import { onUnmounted } from 'vue'

const VOICE_BASE = '/static/training/voice'

export type VoicePromptKey =
    | 'start'
    | 'ready'
    | 'rest'
    | 'next-set'
    | 'last-rep'
    | 'keep-it-up'
    | 'good-job'
    | 'breathe-in'
    | 'breathe-out'

export interface UseVoiceCoachOptions {
    enabled?: boolean
    volume?: number
}

export function useVoiceCoach(options: UseVoiceCoachOptions = {}) {
    const { enabled = true, volume = 1 } = options

    let ctx: UniApp.InnerAudioContext | null = null
    let queue: string[] = []
    let isPlayingQueue = false

    const ensureCtx = () => {
        if (ctx) return
        ctx = uni.createInnerAudioContext()
        ctx.volume = volume
        ctx.obeyMuteSwitch = false
        ctx.onEnded(() => {
            playNextInQueue()
        })
        ctx.onError(() => {
            playNextInQueue()
        })
    }

    const playNextInQueue = () => {
        if (!ctx || queue.length === 0) {
            isPlayingQueue = false
            return
        }
        const nextSrc = queue.shift()!
        ctx.src = nextSrc
        ctx.play()
    }

    const enqueue = (src: string) => {
        if (!enabled) return
        ensureCtx()
        queue.push(src)
        if (!isPlayingQueue) {
            isPlayingQueue = true
            playNextInQueue()
        }
    }

    const speakNumber = (n: number) => {
        if (n < 1 || n > 30) return
        enqueue(`${VOICE_BASE}/numbers/${n}.mp3`)
    }

    const speakPrompt = (key: VoicePromptKey) => {
        enqueue(`${VOICE_BASE}/prompts/${key}.mp3`)
    }

    const stop = () => {
        queue = []
        isPlayingQueue = false
        ctx?.stop()
    }

    onUnmounted(() => {
        stop()
        ctx?.destroy?.()
        ctx = null
    })

    return {
        speakNumber,
        speakPrompt,
        stop,
    }
}