gongxiangp2/app/api/materials/facets/route.ts

import { NextRequest, NextResponse } from 'next/server'
import { getServerSession } from 'next-auth'
import { authOptions } from '@/lib/auth'
import { prisma } from '@/lib/prisma'
import {
  buildMaterialWhereFromSearchParams,
  createMaterialQueryContext,
  MaterialFilterDimension,
  MaterialQueryError,
  normalizeMaterialTypeForUi,
  normalizeSelectableMaterialTypes,
} from '@/lib/material-query'

type FacetField = 'categoryName' | 'sceneName' | 'platformName' | 'productCategoryName'

const FIELD_TO_EXCLUDE: Record<FacetField, MaterialFilterDimension> = {
  categoryName: 'category',
  sceneName: 'scene',
  platformName: 'platform',
  productCategoryName: 'productCategory',
}

function toFacetItems(rows: any[], field: FacetField) {
  return rows
    .map((row) => {
      const name = String(row[field] || '').trim()
      return {
        id: name,
        name,
        count: row._count?._all || 0,
      }
    })
    .filter((item) => item.name && item.count > 0)
    .sort((a, b) => a.name.localeCompare(b.name, 'zh-CN'))
}

function toMonthItems(rows: Array<{ createdAt: Date }>) {
  const monthMap = new Map<string, number>()

  for (const row of rows) {
    const date = new Date(row.createdAt)
    const value = `${date.getFullYear()}-${String(date.getMonth() + 1).padStart(2, '0')}`
    monthMap.set(value, (monthMap.get(value) || 0) + 1)
  }

  return Array.from(monthMap.entries())
    .map(([value, count]) => {
      const [, month] = value.split('-')
      return {
        value,
        label: `${value.slice(0, 4)}年${Number.parseInt(month, 10)}月`,
        count,
      }
    })
    .sort((a, b) => b.value.localeCompare(a.value))
}

function toMaterialTypeItems(rows: any[]) {
  const countMap = new Map<string, number>()

  for (const row of rows) {
    const normalizedType = normalizeMaterialTypeForUi(row.materialType)
    if (!normalizedType) {
      continue
    }
    countMap.set(normalizedType, (countMap.get(normalizedType) || 0) + (row._count?._all || 0))
  }

  const orderedTypes = normalizeSelectableMaterialTypes(Array.from(countMap.keys()))
  return orderedTypes.map((type) => ({
    id: type,
    name: type,
    count: countMap.get(type) || 0,
  }))
}

export async function GET(request: NextRequest) {
  try {
    const session = await getServerSession(authOptions)
    if (!session?.user || !(session.user as any).id) {
      return NextResponse.json(
        { error: '未登录', code: 'UNAUTHORIZED' },
        { status: 401 },
      )
    }

    const searchParams = request.nextUrl.searchParams
    const user = session.user as any
    const context = await createMaterialQueryContext(searchParams, user)

    const buildWhere = async (exclude?: MaterialFilterDimension) =>
      buildMaterialWhereFromSearchParams(searchParams, user, {
        context,
        ...(exclude ? { exclude } : {}),
      })

    const countWithFilters = async (exclude?: MaterialFilterDimension) => {
      const result = await buildWhere(exclude)
      if (result.empty) {
        return 0
      }
      return prisma.material.count({ where: result.where })
    }

    const groupByField = async (field: FacetField) => {
      const result = await buildWhere(FIELD_TO_EXCLUDE[field])
      if (result.empty) {
        return []
      }

      const rows = await (prisma.material.groupBy as any)({
        by: [field],
        where: result.where,
        _count: { _all: true },
      })

      return toFacetItems(rows, field)
    }

    const loadMaterialTypes = async () => {
      const result = await buildWhere('materialType')
      if (result.empty) {
        return []
      }

      const rows = await (prisma.material.groupBy as any)({
        by: ['materialType'],
        where: result.where,
        _count: { _all: true },
      })

      return toMaterialTypeItems(rows)
    }

    const loadMonths = async () => {
      const result = await buildWhere('month')
      if (result.empty) {
        return []
      }

      const rows = await prisma.material.findMany({
        where: result.where,
        select: { createdAt: true },
        orderBy: { createdAt: 'desc' },
      })

      return toMonthItems(rows)
    }

    // 每批最多并发 3 条统计查询，避免多个首页请求同时耗尽 Prisma 连接池。
    const [total, categories, scenes] = await Promise.all([
      countWithFilters(),
      groupByField('categoryName'),
      groupByField('sceneName'),
    ])
    const [platforms, productCategories, months] = await Promise.all([
      groupByField('platformName'),
      groupByField('productCategoryName'),
      loadMonths(),
    ])
    const [materialTypes, materialTypeTotal, categoryTotal] = await Promise.all([
      loadMaterialTypes(),
      countWithFilters('materialType'),
      countWithFilters('category'),
    ])
    const [sceneTotal, platformTotal, productCategoryTotal] = await Promise.all([
      countWithFilters('scene'),
      countWithFilters('platform'),
      countWithFilters('productCategory'),
    ])
    const monthTotal = await countWithFilters('month')

    return NextResponse.json({
      total,
      categories,
      scenes,
      platforms,
      productCategories,
      months,
      materialTypes,
      totals: {
        materialType: materialTypeTotal,
        category: categoryTotal,
        scene: sceneTotal,
        platform: platformTotal,
        productCategory: productCategoryTotal,
        month: monthTotal,
      },
    })
  } catch (error) {
    if (error instanceof MaterialQueryError) {
      return NextResponse.json(
        { error: error.message, code: error.code },
        { status: error.status },
      )
    }

    console.error('[Materials Facets] Error:', error)
    return NextResponse.json(
      { error: '获取首页筛选统计失败', code: 'SERVER_ERROR' },
      { status: 500 },
    )
  }
}