import { NextRequest, NextResponse } from 'next/server'
import { getServerSession } from 'next-auth'
import { Prisma } from '@prisma/client'
import { authOptions } from '@/lib/auth'
import { prisma } from '@/lib/prisma'
import { buildMaterialManagementScopeWhere, getMaterialPermissionActor } from '@/lib/material-permissions'

export const dynamic = 'force-dynamic'

const DEFAULT_EXPORT_LIMIT = 10000
const MAX_EXPORT_LIMIT = 10000

function parseExportLimit(value: string | null) {
  const parsed = Number.parseInt(value || '', 10)
  if (!Number.isFinite(parsed) || parsed <= 0) {
    return DEFAULT_EXPORT_LIMIT
  }
  return Math.min(parsed, MAX_EXPORT_LIMIT)
}

export async function GET(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions)

    if (!session?.user) {
      return NextResponse.json({ error: '未登录' }, { status: 401 })
    }

    const actor = await getMaterialPermissionActor(session)
    if (!actor || (actor.role !== 'ADMIN' && !actor.isSuperAdmin)) {
      return NextResponse.json({ error: '需要管理员权限' }, { status: 403 })
    }

    const { searchParams } = new URL(req.url)
    const limit = parseExportLimit(searchParams.get('limit'))
    const scopeWhere = await buildMaterialManagementScopeWhere(actor)
    const filters: Prisma.MaterialWhereInput[] = [{ deletedAt: null }]
    if (Object.keys(scopeWhere).length > 0) {
      filters.push(scopeWhere)
    }
    const where: Prisma.MaterialWhereInput = filters.length === 1 ? filters[0] : { AND: filters }

    const [totalCount, rawMaterials] = await Promise.all([
      prisma.material.count({ where }),
      prisma.material.findMany({
        where,
        select: {
          id: true,
          productModel: true,
          brandName: true,
          seriesName: true,
          skuCode: true,
          materialTexture: true,
          categoryName: true,
          sceneName: true,
          platformName: true,
          materialType: true,
          renderer: true,
          renderTime: true,
          imageResolution: true,
          colorMode: true,
          authorName: true,
          zipFileName: true,
          zipFileSize: true,
          downloadCount: true,
          likeCount: true,
          isPremium: true,
          createdAt: true,
          updatedAt: true,
          user: {
            select: {
              username: true,
            },
          },
        },
        orderBy: { createdAt: 'desc' },
        take: limit,
      }),
    ])

    const materials = rawMaterials.map((material) => ({
      ...material,
      zipFileSize: material.zipFileSize.toString(),
      createdAt: material.createdAt.toISOString(),
      updatedAt: material.updatedAt.toISOString(),
    }))

    return NextResponse.json({
      materials,
      totalCount,
      exportedCount: materials.length,
      limit,
    })
  } catch (error) {
    console.error('[AdminMaterialsExport] GET error:', error)
    return NextResponse.json({ error: '导出素材数据失败' }, { status: 500 })
  }
}