// Copyright (C) 2017-2023 Smart code 203358507

import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react';
import { useServices } from 'stremio/services';
import useShell, { type WindowVisibility } from '../useShell';
import FullscreenContext, { type FullscreenContextValue } from './FullscreenContext';

type Props = {
    children: React.ReactNode,
};

// Single source of truth for fullscreen state. Mounted once at the app root so
// the value survives route remounts (fixes desync where switching tabs while in
// fullscreen would leave the UI thinking we were still windowed).
//
// We deliberately avoid useSettings()/useProfile() here because those go
// through useModelState -> useCoreSuspender, which is only available beneath
// the router's withCoreSuspender boundary. This provider sits above the
// router (alongside ToastProvider et al.), so we read the single setting we
// need (escExitFullscreen) directly from core.transport, which is provided
// by ServicesProvider higher up the tree.
const FullscreenProvider = ({ children }: Props) => {
    const shell = useShell();
    const { core } = useServices();

    const [fullscreen, setFullscreen] = useState<boolean>(() => {
        if (typeof document === 'undefined') return false;
        return document.fullscreenElement === document.documentElement;
    });

    const escExitFullscreenRef = useRef<boolean>(false);

    const requestFullscreen = useCallback(async () => {
        if (shell.active) {
            shell.send('win-set-visibility', { fullscreen: true });
        } else {
            try {
                await document.documentElement.requestFullscreen();
            } catch (err) {
                console.error('Error enabling fullscreen', err);
            }
        }
    }, [shell]);

    const exitFullscreen = useCallback(() => {
        if (shell.active) {
            shell.send('win-set-visibility', { fullscreen: false });
        } else {
            if (document.fullscreenElement === document.documentElement) {
                document.exitFullscreen();
            }
        }
    }, [shell]);

    const toggleFullscreen = useCallback(() => {
        fullscreen ? exitFullscreen() : requestFullscreen();
    }, [fullscreen, exitFullscreen, requestFullscreen]);

    useEffect(() => {
        if (!core?.active) return;

        let cancelled = false;

        // CoreTransport.on types the listener as () => void, but 'CoreEvent'
        // actually emits { event, args }. Read it via a rest-args wrapper to
        // stay compatible with the ambient signature.
        const onCoreEvent = (...listenerArgs: unknown[]) => {
            const payload = listenerArgs[0] as
                | { event?: string, args?: { settings?: { escExitFullscreen?: boolean } } }
                | undefined;
            if (payload?.event === 'SettingsUpdated' &&
                typeof payload.args?.settings?.escExitFullscreen === 'boolean') {
                escExitFullscreenRef.current = payload.args.settings.escExitFullscreen;
            }
        };

        core.transport.getState('ctx')
            .then((ctx) => {
                if (cancelled) return;
                const settings = (ctx as Ctx | null)?.profile?.settings;
                escExitFullscreenRef.current = !!settings?.escExitFullscreen;
            })
            .catch((err) => {
                console.error('FullscreenProvider: failed to read ctx state', err);
            });

        core.transport.on('CoreEvent', onCoreEvent);

        return () => {
            cancelled = true;
            core.transport.off('CoreEvent', onCoreEvent);
        };
    }, [core]);

    useEffect(() => {
        const onWindowVisibilityChanged = (state: WindowVisibility) => {
            setFullscreen(state.isFullscreen === true);
        };

        const onFullscreenChange = () => {
            setFullscreen(document.fullscreenElement === document.documentElement);
        };

        const onKeyDown = (event: KeyboardEvent) => {
            const activeElement = document.activeElement as HTMLElement;

            const inputFocused =
                activeElement &&
                (activeElement.tagName === 'INPUT' ||
                 activeElement.tagName === 'TEXTAREA' ||
                 activeElement.tagName === 'SELECT' ||
                 activeElement.isContentEditable);

            if (event.code === 'Escape' && escExitFullscreenRef.current) {
                exitFullscreen();
            }

            if (event.code === 'KeyF' && !inputFocused) {
                toggleFullscreen();
            }

            if (event.code === 'F11' && shell.active) {
                toggleFullscreen();
            }
        };

        shell.on('win-visibility-changed', onWindowVisibilityChanged);
        document.addEventListener('keydown', onKeyDown);
        document.addEventListener('fullscreenchange', onFullscreenChange);

        return () => {
            shell.off('win-visibility-changed', onWindowVisibilityChanged);
            document.removeEventListener('keydown', onKeyDown);
            document.removeEventListener('fullscreenchange', onFullscreenChange);
        };
    }, [shell, toggleFullscreen, exitFullscreen]);

    const value = useMemo<FullscreenContextValue>(
        () => [fullscreen, requestFullscreen, exitFullscreen, toggleFullscreen],
        [fullscreen, requestFullscreen, exitFullscreen, toggleFullscreen]
    );

    return (
        <FullscreenContext.Provider value={value}>
            {children}
        </FullscreenContext.Provider>
    );
};

export default FullscreenProvider;