import { useEffect, useRef, useState } from 'react';
import AnimatedAvatar from './AnimatedAvatar';

interface Props {
  isSpeaking: boolean;
  isListening: boolean;
  outfit: string;
  accessory: string | null;
  onTalkToggle: () => void;
}

type ExpressionName = 'Normal' | 'Smile' | 'Sad' | 'Angry' | 'Surprised' | 'Blushing';

const EXPRESSIONS: ExpressionName[] = ['Normal', 'Smile', 'Sad', 'Angry', 'Surprised', 'Blushing'];
const IDLE_EXPRESSIONS: ExpressionName[] = ['Normal', 'Smile', 'Blushing'];

const OUTFIT_TEXTURES: Record<string, string> = {
  'cozy-hoodie': '/live2d/models/kira/outfits/cozy-hoodie.png',
  'girly-dress': '/live2d/models/kira/outfits/girly-dress.png',
  'pajama-set': '/live2d/models/kira/outfits/pajama-set.png',
  'study-sweater': '/live2d/models/kira/outfits/study-sweater.png',
  'going-out': '/live2d/models/kira/outfits/going-out.png',
};

export default function KiraAvatar(props: Props) {
  const canvasRef = useRef<HTMLCanvasElement>(null);
  const modelRef = useRef<any>(null);
  const textureRef = useRef<any>(null);
  const lipSyncRef = useRef<number>(0);
  const idleExprRef = useRef<ReturnType<typeof setInterval> | null>(null);
  const [live2dReady, setLive2dReady] = useState(false);
  const [loadError, setLoadError] = useState(false);
  const [currentExpression, setCurrentExpression] = useState<ExpressionName>('Normal');

  useEffect(() => {
    let mounted = true;
    const canvas = canvasRef.current;
    if (!canvas) return;

    let app: any = null;
    let model: any = null;

    const init = async () => {
      try {
        const resp = await fetch('/live2d/models/kira/kira.model3.json', { method: 'HEAD' });
        if (!resp.ok) { if (mounted) setLoadError(true); return; }

        await loadScript('/live2d/cubism/live2dcubismcore.min.js');
        const { Application, Ticker } = await import('pixi.js');
        const { Live2DModel } = await import('pixi-live2d-display/cubism4');
        (Live2DModel as any).registerTicker(Ticker as any);

        const w = canvas.clientWidth || 260;
        const h = canvas.clientHeight || 320;

        app = new Application({
          view: canvas,
          width: w,
          height: h,
          antialias: true,
          resolution: Math.min(window.devicePixelRatio || 1, 2),
          backgroundAlpha: 0,
          autoDensity: true,
        });
        if (!mounted) { app.destroy(true); return; }

        model = await Live2DModel.from('/live2d/models/kira/kira.model3.json', {
          autoInteract: false,
        });
        modelRef.current = model;

        const fit = () => {
          const sw = app.screen.width;
          const sh = app.screen.height;
          const s = Math.min((sw * 0.82) / model.width, (sh * 0.82) / model.height);
          model.scale.set(s);
          model.anchor.set(0.5, 0.5);
          model.position.set(sw / 2, sh / 2);
        };
        fit();

        app.stage.addChild(model as any);
        (model as any).isInteractive = () => false;

        try {
          textureRef.current = {
            index: 2,
            original: (model.internalModel.coreModel as any).getTexture(2),
          };
        } catch { /* ignore */ }

        if (mounted) setLive2dReady(true);

        try { model.motion('Idle'); } catch { /* no idle */ }
        try { model.expression('Normal'); } catch { /* no expressions */ }

        idleExprRef.current = setInterval(() => {
          if (props.isSpeaking) return;
          const expr = IDLE_EXPRESSIONS[Math.floor(Math.random() * IDLE_EXPRESSIONS.length)];
          try { model.expression(expr); } catch { /* */ }
          setCurrentExpression(expr);
        }, 8000 + Math.random() * 7000);

      } catch (e) {
        console.warn('[Live2D]', e);
        if (mounted) setLoadError(true);
      }
    };

    init();

    return () => {
      mounted = false;
      cancelAnimationFrame(lipSyncRef.current);
      clearInterval(idleExprRef.current ?? undefined);
      if (app) { app.destroy(true, { children: true }); }
      modelRef.current = null;
      textureRef.current = null;
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  // Lip sync from TTS
  useEffect(() => {
    const model = modelRef.current;
    if (!model || !live2dReady) return;
    cancelAnimationFrame(lipSyncRef.current);
    if (props.isSpeaking) {
      let phase = 0;
      const animate = () => {
        phase += 0.12;
        const openness = 0.25 + Math.sin(phase) * 0.35;
        try {
          model.internalModel.coreModel.setParameterValueByIndex(
            findParam(model, 'PARAM_MOUTH_OPEN_Y'), openness,
          );
        } catch { /* */ }
        lipSyncRef.current = requestAnimationFrame(animate);
      };
      animate();
    } else {
      try {
        model.internalModel.coreModel.setParameterValueByIndex(
          findParam(model, 'PARAM_MOUTH_OPEN_Y'), 0,
        );
      } catch { /* */ }
    }
    return () => cancelAnimationFrame(lipSyncRef.current);
  }, [props.isSpeaking, live2dReady]);

  // Outfit texture swapping
  useEffect(() => {
    const model = modelRef.current;
    if (!model || !live2dReady) return;
    const outfitUrl = OUTFIT_TEXTURES[props.outfit];
    if (!outfitUrl) return;
    (async () => {
      try {
        const { Assets } = await import('pixi.js');
        const tex = await Assets.load(outfitUrl);
        if ((model as any).textures) {
          (model as any).textures[2] = tex;
        } else {
          console.warn('[Outfit] cannot swap - no textures array');
        }
      } catch (e) {
        console.warn('[Outfit] texture swap failed:', e);
      }
    })();
  }, [props.outfit, live2dReady]);

  // Accessory toggle
  useEffect(() => {
    const model = modelRef.current;
    if (!model || !live2dReady) return;
  }, [props.accessory, live2dReady]);

  const pulseStyle = `
    @keyframes listening-pulse {
      0%, 100% { box-shadow: 0 0 0 0 rgba(248, 113, 113, 0.4); }
      50% { box-shadow: 0 0 0 12px rgba(248, 113, 113, 0); }
    }
    .animate-listening-pulse {
      animation: listening-pulse 1.5s infinite;
    }
  `;

  return (
    <div className="flex flex-col items-center w-full h-full overflow-hidden">
      <div className="relative w-full flex-1" style={{ minHeight: 250 }}>
        {/* Live2D canvas */}
        <canvas
          ref={canvasRef}
          className="w-full h-full block"
          style={{ opacity: live2dReady ? 1 : 0 }}
        />

        {/* SVG fallback */}
        {(!live2dReady || loadError) && (
          <div className="absolute inset-0 flex items-center justify-center">
            <AnimatedAvatar
              isSpeaking={props.isSpeaking}
              isListening={props.isListening}
              outfit={props.outfit}
              accessory={props.accessory}
              onTalkToggle={props.onTalkToggle}
            />
          </div>
        )}

        {/* Loading */}
        {!live2dReady && !loadError && (
          <div className="absolute inset-0 flex flex-col items-center justify-center gap-2">
            <div className="w-8 h-8 border-3 border-kira-pink border-t-transparent rounded-full animate-spin" />
            <p className="text-[11px] text-kira-plum/40">loading Kira...</p>
          </div>
        )}

        {/* Expression buttons */}
        {live2dReady && (
          <>
            <div className="absolute top-1 left-0 right-0 flex gap-1 justify-center flex-wrap pointer-events-none">
              <div className="pointer-events-auto flex gap-1 flex-wrap justify-center">
                {EXPRESSIONS.map((expr) => (
                  <button
                    key={expr}
                    onClick={() => {
                      try { modelRef.current?.expression(expr); setCurrentExpression(expr); } catch {}
                    }}
                    className={`text-[9px] px-2 py-0.5 rounded-full font-medium transition-all ${
                      currentExpression === expr
                        ? 'bg-kira-pink text-white'
                        : 'bg-white/70 text-kira-plum/40 hover:text-kira-plum/70'
                    }`}
                  >
                    {expr}
                  </button>
                ))}
              </div>
            </div>

            {/* Talk button */}
            <div className="absolute bottom-2 left-0 right-0 flex justify-center pointer-events-none">
              <button
                onClick={props.onTalkToggle}
                className={`pointer-events-auto flex items-center gap-2 px-5 py-2 rounded-full text-sm font-bold transition-all shadow-lg ${
                  props.isListening
                    ? 'bg-red-400 text-white scale-105 animate-listening-pulse'
                    : 'bg-gradient-to-r from-kira-pink to-kira-lav text-white hover:shadow-xl hover:scale-105'
                }`}
              >
                <span className="text-base">{props.isListening ? '⏹️' : '🎤'}</span>
                {props.isListening ? 'Listening...' : 'Talk to Kira'}
              </button>
            </div>

            {/* Status */}
            <div className="absolute bottom-2 right-3 flex items-center gap-2 text-xs text-kira-plum/50 pointer-events-none">
              <span className={`w-2 h-2 rounded-full ${
                props.isSpeaking ? 'bg-kira-pink animate-pulse'
                : props.isListening ? 'bg-red-400 animate-pulse'
                : 'bg-kira-mint'
              }`} />
              <span>
                {props.isSpeaking ? 'speaking...'
                : props.isListening ? 'listening...'
                : 'here with you'}
              </span>
            </div>
          </>
        )}
      </div>

      <style>{pulseStyle}</style>
    </div>
  );
}

function loadScript(src: string): Promise<void> {
  return new Promise((resolve, reject) => {
    if (document.querySelector('script[src="' + src + '"]')) { resolve(); return; }
    const s = document.createElement('script');
    s.src = src;
    s.onload = () => resolve();
    s.onerror = () => reject(new Error('Failed ' + src));
    document.head.appendChild(s);
  });
}

function findParam(model: any, name: string): number {
  try {
    return model.internalModel.coreModel.getParameterIds().indexOf(name);
  } catch { return 0; }
}