import { NextRequest, NextResponse } from 'next/server'
import { getServerSession } from 'next-auth'
import { authOptions } from '@/lib/auth'
import { prisma } from '@/lib/prisma'

// 获取所有使用店铺
export async function GET() {
  try {
    const categories = await prisma.category.findMany({
      orderBy: {
        name: 'asc',
      },
    })

    // 优化：使用SQL聚合查询，避免N+1问题
    const counts = await prisma.$queryRaw<Array<{
      categoryName: string
      count: bigint
    }>>`
      SELECT 
        "categoryName" as "categoryName",
        COUNT(*)::bigint as count
      FROM "materials"
      WHERE "categoryName" IS NOT NULL AND "categoryName" != ''
      GROUP BY "categoryName"
    `
    
    const countMap = new Map<string, number>()
    counts.forEach(item => {
      countMap.set(item.categoryName, Number(item.count))
    })

    const categoriesWithCount = categories.map(category => ({
      ...category,
      count: countMap.get(category.name) || 0,
    }))

    return NextResponse.json(categoriesWithCount)
  } catch (error) {
    console.error('Error fetching categories:', error)
    return NextResponse.json(
      { error: '获取店铺列表失败' },
      { status: 500 }
    )
  }
}

// 添加新的使用店铺
export async function POST(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions)

    if (!session) {
      return NextResponse.json(
        { error: '请先登录' },
        { status: 401 }
      )
    }

    const { name } = await req.json()

    if (!name || !name.trim()) {
      return NextResponse.json(
        { error: '店铺名称不能为空' },
        { status: 400 }
      )
    }

    // 检查店铺是否已存在
    const existing = await prisma.category.findUnique({
      where: { name: name.trim() },
    })

    if (existing) {
      return NextResponse.json(
        { error: '该店铺已存在' },
        { status: 400 }
      )
    }

    // 创建新店铺
    const category = await prisma.category.create({
      data: {
        name: name.trim(),
      },
    })

    return NextResponse.json(category, { status: 201 })
  } catch (error) {
    console.error('Error creating category:', error)
    return NextResponse.json(
      { error: '创建店铺失败' },
      { status: 500 }
    )
  }
}

// 更新店铺名称
export async function PATCH(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions)

    if (!session || (session.user as any)?.role !== 'ADMIN') {
      return NextResponse.json(
        { error: '权限不足' },
        { status: 403 }
      )
    }

    const { id, name, options } = await req.json()

    if (!id || !name || !name.trim()) {
      return NextResponse.json(
        { error: '参数错误' },
        { status: 400 }
      )
    }

    // 检查新名称是否已存在（排除当前店铺）
    const existing = await prisma.category.findFirst({
      where: {
        name: name.trim(),
        NOT: { id },
      },
    })

    if (existing) {
      return NextResponse.json(
        { error: '该店铺名称已存在' },
        { status: 400 }
      )
    }

    // 获取旧名称
    const oldCategory = await prisma.category.findUnique({
      where: { id },
    })

    if (!oldCategory) {
      return NextResponse.json(
        { error: '分类不存在' },
        { status: 404 }
      )
    }

    // 处理options：如果是数组，转换为JSON字符串；如果是字符串，直接使用
    let optionsValue: string | null = null
    if (options !== undefined && options !== null) {
      if (Array.isArray(options)) {
        optionsValue = JSON.stringify(options)
      } else if (typeof options === 'string') {
        // 支持每行一个选项的格式
        const trimmed = options.trim()
        if (trimmed && !trimmed.startsWith('[') && !trimmed.startsWith('{')) {
          const lines = trimmed.split('\n').map(line => line.trim()).filter(Boolean)
          optionsValue = lines.length > 0 ? JSON.stringify(lines) : null
        } else {
          optionsValue = trimmed || null
        }
      }
    }

    // 更新店铺名称和选项
    const category = await prisma.category.update({
      where: { id },
      data: { 
        name: name.trim(),
        options: optionsValue,
      },
    })

    // 同步更新所有使用该分类的素材
    await prisma.material.updateMany({
      where: { categoryName: oldCategory.name },
      data: { categoryName: name.trim() },
    })

    return NextResponse.json(category)
  } catch (error) {
    console.error('Error updating category:', error)
    return NextResponse.json(
      { error: '更新失败' },
      { status: 500 }
    )
  }
}

// 删除店铺
export async function DELETE(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions)

    if (!session || (session.user as any)?.role !== 'ADMIN') {
      return NextResponse.json(
        { error: '权限不足' },
        { status: 403 }
      )
    }

    const { searchParams } = new URL(req.url)
    const id = searchParams.get('id')

    if (!id) {
      return NextResponse.json(
        { error: '缺少ID参数' },
        { status: 400 }
      )
    }

    // 删除店铺
    await prisma.category.delete({
      where: { id },
    })

    return NextResponse.json({ success: true })
  } catch (error) {
    console.error('Error deleting category:', error)
    return NextResponse.json(
      { error: '删除失败' },
      { status: 500 }
    )
  }
}