import type { SteadyDataView } from '@/api/steady/steadyDataView/interface'

export const MAX_TREND_SERIES_COUNT = 24
export const MAX_SELECTED_LINE_COUNT = 6
export const MAX_SELECTED_INDICATOR_COUNT = 6
export const MAX_HARMONIC_ORDER_COUNT = 6

const isSelectableLineNode = (node: SteadyDataView.SteadyLedgerNode) => {
    return node.level === 3 && node.selectable !== false
}

export const collectSelectedLineIds = (nodes: SteadyDataView.SteadyLedgerNode[]) => {
    const lineIds = new Set<string>()

    const collect = (node: SteadyDataView.SteadyLedgerNode) => {
        if (isSelectableLineNode(node)) {
            lineIds.add(node.id)
        }

        node.children?.forEach(collect)
    }

    nodes.forEach(collect)

    return Array.from(lineIds)
}

export const collectLeafIndicators = (nodes: SteadyDataView.SteadyIndicatorNode[]) => {
    const indicators: SteadyDataView.SteadyIndicatorNode[] = []
    const seenIndicatorKeys = new Set<string>()

    const collect = (node: SteadyDataView.SteadyIndicatorNode) => {
        if (node.children?.length) {
            node.children.forEach(collect)
            return
        }

        const indicatorKey = node.indicatorCode || node.treeKey || node.id
        if (!indicatorKey || seenIndicatorKeys.has(indicatorKey)) return

        seenIndicatorKeys.add(indicatorKey)
        indicators.push(node)
    }

    nodes.forEach(collect)

    return indicators
}

export const findFirstSelectableLedgerNode = (
    nodes: SteadyDataView.SteadyLedgerNode[]
): SteadyDataView.SteadyLedgerNode | null => {
    for (const node of nodes) {
        if (isSelectableLineNode(node)) {
            return node
        }

        const childNode = findFirstSelectableLedgerNode(node.children || [])
        if (childNode) return childNode
    }

    return null
}

export const findFirstLeafIndicator = (
    nodes: SteadyDataView.SteadyIndicatorNode[]
): SteadyDataView.SteadyIndicatorNode | null => {
    for (const node of nodes) {
        if (node.children?.length) {
            const childNode = findFirstLeafIndicator(node.children)
            if (childNode) return childNode
            continue
        }

        if (node.indicatorCode) {
            return node
        }
    }

    return null
}

export const hasHarmonicIndicator = (indicators: SteadyDataView.SteadyIndicatorNode[]) => {
    return indicators.some(item => item.harmonic || Boolean(item.harmonicOrderStart || item.harmonicOrderEnd))
}

export const resolveAvailableStats = (indicators: SteadyDataView.SteadyIndicatorNode[]) => {
    const statSet = new Set<SteadyDataView.SteadyTrendStatType>()

    indicators.forEach(indicator => {
        indicator.supportStats?.forEach(stat => statSet.add(stat))
    })

    return Array.from(statSet)
}

export const estimateTrendSeriesCount = (
    lineIds: string[],
    indicators: SteadyDataView.SteadyIndicatorNode[],
    statType: SteadyDataView.SteadyTrendStatType,
    harmonicOrders: number[]
) => {
    const harmonicMultiplier = hasHarmonicIndicator(indicators) ? Math.max(harmonicOrders.length, 1) : 1

    return indicators.reduce((count, indicator) => {
        const phaseCount = indicator.phaseCodes?.length || 1
        const fieldCount = Math.max(indicator.seriesFields?.length || indicator.baseFields?.length || 1, 1)

        return count + lineIds.length * phaseCount * (statType ? 1 : 0) * fieldCount * harmonicMultiplier
    }, 0)
}

export const validateHarmonicOrders = (indicators: SteadyDataView.SteadyIndicatorNode[], harmonicOrders: number[]) => {
    if (!hasHarmonicIndicator(indicators)) return ''
    if (!harmonicOrders.length) return '谐波指标必须选择谐波次数'
    if (harmonicOrders.length > MAX_HARMONIC_ORDER_COUNT) return '谐波次数最多选择 6 个'

    return ''
}

export const validateTrendSelection = (params: {
    lineIds: string[]
    indicators: SteadyDataView.SteadyIndicatorNode[]
    statType: SteadyDataView.SteadyTrendStatType
    harmonicOrders: number[]
}) => {
    const { lineIds, indicators, statType, harmonicOrders } = params

    if (!lineIds.length) return '请选择监测点'
    if (!indicators.length) return '请选择趋势指标'
    if (lineIds.length > 1 && indicators.length > 1) return '多监测点查询时只能选择 1 个指标'
    if (lineIds.length > MAX_SELECTED_LINE_COUNT) return '监测点最多选择 6 个'
    if (indicators.length > MAX_SELECTED_INDICATOR_COUNT) return '趋势指标最多选择 6 个'
    if (!statType) return '请选择统计类型'

    const harmonicError = validateHarmonicOrders(indicators, harmonicOrders)
    if (harmonicError) return harmonicError

    const seriesCount = estimateTrendSeriesCount(lineIds, indicators, statType, harmonicOrders)
    if (seriesCount > MAX_TREND_SERIES_COUNT) {
        return '趋势曲线数量不能超过 24 条，请缩小监测点、指标或统计类型范围'
    }

    return ''
}