<template>
    <view class="page" :style="rootStyle">
        <!-- ===== 主舞台:节拍器圆 ===== -->
        <view class="stage" @click="onCenterTap">
            <view class="ring r1" :class="{ playing: isPlaying }" />
            <view class="ring r2" :class="{ playing: isPlaying }" />
            <view class="core" :class="{ playing: isPlaying }">
                <text class="bpm-num">{{ currentBpm }}</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"
                />
                <!-- #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 LOOP_PRESETS"
                :key="p.id"
                class="preset"
                :class="{ active: currentLoop === p.id }"
                @click="onPresetTap(p.id)"
            >
                <text class="preset-icon">{{ presetIcon(p.id) }}</text>
                <text class="preset-name">{{ presetName(p.id) }}</text>
                <text class="preset-bpm">{{ p.bpm }} BPM</text>
                <text class="preset-desc">{{ presetDesc(p.id) }}</text>
            </view>
        </view>

        <!-- 提示信息(锁屏可继续播放) -->
        <view class="hint">
            <text>🔒 锁屏可继续播放,放兜里走也能听到</text>
        </view>
    </view>
</template>

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

/**
 * 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, playback-rate 范围 [0.5, 2.0] */
const VIDEO_BASE_BPM = 124

const { isPlaying, currentLoop, playLoop, pause, resume, stop, LOOP_PRESETS } =
    useMetronomeBg()

/* 档位元数据(图标/名称/描述) */
const presetIcon = (id: LoopId) =>
    id === 'slow' ? '🚶' : id === 'normal' ? '🏃‍♀️' : '🏃'
const presetName = (id: LoopId) =>
    id === 'slow' ? '慢走' : id === 'normal' ? '健走' : '快走'
const presetDesc = (id: LoopId) =>
    id === 'slow' ? '热身 · 恢复' : id === 'normal' ? '日常 · 通勤' : '提速 · 燃脂'

const currentPreset = computed(() =>
    currentLoop.value
        ? LOOP_PRESETS.find((p) => p.id === currentLoop.value) ?? null
        : null,
)

const currentBpm = computed(() => currentPreset.value?.bpm ?? 110)
const intervalMs = computed(() => 60000 / currentBpm.value)

/* 中央圆按钮:
   - 没选档位 → 默认开"健走"
   - 选了档位且在播 → 暂停
   - 选了档位且暂停 → 恢复 */
const onCenterTap = () => {
    if (!currentLoop.value) {
        playLoop('normal')
        uni.setKeepScreenOn({ keepScreenOn: true })
        return
    }
    if (isPlaying.value) {
        pause()
        uni.setKeepScreenOn({ keepScreenOn: false })
    } else {
        resume()
        uni.setKeepScreenOn({ keepScreenOn: true })
    }
}

/* 档位卡片:
   - 点未选档位 → 切到该档位并播放
   - 点当前档位 → 切到暂停/恢复 */
const onPresetTap = (id: LoopId) => {
    playLoop(id)
    uni.setKeepScreenOn({ keepScreenOn: true })
}

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

const playbackRate = computed(() => {
    const rate = currentBpm.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)
}

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`,
}))

onShow(() => {
    /* BgAudio 全局单例,无需特殊预热,首次 setSrc 时自动初始化 */
})

/**
 * onHide 故意不 stop:
 *   - 切到后台/锁屏/小窗 都会触发 onHide
 *   - 配合 BackgroundAudioManager,音频会通过系统层继续播放
 *   - 用户能从锁屏控制条主动暂停(通过 onPause 回调同步 UI)
 */
onHide(() => {
    /* 不停止,让节拍声后台继续 */
})

onUnmounted(() => {
    /* 页面被销毁(navigateBack/重启)时才真正停止
       否则锁屏控制条会一直挂着无主的"节拍器" */
    if (isPlaying.value) stop()
    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;
$radius-card: 24rpx;
$shadow-sm: 0 4rpx 12rpx rgba(15, 23, 42, 0.04);

/* ============================================================
 * 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;
    }

    .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
 * ============================================================ */
.walker {
    width: 100%;
    height: 260rpx;
    display: flex;
    justify-content: center;
    align-items: center;
}

.walker-box {
    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%;
    background: #e8ecf2;
}

.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;
        }
    }
}

/* ============================================================
 * 底部提示
 * ============================================================ */
.hint {
    margin-top: 8rpx;
    font-size: 22rpx;
    color: $text-3;
    letter-spacing: 1rpx;

    text {
        line-height: 1.6;
    }
}
</style>
