'use client';

import { useState, useEffect, useCallback } from 'react';
import { useLayerStore } from '@/store';
import { useHistoryStore } from '@/store/history-store';
import { applyFilter } from '@/lib/filter-utils';
import { FilterCommand } from '@/core/commands/filter-command';
import type { FilterType, FilterParams } from '@/types/filter';
import { X, RotateCcw } from 'lucide-react';
import { cn } from '@/lib/utils';

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

const FILTER_CATEGORIES = {
  'Color Adjustments': ['brightness', 'contrast', 'hue-saturation'] as FilterType[],
  'Filters': ['blur', 'sharpen'] as FilterType[],
  'Effects': ['invert', 'grayscale', 'sepia', 'threshold', 'posterize'] as FilterType[],
};

const FILTER_NAMES: Record<FilterType, string> = {
  brightness: 'Brightness',
  contrast: 'Contrast',
  'hue-saturation': 'Hue/Saturation',
  blur: 'Blur',
  sharpen: 'Sharpen',
  invert: 'Invert Colors',
  grayscale: 'Grayscale',
  sepia: 'Sepia',
  threshold: 'Threshold',
  posterize: 'Posterize',
};

export function AdjustmentsDialog({ isOpen, onClose }: AdjustmentsDialogProps) {
  const { getActiveLayer } = useLayerStore();
  const { executeCommand } = useHistoryStore();

  const [selectedFilter, setSelectedFilter] = useState<FilterType>('brightness');
  const [params, setParams] = useState<FilterParams>({
    brightness: 0,
    contrast: 0,
    hue: 0,
    saturation: 0,
    lightness: 0,
    radius: 5,
    amount: 50,
    threshold: 128,
    levels: 8,
  });
  const [previewCanvas, setPreviewCanvas] = useState<HTMLCanvasElement | null>(null);

  const activeLayer = getActiveLayer();

  // Update preview when params change
  useEffect(() => {
    if (!isOpen || !activeLayer?.canvas) return;

    const canvas = document.createElement('canvas');
    canvas.width = Math.min(activeLayer.canvas.width, 400);
    canvas.height = Math.min(activeLayer.canvas.height, 400);
    const ctx = canvas.getContext('2d');
    if (!ctx) return;

    // Draw scaled layer
    ctx.drawImage(activeLayer.canvas, 0, 0, canvas.width, canvas.height);

    // Apply filter to preview
    const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
    const filtered = applyFilter(imageData, selectedFilter, params);
    ctx.putImageData(filtered, 0, 0);

    setPreviewCanvas(canvas);
  }, [isOpen, activeLayer, selectedFilter, params]);

  const handleParamChange = useCallback((key: keyof FilterParams, value: number) => {
    setParams((prev) => ({ ...prev, [key]: value }));
  }, []);

  const handleReset = useCallback(() => {
    setParams({
      brightness: 0,
      contrast: 0,
      hue: 0,
      saturation: 0,
      lightness: 0,
      radius: 5,
      amount: 50,
      threshold: 128,
      levels: 8,
    });
  }, []);

  const handleApply = useCallback(async () => {
    if (!activeLayer) return;

    // Use the static method to apply filter and create command
    const command = await FilterCommand.applyToLayerAsync(activeLayer, selectedFilter, params);
    executeCommand(command);

    onClose();
  }, [activeLayer, selectedFilter, params, executeCommand, onClose]);

  if (!isOpen) return null;

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

      {/* Dialog */}
      <div className="fixed inset-0 z-50 flex items-center justify-center p-4 pointer-events-none">
        <div className="w-full max-w-4xl max-h-[90vh] 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">
            <h2 className="text-lg font-semibold text-foreground">Filters & Adjustments</h2>
            <button
              onClick={onClose}
              className="p-2 hover:bg-accent rounded-md transition-colors"
              aria-label="Close"
            >
              <X className="h-4 w-4" />
            </button>
          </div>

          {/* Content */}
          <div className="flex flex-1 overflow-hidden">
            {/* Sidebar - Filter List */}
            <div className="w-56 border-r border-border overflow-y-auto bg-accent/20">
              {Object.entries(FILTER_CATEGORIES).map(([category, filters]) => (
                <div key={category} className="p-2">
                  <div className="text-xs font-semibold text-muted-foreground px-2 py-1 uppercase tracking-wide">
                    {category}
                  </div>
                  <div className="space-y-0.5">
                    {filters.map((filter) => (
                      <button
                        key={filter}
                        onClick={() => setSelectedFilter(filter)}
                        className={cn(
                          'w-full text-left px-3 py-2 rounded-md text-sm transition-colors',
                          selectedFilter === filter
                            ? 'bg-primary text-primary-foreground'
                            : 'hover:bg-accent'
                        )}
                      >
                        {FILTER_NAMES[filter]}
                      </button>
                    ))}
                  </div>
                </div>
              ))}
            </div>

            {/* Main Area */}
            <div className="flex-1 flex flex-col">
              {/* Preview */}
              <div className="flex-1 flex items-center justify-center p-6 bg-accent/10">
                {previewCanvas && (
                  <div className="relative">
                    <canvas
                      ref={(el) => {
                        if (el && previewCanvas) {
                          el.width = previewCanvas.width;
                          el.height = previewCanvas.height;
                          const ctx = el.getContext('2d');
                          if (ctx) ctx.drawImage(previewCanvas, 0, 0);
                        }
                      }}
                      className="border border-border rounded shadow-lg"
                      style={{ maxWidth: '400px', maxHeight: '400px' }}
                    />
                    <div className="absolute bottom-2 right-2 bg-black/70 text-white text-xs px-2 py-1 rounded">
                      Preview
                    </div>
                  </div>
                )}
              </div>

              {/* Controls */}
              <div className="border-t border-border p-4 bg-card">
                <div className="space-y-4">
                  {/* Brightness/Contrast */}
                  {selectedFilter === 'brightness' && (
                    <div className="space-y-2">
                      <label className="text-sm font-medium">Brightness: {params.brightness}</label>
                      <input
                        type="range"
                        min="-100"
                        max="100"
                        value={params.brightness}
                        onChange={(e) => handleParamChange('brightness', Number(e.target.value))}
                        className="w-full"
                      />
                    </div>
                  )}

                  {selectedFilter === 'contrast' && (
                    <div className="space-y-2">
                      <label className="text-sm font-medium">Contrast: {params.contrast}</label>
                      <input
                        type="range"
                        min="-100"
                        max="100"
                        value={params.contrast}
                        onChange={(e) => handleParamChange('contrast', Number(e.target.value))}
                        className="w-full"
                      />
                    </div>
                  )}

                  {selectedFilter === 'hue-saturation' && (
                    <>
                      <div className="space-y-2">
                        <label className="text-sm font-medium">Hue: {params.hue}°</label>
                        <input
                          type="range"
                          min="-180"
                          max="180"
                          value={params.hue}
                          onChange={(e) => handleParamChange('hue', Number(e.target.value))}
                          className="w-full"
                        />
                      </div>
                      <div className="space-y-2">
                        <label className="text-sm font-medium">Saturation: {params.saturation}%</label>
                        <input
                          type="range"
                          min="-100"
                          max="100"
                          value={params.saturation}
                          onChange={(e) => handleParamChange('saturation', Number(e.target.value))}
                          className="w-full"
                        />
                      </div>
                      <div className="space-y-2">
                        <label className="text-sm font-medium">Lightness: {params.lightness}%</label>
                        <input
                          type="range"
                          min="-100"
                          max="100"
                          value={params.lightness}
                          onChange={(e) => handleParamChange('lightness', Number(e.target.value))}
                          className="w-full"
                        />
                      </div>
                    </>
                  )}

                  {selectedFilter === 'blur' && (
                    <div className="space-y-2">
                      <label className="text-sm font-medium">Radius: {params.radius}px</label>
                      <input
                        type="range"
                        min="1"
                        max="50"
                        value={params.radius}
                        onChange={(e) => handleParamChange('radius', Number(e.target.value))}
                        className="w-full"
                      />
                    </div>
                  )}

                  {selectedFilter === 'sharpen' && (
                    <div className="space-y-2">
                      <label className="text-sm font-medium">Amount: {params.amount}%</label>
                      <input
                        type="range"
                        min="0"
                        max="100"
                        value={params.amount}
                        onChange={(e) => handleParamChange('amount', Number(e.target.value))}
                        className="w-full"
                      />
                    </div>
                  )}

                  {selectedFilter === 'threshold' && (
                    <div className="space-y-2">
                      <label className="text-sm font-medium">Threshold: {params.threshold}</label>
                      <input
                        type="range"
                        min="0"
                        max="255"
                        value={params.threshold}
                        onChange={(e) => handleParamChange('threshold', Number(e.target.value))}
                        className="w-full"
                      />
                    </div>
                  )}

                  {selectedFilter === 'posterize' && (
                    <div className="space-y-2">
                      <label className="text-sm font-medium">Levels: {params.levels}</label>
                      <input
                        type="range"
                        min="2"
                        max="256"
                        value={params.levels}
                        onChange={(e) => handleParamChange('levels', Number(e.target.value))}
                        className="w-full"
                      />
                    </div>
                  )}

                  {/* One-click filters (no params) */}
                  {['invert', 'grayscale', 'sepia'].includes(selectedFilter) && (
                    <div className="text-sm text-muted-foreground">
                      This filter has no adjustable parameters. Click Apply to use it.
                    </div>
                  )}
                </div>
              </div>
            </div>
          </div>

          {/* Footer */}
          <div className="flex items-center justify-between p-4 border-t border-border bg-accent/10">
            <button
              onClick={handleReset}
              className="flex items-center gap-2 px-4 py-2 text-sm hover:bg-accent rounded-md transition-colors"
            >
              <RotateCcw className="h-4 w-4" />
              Reset
            </button>
            <div className="flex gap-2">
              <button
                onClick={onClose}
                className="px-4 py-2 text-sm hover:bg-accent rounded-md transition-colors"
              >
                Cancel
              </button>
              <button
                onClick={handleApply}
                className="px-4 py-2 text-sm bg-primary text-primary-foreground hover:bg-primary/90 rounded-md transition-colors"
              >
                Apply
              </button>
            </div>
          </div>
        </div>
      </div>
    </>
  );
}