"use client";

import { useEffect, useCallback, useRef, useMemo } from "react";

export interface KeyboardShortcut {
  key: string;
  description: string;
  action: () => void;
  category: string;
  meta?: boolean;    // Cmd/Ctrl
  shift?: boolean;
  alt?: boolean;
  ctrl?: boolean;
  // When to disable this shortcut (e.g., when typing in input)
  disabledWhen?: () => boolean;
}

export interface ShortcutCategory {
  name: string;
  shortcuts: KeyboardShortcut[];
}

interface UseKeyboardShortcutsOptions {
  shortcuts: KeyboardShortcut[];
  enabled?: boolean;
}

export function useKeyboardShortcuts({ shortcuts, enabled = true }: UseKeyboardShortcutsOptions) {
  const shortcutsRef = useRef(shortcuts);

  useEffect(() => {
    shortcutsRef.current = shortcuts;
  }, [shortcuts]);

  const isInputFocused = useCallback(() => {
    const active = document.activeElement;
    if (!active) return false;
    const tag = active.tagName.toLowerCase();
    return (
      tag === "input" ||
      tag === "textarea" ||
      tag === "select" ||
      (active as HTMLElement).isContentEditable ||
      (active as HTMLElement).closest('[data-radix-popper-content-wrapper], [role="dialog"], [role="menu"]') !== null
    );
  }, []);

  const handleKeyDown = useCallback(
    (event: KeyboardEvent) => {
      if (!enabled) return;

      // Allow shortcuts with meta/ctrl even in inputs for some cases
      const inInput = isInputFocused();
      
      for (const shortcut of shortcutsRef.current) {
        const { key, meta, shift, alt, ctrl, disabledWhen } = shortcut;
        
        // Check if shortcut should be disabled in current context
        if (disabledWhen && disabledWhen()) continue;

        // Don't trigger shortcuts when typing in inputs (unless explicitly allowed)
        if (inInput && !(meta || ctrl)) continue;

        const keyMatches = event.key.toLowerCase() === key.toLowerCase();
        const metaMatches = !!meta === (event.metaKey || event.ctrlKey);
        const shiftMatches = !!shift === event.shiftKey;
        const altMatches = !!alt === event.altKey;
        const ctrlMatches = !!ctrl === (event.ctrlKey || event.metaKey);

        if (keyMatches && metaMatches && shiftMatches && altMatches && ctrlMatches) {
          event.preventDefault();
          event.stopPropagation();
          shortcut.action();
          break;
        }
      }
    },
    [enabled, isInputFocused]
  );

  useEffect(() => {
    if (!enabled) return;
    document.addEventListener("keydown", handleKeyDown);
    return () => document.removeEventListener("keydown", handleKeyDown);
  }, [enabled, handleKeyDown]);

  // Return categorized shortcuts for help modal
  const categorized = useMemo(() => {
    const categories: Record<string, KeyboardShortcut[]> = {};
    for (const shortcut of shortcuts) {
      if (!categories[shortcut.category]) {
        categories[shortcut.category] = [];
      }
      categories[shortcut.category].push(shortcut);
    }
    return Object.entries(categories).map(([name, shortcuts]) => ({ name, shortcuts }));
  }, [shortcuts]);

  return { categorized };
}

export function formatShortcut(shortcut: KeyboardShortcut): string {
  const parts: string[] = [];
  if (shortcut.meta) parts.push(navigator.platform.includes("Mac") ? "⌘" : "Ctrl");
  if (shortcut.ctrl && !shortcut.meta) parts.push("Ctrl");
  if (shortcut.shift) parts.push("Shift");
  if (shortcut.alt) parts.push(navigator.platform.includes("Mac") ? "⌥" : "Alt");
  parts.push(shortcut.key.toUpperCase());
  return parts.join(" + ");
}