import mysql, {
  type ResultSetHeader,
  type RowDataPacket,
} from "mysql2/promise";
import dotenv from "dotenv";
import { GENERAL_ERROR_CODE, USER_ERROR_CODE } from "@stockhome/shared";
import { returnErrorCode } from "../../../services/helperFuncs.js";
import type { AuthTokenPayload } from "../../../services/tokenService";

dotenv.config();

const pool = mysql.createPool({
  host: process.env.DB_HOST!,
  user: process.env.DB_USER!,
  password: process.env.DB_PASSWORD!,
  database: process.env.DB_NAME!,
});

export const findUser = async (username: string, password: string) => {
  const [result] = await pool.query<RowDataPacket[]>(
    "SELECT BIN_TO_UUID(uuid) AS uuid, username, first_name, last_name, email, is_admin, is_active, last_login FROM users WHERE username = ? AND password = ?;",
    [username, password],
  );

  const userRow = result[0];

  if (!userRow) {
    return returnErrorCode(USER_ERROR_CODE.WRONG_USERNAME_PASSWORD);
  }

  // Cast DB row to AuthTokenPayload for token generation / typing
  const user = userRow as unknown as AuthTokenPayload;

  if (!user.is_active) {
    return returnErrorCode(USER_ERROR_CODE.USER_IS_DEACTIVATED);
  }

  return {
    success: true,
    code: "SU001",
    data: user,
    message: "Successfully found user.",
  };
};

export const loginUser = async (username: string) => {
  const [result] = await pool.query<ResultSetHeader>(
    "UPDATE users SET last_login = NOW() WHERE username = ?;",
    [username],
  );

  if (result.affectedRows > 0) {
    return {
      success: true,
      code: "SU002",
      data: null,
      message: "Successfully logged in user.",
    };
  } else {
    return returnErrorCode(GENERAL_ERROR_CODE.UNEXPECTED_SERVER_ERROR);
  }
};

export const updateSettings = async (payload: {
  "app-name": string;
  currency: string;
}) => {
  const appName = payload["app-name"];
  const currency = payload.currency;

  const [result] = await pool.query<ResultSetHeader>(
    `UPDATE app_settings
         SET value = CASE name
                         WHEN "app-name" THEN ?
                         WHEN "currency" THEN ?
                         ELSE value
             END
         WHERE name IN ("app-name", "currency");`,
    [appName, currency],
  );

  if (result.affectedRows > 0) {
    return {
      success: true,
      code: "SU003",
      data: null,
      message: "Successfully updated settings.",
    };
  } else {
    return returnErrorCode(GENERAL_ERROR_CODE.UNEXPECTED_SERVER_ERROR);
  }
};

export const getSettings = async () => {
  const [result] = await pool.query<RowDataPacket[]>(
    `SELECT *
         FROM app_settings;`,
  );

  if (result.length > 0) {
    return {
      success: true,
      code: "SU004",
      data: result,
      message: "Successfully fetched settings.",
    };
  } else {
    return returnErrorCode(GENERAL_ERROR_CODE.UNEXPECTED_SERVER_ERROR);
  }
};

export const changePassword = async (
  username: string,
  currentPasswordUser: string,
  newPassword: string,
) => {
  const [result] = await pool.query<ResultSetHeader>(
    `UPDATE users
         SET password = ?
         WHERE username = ?
           AND password = ?;`,
    [newPassword, username, currentPasswordUser],
  );

  if (result.affectedRows > 0) {
    return {
      success: true,
      code: "SU005",
      data: null,
      message: "Successfully fetched settings.",
    };
  } else {
    return returnErrorCode(USER_ERROR_CODE.PASSWORD_CHANGE_FAILED);
  }
};