import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { Student } from '../student/student.entity';
import * as bcrypt from 'bcrypt';
import * as nodemailer from 'nodemailer';
import { NotFoundException, UnauthorizedException } from '@nestjs/common';

@Injectable()
export class AuthService {

  constructor(
    @InjectRepository(Student)
    private studentRepository: Repository<Student>,
  ) {}

  // REGISTER PASSWORD
  async register(data: any) {

  const student = await this.studentRepository.findOne({
    where: { EmailAddress: data.email }
  });

  if (!student) {
    throw new NotFoundException('Email not found');
    
  }

  if (data.password !== data.confirmPassword) {
    throw new Error('Passwords do not match');
  }

  const hashedPassword = await bcrypt.hash(data.password, 10);

  student.Password = hashedPassword;
  student.StudentStatus = 'Active';   // ⭐ IMPORTANT LINE
  student.LastUpdatedDate = new Date();
  student.LastUpdatedBy = 'System';

  await this.studentRepository.save(student);

  return {
    message: 'Registration successful'
  };
}

  // LOGIN
 async login(data: any) {

  const student = await this.studentRepository.findOne({
    where: { EmailAddress: data.email }
  });

  if (!student) {
    throw new NotFoundException("Email not found");
  }

  const match = await bcrypt.compare(data.password, student.Password);

  if (!match) {
    throw new UnauthorizedException("Invalid password");
  }

  return {
    message: "Login successful",
    studentId: student.StudentID,
    name: student.Name
  };
}

  // FORGOT PASSWORD (SEND RESET LINK)
  async forgotPassword(data: any) {

    const student = await this.studentRepository.findOne({
      where: { EmailAddress: data.email }
    });

    if (!student) {
      return { message: "Email not found" };
    }

    const resetLink = `http://localhost:3000/reset-password?email=${data.email}`;

    const transporter = nodemailer.createTransport({
      service: 'gmail',
      auth: {
        user: '2003nithi@gmail.com',
        pass: 'qgxu ufou sycd iyjm'
      }
    });

    await transporter.sendMail({
      from: 'yourgmail@gmail.com',
      to: data.email,
      subject: 'Password Reset Link',
      text: `Click the link to reset your password: ${resetLink}`
    });

    return {
      message: "Password reset link sent to your email"
    };
  }

  // RESET PASSWORD
  async resetPassword(data: any) {

    const student = await this.studentRepository.findOne({
      where: { EmailAddress: data.email }
    });

    if (!student) {
      return { message: "Invalid email address" };
    }
    const bcrypt=require('bcrypt');

    const hashedPassword = await bcrypt.hash(data.newPassword, 10);

    student.Password = hashedPassword;

    await this.studentRepository.save(student);

    return {
      message: "Password reset successfully"
    };
  }

}