import { computed, ref } from 'vue'
import type { Ref } from 'vue'
import type { ReceptionData, WeightEntryData } from '~/services/dto/reception-data'
import type { WeightData } from '~/services/dto/weight-data'
import { getWeight } from '~/services/reception'
import { createWeight, updateWeight } from '~/services/weight'

export type WeighingMode = 'gross' | 'tare'

type UseWeighingOptions = {
    mode: WeighingMode
    reception: Ref<ReceptionData | null>
    updateReception: (id: number, payload: Partial<ReceptionData>) => Promise<ReceptionData | null>
    loadReception?: (id: number) => Promise<ReceptionData | null>
    storeError?: Ref<string | null>
}

export const useWeighing = ({
    mode,
    reception,
    updateReception,
    loadReception,
    storeError
}: UseWeighingOptions) => {
    const weightData = ref<WeightData | null>(null)
    const localErrorMessage = ref<string | null>(null)

    const currentWeightEntry = computed<WeightEntryData | null>(() => {
        const weights = reception.value?.weights ?? []
        return weights.find((entry) => entry.type === mode) ?? null
    })

    const displayWeight = computed(() => weightData.value?.weight ?? currentWeightEntry.value?.weight ?? null)
    const displayDsd = computed(() => weightData.value?.dsd ?? currentWeightEntry.value?.dsd ?? '-')
    const title = computed(() => (mode === 'gross' ? 'Pesée à plein' : 'Pesée à vide'))
    const errorMessage = computed(() => localErrorMessage.value ?? storeError?.value ?? null)
    const showLoadingBox = computed(() => displayWeight.value === null && !errorMessage.value)

    const fetchWeight = async () => {
        localErrorMessage.value = null
        try {
            weightData.value = await getWeight()
        } catch (error) {
            localErrorMessage.value = error?.data?.error ?? error?.message ?? 'Erreur inconnue.'
        }
    }

    const saveWeight = async () => {
        localErrorMessage.value = null
        if (!reception.value) {
            localErrorMessage.value = 'Réception introuvable.'
            return
        }

        const existingEntry = currentWeightEntry.value
        const baseDsd = weightData.value?.dsd ?? existingEntry?.dsd ?? null
        const baseWeight = weightData.value?.weight ?? existingEntry?.weight ?? null
        const baseWeighedAt = weightData.value?.weighedAt ?? existingEntry?.weighedAt ?? null

        if (baseWeight === null) {
            localErrorMessage.value = 'Veuillez d’abord peser.'
            return
        }

        try {
            if (existingEntry?.id) {
                await updateWeight(existingEntry.id, {
                    type: mode,
                    dsd: baseDsd,
                    weight: baseWeight,
                    weighedAt: baseWeighedAt
                })
            } else {
                await createWeight({
                    reception: `/receptions/${reception.value.id}`,
                    type: mode,
                    dsd: baseDsd,
                    weight: baseWeight,
                    weighedAt: baseWeighedAt
                })
            }
        } catch (error) {
            localErrorMessage.value = error?.data?.error ?? error?.message ?? 'Erreur inconnue.'
            return
        }

        const nextStep = reception.value.currentStep + 1
        await updateReception(reception.value.id, {
            currentStep: nextStep,
            isValid: mode === 'tare' ? true : reception.value.isValid
        })

        if (loadReception) {
            await loadReception(reception.value.id)
        }
    }

    return {
        weightData,
        currentWeightEntry,
        displayWeight,
        displayDsd,
        title,
        errorMessage,
        showLoadingBox,
        fetchWeight,
        saveWeight
    }
}