import {computed, ref, watch} from 'vue';
import {toValue} from "@vueuse/core";
import {useInjectVoluntaryCart} from "@/pages/voluntary/hooks/useVoluntaryCartInjection";
import {useInjectVoluntaryData} from "@/hooks/useVoluntaryDataInjection";
import MxConst from "@/common/mxConst";

export const useVoluntarySortService = function (popupRef, defaultSort = []) {

    const {selectedList} = useInjectVoluntaryCart()
    const {voluntaryData} = useInjectVoluntaryData()
    const showPopup = computed(() => toValue(popupRef).showPopup)
    const cancelSortText = computed(() => toValue(defaultSort).length ? '重置排序' : '清除排序')

    // sort related
    const firedSorts = ref([])
    const localSort = ref([]) // 这里放本地手工操作影响的排序结果
    const sortList = ref([{
        name: '录取概率从低到高',
        short: '录取率',
        icon: 'arrow-downward',
        compare: (a, b) => {
            const aRatio = a.enrollRatio * 1
            const bRatio = b.enrollRatio * 1
            return aRatio - bRatio
        }
    }, {
        name: '录取概率从高到低',
        short: '录取率',
        icon: 'arrow-upward',
        compare: (a, b) => {
            const aRatio = a.enrollRatio * 1
            const bRatio = b.enrollRatio * 1
            return bRatio - aRatio
        }
    }, {
        name: '最低位次从低到高',
        short: '位次',
        icon: 'arrow-downward',
        compare: (a, b) => {
            const aSeat = a.history?.seat || 9999
            const bSeat = b.history?.seat || 9999
            return bSeat - aSeat // 数字越小位次越高
        }
    }, {
        name: '最低位次从高到低',
        short: '位次',
        icon: 'arrow-upward',
        compare: (a, b) => {
            const aSeat = a.history?.seat || -1
            const bSeat = b.history?.seat || -1
            return aSeat - bSeat
        }
    }, {
        name: '院校排名从低到高',
        short: '院校排名',
        icon: 'arrow-downward',
        compare: (a, b) => {
            const aRank = a.university.ranking * 1
            const bRank = b.university.ranking * 1
            return bRank - aRank // 数字越小排名越高
        }
    }, {
        name: '院校排名从高到低',
        short: '院校排名',
        icon: 'arrow-upward',
        compare: (a, b) => {
            const aRank = a.university.ranking * 1
            const bRank = b.university.ranking * 1
            return aRank - bRank
        }
    }])
    const resetCompare = (a, b) => {
        const restoreSort = toValue(localSort).length ? toValue(localSort) : toValue(defaultSort)
        let aIdx = restoreSort.findIndex(id => id == a.uniqueCode)
        let bIdx = restoreSort.findIndex(id => id == b.uniqueCode)
        if (aIdx === -1) aIdx = 9999
        if (bIdx === -1) bIdx = 9999
        return aIdx - bIdx
    }
    const sequenceOptions = computed(() => {
        // Note: Here we return a 2 dimension array, because `u-picker` is a multi-column picker
        return selectedList.value.map((item, index) => ({
            value: index,
            text: generateSeq(index)
        }))
    })

    // methods
    const generateSeq = (index) => {
        switch (toValue(voluntaryData).sort) {
            case 'letter':
                return String.fromCharCode(65 + index)
            default:
                return index + 1
        }
    }
    const sortInterrupt = (sorts = null) => {
        firedSorts.value = []
        localSort.value = sorts || toValue(selectedList).map(g => g.uniqueCode)
    }
    const _orderByAndThen = () => {
        const sortsRef = toValue(firedSorts)
        toValue(selectedList).sort((a, b) => {
            for (let idx = 0; idx < sortsRef.length; idx++) {
                const curSort = sortsRef[idx]
                const curCompare = curSort.compare(a, b)
                if (curCompare === 0) continue // 如果先选条件相等才比较下一条
                return curCompare
            }
            return 0
        })
    }
    const handleSort = (sort) => {
        // 搜索已经存在的互斥条件
        const sortsRef = toValue(firedSorts)
        const idx = sortsRef.findIndex(s => s.short == sort.short)
        if (idx != -1) sortsRef.splice(idx, 1)
        sortsRef.push(sort)
        _orderByAndThen()
    }
    const handleSortRemove = (sort) => {
        const sortsRef = toValue(firedSorts)
        const idx = sortsRef.indexOf(sort)
        sortsRef.splice(idx, 1)
        toValue(selectedList).sort(resetCompare)
        _orderByAndThen()
    }
    const handleSortReset = () => {
        toValue(selectedList).sort(resetCompare)
        firedSorts.value = []
    }

    const handleMoveUp = (group) => {
        const idx = selectedList.value.indexOf(group)
        const target = idx - 1
        if (target > -1) {
            selectedList.value.splice(idx, 1)
            selectedList.value.splice(target, 0, group)
            sortInterrupt()
        }
    }
    const handleMoveDown = (group) => {
        const idx = selectedList.value.indexOf(group)
        const target = idx + 1
        if (target < selectedList.value.length) {
            selectedList.value.splice(idx, 1)
            selectedList.value.splice(target, 0, group)
            sortInterrupt()
        }
    }

    const getSelectedSortedMajors = (group) => {
        return group.majors.filter(m => m.selected).sort(MxConst.recommendMajorSortFn)
    }

    // hooks
    watch(() => toValue(selectedList).map(g => g.uniqueCode), (sorts) => {
        if (!showPopup.value) {
            sortInterrupt(sorts)
        }
    })

    return {
        firedSorts, localSort, sortList, cancelSortText,
        sequenceOptions, generateSeq, sortInterrupt,
        handleSort, handleSortReset, handleSortRemove,
        getSelectedSortedMajors,
        handleMoveDown, handleMoveUp
    }
}