<template>
    <view class="page" :style="rootStyle">
        <!-- ===== 主舞台:节拍器圆 ===== -->
        <view class="stage" @click="togglePlay">
            <view class="ring r1" :class="{ playing: isPlaying }" />
            <view class="ring r2" :class="{ playing: isPlaying }" />
            <view class="core" :class="{ playing: isPlaying, accent: isAccent }">
                <text class="bpm-num">{{ bpm }}</text>
                <text class="bpm-label">BPM</text>
                <view class="ctrl">
                    <view v-if="isPlaying" class="icon-pause">
                        <view class="bar" />
                        <view class="bar" />
                    </view>
                    <view v-else class="icon-play" />
                </view>
            </view>
        </view>

        <!-- ===== 跑步小人(矩形完整显示,跟白底融合) ===== -->
        <view class="walker">
            <view class="walker-box">
                <video
                    id="runner-video"
                    class="runner-video"
                    :src="RUNNER_VIDEO_URL"
                    :muted="true"
                    :loop="true"
                    :autoplay="true"
                    :show-controls="false"
                    :show-fullscreen-btn="false"
                    :show-play-btn="false"
                    :show-center-play-btn="false"
                    :enable-progress-gesture="false"
                    :show-mute-btn="false"
                    :picture-in-picture-mode="[]"
                    object-fit="contain"
                    @error="onVideoError"
                    @loadedmetadata="onVideoLoaded"
                />
                <!-- 微信原生 video 右上角的 PIP/小窗按钮无法靠属性彻底关掉,
                     用 cover-view 覆盖一个跟背景同色的小色块盖住它 -->
                <!-- #ifdef MP-WEIXIN -->
                <!-- <cover-view class="pip-mask">&nbsp;</cover-view> -->
                <!-- #endif -->
            </view>
        </view>

        <!-- ===== 推荐档位(3 选 1) ===== -->
        <view class="presets">
            <view
                v-for="p in PRESETS"
                :key="p.id"
                class="preset"
                :class="{ active: activePreset === p.id }"
                @click="applyPreset(p)"
            >
                <text class="preset-icon">{{ p.icon }}</text>
                <text class="preset-name">{{ p.name }}</text>
                <text class="preset-bpm">{{ p.bpm }} BPM</text>
                <text class="preset-desc">{{ p.desc }}</text>
            </view>
        </view>

        <!-- ===== 右下角微调(不显眼) ===== -->
        <view class="quick-adjust">
            <view class="qa-group">
                <view class="qa-btn" @click.stop="adjustBpm(-1)">−</view>
                <text class="qa-label">微调</text>
                <view class="qa-btn" @click.stop="adjustBpm(1)">+</view>
            </view>
            <view class="qa-divider" />
            <view class="qa-group">
                <view
                    v-for="m in METER_OPTIONS"
                    :key="m.value"
                    class="qa-meter"
                    :class="{ active: accentEvery === m.value }"
                    @click.stop="onMeterChange(m.value)"
                >
                    {{ m.label }}
                </view>
                <text class="qa-label">拍</text>
            </view>
        </view>
    </view>
</template>

<script setup lang="ts">
import { computed, onMounted, onUnmounted, ref, watch } from 'vue'
import { onShow, onHide } from '@dcloudio/uni-app'
import { useMetronome } from '../hooks/useMetronome'

/**
 * 跑步动画视频(腾讯云 COS CDN)
 * 注意:小程序后台需将 cos.ap-guangzhou.myqcloud.com 加入 downloadFile 合法域名,
 *       否则正式发布版会被拦截(开发版默认不校验)
 */
const RUNNER_VIDEO_URL =
    'https://gz-1349751149.cos.ap-guangzhou.myqcloud.com/uploads/video/20260525/20260525164014ef89f8862.mp4'

/**
 * 视频原速对应的 BPM 基准(参见 hooks 实现注释)
 * playback-rate 范围 [0.5, 2.0]
 */
const VIDEO_BASE_BPM = 124

/**
 * 推荐档位:覆盖大多数老人健走场景,一键切换 BPM + 拍号
 * 不在档位的中间数值用右下角微调即可
 */
const PRESETS = [
    {
        id: 'slow',
        icon: '🚶',
        name: '慢走',
        bpm: 80,
        accent: 2,
        desc: '热身 · 恢复',
    },
    {
        id: 'normal',
        icon: '🏃‍♀️',
        name: '健走',
        bpm: 110,
        accent: 2,
        desc: '日常 · 通勤',
    },
    {
        id: 'brisk',
        icon: '🏃',
        name: '快走',
        bpm: 130,
        accent: 2,
        desc: '提速 · 燃脂',
    },
] as const

const METER_OPTIONS = [
    { label: '2', value: 2 },
    { label: '3', value: 3 },
    { label: '4', value: 4 },
]

const metronome = useMetronome({
    initialBpm: 80,
    accentEvery: 4,
    clickSrc: '/training/static/audio/click.mp3',
    accentSrc: '/training/static/audio/click-wood.mp3',
})
const {
    bpm,
    isPlaying,
    isAccent,
    accentEvery,
    intervalMs,
    start,
    stop,
    setBpm,
    setAccentEvery,
    preload,
} = metronome

const adjustBpm = (delta: number) => {
    setBpm(bpm.value + delta)
}

const onMeterChange = (val: number) => {
    setAccentEvery(val)
}

const togglePlay = () => {
    if (isPlaying.value) {
        stop()
        uni.setKeepScreenOn({ keepScreenOn: false })
    } else {
        start()
        uni.setKeepScreenOn({ keepScreenOn: true })
    }
}

/* 当前命中的档位(BPM + 拍号都匹配才算选中) */
const activePreset = computed(() => {
    const hit = PRESETS.find(
        (p) => p.bpm === bpm.value && p.accent === accentEvery.value,
    )
    return hit?.id ?? null
})

const applyPreset = (p: (typeof PRESETS)[number]) => {
    setBpm(p.bpm)
    setAccentEvery(p.accent)
}

/* 视频实例与 BPM 同步 */
let videoCtx: UniApp.VideoContext | null = null

const playbackRate = computed(() => {
    const rate = bpm.value / VIDEO_BASE_BPM
    return Math.max(0.5, Math.min(2.0, +rate.toFixed(2)))
})

onMounted(() => {
    videoCtx = uni.createVideoContext('runner-video')
    setTimeout(() => videoCtx?.pause(), 50)
})

const onVideoError = (e: any) => {
    console.error('[runner-video] error:', e?.detail || e)
    uni.showToast({
        title: '视频加载失败,请用真机预览',
        icon: 'none',
        duration: 2500,
    })
}

const onVideoLoaded = (e: any) => {
    console.log('[runner-video] metadata loaded:', e?.detail)
    try {
        videoCtx?.playbackRate?.(playbackRate.value)
    } catch (_) {}
}

watch(isPlaying, (playing) => {
    if (playing) {
        videoCtx?.play()
    } else {
        videoCtx?.pause()
    }
})

watch(playbackRate, (rate) => {
    try {
        videoCtx?.playbackRate?.(rate)
    } catch (_) {}
})

const rootStyle = computed(() => ({
    '--beat-duration': `${intervalMs.value}ms`,
    '--step-duration': `${intervalMs.value}ms`,
}))

onShow(() => {
    preload()
})

onHide(() => {
    if (isPlaying.value) {
        stop()
        uni.setKeepScreenOn({ keepScreenOn: false })
    }
})

onUnmounted(() => {
    uni.setKeepScreenOn({ keepScreenOn: false })
})
</script>

<style lang="scss" scoped>
/* ============================================================
 * 设计 token —— 浅色清爽
 * ============================================================ */
$bg-color: #f8fafc;
$card-bg: #ffffff;
$card-border: rgba(15, 23, 42, 0.06);
$text-1: #0f172a;
$text-2: #475569;
$text-3: #94a3b8;
$brand: #10b981;
$brand-soft: #d1fae5;
$brand-deep: #047857;
$accent: #f59e0b;
$accent-soft: #fef3c7;
$radius-card: 24rpx;
$radius-btn: 18rpx;
$shadow-sm: 0 4rpx 12rpx rgba(15, 23, 42, 0.04);
$shadow-md: 0 12rpx 28rpx rgba(15, 23, 42, 0.08);

/* ============================================================
 * 页面容器
 * ============================================================ */
.page {
    position: relative;
    height: 100vh;
    box-sizing: border-box;
    padding: 30rpx 28rpx 80rpx;
    background: $bg-color;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 22rpx;
    color: $text-1;
    overflow: hidden;
}

/* ============================================================
 * 节拍器主舞台
 * ============================================================ */
.stage {
    position: relative;
    width: 480rpx;
    height: 480rpx;
    margin-top: 16rpx;
    display: flex;
    align-items: center;
    justify-content: center;

    &:active .core {
        transform: scale(0.97);
    }
}

.ring {
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    border: 3rpx solid rgba(16, 185, 129, 0.12);
    pointer-events: none;

    &.playing {
        animation: ring-pulse var(--beat-duration, 750ms) ease-out infinite;
    }
    &.r2.playing {
        animation-delay: calc(var(--beat-duration, 750ms) * -0.5);
    }
}
@keyframes ring-pulse {
    0% {
        transform: scale(0.94);
        opacity: 0.85;
        border-color: rgba(16, 185, 129, 0.4);
    }
    100% {
        transform: scale(1.18);
        opacity: 0;
        border-color: rgba(16, 185, 129, 0);
    }
}

.core {
    position: relative;
    width: 380rpx;
    height: 380rpx;
    border-radius: 50%;
    background: linear-gradient(140deg, #34d399 0%, $brand-deep 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow:
        inset 0 -16rpx 50rpx rgba(0, 0, 0, 0.18),
        inset 0 16rpx 50rpx rgba(255, 255, 255, 0.18),
        0 16rpx 40rpx rgba(16, 185, 129, 0.32);
    transition: transform 0.12s, background 0.18s, box-shadow 0.18s;

    &.playing {
        animation: core-beat var(--beat-duration, 750ms) ease-in-out infinite;
    }

    &.playing.accent {
        background: linear-gradient(140deg, #fbbf24 0%, #d97706 100%);
        box-shadow:
            inset 0 -16rpx 50rpx rgba(0, 0, 0, 0.18),
            inset 0 16rpx 50rpx rgba(255, 255, 255, 0.22),
            0 16rpx 40rpx rgba(245, 158, 11, 0.4);
    }

    .bpm-num {
        font-size: 168rpx;
        font-weight: 800;
        color: #fff;
        line-height: 1;
        letter-spacing: -2rpx;
        font-variant-numeric: tabular-nums;
        text-shadow: 0 4rpx 12rpx rgba(0, 0, 0, 0.16);
    }

    .bpm-label {
        font-size: 22rpx;
        color: rgba(255, 255, 255, 0.7);
        letter-spacing: 6rpx;
        margin-top: 10rpx;
        font-weight: 600;
    }

    .ctrl {
        margin-top: 22rpx;
        height: 64rpx;
        display: flex;
        align-items: center;
        justify-content: center;
    }
}
@keyframes core-beat {
    0%,
    100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.04);
    }
}

/* 播放/暂停 icon */
.icon-play {
    width: 0;
    height: 0;
    border-left: 52rpx solid #fff;
    border-top: 32rpx solid transparent;
    border-bottom: 32rpx solid transparent;
    margin-left: 12rpx;
    filter: drop-shadow(0 2rpx 6rpx rgba(0, 0, 0, 0.18));
}
.icon-pause {
    display: flex;
    gap: 16rpx;
    height: 60rpx;

    .bar {
        width: 16rpx;
        height: 100%;
        background: #fff;
        border-radius: 4rpx;
        box-shadow: 0 2rpx 6rpx rgba(0, 0, 0, 0.18);
    }
}

/* ============================================================
 * 跑步小人(无边框,跟白底融合)
 * ============================================================ */
.walker {
    width: 100%;
    height: 260rpx;
    display: flex;
    justify-content: center;
    align-items: center;
}

.walker-box {
    /* 1:1 矩形,跟 video 内容比例一致,消除左右黑边
       background 设成 video 内容右上角的浅灰白色,
       万一还有 1rpx 缝隙也不会出现刺眼黑边 */
    position: relative;
    width: 260rpx;
    height: 260rpx;
    background: #e8ecf2;
    border-radius: 24rpx;
    overflow: hidden;
    box-shadow: 0 4rpx 14rpx rgba(15, 23, 42, 0.06);
}

.runner-video {
    width: 100%;
    height: 100%;
    /* 微信 native video 自身默认是 #000 黑底,父容器 bg 在 web 看不到,
       只能让 video 占满 + 让父 bg 跟 video 内容色融合 */
    background: #e8ecf2;
}

/* 覆盖在 video 右上角原生 PIP/小窗按钮上的色块
   颜色取 video 内容右上角的浅灰白渐变(#dde2eb 左右),让色块融入视频画面
   仅小程序端有效(cover-view 是小程序唯一能盖住 native 组件的元素) */
.pip-mask {
    position: absolute;
    top: 0;
    right: 0;
    width: 80rpx;
    height: 56rpx;
    background-color: #dde2eb;
    border-bottom-left-radius: 18rpx;
    border-top-right-radius: 24rpx;
}

/* ============================================================
 * 三档位推荐
 * ============================================================ */
.presets {
    width: 100%;
    display: flex;
    gap: 16rpx;
}

.preset {
    flex: 1;
    background: $card-bg;
    border: 2rpx solid $card-border;
    border-radius: $radius-card;
    padding: 22rpx 12rpx 20rpx;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6rpx;
    box-shadow: $shadow-sm;
    transition: all 0.18s;

    .preset-icon {
        font-size: 44rpx;
        line-height: 1;
        margin-bottom: 6rpx;
    }
    .preset-name {
        font-size: 30rpx;
        font-weight: 700;
        color: $text-1;
        letter-spacing: 2rpx;
    }
    .preset-bpm {
        font-size: 24rpx;
        color: $text-2;
        font-weight: 600;
        font-variant-numeric: tabular-nums;
    }
    .preset-desc {
        font-size: 20rpx;
        color: $text-3;
        letter-spacing: 1rpx;
        margin-top: 2rpx;
    }

    &:active {
        transform: scale(0.97);
    }

    &.active {
        background: $brand-soft;
        border-color: $brand;
        box-shadow:
            0 8rpx 20rpx rgba(16, 185, 129, 0.18),
            inset 0 0 0 2rpx rgba(16, 185, 129, 0.4);

        .preset-name {
            color: $brand-deep;
        }
        .preset-bpm {
            color: $brand-deep;
        }
        .preset-desc {
            color: $brand;
        }
    }
}

/* ============================================================
 * 右下角微调(不显眼)
 * ============================================================ */
.quick-adjust {
    position: absolute;
    right: 28rpx;
    bottom: 22rpx;
    display: flex;
    align-items: center;
    gap: 14rpx;
    padding: 10rpx 18rpx;
    background: rgba(255, 255, 255, 0.7);
    border: 1rpx solid rgba(15, 23, 42, 0.05);
    border-radius: 999rpx;
    backdrop-filter: blur(10rpx);
    opacity: 0.7;
    transition: opacity 0.2s;

    &:active {
        opacity: 1;
    }
}

.qa-group {
    display: flex;
    align-items: center;
    gap: 6rpx;
}

.qa-label {
    font-size: 20rpx;
    color: $text-3;
    margin: 0 4rpx;
    letter-spacing: 1rpx;
}

.qa-btn {
    width: 40rpx;
    height: 40rpx;
    border-radius: 50%;
    background: rgba(15, 23, 42, 0.05);
    color: $text-2;
    font-size: 26rpx;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;

    &:active {
        background: rgba(16, 185, 129, 0.18);
        color: $brand-deep;
    }
}

.qa-meter {
    min-width: 36rpx;
    height: 36rpx;
    padding: 0 10rpx;
    border-radius: 999rpx;
    font-size: 22rpx;
    color: $text-3;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
    transition: all 0.15s;

    &.active {
        background: $brand;
        color: #fff;
        box-shadow: 0 2rpx 6rpx rgba(16, 185, 129, 0.4);
    }
}

.qa-divider {
    width: 1rpx;
    height: 22rpx;
    background: rgba(15, 23, 42, 0.08);
}
</style>
