import { ref, onUnmounted } from 'vue'

declare global {
    interface Window {
        BarcodeDetector: new (options?: { formats: string[] }) => {
            detect(source: HTMLVideoElement | ImageBitmapSource): Promise<{ rawValue: string }[]>
        }
    }
    const BarcodeDetector: Window['BarcodeDetector'] | undefined
}

export function useBarcodeScanner(onDetected: (code: string) => void) {
    const isSupported = ref('BarcodeDetector' in globalThis)
    const isScanning = ref(false)
    const error = ref<string | null>(null)

    let detector: InstanceType<Window['BarcodeDetector']> | null = null
    let stream: MediaStream | null = null
    let animationFrameId: number | null = null
    let lastDetectedCode = ''
    let lastDetectedTime = 0

    const COOLDOWN_MS = 2000

    async function start(videoElement: HTMLVideoElement) {
        if (!isSupported.value) {
            error.value = 'BarcodeDetector non supporté. Utilisez Chrome sur Android.'
            return
        }

        try {
            detector = new BarcodeDetector({ formats: ['code_39', 'code_128'] })

            stream = await navigator.mediaDevices.getUserMedia({
                video: {
                    facingMode: 'environment',
                    width: { ideal: 1280 },
                    height: { ideal: 720 }
                }
            })

            videoElement.srcObject = stream
            await videoElement.play()
            isScanning.value = true
            error.value = null

            scanLoop(videoElement)
        } catch (e) {
            error.value = e instanceof Error ? e.message : 'Erreur lors du démarrage de la caméra'
            isScanning.value = false
        }
    }

    function scanLoop(videoElement: HTMLVideoElement) {
        if (!isScanning.value || !detector) return

        animationFrameId = requestAnimationFrame(async () => {
            try {
                if (videoElement.readyState >= HTMLMediaElement.HAVE_ENOUGH_DATA) {
                    const barcodes = await detector!.detect(videoElement)

                    if (barcodes.length > 0) {
                        const code = barcodes[0].rawValue.slice(4)
                        const now = Date.now()

                        if (code !== lastDetectedCode || now - lastDetectedTime > COOLDOWN_MS) {
                            lastDetectedCode = code
                            lastDetectedTime = now

                            if (navigator.vibrate) {
                                navigator.vibrate(100)
                            }

                            onDetected(code)
                        }
                    }
                }
            } catch {
                // Detection error on single frame, continue
            }

            scanLoop(videoElement)
        })
    }

    function stop() {
        isScanning.value = false

        if (animationFrameId !== null) {
            cancelAnimationFrame(animationFrameId)
            animationFrameId = null
        }

        if (stream) {
            stream.getTracks().forEach(track => track.stop())
            stream = null
        }

        detector = null
    }

    onUnmounted(() => {
        stop()
    })

    return {
        isSupported,
        isScanning,
        error,
        start,
        stop
    }
}