import { prisma } from '@app/lib/prisma';

import { Prisma, User } from '@prisma/client';

import bcrypt from "bcryptjs";

import crypto from "crypto";

import { addMinutes } from "date-fns";

import {

  generateToken as createJWT,

  generatePasswordResetToken,

  getPasswordResetExpiration,

  isTokenExpired

} from '@app/lib/jwt';

import {

  findUserByEmail

} from '@app/services/user.service'; // Replace with a barrel import

import {

  LoginInput,

  PasswordResetRequestInput,

  PasswordResetInput,

  ActivateUserInput

} from '@app/schemas'

import { getQueue, MailJobName } from '@app/lib/queue';

class InvalidCredentialsError extends Error {

  constructor() { super('Invalid credentials') }

}

class InvalidOrExpiredTokenError extends Error {

  constructor() { super('Invalid or Expired reset token') }

}

export const login = async({ email, password }: LoginInput) => {

  const user = await findUserByEmail(email)!;

  if (!user || !bcrypt.compareSync(password, user.encryptedPassword)) {

    throw new InvalidCredentialsError();

  }

  const token = generateToken(user.id, user.email);

  return { user, token };

};

export const requestPasswordReset = async ({ email }: PasswordResetRequestInput) => {

  const user = await findUserByEmail(email);

  if (!user) {

    return { success: true };

  }

  const resetToken = generatePasswordResetToken();

  const resetExpires = getPasswordResetExpiration();

  await prisma.user.update({

    where: {

      id: user.id

    },

    data: {

      passwordResetToken: resetToken,

      passwordResetExpires: resetExpires

    }

  });

  const mailQueue = getQueue('mail');

  const job = await mailQueue.add(MailJobName.PasswordReset, {

    userId: user.id,

    token: resetToken

  });

  return { success: true };

};

export const resetPassword = async ({ token, newPassword }: PasswordResetInput) => {

  const user = await prisma.user.findFirst({

    where: {

      passwordResetToken: token,

      passwordResetExpires: { not: null }

    }

  });

  if (!user || !user.passwordResetExpires || isTokenExpired(user.passwordResetExpires)) {

    throw new InvalidOrExpiredTokenError();

  }

  await prisma.user.update({

    where: { id: user.id },

    data: {

      encryptedPassword: bcrypt.hashSync(newPassword, 10),

      passwordResetToken: null,

      passwordResetExpires: null

    }

  });

  return {

    success: true

  };

};

export const generateToken = (userId: number, email: string) => {

  return createJWT(userId, email);

};

export const activateUser = async(user: User): Promise<User> => {

  return await prisma.user.update({

    where: {

      id: user.id

    },

    data: {

      active: true,

      activationCode: null,

      activationCodeExpiresAt: null

    }

  });

}

const ACTIVATION_CODE_LENGTH = 6;

const ACTIVATION_CODE_TTL_MINUTES = 5;

const ACTIVATION_CODE_MAX_ATTEMPTS = 5;

export const generateActivationCode = (): string =>

  Array.from({ length: ACTIVATION_CODE_LENGTH }, () => crypto.randomInt(0, 10)).join("");

const isUniqueConstraintViolation = (err: unknown): boolean =>

  err instanceof Prisma.PrismaClientKnownRequestError && err.code === "P2002";

export const issueActivationCode = async(userId: number): Promise<string> => {

  for (let attempt = 0; attempt < ACTIVATION_CODE_MAX_ATTEMPTS; attempt++) {

    const code = generateActivationCode();

    const expiresAt = addMinutes(new Date(), ACTIVATION_CODE_TTL_MINUTES);

    try {

      await prisma.user.update({

        where: {

          id: userId

        },

        data: {

          activationCode: code,

          activationCodeExpiresAt: expiresAt

        }

      });

      return code;

    } catch (err) {

      if (!isUniqueConstraintViolation(err)) throw err;

    }

  }

  throw new Error("Could not issue a unique activation code");

}