import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
import {
  HQ_PERMISSION_CATALOG,
  HQ_ROLE_DEFAULT_PERMISSIONS,
  LEGACY_SYSTEM_SETTINGS_KEY,
  expandHqPermissionKeys,
  type HqPermissionKey,
} from '@dukang/shared-types';
import { PrismaService } from '../../common/prisma/prisma.module';
import { serializeBigInt } from '../../common/decorators/current-user.decorator';

const VALID_PERMISSION_KEYS = new Set<string>([
  ...HQ_PERMISSION_CATALOG.map((p) => p.key),
  LEGACY_SYSTEM_SETTINGS_KEY,
]);

function assertPermissionKeys(keys: string[]) {
  const invalid = keys.filter((key) => !VALID_PERMISSION_KEYS.has(key));
  if (invalid.length) {
    throw new BadRequestException(`无效权限项: ${invalid.join(', ')}`);
  }
}

@Injectable()
export class AdminHqPermissionsService {
  constructor(private readonly prisma: PrismaService) {}

  catalog() {
    return {
      permissions: HQ_PERMISSION_CATALOG,
      roles: Object.entries(HQ_ROLE_DEFAULT_PERMISSIONS).map(([role, permissionKeys]) => ({
        role,
        permissionKeys,
      })),
    };
  }

  async getRolePermissions(role: string) {
    const rows = await this.prisma.hqRolePermission.findMany({
      where: { adminRole: role as 'SUPER_ADMIN' | 'OPS' | 'FINANCE' | 'CUSTOMER_SERVICE' },
      select: { permissionKey: true },
    });
    const permissionKeys =
      rows.length > 0
        ? expandHqPermissionKeys(rows.map((r) => r.permissionKey))
        : [...(HQ_ROLE_DEFAULT_PERMISSIONS[role] ?? [])];
    return { role, permissionKeys };
  }

  async saveRolePermissions(role: string, permissionKeys: string[]) {
    if (role === 'SUPER_ADMIN') {
      throw new BadRequestException('超级管理员基础权限固定，危险操作请按用户单独授权');
    }
    assertPermissionKeys(permissionKeys);
    const normalized = expandHqPermissionKeys(permissionKeys);
    const adminRole = role as 'OPS' | 'FINANCE' | 'CUSTOMER_SERVICE';
    await this.prisma.$transaction([
      this.prisma.hqRolePermission.deleteMany({ where: { adminRole } }),
      ...(normalized.length
        ? [
            this.prisma.hqRolePermission.createMany({
              data: normalized.map((permissionKey) => ({ adminRole, permissionKey })),
            }),
          ]
        : []),
    ]);
    return this.getRolePermissions(role);
  }

  async getAccountPermissions(accountId: bigint) {
    const account = await this.prisma.hqAccount.findUnique({
      where: { id: accountId },
      select: { id: true, name: true, phone: true, loginName: true, adminRole: true, status: true },
    });
    if (!account) throw new NotFoundException('HQ 账号不存在');

    const userPerms = await this.prisma.hqAccountPermission.findMany({
      where: { hqAccountId: accountId },
      select: { permissionKey: true },
    });
    const userPermissionKeys = expandHqPermissionKeys(userPerms.map((p) => p.permissionKey));

    if (account.adminRole === 'SUPER_ADMIN') {
      const rolePermissionKeys = HQ_PERMISSION_CATALOG.map(
        (p) => p.key,
      ) as HqPermissionKey[];
      const effectivePermissionKeys = [
        ...new Set([...rolePermissionKeys, ...userPermissionKeys]),
      ] as HqPermissionKey[];
      return serializeBigInt({
        account,
        permissionKeys: userPermissionKeys,
        rolePermissionKeys,
        userPermissionKeys,
        effectivePermissionKeys,
      });
    }

    const rolePerms = await this.getRolePermissions(account.adminRole);
    const effectivePermissionKeys = [
      ...new Set([...rolePerms.permissionKeys, ...userPermissionKeys]),
    ] as HqPermissionKey[];

    return serializeBigInt({
      account,
      permissionKeys: userPermissionKeys,
      rolePermissionKeys: rolePerms.permissionKeys,
      userPermissionKeys,
      effectivePermissionKeys,
    });
  }

  async saveAccountPermissions(accountId: bigint, permissionKeys: string[]) {
    const account = await this.prisma.hqAccount.findUnique({ where: { id: accountId } });
    if (!account) throw new NotFoundException('HQ 账号不存在');
    assertPermissionKeys(permissionKeys);
    const normalized = expandHqPermissionKeys(permissionKeys);
    await this.prisma.$transaction([
      this.prisma.hqAccountPermission.deleteMany({ where: { hqAccountId: accountId } }),
      ...(normalized.length
        ? [
            this.prisma.hqAccountPermission.createMany({
              data: normalized.map((permissionKey) => ({ hqAccountId: accountId, permissionKey })),
            }),
          ]
        : []),
    ]);
    return this.getAccountPermissions(accountId);
  }
}