import { HttpStatus, Injectable } from '@nestjs/common';
import { randomUUID } from 'node:crypto';
import type { PrismaClient } from '@prisma/client';
import { BaseCrudService } from '../common/base-crud.service.js';
import { PrismaService } from '../prisma/prisma.service.js';
import { RedisService } from '../common/redis/redis.service.js';
import { getRequestContext } from '../common/context/request-context.js';
import { TENANT_ADMIN_ROLE_CODE } from '../common/constants.js';
import { BusinessException } from '../common/business-exception.js';
import { ErrorCodes } from '../common/error-codes.js';
import { initTenant } from '../common/tenant-template.js';
import { CreateTenantDto, ListTenantQuery, UpdateTenantDto } from './dto.js';

@Injectable()
export class TenantsService extends BaseCrudService {
  constructor(
    prisma: PrismaService,
    private readonly redis: RedisService,
  ) {
    super(prisma, 'tenant');
  }

  /** 创建租户并初始化（事务化）；未提供管理员密码时生成随机密码返回。 */
  async createTenant(dto: CreateTenantDto) {
    const ctx = getRequestContext();
    const code = dto.code;
    const adminPassword = dto.adminPassword ?? randomUUID().slice(0, 12);
    await this.prisma.raw.$transaction(async (tx) => {
      await tx.tenant.create({
        data: {
          code,
          name: dto.name,
          status: dto.status ?? 'enabled',
          remark: dto.remark,
          brandName: dto.brandName,
          logoUrl: dto.logoUrl,
          themeColor: dto.themeColor,
          copyright: dto.copyright,
          createdBy: ctx?.userId ?? null,
        },
      });
      await initTenant({
        prisma: tx as unknown as PrismaClient,
        tenantCode: code,
        tenantName: dto.name,
        adminRoleCode: TENANT_ADMIN_ROLE_CODE,
        adminRoleName: '租户管理员',
        adminUsername: dto.adminUsername ?? 'admin',
        adminPassword,
        includePlatformPerms: false,
        forcePasswordChange: true,
      });
    });
    const tenant = await this.db().findUnique({ where: { code } });
    return dto.adminPassword ? tenant : { ...tenant, adminPassword };
  }

  listTenants(q: ListTenantQuery) {
    const where: Record<string, unknown> = {};
    if (q.name) where.name = { contains: q.name };
    if (q.code) where.code = { contains: q.code };
    if (q.status) where.status = q.status;
    return this.paginate(q.page, q.pageSize, where);
  }

  async updateTenant(id: string, dto: UpdateTenantDto) {
    const existing = await this.findById(id);
    if (!existing) throw new BusinessException(ErrorCodes.TENANT_NOT_FOUND, '租户不存在', HttpStatus.NOT_FOUND);
    return this.update(id, { ...dto });
  }

  /** 删除租户并级联清理全部业务数据与 Redis 缓存。 */
  async removeTenant(id: string) {
    const existing = await this.findById(id);
    if (!existing) throw new BusinessException(ErrorCodes.TENANT_NOT_FOUND, '租户不存在', HttpStatus.NOT_FOUND);
    const code = existing.code;
    const db = this.prisma.raw;
    await db.$transaction([
      db.userRole.deleteMany({ where: { tenantCode: code } }),
      db.roleResource.deleteMany({ where: { tenantCode: code } }),
      db.roleOrg.deleteMany({ where: { tenantCode: code } }),
      db.refreshToken.deleteMany({ where: { tenantCode: code } }),
      db.loginLog.deleteMany({ where: { tenantCode: code } }),
      db.auditLog.deleteMany({ where: { tenantCode: code } }),
      db.config.deleteMany({ where: { tenantCode: code } }),
      db.dictItem.deleteMany({ where: { tenantCode: code } }),
      db.dictType.deleteMany({ where: { tenantCode: code } }),
      db.org.deleteMany({ where: { tenantCode: code } }),
      db.resource.deleteMany({ where: { tenantCode: code } }),
      db.role.deleteMany({ where: { tenantCode: code } }),
      db.user.deleteMany({ where: { tenantCode: code } }),
      db.tenant.delete({ where: { id } }),
    ]);
    // 清该租户的权限缓存与用户状态缓存（旧 token 立即失效）
    await this.redis.delByPrefix(`perm:${code}:`);
    await this.redis.delByPrefix(`user:${code}:`);
    return null;
  }
}