import { BadRequestException, ForbiddenException, Injectable, NotFoundException } from '@nestjs/common';
import * as bcrypt from 'bcryptjs';
import { UserStatus } from '../generated/prisma/client';
import { PrismaService } from '../infra/prisma.service';
import { AccessService } from './access.service';

@Injectable()
export class AdminService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly access: AccessService
  ) {}

  async listUsers(search?: string) {
    const users = await this.prisma.user.findMany({
      where: search
        ? {
            OR: [
              { email: { contains: search, mode: 'insensitive' } },
              { phone: { contains: search, mode: 'insensitive' } },
              { displayName: { contains: search, mode: 'insensitive' } },
              { username: { contains: search, mode: 'insensitive' } }
            ]
          }
        : undefined,
      orderBy: { createdAt: 'desc' },
      include: {
        userRoles: { include: { role: true } },
        userPermissions: { include: { permission: true } }
      }
    });

    return users.map((user) => this.toAdminUser(user));
  }

  async updateUserProfile(userId: string, data: { displayName?: string; email?: string; phone?: string; backupEmail?: string; backupPhone?: string; status?: UserStatus }) {
    await this.ensureUserExists(userId);
    const user = await this.prisma.user.update({
      where: { id: userId },
      data,
      include: { userRoles: { include: { role: true } }, userPermissions: { include: { permission: true } } }
    });
    return this.toAdminUser(user);
  }

  async resetPassword(userId: string, newPassword: string) {
    if (newPassword.length < 8) {
      throw new BadRequestException('Пароль должен содержать минимум 8 символов');
    }

    await this.ensureUserExists(userId);
    const user = await this.prisma.user.update({
      where: { id: userId },
      data: { passwordHash: await bcrypt.hash(newPassword, 12) },
      include: { userRoles: { include: { role: true } }, userPermissions: { include: { permission: true } } }
    });
    return this.toAdminUser(user);
  }

  async suspendUser(userId: string) {
    await this.ensureUserExists(userId);
    await this.prisma.session.updateMany({ where: { userId }, data: { status: 'REVOKED' } });
    const user = await this.prisma.user.update({
      where: { id: userId },
      data: { status: UserStatus.SUSPENDED },
      include: { userRoles: { include: { role: true } }, userPermissions: { include: { permission: true } } }
    });
    return this.toAdminUser(user);
  }

  async setSuperAdmin(actorUserId: string, userId: string, isSuperAdmin: boolean) {
    await this.access.assertSuperAdmin(actorUserId);
    await this.ensureUserExists(userId);

    const target = await this.prisma.user.findUnique({ where: { id: userId } });
    if (!target) {
      throw new NotFoundException('Пользователь не найден');
    }

    if (target.isSuperAdmin && !isSuperAdmin) {
      const superAdmins = await this.prisma.user.count({ where: { isSuperAdmin: true, status: UserStatus.ACTIVE } });
      if (superAdmins <= 1) {
        throw new BadRequestException('Нельзя снять права у единственного супер-администратора');
      }
    }

    const user = await this.prisma.user.update({
      where: { id: userId },
      data: { isSuperAdmin },
      include: { userRoles: { include: { role: true } }, userPermissions: { include: { permission: true } } }
    });
    return this.toAdminUser(user);
  }

  async deleteUser(userId: string) {
    await this.ensureUserExists(userId);
    const user = await this.prisma.user.update({
      where: { id: userId },
      data: { status: UserStatus.DELETED, deletedAt: new Date() },
      include: { userRoles: { include: { role: true } }, userPermissions: { include: { permission: true } } }
    });
    return this.toAdminUser(user);
  }

  private toAdminUser(user: {
    id: string;
    email: string | null;
    phone: string | null;
    backupEmail: string | null;
    backupPhone: string | null;
    displayName: string;
    username: string | null;
    isSuperAdmin: boolean;
    status: UserStatus;
    createdAt: Date;
    userRoles?: { role: { slug: string } }[];
    userPermissions?: { permission: { slug: string } }[];
  }) {
    return {
      id: user.id,
      email: user.email ?? undefined,
      phone: user.phone ?? undefined,
      backupEmail: user.backupEmail ?? undefined,
      backupPhone: user.backupPhone ?? undefined,
      displayName: user.displayName,
      username: user.username ?? undefined,
      isSuperAdmin: user.isSuperAdmin,
      status: user.status,
      createdAt: user.createdAt.toISOString(),
      roles: user.userRoles?.map((link) => link.role.slug) ?? [],
      directPermissions: user.userPermissions?.map((link) => link.permission.slug) ?? []
    };
  }

  private async ensureUserExists(userId: string) {
    const user = await this.prisma.user.findUnique({ where: { id: userId } });
    if (!user) {
      throw new NotFoundException('Пользователь не найден');
    }
  }
}