import { Injectable } from '@nestjs/common';
import { PrismaClient } from '@prisma/client';
import * as bcrypt from 'bcryptjs';
import { ROLE, USER_STATUS } from '../../../common/utils/constants/common.constant';
import ApiError from '../../../common/utils/helper/ApiError';
import { OtpGeneratorSixDigit } from '../../../common/utils/helper/OtpGenerator';

type OperatorSignupInput = {
  firstName?: string;
  lastName?: string;
  emailAddress?: string;
  isdCode?: string;
  mobileNumber?: string;
};

@Injectable()
export class OperatorAuthService {
  constructor(private prisma: PrismaClient) {}

  async findInvitedOperator(input: {
    emailAddress?: string;
    mobileNumber?: string;
  }) {
    const emailAddress = input.emailAddress?.trim().toLowerCase();
    const mobileNumber = input.mobileNumber?.trim();

    if (!emailAddress && !mobileNumber) {
      throw new ApiError(400, 'Email address or mobile number is required');
    }

    const invitedOperator = await this.prisma.user.findFirst({
      where: {
        roleXid: ROLE.OPERATOR,
        isActive: true,
        OR: [
          ...(emailAddress ? [{ emailAddress }] : []),
          ...(mobileNumber ? [{ mobileNumber }] : []),
        ],
      },
      select: {
        id: true,
        firstName: true,
        lastName: true,
        emailAddress: true,
        isdCode: true,
        mobileNumber: true,
        roleXid: true,
        userPassword: true,
        isEmailVerfied: true,
        userStatus: true,
      },
    });

    if (!invitedOperator) {
      throw new ApiError(
        403,
        'Operator record not found. Please contact your host.',
      );
    }

    return invitedOperator;
  }

  async signUpOperator(input: OperatorSignupInput) {
    const emailAddress = input.emailAddress?.trim().toLowerCase();
    const mobileNumber = input.mobileNumber?.trim();
    const invitedOperator = await this.findInvitedOperator({
      emailAddress,
      mobileNumber,
    });

    if (invitedOperator.userPassword) {
      return {
        userId: invitedOperator.id,
        emailAddress: emailAddress || invitedOperator.emailAddress,
        mobileNumber: mobileNumber || invitedOperator.mobileNumber,
        otp: null,
        expiresOn: null,
        isNewOperator: false,
      };
    }

    const otp = OtpGeneratorSixDigit.generateOtp();
    const hashedOtp = await bcrypt.hash(otp, 10);
    const expiry = new Date(Date.now() + 5 * 60 * 1000);

    await this.prisma.$transaction(async (tx) => {
      await tx.user.update({
        where: { id: invitedOperator.id },
        data: {
          firstName: input.firstName?.trim() || invitedOperator.firstName || null,
          lastName: input.lastName?.trim() || invitedOperator.lastName || null,
          emailAddress: emailAddress || invitedOperator.emailAddress,
          isdCode: input.isdCode?.trim() || invitedOperator.isdCode || null,
          mobileNumber: mobileNumber || invitedOperator.mobileNumber,
          userStatus: USER_STATUS.INVITED,
        },
      });

      await tx.userOtp.updateMany({
        where: {
          userXid: invitedOperator.id,
          otpType: 'Register',
          isActive: true,
        },
        data: {
          isActive: false,
          isVerified: true,
        },
      });

      await tx.userOtp.create({
        data: {
          userXid: invitedOperator.id,
          otpType: 'Register',
          otpCode: hashedOtp,
          expiresOn: expiry,
          isVerified: false,
          isActive: true,
        },
      });
    });

    return {
      isNewOperator: true,
    };
  }

  async verifyOperatorOtp(input: { emailAddress?: string; mobileNumber?: string; otp: string }) {
    const emailAddress = input.emailAddress?.trim().toLowerCase();
    const mobileNumber = input.mobileNumber?.trim();
    const otp = input.otp.trim();

    const invitedOperator = await this.findInvitedOperator({
      emailAddress,
      mobileNumber,
    });

    const latestOtp = await this.prisma.userOtp.findFirst({
      where: {
        userXid: invitedOperator.id,
        otpType: 'Register',
        isActive: true,
        isVerified: false,
      },
      orderBy: { createdAt: 'desc' },
    });

    if (!latestOtp) {
      throw new ApiError(400, 'No OTP found.');
    }

    if (new Date() > latestOtp.expiresOn) {
      throw new ApiError(400, 'OTP has expired.');
    }

    const isMatch = await bcrypt.compare(otp, latestOtp.otpCode);

    if (!isMatch) {
      throw new ApiError(400, 'Invalid OTP.');
    }

    await this.prisma.userOtp.update({
      where: { id: latestOtp.id },
      data: {
        isVerified: true,
        verifiedOn: new Date(),
        isActive: false,
      },
    });

    await this.prisma.user.update({
      where: { id: invitedOperator.id },
      data: {
        isEmailVerfied: emailAddress ? true : invitedOperator.isEmailVerfied,
      },
    });

    return invitedOperator;
  }

  async createOperatorPassword(userId: number, password: string) {
    const user = await this.prisma.user.findFirst({
      where: {
        id: userId,
        roleXid: ROLE.OPERATOR,
        isActive: true,
      },
      select: {
        id: true,
        emailAddress: true,
        userPassword: true,
      },
    });

    if (!user) {
      throw new ApiError(404, 'Operator not found');
    }

    if (user.userPassword) {
      throw new ApiError(400, 'Password already exists. Please login.');
    }

    const saltRounds = parseInt(process.env.SALT_ROUNDS || '10', 10);
    const hashedPassword = await bcrypt.hash(password, saltRounds);

    await this.prisma.user.update({
      where: { id: user.id },
      data: {
        userPassword: hashedPassword,
        userStatus: USER_STATUS.ACTIVE,
        isEmailVerfied: true,
      },
    });

    return {
      id: user.id,
      emailAddress: user.emailAddress,
    };
  }

  async loginForOperator(emailAddress: string, userPassword: string) {
    const existingOperator = await this.prisma.user.findFirst({
      where: {
        emailAddress,
        roleXid: ROLE.OPERATOR,
        isActive: true,
        userStatus: USER_STATUS.ACTIVE,
      },
      select: {
        id: true,
        firstName: true,
        lastName: true,
        emailAddress: true,
        mobileNumber: true,
        roleXid: true,
        isActive: true,
        userStatus: true,
        userPassword: true,
      },
    });

    if (!existingOperator) {
      throw new ApiError(404, 'Operator not found');
    }

    const isPasswordMatched = await bcrypt.compare(
      userPassword,
      existingOperator.userPassword || '',
    );

    if (!isPasswordMatched) {
      throw new ApiError(401, 'Invalid credentials');
    }

    delete existingOperator.userPassword;

    return existingOperator;
  }

  async verifyPasswordForOperator(emailAddress: string, userPassword: string) {
    const existingOperator = await this.prisma.user.findFirst({
      where: {
        emailAddress,
        roleXid: ROLE.OPERATOR,
        isActive: true,
        userStatus: USER_STATUS.ACTIVE,
      },
      select: {
        id: true,
        userPassword: true,
      },
    });

    if (!existingOperator) {
      throw new ApiError(404, 'Operator not found');
    }

    const isPasswordMatched = await bcrypt.compare(
      userPassword,
      existingOperator.userPassword || '',
    );

    return isPasswordMatched;
  }
}