import { useMemo } from "react";
import { toast } from "sonner";
import { useTimelineStore } from "@/stores/timeline-store";
import { usePlaybackStore } from "@/stores/playback-store";

export function useTimelineActionHandlers() {
	const {
		tracks,
		addElementToTrack,
		removeElementFromTrack,
		selectedElements,
		clearSelectedElements,
		splitElement,
		splitAndKeepLeft,
		splitAndKeepRight,
		separateAudio,
	} = useTimelineStore();
	const { currentTime } = usePlaybackStore();

	// Create optimized lookup maps for O(1) access instead of O(n) find operations
	const trackMap = useMemo(() => {
		const map = new Map();
		tracks.forEach((track) => {
			map.set(track.id, track);
			// Also create element lookup for this track
			const elementMap = new Map();
			track.elements.forEach((element) => {
				elementMap.set(element.id, element);
			});
			map.set(`${track.id}_elements`, elementMap);
		});
		return map;
	}, [tracks]);

	// Helper function for O(1) track/element lookup
	const findTrackAndElement = (trackId: string, elementId: string) => {
		const track = trackMap.get(trackId);
		const elementMap = trackMap.get(`${trackId}_elements`);
		const element = elementMap?.get(elementId);
		return { track, element };
	};

	// Action handlers for toolbar
	const handleSplitSelected = () => {
		if (selectedElements.length === 0) {
			toast.error("No elements selected");
			return;
		}
		let splitCount = 0;
		selectedElements.forEach(({ trackId, elementId }) => {
			const { track, element } = findTrackAndElement(trackId, elementId);
			if (element && track) {
				const effectiveStart = element.startTime;
				const effectiveEnd =
					element.startTime +
					(element.duration - element.trimStart - element.trimEnd);

				if (currentTime > effectiveStart && currentTime < effectiveEnd) {
					const newElementId = splitElement(trackId, elementId, currentTime);
					if (newElementId) splitCount++;
				}
			}
		});
		if (splitCount === 0) {
			toast.error("Playhead must be within selected elements to split");
		}
	};

	const handleDuplicateSelected = () => {
		if (selectedElements.length === 0) {
			toast.error("No elements selected");
			return;
		}
		const canDuplicate = selectedElements.length === 1;
		if (!canDuplicate) return;

		selectedElements.forEach(({ trackId, elementId }) => {
			const { element } = findTrackAndElement(trackId, elementId);

			if (element) {
				const newStartTime =
					element.startTime +
					(element.duration - element.trimStart - element.trimEnd) +
					0.1;

				// Create element without id (will be generated by store)
				const { id, ...elementWithoutId } = element;

				addElementToTrack(trackId, {
					...elementWithoutId,
					startTime: newStartTime,
				});

				// We can't predict the new id, so just clear selection for now
				// TODO: addElementToTrack could return the new element id
			}
		});

		clearSelectedElements();
	};

	const handleFreezeSelected = () => {
		toast.info("Freeze frame functionality coming soon!");
	};

	const handleSplitAndKeepLeft = () => {
		if (selectedElements.length !== 1) {
			toast.error("Select exactly one element");
			return;
		}
		const { trackId, elementId } = selectedElements[0];
		const { element } = findTrackAndElement(trackId, elementId);
		if (!element) return;
		const effectiveStart = element.startTime;
		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");
			return;
		}
		const { trackId, elementId } = selectedElements[0];
		const { element } = findTrackAndElement(trackId, elementId);
		if (!element) return;
		const effectiveStart = element.startTime;
		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 } = findTrackAndElement(trackId, elementId);
		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 }) => {
			removeElementFromTrack(trackId, elementId);
		});
		clearSelectedElements();
	};

	return {
		handleSplitSelected,
		handleDuplicateSelected,
		handleFreezeSelected,
		handleSplitAndKeepLeft,
		handleSplitAndKeepRight,
		handleSeparateAudio,
		handleDeleteSelected,
	};
}