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

// GET - 获取所有使用店铺分类
export async function GET() {
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user) {
      return NextResponse.json({ error: '未登录' }, { status: 401 });
    }

    const categories = await prisma.category.findMany({
      orderBy: { name: 'asc' },
    });

    // 统计每个分类的素材数量（只统计未删除的素材）
    const categoriesWithCount = await Promise.all(
      categories.map(async (category) => {
        let count: number;
        try {
          count = await prisma.material.count({
            where: { 
              categoryName: category.name,
              deletedAt: null,
            } as any,
          });
        } catch (e: any) {
          // 兼容旧版本数据库（没有deletedAt字段）
          if (e?.meta?.column?.includes('deletedAt')) {
            count = await prisma.material.count({
          where: { categoryName: category.name },
        });
          } else {
            throw e;
          }
        }
        return {
          ...category,
          count,
        };
      })
    );

    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 }
    );
  }
}

// POST - 创建新的使用店铺分类
export async function POST(request: NextRequest) {
  try {
    const session = await getServerSession(authOptions);

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

    const { name } = await request.json();

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

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

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

    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 }
    );
  }
}

// PATCH - 更新使用店铺分类
export async function PATCH(request: NextRequest) {
  try {
    const session = await getServerSession(authOptions);

    if (!session?.user || !(session.user as any).id) {
      return NextResponse.json(
        { error: '未登录' },
        { status: 401 }
      );
    }
    const userRole = (session.user as any).role;
    if (userRole !== 'ADMIN') {
      return NextResponse.json({ error: '权限不足' }, { status: 403 });
    }

    const { id, name } = await request.json();

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

    // 检查新名称是否已被其他分类使用
    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 });
    }

    // 更新分类
    const updated = await prisma.category.update({
      where: { id },
      data: { name: name.trim() },
    });

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

// DELETE - 删除使用店铺分类
export async function DELETE(request: NextRequest) {
  try {
    const session = await getServerSession(authOptions);

    if (!session?.user || !(session.user as any).id) {
      return NextResponse.json(
        { error: '未登录' },
        { status: 401 }
      );
    }
    const userRole = (session.user as any).role;
    if (userRole !== 'ADMIN') {
      return NextResponse.json({ error: '权限不足' }, { status: 403 });
    }

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

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

    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 });
  }
}