import {
  Injectable,
  UnauthorizedException,
  BadRequestException,
} from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { PrismaService } from '../../shared/services/prisma.service';
import { OperatorsService } from '../operators/operators.service';
import * as bcrypt from 'bcrypt';
import { AuthInitDto, AuthValidateDto, LoginDto } from './dto/auth.dto';

@Injectable()
export class AuthService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly jwtService: JwtService,
    private readonly operatorsService: OperatorsService,
  ) {}

  async initializeUserAuth(partnerId: string, dto: AuthInitDto) {
    // Vérifier le partenaire
    const partner = await this.prisma.partner.findUnique({
      where: { id: partnerId },
    });

    if (!partner || partner.status !== 'ACTIVE') {
      throw new UnauthorizedException('Invalid partner');
    }

    // Déterminer l'opérateur basé sur le numéro
    const operator = this.detectOperator(dto.msisdn, dto.country);

    // Obtenir l'adaptateur approprié
    const adapter = this.operatorsService.getAdapter(operator, dto.country);

    // Initialiser l'authentification avec l'opérateur
    const authResponse = await adapter.initializeAuth({
      msisdn: dto.msisdn,
      country: dto.country,
      metadata: dto.metadata,
    });

    // Créer une session temporaire
    const session = await this.prisma.authSession.create({
      data: {
        sessionId: authResponse.sessionId,
        partnerId: partnerId,
        msisdn: dto.msisdn,
        operator: operator,
        country: dto.country,
        authMethod: dto.authMethod,
        challengeId: authResponse.challengeId,
        status: 'PENDING',
        expiresAt: authResponse.expiresAt,
      },
    });

    return {
      sessionId: session.sessionId,
      authMethod: dto.authMethod,
      status: 'PENDING',
      redirectUrl: authResponse.redirectUrl,
      challengeId: authResponse.challengeId,
      expiresAt: authResponse.expiresAt,
    };
  }

  async validateUserAuth(dto: AuthValidateDto) {
    // Récupérer la session
    const session = await this.prisma.authSession.findUnique({
      where: { sessionId: dto.sessionId },
    });

    if (!session) {
      throw new BadRequestException('Invalid session');
    }

    if (session.status !== 'PENDING') {
      throw new BadRequestException('Session already processed');
    }

    if (new Date() > session.expiresAt) {
      throw new BadRequestException('Session expired');
    }

    // Obtenir l'adaptateur
    const adapter = this.operatorsService.getAdapter(
      session.operator,
      session.country,
    );

    // Valider avec l'opérateur
    const validationResponse = await adapter.validateAuth({
      challengeId: session.challengeId,
      otpCode: dto.otpCode,
      msisdn: session.msisdn,
      country: session.country,
    });

    if (!validationResponse.success) {
      await this.prisma.authSession.update({
        where: { id: session.id },
        data: { status: 'FAILED' },
      });
      throw new UnauthorizedException('Authentication failed');
    }

    // Créer ou mettre à jour l'utilisateur
    const user = await this.prisma.user.upsert({
      where: { msisdn: session.msisdn },
      update: {
        userToken: validationResponse.userToken,
        userAlias: validationResponse.userAlias,
        updatedAt: new Date(),
      },
      create: {
        msisdn: session.msisdn,
        userToken: validationResponse.userToken,
        userAlias: validationResponse.userAlias,
        operatorId: await this.getOperatorId(session.operator, session.country),
        partnerId: session.partnerId,
        country: session.country,
      },
    });

    // Mettre à jour la session
    await this.prisma.authSession.update({
      where: { id: session.id },
      data: {
        status: 'SUCCESS',
        userId: user.id,
      },
    });

    // Créer un JWT pour le partenaire
    const payload = {
      userId: user.id,
      partnerId: session.partnerId,
      msisdn: user.msisdn,
      operator: session.operator,
    };

    return {
      success: true,
      accessToken: this.jwtService.sign(payload),
      userToken: validationResponse.userToken,
      userAlias: validationResponse.userAlias,
      msisdn: session.msisdn,
      operator: session.operator,
      country: session.country,
      expiresAt: validationResponse.expiresAt,
    };
  }

  async loginPartner(dto: LoginDto) {
    const partner = await this.prisma.partner.findUnique({
      where: { email: dto.email },
    });

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

    const isPasswordValid = await bcrypt.compare(
      dto.password,
      partner.passwordHash,
    );

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

    const payload = {
      partnerId: partner.id,
      email: partner.email,
      type: 'partner',
    };

    return {
      accessToken: this.jwtService.sign(payload),
      partner: {
        id: partner.id,
        name: partner.name,
        email: partner.email,
        status: partner.status,
      },
    };
  }

  private detectOperator(msisdn: string, country: string): string {
    // Logique pour détecter l'opérateur basé sur le préfixe
    const prefixMap = {
      CI: {
        '07': 'ORANGE',
        '08': 'ORANGE',
        '09': 'ORANGE',
        '04': 'MTN',
        '05': 'MTN',
        '06': 'MTN',
        '01': 'MOOV',
      },
      SN: {
        '77': 'ORANGE',
        '78': 'ORANGE',
        '76': 'FREE',
        '70': 'EXPRESSO',
      },
      // Ajouter d'autres pays
    };

    const countryPrefixes = prefixMap[country];
    if (!countryPrefixes) {
      throw new BadRequestException(`Country ${country} not supported`);
    }

    const prefix = msisdn.substring(0, 2);
    const operator = countryPrefixes[prefix];

    if (!operator) {
      throw new BadRequestException(`Cannot detect operator for ${msisdn}`);
    }

    return operator;
  }

  private async getOperatorId(
    operatorCode: string,
    country: string,
  ): Promise<string> {
    const operator = await this.prisma.operator.findFirst({
      where: {
        code: operatorCode as any,
        country: country,
      },
    });

    if (!operator) {
      throw new BadRequestException(
        `Operator ${operatorCode} not found in ${country}`,
      );
    }

    return operator.id;
  }
}