import { useEffect, useRef, type CSSProperties } from 'react';
import { getLocalizedPath, getTranslation, type Locale } from '../i18n/utils';
import { PLACEHOLDER_IMG } from '../placeholder';
import { cssVars } from './css';
import { Icon, statsIcons } from '../icons';

/**
 * 首屏全屏粒子 + 邻近连线 Canvas 背景：
 * - 4 色粒子（白/蓝/紫/极光淡粉）约 70~95 颗（按屏幕面积自适应）
 * - 邻近粒子间画淡蓝连线（dist < 120）形成柔和"网"
 * - 鼠标靠近时粒子轻微吸附，连线高亮
 * - prefers-reduced-motion 下固定为静态散点，不执行动画
 */
function HeroParticleCanvas() {
  const ref = useRef<HTMLCanvasElement>(null);

  useEffect(() => {
    const canvas = ref.current;
    if (!canvas) return;
    const ctx = canvas.getContext('2d');
    if (!ctx) return;

    const reduced = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
    let raf = 0;
    let dpr = Math.min(window.devicePixelRatio || 1, 2);

    type P = {
      x: number; y: number;
      vx: number; vy: number;
      r: number;
      color: string;
      alpha: number;
      alphaSpeed: number;
    };

    const PALETTE = [
      '255, 255, 255',          // 白星
      '148, 184, 255',          // 品牌淡蓝
      '196, 178, 255',          // 薰衣草紫
      '255, 180, 215',          // 极光淡粉
    ];

    let W = 0, H = 0;
    let particles: P[] = [];
    const mouse = { x: -9999, y: -9999, active: false };

    const resize = () => {
      const { clientWidth, clientHeight } = canvas.parentElement || canvas;
      W = clientWidth;
      H = clientHeight;
      dpr = Math.min(window.devicePixelRatio || 1, 2);
      canvas.width = Math.floor(W * dpr);
      canvas.height = Math.floor(H * dpr);
      canvas.style.width = W + 'px';
      canvas.style.height = H + 'px';
      ctx.setTransform(dpr, 0, 0, dpr, 0, 0);

      const area = W * H;
      const count = Math.max(55, Math.min(100, Math.floor(area / 14000)));
      particles = Array.from({ length: count }, () => ({
        x: Math.random() * W,
        y: Math.random() * H,
        vx: (Math.random() - 0.5) * 0.10,  // 速度砍 71%，停止"游来游去"的感觉
        vy: (Math.random() - 0.5) * 0.10,
        r: Math.random() * 1.4 + 0.6,
        color: PALETTE[Math.floor(Math.random() * PALETTE.length)],
        alpha: Math.random() * 0.5 + 0.4,
        alphaSpeed: (Math.random() - 0.5) * 0.008,
      }));
    };

    const step = () => {
      ctx.clearRect(0, 0, W, H);

      // 1) 粒子
      for (let i = 0; i < particles.length; i++) {
        const p = particles[i];
        if (!reduced) {
          // 鼠标吸附（力度很小，避免头晕）
          if (mouse.active) {
            const dx = mouse.x - p.x, dy = mouse.y - p.y;
            const d2 = dx * dx + dy * dy;
            if (d2 < 140 * 140) {
              const f = (1 - Math.sqrt(d2) / 140) * 0.04;
              p.vx += dx * f * 0.02;
              p.vy += dy * f * 0.02;
            }
          }
          p.x += p.vx;
          p.y += p.vy;
          // 速度阻尼
          p.vx *= 0.992; p.vy *= 0.992;
          // 边界反弹
          if (p.x < p.r) { p.x = p.r; p.vx = Math.abs(p.vx); }
          if (p.x > W - p.r) { p.x = W - p.r; p.vx = -Math.abs(p.vx); }
          if (p.y < p.r) { p.y = p.r; p.vy = Math.abs(p.vy); }
          if (p.y > H - p.r) { p.y = H - p.r; p.vy = -Math.abs(p.vy); }

          // 闪烁 alpha
          p.alpha += p.alphaSpeed;
          if (p.alpha > 0.95 || p.alpha < 0.35) p.alphaSpeed = -p.alphaSpeed;
        }

        ctx.beginPath();
        const g = ctx.createRadialGradient(p.x, p.y, 0, p.x, p.y, p.r * 3);
        g.addColorStop(0, `rgba(${p.color}, ${p.alpha})`);
        g.addColorStop(0.5, `rgba(${p.color}, ${p.alpha * 0.35})`);
        g.addColorStop(1, `rgba(${p.color}, 0)`);
        ctx.fillStyle = g;
        ctx.arc(p.x, p.y, p.r * 3, 0, Math.PI * 2);
        ctx.fill();
      }

      // 2) 邻近连线（仅动画模式执行，静态省开销）
      if (!reduced) {
        const MAX = 120;
        for (let i = 0; i < particles.length; i++) {
          const a = particles[i];
          for (let j = i + 1; j < particles.length; j++) {
            const b = particles[j];
            const dx = a.x - b.x, dy = a.y - b.y;
            const d2 = dx * dx + dy * dy;
            if (d2 < MAX * MAX) {
              const d = Math.sqrt(d2);
              const t = 1 - d / MAX;
              // 鼠标增强：若 a 或 b 靠近鼠标，连线加亮
              let boost = 0;
              if (mouse.active) {
                const adx = a.x - mouse.x, ady = a.y - mouse.y;
                const bdx = b.x - mouse.x, bdy = b.y - mouse.y;
                const near = Math.min(adx * adx + ady * ady, bdx * bdx + bdy * bdy);
                if (near < 120 * 120) boost = (1 - Math.sqrt(near) / 120) * 0.45;
              }
              const alpha = Math.min(0.55, t * 0.28 + boost);
              ctx.strokeStyle = `rgba(148, 184, 255, ${alpha})`;
              ctx.lineWidth = 0.7;
              ctx.beginPath();
              ctx.moveTo(a.x, a.y);
              ctx.lineTo(b.x, b.y);
              ctx.stroke();
            }
          }
        }
      }

      if (!reduced) raf = requestAnimationFrame(step);
    };

    const onMove = (e: PointerEvent) => {
      const rect = canvas.getBoundingClientRect();
      mouse.x = e.clientX - rect.left;
      mouse.y = e.clientY - rect.top;
      mouse.active = true;
    };
    const onLeave = () => { mouse.active = false; mouse.x = -9999; mouse.y = -9999; };
    const onResize = () => { resize(); };

    resize();
    raf = requestAnimationFrame(step);
    window.addEventListener('resize', onResize);
    window.addEventListener('pointermove', onMove, { passive: true });
    window.addEventListener('pointerleave', onLeave);

    return () => {
      cancelAnimationFrame(raf);
      window.removeEventListener('resize', onResize);
      window.removeEventListener('pointermove', onMove);
      window.removeEventListener('pointerleave', onLeave);
    };
  }, []);

  return (
    <canvas
      ref={ref}
      aria-hidden="true"
      className="absolute inset-0 w-full h-full pointer-events-none"
      style={{ zIndex: 3 }}
    />
  );
}

/** 4 颗雾化光晕 orb，慢速漂浮在背景（品牌蓝 / 薰衣草紫 / 极光粉 / 淡绿） */
const HERO_GLOW_ORBS = [
  { c: 'rgba(61, 90, 254, 0.20)',  x: '8%',   y: '15%', sz: 380, delay: '0s',   anim: 'hero-orb-float-1' },
  { c: 'rgba(166, 140, 255, 0.18)', x: '78%',  y: '72%', sz: 460, delay: '-6s',  anim: 'hero-orb-float-2' },
  { c: 'rgba(255, 145, 193, 0.14)', x: '35%',  y: '82%', sz: 340, delay: '-11s', anim: 'hero-orb-float-1' },
  { c: 'rgba(120, 220, 190, 0.12)', x: '60%',  y: '8%',  sz: 300, delay: '-3s',  anim: 'hero-orb-float-2' },
] as const;

export default function Home({ locale }: { locale: Locale }) {
  const t = getTranslation(locale);
  const h = t.home;
  const stats = h.stats.items;
  const pillars = t.home.pillars.items;

  // 三语辅助：英文 / 繁体 / 简体
  const tr = (en: string, hk: string, zh: string) =>
    locale === 'en' ? en : locale === 'hk' ? hk : zh;

  const news = t.news.items.slice(0, 3);

  // 环绕中央玻璃球的轨道粒子：4 圈 · 12 颗发光星芒（颜色 4 色循环）
  // （方案B：用户不喜欢游来游去 → 已在 global.css 停掉公转和光晕漂浮，只保留呼吸闪烁）
  // 半径 65px 等差，角度使用非机械等分（非 0/120/240），让分布更自然
  const DOT_PALETTE = ['white', 'blue', 'violet', 'pink'] as const;
  const orbits = [
    { r: 145, d: '18s', rev: false, dots: [{ sz: 5, a: '8deg'    }, { sz: 4, a: '148deg' }, { sz: 5, a: '268deg' }] },
    { r: 210, d: '24s', rev: true,  dots: [{ sz: 5, a: '62deg'   }, { sz: 4, a: '188deg' }, { sz: 5, a: '308deg' }] },
    { r: 275, d: '30s', rev: false, dots: [{ sz: 4, a: '22deg'   }, { sz: 4, a: '142deg' }, { sz: 4, a: '270deg' }] },
    { r: 340, d: '36s', rev: true,  dots: [{ sz: 4, a: '78deg'   }, { sz: 3, a: '200deg' }, { sz: 4, a: '322deg' }] },
  ] as const;
  // 展开总长度，用于 stagger 相位
  const totalOrbitDots = orbits.reduce((n, o) => n + o.dots.length, 0);
  void totalOrbitDots;

  return (
    <>
      {/* ===== HERO：品牌背景图 + Canvas 粒子网 + 雾化光晕 + 玻璃球轨道粒子 ===== */}
      <section
        className="relative w-full h-[calc(100vh-60px)] min-h-[520px] max-h-[900px] overflow-hidden"
        style={{
          background:
            'linear-gradient(135deg, #0a0e2a 0%, #14182f 50%, #1d2150 100%)',
        }}
      >
        {/* 背景图：玻璃球/水滴主题图，匹配品牌色 */}
        <img
          src="/hero-bg.jpg"
          alt=""
          aria-hidden="true"
          className="absolute inset-0 w-full h-full object-cover"
          style={{ zIndex: 0 }}
          loading="eager"
          decoding="async"
        />

        {/* 方案A：半透明深色蒙层 → 让粒子/光晕从浅色背景中"显形"，同时增强左下白字对比度 */}
        <div
          aria-hidden="true"
          className="absolute inset-0 pointer-events-none"
          style={{
            zIndex: 1,
            background:
              'linear-gradient(135deg, rgba(10, 14, 42, 0.62) 0%, rgba(20, 24, 47, 0.54) 50%, rgba(29, 33, 80, 0.50) 100%)',
          }}
        />

        {/* 雾化光晕 4 球（慢速漂浮，最底层之上但粒子网之下） */}
        <div aria-hidden="true" className="absolute inset-0 pointer-events-none" style={{ zIndex: 2, overflow: 'hidden' }}>
          {HERO_GLOW_ORBS.map((o, i) => (
            <span
              key={i}
              className="hero-glow-orb"
              style={cssVars({
                '--orb-x': o.x,
                '--orb-y': o.y,
                '--orb-sz': o.sz + 'px',
                '--orb-color': o.c,
                animationName: o.anim,
                animationDelay: o.delay,
              })}
            />
          ))}
        </div>

        {/* Canvas 全屏粒子 + 邻近连线（白/蓝/紫/粉 4 色），z-index:3 */}
        <HeroParticleCanvas />

        {/* 粒子层：环绕中央玻璃球的轨道粒子（7 圈 / 22 颗，4 色分色，linear 匀速环绕） */}
        <div className="hero-orbit pointer-events-none" aria-hidden="true" style={{ left: '70%', top: '46%', zIndex: 4 }}>
          {orbits.flatMap((o, i) =>
            o.dots.map((d, j) => {
              // 全局 dot 序号，用于 stagger 脉冲相位 + 颜色循环
              const globalIdx = orbits.slice(0, i).reduce((n, x) => n + x.dots.length, 0) + j;
              const palette = DOT_PALETTE[globalIdx % DOT_PALETTE.length];
              return (
                <div
                  key={`${i}-${j}`}
                  className={`hero-ring${o.rev ? ' is-rev' : ''}`}
                  style={{
                    animationDuration: o.d,
                    animationDirection: o.rev ? 'reverse' : 'normal',
                    '--r': `${o.r}px`,
                  } as CSSProperties}
                >
                  <div className="hero-orbit-slot" style={{ '--a': d.a } as CSSProperties}>
                    <span
                      className={`hero-orbit-dot dot-${palette}`}
                      style={{
                        width: d.sz,
                        height: d.sz,
                        animationDelay: `${-(globalIdx * 0.35).toFixed(2)}s`,
                      }}
                    />
                  </div>
                </div>
              );
            }),
          )}
        </div>

        <div className="relative z-10 h-full w-full max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 flex flex-col justify-end pb-16 md:pb-24">
          <div className="max-w-3xl scroll-reveal">
            <h1 className="text-h1 font-bold leading-[1.1] tracking-tight text-white font-[var(--font-display)]">
              {h.heroTitle}
            </h1>
            <p className="mt-5 text-body md:text-body text-white/90 max-w-xl leading-relaxed">
              {h.sloganIntro}
            </p>
            <a
              href={getLocalizedPath('/about', locale)}
              className="mt-8 inline-flex items-center gap-2 text-body font-semibold text-white border-b border-white/60 pb-1 hover:border-white hover:gap-3 transition-all duration-300 group"
            >
              {h.heroCta}
              <Icon name="arrowRight" className="w-4 h-4 transition-transform duration-300 group-hover:translate-x-1" />
            </a>
          </div>
        </div>
      </section>

      {/* ===== 最新资讯（腾讯式三列卡片） ===== */}
      <section className="bg-[var(--bg-primary)]">
        <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-[var(--space-10)]">
          <div className="flex flex-col sm:flex-row sm:items-end justify-between gap-4 mb-8">
            <div className="text-left">
              <span className="section-eyebrow">NEWSROOM</span>
              <h2 className="section-title mt-3">{t.news.title}</h2>
            </div>
            <a href={getLocalizedPath('/news', locale)} className="inline-flex items-center gap-1.5 text-body font-semibold text-[var(--brand-accent)] hover:gap-2.5 transition-all duration-300">
              {tr('View all news', '查看全部新聞', '查看全部新闻')}
              <Icon name="arrowRight" className="w-4 h-4" />
            </a>
          </div>
          <div className="grid sm:grid-cols-2 lg:grid-cols-3 gap-6">
            {news.map((item, idx) => (
              <a key={idx} href={getLocalizedPath('/news', locale)} className="track-card group overflow-hidden flex flex-col scroll-reveal">
                <div className="relative aspect-[16/10] overflow-hidden border-b border-[var(--border-light)]">
                  <img src={PLACEHOLDER_IMG} alt={item.title} className="w-full h-full object-cover transition-transform duration-700 group-hover:scale-105" loading="lazy" decoding="async" />
                  <span className="absolute top-3 left-3 text-body px-2 py-1 rounded-md bg-white/80 text-[var(--brand-accent)] font-semibold">{item.category}</span>
                </div>
                <div className="p-5">
                  <span className="text-body text-[var(--text-muted)] font-mono">{item.date}</span>
                  <h3 className="mt-2 text-body font-semibold text-[var(--brand-black)] leading-snug group-hover:text-[var(--brand-accent)] transition-colors duration-200">{item.title}</h3>
                </div>
              </a>
            ))}
          </div>
        </div>
      </section>

      {/* ===== 大文案 + 向下滚动指示（腾讯式） ===== */}
      <section className="bg-[var(--bg-primary)] pb-[var(--space-10)]">
        <div className="max-w-5xl mx-auto px-4 sm:px-6 lg:px-8 text-center scroll-reveal">
          <p className="text-body md:text-h1 font-bold font-[var(--font-display)] text-[var(--brand-black)] leading-[1.35] tracking-tight">
            {tr(
              'BaskBuddy improves the quality of life for people around the world through innovative technology, products and services.',
              '巴適夥伴透過創新的科技、產品和服務，提升全球各地人們的生活品質。',
              '巴适伙伴通过创新的科技、产品和服务，提升全球各地人们的生活品质。',
            )}
          </p>
        </div>
        <div className="mt-16 flex flex-col items-center text-[var(--text-muted)]">
          <span className="text-body font-mono tracking-[0.3em]">SCROLL</span>
          <span className="mt-3 w-px h-14 bg-gradient-to-b from-[var(--text-muted)] to-transparent animate-pulse" />
          <Icon name="arrowDown" className="w-4 h-4 mt-1 animate-bounce" />
        </div>
      </section>

      {/* ===== 业务大图入口（黑底 · 文字左侧，对应腾讯 "面向消费者 / 企业 / 未来"） ===== */}
      <section className="bg-[var(--brand-black)]">
        {pillars.map((p, i) => (
          <a
            key={p.name}
            href={getLocalizedPath('/business', locale) + '#ecosystem'}
            className="group relative block h-[68vh] min-h-[420px] overflow-hidden"
          >
            <img
              src={p.img}
              alt={p.name}
              className="absolute inset-0 w-full h-full object-cover transition-transform duration-[900ms] group-hover:scale-105"
              loading="lazy"
              decoding="async"
            />
            {/* 左深右透蒙层：保证左侧白色标题在浅色图上仍清晰 */}
            <div
              className="absolute inset-0 pointer-events-none"
              aria-hidden="true"
              style={{
                background:
                  'linear-gradient(90deg, rgba(10, 14, 42, 0.78) 0%, rgba(10, 14, 42, 0.55) 35%, rgba(10, 14, 42, 0.15) 70%, transparent 100%)',
              }}
            />
            <div className="relative z-10 h-full max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 flex flex-col justify-center">
              <span className="text-body font-mono tracking-[0.3em] text-[var(--brand-accent)]">0{i + 1}</span>
              <h2 className="mt-3 text-h1 font-bold font-[var(--font-display)] text-white leading-tight">
                {p.name}
              </h2>
              <p className="mt-4 text-body md:text-body text-white/80 max-w-xl leading-relaxed">{p.desc}</p>
              <span className="mt-7 inline-flex items-center gap-2 text-body font-semibold text-white border-b border-white/50 pb-1 w-fit transition-all duration-300 group-hover:gap-3 group-hover:border-white">
                {tr('Learn more', '了解更多', '了解更多')}
                <Icon name="arrowRight" className="w-4 h-4" />
              </span>
            </div>
          </a>
        ))}
      </section>

      {/* ===== 愿景带 + 巴适速度 大数字 ===== */}
      <section className="band !bg-[var(--bg-subtle)]">
        <div className="max-w-5xl mx-auto px-4 sm:px-6 lg:px-8 pt-[var(--space-10)] text-center">
          <span className="section-eyebrow">OUR VISION</span>
          <h2 className="text-h1 md:text-h1 font-bold font-[var(--font-display)] text-[var(--brand-black)] mt-3">
            {tr('Value for Users, Tech for Good', '用戶為本 · 科技向善', '用户为本 · 科技向善')}
          </h2>
          <p className="mt-5 text-body text-[var(--text-secondary)] max-w-3xl mx-auto leading-relaxed">
            {tr(
              'Connect people and services through innovative technology — creating a better life for users and long-term value for society.',
              '以創新技術連接人與服務，為用戶創造美好生活，為社會創造長期價值。',
              '以创新技术连接人与服务，为用户创造美好生活，为社会创造长期价值。',
            )}
          </p>
        </div>
        <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-[var(--space-9)]">
          <div className="stat-band scroll-reveal mt-6">
            {stats.map((sItem, idx) => (
              <div className="stat-cell" key={sItem.label} style={cssVars({ '--track-color': 'var(--accent)' })}>
                <Icon name={statsIcons[idx]} className="w-8 h-8 mx-auto mb-3" style={{ color: 'var(--brand-accent)' }} />
                <div className="stat-num">
                  <span className="stat-value">{sItem.value}</span>
                  {sItem.suffix && <span className="stat-suffix">{sItem.suffix}</span>}
                </div>
                <div className="stat-label">{sItem.label}</div>
                <div className="stat-sub">{sItem.sub}</div>
              </div>
            ))}
          </div>
        </div>
      </section>

      {/* ===== CTA Band ===== */}
      <section className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 pb-[var(--space-10)]">
        <div className="cta-band scroll-reveal px-8 py-14 md:py-16 text-center">
          <h2 className="relative z-10 text-h1 font-bold font-[var(--font-display)] text-white">{t.contact.subtitle}</h2>
          <p className="relative z-10 mt-3 text-body text-[rgba(255,255,255,0.7)] max-w-xl mx-auto">
            {tr(
              'Whether for a job inquiry or business cooperation, we look forward to meeting you with warmth.',
              '無論是求職諮詢還是商務合作，我們都期待與你溫暖相遇。',
              '无论是求职咨询还是商务合作，我们都期待与你温暖相遇。',
            )}
          </p>
          <div className="relative z-10 mt-8 flex flex-col sm:flex-row items-center justify-center gap-3.5">
            <a href={getLocalizedPath('/contact', locale)} className="btn btn-light btn-lg">
              {t.contact.title}
            </a>
            <a href={getLocalizedPath('/about', locale)} className="btn btn-outline-light btn-lg">
              {tr('About Us', '了解我們', '了解我们')}
            </a>
          </div>
        </div>
      </section>
    </>
  );
}