setIsDraggedOver(false);
      setDropPosition(null);
    }
  };

  const handleTrackDrop = (e: React.DragEvent) => {
    e.preventDefault();

    // Reset all drag states
    dragCounterRef.current = 0;
    setIsDropping(false);
    setIsDraggedOver(false);
    setDropPosition(null);

    if (!e.dataTransfer.types.includes("application/x-timeline-clip")) return;

    const timelineClipData = e.dataTransfer.getData("application/x-timeline-clip");
    if (!timelineClipData) return;

    try {
      const { clipId, trackId: fromTrackId } = JSON.parse(timelineClipData);
      const trackContainer = e.currentTarget.querySelector(".track-clips-container") as HTMLElement;

      if (!trackContainer) return;

      const rect = trackContainer.getBoundingClientRect();
      const mouseX = Math.max(0, e.clientX - rect.left);
      const newStartTime = mouseX / (50 * zoomLevel);

      // Snap to grid (optional - every 0.1 seconds)
      const snappedTime = Math.round(newStartTime * 10) / 10;

      if (fromTrackId === track.id) {
        updateClipStartTime(track.id, clipId, snappedTime);
      } else {
        moveClipToTrack(fromTrackId, track.id, clipId);
        // Use a small delay to ensure the clip is moved before updating position
        requestAnimationFrame(() => {
          updateClipStartTime(track.id, clipId, snappedTime);
        });
      }
    } catch (error) {
      console.error("Error moving clip:", error);
      toast.error("Failed to move clip");
    }
  };

  const getTrackColor = (type: string) => {
    switch (type) {
      case "video":
        return "bg-blue-500/20 border-blue-500/30";
      case "audio":
        return "bg-green-500/20 border-green-500/30";
      case "effects":
        return "bg-purple-500/20 border-purple-500/30";
      default:
        return "bg-gray-500/20 border-gray-500/30";
    }
  };

  const renderClipContent = (clip: any) => {
    const mediaItem = mediaItems.find((item) => item.id === clip.mediaId);

    if (!mediaItem) {
      return (
        <span className="text-xs text-foreground/80 truncate">{clip.name}</span>
      );
    }

    if (mediaItem.type === "image") {
      return (
        <div className="w-full h-full flex items-center justify-center">
          <img
            src={mediaItem.url}
            alt={mediaItem.name}
            className="w-full h-full object-cover"
          />
        </div>
      );
    }

    if (mediaItem.type === "video" && mediaItem.thumbnailUrl) {
      return (
        <div className="w-full h-full flex items-center gap-2">
          <div className="w-8 h-8 flex-shrink-0">
            <img
              src={mediaItem.thumbnailUrl}
              alt={mediaItem.name}
              className="w-full h-full object-cover rounded-sm"
            />
          </div>
          <span className="text-xs text-foreground/80 truncate flex-1">
            {clip.name}
          </span>
        </div>
      );
    }

    // Fallback for audio or videos without thumbnails
    return (
      <span className="text-xs text-foreground/80 truncate">{clip.name}</span>
    );
  };

  return (
    <div className="flex items-center px-2">
      <div className="w-24 text-xs text-muted-foreground flex-shrink-0 mr-2">
        {track.name}
      </div>

      <div
        className={`flex-1 h-[60px] transition-all duration-150 ease-out ${isDraggedOver
          ? "bg-blue-500/15 border-2 border-dashed border-blue-400 shadow-lg transform scale-[1.02]"
          : "border border-transparent hover:bg-muted/30"
          }`}
        onDragOver={handleTrackDragOver}
        onDragEnter={handleTrackDragEnter}
        onDragLeave={handleTrackDragLeave}
        onDrop={handleTrackDrop}
        onMouseMove={handleResizeMove}
        onMouseUp={handleResizeEnd}
        onMouseLeave={handleResizeEnd}
      >
        <div className="h-full relative track-clips-container min-w-full">
          {track.clips.length === 0 ? (
            <div className={`h-full w-full rounded-sm border-2 border-dashed flex items-center justify-center text-xs text-muted-foreground transition-colors ${isDropping ? "border-blue-500 bg-blue-500/10 text-blue-600" : "border-muted/30"
              }`}>
              {isDropping ? "Drop clip here" : "Drop media here"}
            </div>
          ) : (
            <>
              {track.clips.map((clip) => {
                const effectiveDuration = clip.duration - clip.trimStart - clip.trimEnd;
                const clipWidth = Math.max(80, effectiveDuration * 50 * zoomLevel);
                const clipLeft = clip.startTime * 50 * zoomLevel;

                return (
                  <div
                    key={clip.id}
                    className={`timeline-clip absolute h-full rounded-sm border transition-all duration-200 ${getTrackColor(track.type)} flex items-center py-3 min-w-[80px] overflow-hidden group hover:shadow-lg`}
                    style={{ width: `${clipWidth}px`, left: `${clipLeft}px` }}
                  >
                    <div
                      className="absolute left-0 top-0 bottom-0 w-2 cursor-w-resize opacity-0 group-hover:opacity-100 transition-opacity bg-blue-500/50 hover:bg-blue-500"
                      onMouseDown={(e) => handleResizeStart(e, clip.id, 'left')}
                    />

                    <div
                      className="flex-1 cursor-grab active:cursor-grabbing"
                      draggable={true}
                      onDragStart={(e) => handleClipDragStart(e, clip)}
                      onDragEnd={handleClipDragEnd}
                    >
                      {renderClipContent(clip)}
                    </div>

                    <div
                      className="absolute right-0 top-0 bottom-0 w-2 cursor-e-resize opacity-0 group-hover:opacity-100 transition-opacity bg-blue-500/50 hover:bg-blue-500"
                      onMouseDown={(e) => handleResizeStart(e, clip.id, 'right')}
                    />
                  </div>
                );
              })}

              {/* Drop position indicator */}
              {isDraggedOver && dropPosition !== null && (
                <div
                  className="absolute top-0 bottom-0 w-1 bg-blue-500 pointer-events-none z-30 transition-all duration-75 ease-out"
                  style={{ left: `${dropPosition * 50 * zoomLevel}px`, transform: 'translateX(-50%)' }}
                >
                  <div className="absolute -top-2 left-1/2 transform -translate-x-1/2 w-3 h-3 bg-blue-500 rounded-full border-2 border-white shadow-md" />
                  <div className="absolute -bottom-2 left-1/2 transform -translate-x-1/2 w-3 h-3 bg-blue-500 rounded-full border-2 border-white shadow-md" />
                  <div className="absolute top-1/2 left-1/2 transform -translate-x-1/2 -translate-y-1/2 text-xs text-white bg-blue-500 px-1 py-0.5 rounded whitespace-nowrap">
                    {dropPosition.toFixed(1)}s
                  </div>
                </div>
              )}
            </>
          )}
        </div>
      </div>
    </div>
  );
}