import {
  Injectable,
  UnauthorizedException,
  ConflictException,
} from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { SuperAdmin, SESSION_STATUS } from '@prisma/client';
import { StringValue } from 'ms';
import { SuperAdminCoreService } from 'src/core/super-admin-core/super-admin-core.service';
import { SuperAdminCredentialCoreService } from 'src/core/super-admin-credential-core/super-admin-credential-core.service';
import { SuperAdminSessionCoreService } from 'src/core/super-admin-session-core/super-admin-session-core.service';
import { SuperAdminTwoFactorMethodCoreService } from 'src/core/super-admin-two-factor-method-core/super-admin-two-factor-method-core.service';
import { SuperAdminTrustedDeviceCoreService } from 'src/core/super-admin-trusted-device-core/super-admin-trusted-device-core.service';
import { CommonService } from 'src/shared/modules/common/common.service';
import { SuperAdminRegisterDto } from './dto/register.dto';
import { SuperAdminLoginDto } from './dto/login.dto';
import { SuperAdminRefreshTokenDto } from './dto/refresh-token.dto';
import { SuperAdminSessionType } from 'src/shared/types/super-admin-session.type';
import {
  accessTokenSignSettings,
  refreshTokenSignSettings,
  refreshTokenVerifySettings,
  TOKEN_TYPE,
  TOKEN_USER_TYPE,
  AuthMessages,
} from 'src/shared/keys/auth.keys';

@Injectable()
export class SuperAdminAuthService {
  constructor(
    private readonly jwtService: JwtService,
    private readonly superAdminCoreService: SuperAdminCoreService,
    private readonly superAdminCredentialCoreService: SuperAdminCredentialCoreService,
    private readonly superAdminSessionCoreService: SuperAdminSessionCoreService,
    private readonly twoFactorMethodCoreService: SuperAdminTwoFactorMethodCoreService,
    private readonly trustedDeviceCoreService: SuperAdminTrustedDeviceCoreService,
    private readonly commonService: CommonService,
  ) {}

  async register(
    registerDto: SuperAdminRegisterDto,
    request: any,
  ): Promise<{
    superAdmin: SuperAdmin;
    accessToken: string;
    refreshToken: string;
  }> {
    const { email, password, name, profileImage } = registerDto;

    // Check if super admin already exists
    const existingSuperAdmin = await this.superAdminCoreService
      .findFirst({
        where: { email, isDeleted: false },
      })
      .catch(() => null);

    if (existingSuperAdmin) {
      throw new ConflictException('Super admin with this email already exists');
    }

    // Create super admin
    const superAdmin = await this.superAdminCoreService.create({
      data: {
        email,
        name,
        profileImage,
      },
    });

    // Hash and store password
    const hashedPassword = await this.commonService.hashPassword(password);
    await this.superAdminCredentialCoreService.create({
      data: {
        superAdminId: superAdmin.id,
        password: hashedPassword,
      },
    });

    // Generate tokens
    const { accessToken, refreshToken } = await this.getNewToken(superAdmin);

    // Get client info
    const clientInfo = this.commonService.getClientInfo(request);

    // Create session
    await this.superAdminSessionCoreService.create({
      data: {
        superAdminId: superAdmin.id,
        accessToken,
        refreshToken,
        ipAddress: clientInfo.ipAddress,
        userAgent: clientInfo.userAgent,
        geoIpCountry: clientInfo.geoLocation?.country || '',
        city: clientInfo.geoLocation?.city || '',
        state: clientInfo.geoLocation?.region || '',
        latitude: clientInfo.geoLocation?.ll?.[0] || null,
        longitude: clientInfo.geoLocation?.ll?.[1] || null,
        isFromAdmin: true,
        status: SESSION_STATUS.CURRENT,
        loginAt: new Date(),
      },
    });

    return {
      superAdmin,
      accessToken,
      refreshToken,
    };
  }

  async login(
    loginDto: SuperAdminLoginDto,
    request: any,
  ): Promise<
    | {
        superAdmin: SuperAdmin;
        accessToken: string;
        refreshToken: string;
      }
    | {
        requires2FA: true;
        pending2faToken: string;
        availableMethods: string[];
        message: string;
      }
  > {
    const { email, password, deviceId } = loginDto;

    // Find super admin
    const superAdmin = await this.superAdminCoreService
      .findFirst({
        where: { email, isDeleted: false },
      })
      .catch(() => null);

    if (!superAdmin) {
      throw new UnauthorizedException('Invalid credentials');
    }

    // Get super admin credential
    const credential = await this.superAdminCredentialCoreService
      .findFirst({
        where: { superAdminId: superAdmin.id, isDeleted: false },
      })
      .catch(() => null);

    if (!credential) {
      throw new UnauthorizedException('Invalid credentials');
    }

    // Verify password
    const isPasswordValid = await this.commonService.comparePassword(
      password,
      credential.password,
    );

    if (!isPasswordValid) {
      throw new UnauthorizedException('Invalid credentials');
    }

    // Check if 2FA is enabled
    if (superAdmin.isTwoFactorEnabled) {
      // Check if device is trusted (skip 2FA)
      if (deviceId) {
        const trustedDevice = await this.checkTrustedDevice(
          superAdmin.id,
          deviceId,
        );

        if (trustedDevice) {
          // Device is trusted, proceed with normal login
          return await this.completeLogin(superAdmin, request);
        }
      }

      // Require 2FA verification
      const enabledMethods = await this.getEnabled2FAMethods(superAdmin.id);

      if (enabledMethods.length === 0) {
        // No 2FA methods enabled, proceed with normal login
        return await this.completeLogin(superAdmin, request);
      }

      // Generate pending 2FA token
      const pending2FATokenSettings = {
        secret: process.env.PENDING_2FA_TOKEN_SECRET,
        expiresIn: (process.env.PENDING_2FA_TOKEN_EXPIRY ||
          '10m') as StringValue,
      };

      const pending2faToken = await this.jwtService.signAsync(
        {
          superAdminId: superAdmin.id,
          type: 'PENDING_2FA',
        },
        pending2FATokenSettings,
      );

      return {
        requires2FA: true,
        pending2faToken,
        availableMethods: enabledMethods,
        message:
          'Two-factor authentication required. Please verify using one of the available methods.',
      };
    }

    // 2FA not enabled, proceed with normal login
    return await this.completeLogin(superAdmin, request);
  }

  private async completeLogin(
    superAdmin: SuperAdmin,
    request: any,
  ): Promise<{
    superAdmin: SuperAdmin;
    accessToken: string;
    refreshToken: string;
  }> {
    // Generate tokens
    const { accessToken, refreshToken } = await this.getNewToken(superAdmin);

    // Get client info
    const clientInfo = this.commonService.getClientInfo(request);

    // Create session
    await this.superAdminSessionCoreService.create({
      data: {
        superAdminId: superAdmin.id,
        accessToken,
        refreshToken,
        ipAddress: clientInfo.ipAddress,
        userAgent: clientInfo.userAgent,
        geoIpCountry: clientInfo.geoLocation?.country || '',
        city: clientInfo.geoLocation?.city || '',
        state: clientInfo.geoLocation?.region || '',
        latitude: clientInfo.geoLocation?.ll?.[0] || null,
        longitude: clientInfo.geoLocation?.ll?.[1] || null,
        isFromAdmin: true,
        status: SESSION_STATUS.CURRENT,
        loginAt: new Date(),
      },
    });

    return {
      superAdmin,
      accessToken,
      refreshToken,
    };
  }

  private async checkTrustedDevice(
    superAdminId: string,
    deviceId: string,
  ): Promise<boolean> {
    try {
      const device = await this.trustedDeviceCoreService.findFirst({
        where: {
          deviceId,
          superAdminId,
          isDeleted: false,
        },
      });

      if (!device) {
        return false;
      }

      // Check if device is still valid (not expired)
      const now = new Date();
      if (device.expiresAt < now) {
        return false;
      }

      // Update last used timestamp
      await this.trustedDeviceCoreService.update({
        where: { id: device.id },
        data: { lastUsedAt: now },
      });

      return true;
    } catch {
      return false;
    }
  }

  private async getEnabled2FAMethods(superAdminId: string): Promise<string[]> {
    try {
      const methods = await this.twoFactorMethodCoreService.findMany({
        where: {
          superAdminId,
          isEnabled: true,
          isDeleted: false,
        },
      });

      return methods.map((method) => method.type);
    } catch {
      return [];
    }
  }

  async logout(
    sessionData: SuperAdminSessionType,
  ): Promise<{ message: string }> {
    const { session } = sessionData;

    // Update session to expired
    await this.superAdminSessionCoreService.update({
      where: { id: session.id },
      data: {
        status: SESSION_STATUS.EXPIRED,
        expiredAt: new Date(),
      },
    });

    return { message: AuthMessages.LOGOUT_SUCCESS };
  }

  async refreshToken(refreshTokenDto: SuperAdminRefreshTokenDto): Promise<{
    accessToken: string;
    refreshToken: string;
  }> {
    const { refreshToken } = refreshTokenDto;

    let validateRefreshToken: any = null;

    try {
      validateRefreshToken = await this.jwtService.verifyAsync(
        refreshToken,
        refreshTokenVerifySettings,
      );
    } catch {
      throw new UnauthorizedException('Invalid refresh token');
    }

    // Verify user type
    if (validateRefreshToken.userType !== TOKEN_USER_TYPE.SUPER_ADMIN) {
      throw new UnauthorizedException('Invalid token type');
    }

    const superAdmin = await this.superAdminCoreService.findUnique({
      where: { id: validateRefreshToken.id, isDeleted: false },
    });

    if (!superAdmin) {
      throw new UnauthorizedException('Super admin not found');
    }

    // Generate new tokens
    const newTokens = await this.getNewToken(superAdmin);

    // Update session with new tokens
    await this.superAdminSessionCoreService.updateMany({
      where: {
        superAdminId: superAdmin.id,
        refreshToken,
        status: SESSION_STATUS.CURRENT,
      },
      data: {
        accessToken: newTokens.accessToken,
        refreshToken: newTokens.refreshToken,
      },
    });

    return newTokens;
  }

  private async getNewToken(superAdmin: SuperAdmin): Promise<{
    accessToken: string;
    refreshToken: string;
  }> {
    const payload = {
      id: superAdmin.id,
      email: superAdmin.email,
      userType: TOKEN_USER_TYPE.SUPER_ADMIN,
    };

    const accessToken = await this.jwtService.signAsync(
      { ...payload, type: TOKEN_TYPE.ACCESS },
      accessTokenSignSettings,
    );

    const refreshToken = await this.jwtService.signAsync(
      { ...payload, type: TOKEN_TYPE.REFRESH },
      refreshTokenSignSettings,
    );

    return { accessToken, refreshToken };
  }

  async performJWTStrategy({
    request,
    superAdmin,
  }: {
    request: Request & { headers: { authorization: string } };
    superAdmin: SuperAdmin;
  }): Promise<SuperAdminSessionType> {
    const accessToken = request.headers.authorization?.replace('Bearer ', '');

    if (!accessToken) {
      throw new UnauthorizedException('Invalid token');
    }

    // Get full super admin object
    const fullSuperAdmin = await this.superAdminCoreService.findUnique({
      where: { id: superAdmin.id, isDeleted: false },
    });

    if (!fullSuperAdmin) {
      throw new UnauthorizedException('Super admin not found');
    }

    // Find active session
    const session = await this.superAdminSessionCoreService.findFirst({
      where: {
        superAdminId: superAdmin.id,
        accessToken,
        status: SESSION_STATUS.CURRENT,
        isDeleted: false,
      },
    });

    if (!session) {
      throw new UnauthorizedException('Session not found or expired');
    }

    return {
      superAdmin: fullSuperAdmin,
      session,
    };
  }
}