import { useEffect } from "react";

export interface ShortcutDefinition {
    key: string;
    meta?: boolean; // Cmd on Mac, Ctrl on Windows/Linux
    shift?: boolean;
    alt?: boolean;
    ctrl?: boolean;
    handler: () => void;
    description: string;
    enabled?: boolean; // Allow dynamic enable/disable
}

interface ShortcutMap {
    [key: string]: ShortcutDefinition;
}

/**
 * Convert keyboard event to a shortcut key string
 * Format: "Meta+Shift+R" or "Space" or "ArrowLeft"
 */
export function getShortcutKey(e: KeyboardEvent): string {
    const parts: string[] = [];

    if (e.metaKey) parts.push("Meta");
    if (e.ctrlKey) parts.push("Ctrl");
    if (e.altKey) parts.push("Alt");
    if (e.shiftKey) parts.push("Shift");

    // Normalize key names
    let key = e.key;
    if (key === " ") key = "Space";

    parts.push(key);

    return parts.join("+");
}

/**
 * Check if a shortcut definition matches a keyboard event
 */
function matchesShortcut(e: KeyboardEvent, shortcut: ShortcutDefinition): boolean {
    // Check modifier keys
    if (shortcut.meta && !e.metaKey) return false;
    if (!shortcut.meta && e.metaKey) return false;

    if (shortcut.shift && !e.shiftKey) return false;
    if (!shortcut.shift && e.shiftKey) return false;

    if (shortcut.alt && !e.altKey) return false;
    if (!shortcut.alt && e.altKey) return false;

    if (shortcut.ctrl && !e.ctrlKey) return false;
    if (!shortcut.ctrl && e.ctrlKey) return false;

    // Check key (normalize space)
    let eventKey = e.key;
    if (eventKey === " ") eventKey = "Space";

    return eventKey === shortcut.key;
}

/**
 * Hook for registering keyboard shortcuts
 *
 * @example
 * ```tsx
 * useKeyboardShortcuts({
 *   "play-pause": {
 *     key: "Space",
 *     handler: () => togglePlay(),
 *     description: "Play/pause video"
 *   },
 *   "help": {
 *     key: "?",
 *     meta: true,
 *     shift: true,
 *     handler: () => setShowHelp(true),
 *     description: "Show keyboard shortcuts"
 *   }
 * });
 * ```
 */
export function useKeyboardShortcuts(shortcuts: ShortcutMap, enabled: boolean = true) {
    useEffect(() => {
        if (!enabled) return;

        const handler = (e: KeyboardEvent) => {
            // Find matching shortcut
            for (const [_id, shortcut] of Object.entries(shortcuts)) {
                if (shortcut.enabled === false) continue;

                if (matchesShortcut(e, shortcut)) {
                    e.preventDefault();
                    e.stopPropagation();
                    shortcut.handler();
                    break;
                }
            }
        };

        window.addEventListener("keydown", handler);
        return () => window.removeEventListener("keydown", handler);
    }, [shortcuts, enabled]);
}