import React from "react";
import { useToast } from "@chakra-ui/react";

import { emptySearchQuery } from "./SearchToolbar";
import ItemsAndSearchPanels from "./ItemsAndSearchPanels";
import SearchFooter from "./SearchFooter";
import useOutfitSaving from "./useOutfitSaving";
import useOutfitState, { OutfitStateContext } from "./useOutfitState";
import WardrobePageLayout from "./WardrobePageLayout";
import WardrobePreviewAndControls from "./WardrobePreviewAndControls";

/**
 * WardrobePage is the most fun page on the site - it's where you create
 * outfits!
 *
 * This page has two sections: the OutfitPreview, where we show the outfit as a
 * big image; and the ItemsAndSearchPanels, which let you manage which items
 * are in the outfit and find new ones.
 *
 * This component manages shared outfit state, and the fullscreen responsive
 * page layout.
 */
function WardrobePage() {
	const toast = useToast();
	const { loading, error, outfitState, dispatchToOutfit } = useOutfitState();

	const [searchQuery, setSearchQuery] = React.useState(emptySearchQuery);

	// We manage outfit saving up here, rather than at the point of the UI where
	// "Saving" indicators appear. That way, auto-saving still happens even when
	// the indicator isn't on the page, e.g. when searching.
	// NOTE: This only applies to navigations leaving the wardrobe-2020 app, not
	// within!
	const outfitSaving = useOutfitSaving(outfitState, dispatchToOutfit);

	// TODO: I haven't found a great place for this error UI yet, and this case
	// isn't very common, so this lil toast notification seems good enough!
	React.useEffect(() => {
		if (error) {
			console.error(error);
			toast({
				title: "We couldn't load this outfit 😖",
				description: "Please reload the page to try again. Sorry!",
				status: "error",
				isClosable: true,
				duration: 999999999,
			});
		}
	}, [error, toast]);

	// For new outfits, we only block navigation while saving. For existing
	// outfits, we block navigation while there are any unsaved changes.
	const shouldBlockNavigation =
		outfitSaving.canSaveOutfit &&
		((outfitSaving.isNewOutfit && outfitSaving.isSaving) ||
			(!outfitSaving.isNewOutfit && !outfitSaving.latestVersionIsSaved));

	// In addition to a <Prompt /> for client-side nav, we need to block full nav!
	React.useEffect(() => {
		if (shouldBlockNavigation) {
			const onBeforeUnload = (e) => {
				// https://developer.mozilla.org/en-US/docs/Web/API/WindowEventHandlers/onbeforeunload#example
				e.preventDefault();
				e.returnValue = "";
			};

			window.addEventListener("beforeunload", onBeforeUnload);
			return () => window.removeEventListener("beforeunload", onBeforeUnload);
		}
	}, [shouldBlockNavigation]);

	const title = `${outfitState.name || "Untitled outfit"} | Dress to Impress`;
	React.useEffect(() => {
		document.title = title;
	}, [title]);

	// NOTE: Most components pass around outfitState directly, to make the data
	//       relationships more explicit... but there are some deep components
	//       that need it, where it's more useful and more performant to access
	//       via context.
	return (
		<OutfitStateContext.Provider value={outfitState}>
			<WardrobePageLayout
				previewAndControls={
					<WardrobePreviewAndControls
						isLoading={loading}
						outfitState={outfitState}
						dispatchToOutfit={dispatchToOutfit}
					/>
				}
				itemsAndMaybeSearchPanel={
					<ItemsAndSearchPanels
						loading={loading}
						searchQuery={searchQuery}
						onChangeSearchQuery={setSearchQuery}
						outfitState={outfitState}
						outfitSaving={outfitSaving}
						dispatchToOutfit={dispatchToOutfit}
					/>
				}
				searchFooter={
					<SearchFooter
						searchQuery={searchQuery}
						onChangeSearchQuery={setSearchQuery}
						outfitState={outfitState}
					/>
				}
			/>
		</OutfitStateContext.Provider>
	);
}

export default WardrobePage;