import React, { useState } from 'react';
import { generateAvatarImage } from '../services/geminiService';
import { analyzeAvatarImage } from '../services/visionService';
import { stitchAssets, fileToDataUrl } from '../services/imageService';
import LoadingSpinner from './LoadingSpinner';
import { Rect } from '../types';

interface AvatarCreatorProps {
  onAvatarGenerated: (url: string, name: string, initialData?: { 
    leftEye?: Rect, rightEye?: Rect, mouth?: Rect, skinColor?: string,
    mainBody?: Rect, textureClosedEye?: Rect, textureOpenMouth?: Rect 
  }) => void;
}

const AvatarCreator: React.FC<AvatarCreatorProps> = ({ onAvatarGenerated }) => {
  const [mode, setMode] = useState<'generate' | 'upload'>('generate');
  
  // Generation State
  const [prompt, setPrompt] = useState('');
  const [name, setName] = useState('');
  const [status, setStatus] = useState<'idle' | 'generating' | 'analyzing' | 'stitching'>('idle');
  const [error, setError] = useState<string | null>(null);

  // Upload State
  const [baseFile, setBaseFile] = useState<File | null>(null);
  const [blinkFile, setBlinkFile] = useState<File | null>(null);
  const [talkFile, setTalkFile] = useState<File | null>(null);

  const handleGenerate = async () => {
    if (!prompt || !name) return;
    
    setStatus('generating');
    setError(null);
    
    try {
      // 1. Generate Image (Now creates a character sheet)
      const imageUrl = await generateAvatarImage(prompt);
      
      // 2. Analyze Image for Landmarks
      setStatus('analyzing');
      const analysisData = await analyzeAvatarImage(imageUrl);
      
      // 3. Pass to parent
      if (analysisData) {
        onAvatarGenerated(imageUrl, name, analysisData);
      } else {
        onAvatarGenerated(imageUrl, name);
      }
    } catch (err) {
      console.error(err);
      setError("Failed to generate avatar. Please try again.");
    } finally {
      setStatus('idle');
    }
  };

  const handleUpload = async () => {
    if (!baseFile || !name) return;

    setStatus('stitching');
    setError(null);

    try {
      // 1. Prepare Base Image and Analyze it separately
      // Analyzing separately ensures we get landmarks for the main face correctly 
      // without interference from other faces in a stitched sheet.
      const baseDataUrl = await fileToDataUrl(baseFile);
      const baseAnalysis = await analyzeAvatarImage(baseDataUrl);

      // 2. Prepare and Analyze Variant Images
      let blinkDataUrl, blinkAnalysis;
      if (blinkFile) {
        blinkDataUrl = await fileToDataUrl(blinkFile);
        // Try to find eyes in the blink image to use as tight texture crop
        blinkAnalysis = await analyzeAvatarImage(blinkDataUrl);
      }

      let talkDataUrl, talkAnalysis;
      if (talkFile) {
        talkDataUrl = await fileToDataUrl(talkFile);
        // Try to find mouth in the talk image
        talkAnalysis = await analyzeAvatarImage(talkDataUrl);
      }

      // 3. Stitch Assets into Sheet
      const { imageUrl, mainBody, textureClosedEye: stitchBlinkRect, textureOpenMouth: stitchTalkRect } = await stitchAssets(baseDataUrl, blinkDataUrl, talkDataUrl);

      // 4. Map Analysis Data to Stitched Coordinate Space
      
      // Helper to map a rect from (0-1 in sub-image) to (0-1 in stitched-image)
      const mapRect = (r: Rect, container: Rect) => ({
        x: container.x + r.x * container.w,
        y: container.y + r.y * container.h,
        w: r.w * container.w,
        h: r.h * container.h
      });

      let initialData: any = {
        mainBody,
        textureClosedEye: stitchBlinkRect,
        textureOpenMouth: stitchTalkRect
      };

      // Map Base Targets (Eyes, Mouth on main body)
      if (baseAnalysis) {
        initialData.leftEye = mapRect(baseAnalysis.leftEye, mainBody);
        initialData.rightEye = mapRect(baseAnalysis.rightEye, mainBody);
        initialData.mouth = mapRect(baseAnalysis.mouth, mainBody);
        initialData.skinColor = baseAnalysis.skinColor;
      }

      // Map Source Textures (Tight crop around features if detected)
      // If detections fail (e.g. eyes closed might not be detected), we fall back to the whole image (stitchBlinkRect)
      if (blinkAnalysis && stitchBlinkRect) {
         // Calculate a bounding box around both eyes in the blink image
         const be = blinkAnalysis;
         const minX = Math.min(be.leftEye.x, be.rightEye.x);
         const minY = Math.min(be.leftEye.y, be.rightEye.y);
         const maxX = Math.max(be.leftEye.x + be.leftEye.w, be.rightEye.x + be.rightEye.w);
         const maxY = Math.max(be.leftEye.y + be.leftEye.h, be.rightEye.y + be.rightEye.h);
         
         const eyesRect = { x: minX, y: minY, w: maxX - minX, h: maxY - minY };
         initialData.textureClosedEye = mapRect(eyesRect, stitchBlinkRect);
      }

      if (talkAnalysis && stitchTalkRect) {
         initialData.textureOpenMouth = mapRect(talkAnalysis.mouth, stitchTalkRect);
      }

      onAvatarGenerated(imageUrl, name, initialData);
    } catch (err) {
      console.error(err);
      setError("Failed to process uploaded images. Please ensure they are valid image files.");
    } finally {
      setStatus('idle');
    }
  };

  const handleFileChange = (e: React.ChangeEvent<HTMLInputElement>, setter: (f: File | null) => void) => {
    if (e.target.files && e.target.files[0]) {
      setter(e.target.files[0]);
    }
  };

  return (
    <div className="max-w-2xl mx-auto bg-slate-800/50 backdrop-blur-lg border border-slate-700 rounded-2xl shadow-2xl overflow-hidden">
      {/* Tabs */}
      <div className="flex border-b border-slate-700">
        <button
          onClick={() => setMode('generate')}
          className={`flex-1 py-4 text-sm font-bold uppercase tracking-wider transition-colors ${
            mode === 'generate' 
              ? 'bg-slate-700/50 text-cyan-400 border-b-2 border-cyan-400' 
              : 'text-slate-500 hover:text-slate-300'
          }`}
        >
          AI Generator
        </button>
        <button
          onClick={() => setMode('upload')}
          className={`flex-1 py-4 text-sm font-bold uppercase tracking-wider transition-colors ${
            mode === 'upload' 
              ? 'bg-slate-700/50 text-purple-400 border-b-2 border-purple-400' 
              : 'text-slate-500 hover:text-slate-300'
          }`}
        >
          Upload Assets
        </button>
      </div>

      <div className="p-8">
        <div className="text-center mb-8">
          <h2 className="text-3xl font-bold text-transparent bg-clip-text bg-gradient-to-r from-cyan-400 to-purple-500 mb-2">
            {mode === 'generate' ? 'Design Your Avatar' : 'Import Your Model'}
          </h2>
          <p className="text-slate-400">
            {mode === 'generate' 
              ? 'Describe your dream VTuber model. Gemini will generate a character sheet with expression assets.'
              : 'Upload your existing character art. We support separate files for blink and talk variants.'
            }
          </p>
        </div>

        <div className="space-y-6">
          <div>
            <label className="block text-sm font-medium text-slate-300 mb-2">Model Name</label>
            <input
              type="text"
              value={name}
              onChange={(e) => setName(e.target.value)}
              placeholder="e.g., Neon Kitsune"
              className="w-full bg-slate-900/50 border border-slate-600 rounded-xl px-4 py-3 text-white placeholder-slate-500 focus:ring-2 focus:ring-cyan-500 focus:border-transparent transition-all outline-none"
            />
          </div>

          {mode === 'generate' ? (
            <div>
              <label className="block text-sm font-medium text-slate-300 mb-2">Description</label>
              <textarea
                value={prompt}
                onChange={(e) => setPrompt(e.target.value)}
                placeholder="e.g., A cyberpunk anime girl with neon blue hair, glowing headphones, wearing a futuristic jacket..."
                className="w-full h-32 bg-slate-900/50 border border-slate-600 rounded-xl px-4 py-3 text-white placeholder-slate-500 focus:ring-2 focus:ring-cyan-500 focus:border-transparent transition-all outline-none resize-none"
              />
            </div>
          ) : (
            <div className="space-y-4">
              <div className="p-4 bg-slate-900/50 rounded-xl border border-slate-600 border-dashed">
                 <label className="block text-sm font-bold text-slate-300 mb-2">Base Model (Required)</label>
                 <input type="file" accept="image/*" onChange={(e) => handleFileChange(e, setBaseFile)} className="text-sm text-slate-400 file:mr-4 file:py-2 file:px-4 file:rounded-full file:border-0 file:text-sm file:font-semibold file:bg-cyan-500/10 file:text-cyan-400 hover:file:bg-cyan-500/20"/>
                 <p className="text-xs text-slate-500 mt-1">The main look of your character (Eyes Open, Mouth Closed).</p>
              </div>
              
              <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
                <div className="p-4 bg-slate-900/50 rounded-xl border border-slate-600 border-dashed">
                  <label className="block text-sm font-bold text-slate-300 mb-2">Closed Eyes (Optional)</label>
                  <input type="file" accept="image/*" onChange={(e) => handleFileChange(e, setBlinkFile)} className="text-sm text-slate-400 file:mr-4 file:py-2 file:px-4 file:rounded-full file:border-0 file:text-sm file:font-semibold file:bg-purple-500/10 file:text-purple-400 hover:file:bg-purple-500/20"/>
                </div>
                <div className="p-4 bg-slate-900/50 rounded-xl border border-slate-600 border-dashed">
                  <label className="block text-sm font-bold text-slate-300 mb-2">Open Mouth (Optional)</label>
                  <input type="file" accept="image/*" onChange={(e) => handleFileChange(e, setTalkFile)} className="text-sm text-slate-400 file:mr-4 file:py-2 file:px-4 file:rounded-full file:border-0 file:text-sm file:font-semibold file:bg-pink-500/10 file:text-pink-400 hover:file:bg-pink-500/20"/>
                </div>
              </div>
            </div>
          )}

          {error && (
            <div className="p-3 bg-red-500/20 border border-red-500/50 rounded-lg text-red-200 text-sm">
              {error}
            </div>
          )}

          <button
            onClick={mode === 'generate' ? handleGenerate : handleUpload}
            disabled={status !== 'idle' || !name || (mode === 'generate' && !prompt) || (mode === 'upload' && !baseFile)}
            className={`w-full py-4 rounded-xl font-bold text-lg transition-all duration-200 ${
              status !== 'idle' || !name || (mode === 'generate' && !prompt) || (mode === 'upload' && !baseFile)
                ? 'bg-slate-700 text-slate-500 cursor-not-allowed'
                : 'bg-gradient-to-r from-cyan-500 to-blue-600 hover:from-cyan-400 hover:to-blue-500 text-white shadow-lg shadow-cyan-500/25 transform hover:scale-[1.02]'
            }`}
          >
            {status !== 'idle' ? (
              <div className="flex items-center justify-center gap-3">
                 <LoadingSpinner />
                 <span>
                   {status === 'generating' ? 'Dreaming up Sheet...' : 
                    status === 'stitching' ? 'Processing Assets...' :
                    'Analyzing Features...'}
                 </span>
              </div>
            ) : (
              <div className="flex items-center justify-center gap-2">
                <span>{mode === 'generate' ? 'Generate Model' : 'Create Model'}</span>
                <svg xmlns="http://www.w3.org/2000/svg" className="h-5 w-5" viewBox="0 0 20 20" fill="currentColor">
                  <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zm3.707-8.707l-3-3a1 1 0 00-1.414 1.414L10.586 9H7a1 1 0 100 2h3.586l-1.293 1.293a1 1 0 101.414 1.414l3-3a1 1 0 000-1.414z" clipRule="evenodd" />
                </svg>
              </div>
            )}
          </button>
        </div>
      </div>
    </div>
  );
};

export default AvatarCreator;