import React, { useState, useEffect, useRef, useCallback, useMemo } from 'react';
import { RotateCcw } from 'lucide-react';

import { Alert, AlertDescription, AlertTitle } from '@/components/ui/alert';
import { truncateFileName } from './lib/utils';
import { useFaceLandmarkDetection } from './hooks/useFaceLandmarkDetection';
import { PoweredBy } from './components/PoweredBy';
import { Spinner } from './components/Spinner';
import { DoubleCard } from './components/DoubleCard';
import { useFacePokeAPI } from './hooks/useFacePokeAPI';
import { Layout } from './layout';
import { useMainStore } from './hooks/useMainStore';
import { convertImageToBase64 } from './lib/convertImageToBase64';

export function App() {
  const error = useMainStore(s => s.error);
  const setError = useMainStore(s => s.setError);
  const imageFile = useMainStore(s => s.imageFile);
  const setImageFile = useMainStore(s => s.setImageFile);
  const originalImage = useMainStore(s => s.originalImage);
  const setOriginalImage = useMainStore(s => s.setOriginalImage);
  const previewImage = useMainStore(s => s.previewImage);
  const setPreviewImage = useMainStore(s => s.setPreviewImage);
  const resetImage = useMainStore(s => s.resetImage);

  const {
    status,
    setStatus,
    isDebugMode,
    setIsDebugMode,
    interruptMessage,
  } = useFacePokeAPI()

  // State for face detection
  const {
    canvasRef,
    canvasRefCallback,
    mediaPipeRef,
    faceLandmarks,
    isMediaPipeReady,
    blendShapes,

    setFaceLandmarks,
    setBlendShapes,

    handleMouseDown,
    handleMouseUp,
    handleMouseMove,
    handleMouseEnter,
    handleMouseLeave,
    currentOpacity
  } = useFaceLandmarkDetection()

  // Refs
  const videoRef = useRef<HTMLDivElement>(null);

  // Handle file change
  const handleFileChange = useCallback(async (event: React.ChangeEvent<HTMLInputElement>) => {
    const files = event.target.files;
    if (files && files[0]) {
      setImageFile(files[0]);
      setStatus(`File selected: ${truncateFileName(files[0].name, 16)}`);

      try {
        const image = await convertImageToBase64(files[0]);
        setPreviewImage(image);
        setOriginalImage(image);
      } catch (err) {
        console.log(`failed to convert the image: `, err);
        setImageFile(null);
        setStatus('');
        setPreviewImage('');
        setOriginalImage('');
        setFaceLandmarks([]);
        setBlendShapes([]);
      }
    } else {
      setImageFile(null);
      setStatus('');
      setPreviewImage('');
      setOriginalImage('');
      setFaceLandmarks([]);
      setBlendShapes([]);
    }
  }, [isMediaPipeReady, setImageFile, setPreviewImage, setOriginalImage, setFaceLandmarks, setBlendShapes, setStatus]);

  const canDisplayBlendShapes = false

  // Display blend shapes
  const displayBlendShapes = useMemo(() => (
      <div className="mt-4">
        <h3 className="text-lg font-semibold mb-2">Blend Shapes</h3>
        <ul className="space-y-1">
          {(blendShapes?.[0]?.categories || []).map((shape, index) => (
            <li key={index} className="flex items-center">
              <span className="w-32 text-sm">{shape.categoryName || shape.displayName}</span>
              <div className="w-full bg-gray-200 rounded-full h-2.5">
                <div
                  className="bg-blue-600 h-2.5 rounded-full"
                  style={{ width: `${shape.score * 100}%` }}
                ></div>
              </div>
              <span className="ml-2 text-sm">{shape.score.toFixed(2)}</span>
            </li>
          ))}
        </ul>
      </div>
  ), [JSON.stringify(blendShapes)])

  // JSX
  return (
    <Layout>
        {error && (
          <Alert variant="destructive">
            <AlertTitle>Error</AlertTitle>
            <AlertDescription>{error}</AlertDescription>
          </Alert>
        )}
        {interruptMessage && (
          <Alert>
            <AlertTitle>Notice</AlertTitle>
            <AlertDescription>{interruptMessage}</AlertDescription>
          </Alert>
        )}
        <div className="mb-5 relative">
          <div className="flex flex-row items-center justify-between w-full">
            <div className="relative">
              <input
                id="imageInput"
                type="file"
                accept="image/*"
                onChange={handleFileChange}
                className="hidden"
                disabled={!isMediaPipeReady}
              />
              <label
                htmlFor="imageInput"
                className={`cursor-pointer inline-flex items-center px-3 py-1.5 border border-transparent text-sm font-medium rounded-md text-white ${
                  isMediaPipeReady ? 'bg-gray-600 hover:bg-gray-500' : 'bg-gray-500 cursor-not-allowed'
                } focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-gray-500 shadow-xl`}
              >
                <Spinner />
                {imageFile ? truncateFileName(imageFile.name, 32) : (isMediaPipeReady ? 'Choose an image' : 'Initializing...')}
              </label>
            </div>
            {previewImage && <label className="mt-4 flex items-center">
              <input
                type="checkbox"
                checked={isDebugMode}
                onChange={(e) => setIsDebugMode(e.target.checked)}
                className="mr-2"
              />
              Show face landmarks on hover
            </label>}
          </div>
          {previewImage && (
            <div className="mt-5 relative shadow-2xl rounded-xl overflow-hidden">
              <img
                src={previewImage}
                alt="Preview"
                className="w-full"
              />
              <canvas
                ref={canvasRefCallback}
                className="absolute top-0 left-0 w-full h-full select-none"
                onMouseEnter={handleMouseEnter}
                onMouseLeave={handleMouseLeave}
                onMouseDown={handleMouseDown}
                onMouseUp={handleMouseUp}
                onMouseMove={handleMouseMove}
                style={{
                  position: 'absolute',
                  top: 0,
                  left: 0,
                  width: '100%',
                  height: '100%',
                  opacity: isDebugMode ? currentOpacity : 0.0,
                  transition: 'opacity 0.2s ease-in-out'
                }}

              />
            </div>
          )}
          {canDisplayBlendShapes && displayBlendShapes}
        </div>
        <PoweredBy />

    </Layout>
  );
}