'use client';

import { useState, useEffect } from 'react';
import { X, Search, Keyboard } from 'lucide-react';
import { cn } from '@/lib/utils';

interface Shortcut {
  category: string;
  action: string;
  keys: string[];
  description?: string;
}

const SHORTCUTS: Shortcut[] = [
  // File Operations
  { category: 'File', action: 'New', keys: ['Ctrl', 'N'] },
  { category: 'File', action: 'Open', keys: ['Ctrl', 'O'] },
  { category: 'File', action: 'Save', keys: ['Ctrl', 'S'] },
  { category: 'File', action: 'Save As', keys: ['Ctrl', 'Shift', 'S'] },
  { category: 'File', action: 'Export', keys: ['Ctrl', 'E'] },

  // Edit Operations
  { category: 'Edit', action: 'Undo', keys: ['Ctrl', 'Z'] },
  { category: 'Edit', action: 'Redo', keys: ['Ctrl', 'Shift', 'Z'] },
  { category: 'Edit', action: 'Cut', keys: ['Ctrl', 'X'] },
  { category: 'Edit', action: 'Copy', keys: ['Ctrl', 'C'] },
  { category: 'Edit', action: 'Paste', keys: ['Ctrl', 'V'] },
  { category: 'Edit', action: 'Select All', keys: ['Ctrl', 'A'] },
  { category: 'Edit', action: 'Deselect', keys: ['Ctrl', 'D'] },

  // View Operations
  { category: 'View', action: 'Zoom In', keys: ['Ctrl', '+'] },
  { category: 'View', action: 'Zoom Out', keys: ['Ctrl', '-'] },
  { category: 'View', action: 'Zoom to 100%', keys: ['Ctrl', '0'] },
  { category: 'View', action: 'Fit to Screen', keys: ['Ctrl', '1'] },
  { category: 'View', action: 'Toggle Grid', keys: ['Ctrl', 'G'] },

  // Tools (Single Key)
  { category: 'Tools', action: 'Move Tool', keys: ['V'] },
  { category: 'Tools', action: 'Rectangle Select', keys: ['M'] },
  { category: 'Tools', action: 'Lasso Select', keys: ['L'] },
  { category: 'Tools', action: 'Wand Select', keys: ['W'] },
  { category: 'Tools', action: 'Pencil Tool', keys: ['P'] },
  { category: 'Tools', action: 'Brush Tool', keys: ['B'] },
  { category: 'Tools', action: 'Eraser Tool', keys: ['E'] },
  { category: 'Tools', action: 'Fill Bucket', keys: ['G'] },
  { category: 'Tools', action: 'Eyedropper', keys: ['I'] },
  { category: 'Tools', action: 'Text Tool', keys: ['T'] },
  { category: 'Tools', action: 'Shape Tool', keys: ['U'] },
  { category: 'Tools', action: 'Hand Tool (Pan)', keys: ['H'] },
  { category: 'Tools', action: 'Temporary Hand', keys: ['Space'], description: 'Hold to pan' },

  // Layers
  { category: 'Layers', action: 'New Layer', keys: ['Ctrl', 'Shift', 'N'] },
  { category: 'Layers', action: 'Duplicate Layer', keys: ['Ctrl', 'J'] },
  { category: 'Layers', action: 'Merge Down', keys: ['Ctrl', 'E'] },
  { category: 'Layers', action: 'Next Layer', keys: ['['] },
  { category: 'Layers', action: 'Previous Layer', keys: [']'] },

  // Transform
  { category: 'Transform', action: 'Free Transform', keys: ['Ctrl', 'T'] },
  { category: 'Transform', action: 'Rotate 90° CW', keys: ['Ctrl', 'R'] },
  { category: 'Transform', action: 'Flip Horizontal', keys: ['Ctrl', 'Shift', 'H'] },
  { category: 'Transform', action: 'Flip Vertical', keys: ['Ctrl', 'Shift', 'V'] },

  // Adjustments
  { category: 'Adjustments', action: 'Brightness/Contrast', keys: ['Ctrl', 'M'] },
  { category: 'Adjustments', action: 'Hue/Saturation', keys: ['Ctrl', 'U'] },
  { category: 'Adjustments', action: 'Invert Colors', keys: ['Ctrl', 'I'] },

  // Help
  { category: 'Help', action: 'Keyboard Shortcuts', keys: ['?'] },
  { category: 'Help', action: 'Keyboard Shortcuts (Alt)', keys: ['F1'] },
];

interface ShortcutsHelpPanelProps {
  isOpen: boolean;
  onClose: () => void;
}

export function ShortcutsHelpPanel({ isOpen, onClose }: ShortcutsHelpPanelProps) {
  const [searchQuery, setSearchQuery] = useState('');

  // Handle Escape key to close
  useEffect(() => {
    if (!isOpen) return;

    const handleKeyDown = (e: KeyboardEvent) => {
      if (e.key === 'Escape') {
        onClose();
      }
    };

    window.addEventListener('keydown', handleKeyDown);
    return () => window.removeEventListener('keydown', handleKeyDown);
  }, [isOpen, onClose]);

  if (!isOpen) return null;

  // Filter shortcuts based on search
  const filteredShortcuts = SHORTCUTS.filter((shortcut) => {
    const query = searchQuery.toLowerCase();
    return (
      shortcut.action.toLowerCase().includes(query) ||
      shortcut.category.toLowerCase().includes(query) ||
      shortcut.keys.some((key) => key.toLowerCase().includes(query)) ||
      shortcut.description?.toLowerCase().includes(query)
    );
  });

  // Group by category
  const categories = Array.from(new Set(filteredShortcuts.map((s) => s.category)));

  return (
    <>
      {/* Backdrop */}
      <div
        className="fixed inset-0 z-50 bg-black/50 backdrop-blur-sm"
        onClick={onClose}
      />

      {/* Panel */}
      <div className="fixed inset-0 z-50 flex items-center justify-center p-4 pointer-events-none">
        <div className="w-full max-w-3xl max-h-[80vh] bg-card border border-border rounded-lg shadow-xl flex flex-col pointer-events-auto">
          {/* Header */}
          <div className="flex items-center justify-between p-4 border-b border-border">
            <div className="flex items-center gap-2">
              <Keyboard className="h-5 w-5 text-primary" />
              <h2 className="text-lg font-semibold text-foreground">Keyboard Shortcuts</h2>
            </div>
            <button
              onClick={onClose}
              className="p-2 hover:bg-accent rounded-md transition-colors"
              aria-label="Close"
            >
              <X className="h-4 w-4" />
            </button>
          </div>

          {/* Search */}
          <div className="p-4 border-b border-border">
            <div className="relative">
              <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
              <input
                type="text"
                placeholder="Search shortcuts..."
                value={searchQuery}
                onChange={(e) => setSearchQuery(e.target.value)}
                className="w-full pl-10 pr-4 py-2 bg-background border border-border rounded-md text-sm text-foreground placeholder:text-muted-foreground focus:outline-none focus:ring-2 focus:ring-primary"
                autoFocus
              />
            </div>
          </div>

          {/* Shortcuts List */}
          <div className="flex-1 overflow-y-auto p-4">
            {categories.length === 0 ? (
              <div className="text-center text-muted-foreground py-8">
                No shortcuts found matching &quot;{searchQuery}&quot;
              </div>
            ) : (
              <div className="space-y-6">
                {categories.map((category) => {
                  const categoryShortcuts = filteredShortcuts.filter(
                    (s) => s.category === category
                  );

                  return (
                    <div key={category}>
                      <h3 className="text-sm font-semibold text-foreground mb-3 uppercase tracking-wide">
                        {category}
                      </h3>
                      <div className="space-y-2">
                        {categoryShortcuts.map((shortcut, index) => (
                          <div
                            key={`${category}-${index}`}
                            className="flex items-center justify-between py-2 px-3 rounded-md hover:bg-accent/50 transition-colors"
                          >
                            <div className="flex-1">
                              <div className="text-sm text-foreground">{shortcut.action}</div>
                              {shortcut.description && (
                                <div className="text-xs text-muted-foreground mt-0.5">
                                  {shortcut.description}
                                </div>
                              )}
                            </div>
                            <div className="flex items-center gap-1">
                              {shortcut.keys.map((key, keyIndex) => (
                                <div key={keyIndex} className="flex items-center gap-1">
                                  <kbd className="px-2 py-1 text-xs font-mono bg-background border border-border rounded shadow-sm">
                                    {key}
                                  </kbd>
                                  {keyIndex < shortcut.keys.length - 1 && (
                                    <span className="text-muted-foreground">+</span>
                                  )}
                                </div>
                              ))}
                            </div>
                          </div>
                        ))}
                      </div>
                    </div>
                  );
                })}
              </div>
            )}
          </div>

          {/* Footer */}
          <div className="p-4 border-t border-border bg-accent/30">
            <p className="text-xs text-center text-muted-foreground">
              Press <kbd className="px-1.5 py-0.5 text-xs font-mono bg-background border border-border rounded">Esc</kbd> to close
              or <kbd className="px-1.5 py-0.5 text-xs font-mono bg-background border border-border rounded">?</kbd> / <kbd className="px-1.5 py-0.5 text-xs font-mono bg-background border border-border rounded">F1</kbd> to open
            </p>
          </div>
        </div>
      </div>
    </>
  );
}