import { ref, computed, onUnmounted } from 'vue'
import { calculateCalories, getFoodComparison } from '../utils/calorie'
import type { FoodComparison } from '../utils/calorie'

export type SessionPhase = 'idle' | 'training' | 'resting' | 'done'

export type CrushItemType = 'egg' | 'walnut' | 'can' | 'balloon'

export interface TrainingSessionConfig {
    sets: number
    reps: number
    restSec: number
    beatsPerRep?: number
    onRepComplete?: (currentRep: number, totalReps: number) => void
    onSetComplete?: (currentSet: number, totalSets: number) => void
    onEnterRest?: (restSec: number) => void
    onExitRest?: () => void
    onDone?: () => void
    onCountdownTick?: (remainingSec: number) => void
    onCrushTrigger?: (itemType: CrushItemType) => void
}

export interface TrainingStats {
    totalSets: number
    totalReps: number
    durationSeconds: number
    calories: number
    foodComparison: FoodComparison
}

// 捏碎特效配置
const CRUSH_TRIGGER_INTERVAL_MIN = 8  // 最小触发间隔
const CRUSH_TRIGGER_INTERVAL_MAX = 12 // 最大触发间隔
const CRUSH_ITEMS: CrushItemType[] = ['egg', 'walnut', 'can', 'balloon']

// 随机触发判断（平均每 8-12 次触发一次）
function shouldTriggerCrush(): boolean {
    // 使用随机间隔的平均值：(8 + 12) / 2 = 10
    const avgInterval = (CRUSH_TRIGGER_INTERVAL_MIN + CRUSH_TRIGGER_INTERVAL_MAX) / 2
    return Math.random() < (1 / avgInterval)
}

// 随机选择物品
function randomCrushItem(): CrushItemType {
    return CRUSH_ITEMS[Math.floor(Math.random() * CRUSH_ITEMS.length)]
}

export function useTrainingSession(bpm?: number) {
    const phase = ref<SessionPhase>('idle')
    const currentSet = ref<number>(0)
    const currentRep = ref<number>(0)
    const restRemainingSec = ref<number>(0)
    const beatCounter = ref<number>(0)

    let config: TrainingSessionConfig | null = null
    let restTimer: ReturnType<typeof setInterval> | null = null
    let crushTimers: ReturnType<typeof setTimeout>[] = [] // 存储所有捏碎特效的 setTimeout
    let currentBpm = bpm ?? 80
    let startTime = 0 // 训练开始时间戳

    const totalReps = computed(() => config?.reps ?? 0)
    const totalSets = computed(() => config?.sets ?? 0)
    const beatsPerRep = computed(() => config?.beatsPerRep ?? 2)

    const isTraining = computed(() => phase.value === 'training')
    const isResting = computed(() => phase.value === 'resting')
    const isDone = computed(() => phase.value === 'done')

    const setBpm = (newBpm: number) => {
        currentBpm = newBpm
    }

    const start = (cfg: TrainingSessionConfig) => {
        config = cfg
        phase.value = 'training'
        currentSet.value = 1
        currentRep.value = 0
        beatCounter.value = 0
        restRemainingSec.value = 0
        startTime = Date.now() // 记录开始时间
    }

    // 获取训练统计数据
    const getStats = (): TrainingStats => {
        const durationSeconds = Math.floor((Date.now() - startTime) / 1000)
        const actualTotalReps = (config?.sets ?? 0) * (config?.reps ?? 0)

        const calories = calculateCalories({
            totalReps: actualTotalReps,
            bpm: currentBpm,
            userWeight: 60, // 默认 60kg
        })

        return {
            totalSets: config?.sets ?? 0,
            totalReps: actualTotalReps,
            durationSeconds,
            calories,
            foodComparison: getFoodComparison(calories),
        }
    }

    const onBeat = () => {
        if (phase.value !== 'training' || !config) return

        beatCounter.value++

        if (beatCounter.value % beatsPerRep.value !== 0) return

        currentRep.value++
        config.onRepComplete?.(currentRep.value, totalReps.value)

        // 随机触发捏碎特效
        if (shouldTriggerCrush() && config.onCrushTrigger) {
            const item = randomCrushItem()
            // 延迟到动画峰值（50%）触发
            const repDurationMs = (60000 / currentBpm) * beatsPerRep.value
            const timer = setTimeout(() => {
                config?.onCrushTrigger?.(item)
            }, repDurationMs / 2)
            crushTimers.push(timer)
        }

        if (currentRep.value >= totalReps.value) {
            config.onSetComplete?.(currentSet.value, totalSets.value)

            if (currentSet.value >= totalSets.value) {
                phase.value = 'done'
                config.onDone?.()
                return
            }

            enterRest()
        }
    }

    const enterRest = () => {
        if (!config) return
        phase.value = 'resting'
        restRemainingSec.value = config.restSec
        config.onEnterRest?.(config.restSec)

        restTimer = setInterval(() => {
            restRemainingSec.value--
            config?.onCountdownTick?.(restRemainingSec.value)
            if (restRemainingSec.value <= 0) {
                exitRest()
            }
        }, 1000)
    }

    const exitRest = () => {
        if (restTimer) {
            clearInterval(restTimer)
            restTimer = null
        }
        if (!config) return

        currentSet.value++
        currentRep.value = 0
        beatCounter.value = 0
        phase.value = 'training'
        config.onExitRest?.()
    }

    const skipRest = () => {
        if (phase.value !== 'resting') return
        exitRest()
    }

    const stop = () => {
        if (restTimer) {
            clearInterval(restTimer)
            restTimer = null
        }
        // 清理所有待触发的捏碎特效
        crushTimers.forEach(timer => clearTimeout(timer))
        crushTimers = []

        phase.value = 'idle'
        currentSet.value = 0
        currentRep.value = 0
        beatCounter.value = 0
        restRemainingSec.value = 0
    }

    onUnmounted(() => {
        if (restTimer) clearInterval(restTimer)
        crushTimers.forEach(timer => clearTimeout(timer))
        crushTimers = []
    })

    return {
        phase,
        currentSet,
        currentRep,
        restRemainingSec,
        totalReps,
        totalSets,
        isTraining,
        isResting,
        isDone,
        start,
        stop,
        skipRest,
        onBeat,
        setBpm,
        getStats,
    }
}