const mysql = require("mysql");

function getConnection() {
  return mysql.createConnection({
    host: process.env.MYSQL_HOST,
    user: process.env.MYSQL_USER,
    password: process.env.MYSQL_PASSWORD,
    database: process.env.MYSQL_DATABASE,
  });
}

function getUser(connection, id) {
  return new Promise((resolve, reject) => {
    connection.query(
      `SELECT * FROM users WHERE id = ${id}`,
      (error, result) => {
        if (error) {
          reject(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

function getUserByUsername(connection, username) {
    return new Promise((resolve, reject) => {
        connection.query(
        `SELECT * FROM users WHERE username = '${username}'`,
        (error, result) => {
            if (error) {
            reject(new Error(error));
            }
            resolve(result);
        }
        );
    });
}

function addUser(connection, username, password) {
  return new Promise((resolve, reject) => {
    connection.query(
      `INSERT INTO users (username, password) VALUES ('${username}', '${password}')`,
      (error, result) => {
        if (error) {
          reject(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

function getChannels(connection) {
  return new Promise((resolve, reject) => {
    connection.query(
      `SELECT * FROM channels`,
      (error, result) => {
        if (error) {
          reject(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

function getChannel(connection, name) {
  return new Promise((resolve, reject) => {
    connection.query(
      `SELECT * FROM channels WHERE name = "${name}"`,
      (error, result) => {
        if (error) {
          reject(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

function addChannel(connection, name, description, owner_id) {
    return new Promise((resolve, reject) => {
        connection.query(
        `INSERT INTO channels (name, description, owner_id) VALUES ('${name}', '${description}', ${owner_id})`,
        (error, result) => {
            if (error) {
            reject(new Error(error));
            }
            resolve(result);
        }
        );
    });
}

function getMessages(connection, channel_id) {
    return new Promise((resolve, reject) => {
        connection.query(
        `SELECT messages.id, user_id, username, content, date FROM messages JOIN users ON messages.user_id = users.id WHERE channel_id = ${channel_id} ORDER BY date DESC`,
        (error, result) => {
            if (error) {
            reject(new Error(error));
            }
            resolve(result);
        }
        );
    });
}

function addMessage(connection, channel_id, user_id, message) {
    return new Promise((resolve, reject) => {
        connection.query(
        `INSERT INTO messages (channel_id, user_id, content, date) VALUES (${channel_id}, ${user_id}, "${message}", ${Math.floor(Date.now() / 1000)})`,
        (error, result) => {
            if (error) {
            reject(new Error(error));
            }
            resolve(result);
        }
        );
    });
}

function deleteMessage(connection, message_id) {
    return new Promise((resolve, reject) => {
        connection.query(
        `DELETE FROM messages WHERE id = ${message_id}`,
        (error, result) => {
            if (error) {
            reject(new Error(error));
            }
            resolve(result);
        }
        );
    });
}

module.exports = {
  getConnection,
  getUser,
  getUserByUsername,
  addUser,
  getChannels,
  getChannel,
  addChannel,
  getMessages,
  addMessage,
  deleteMessage
};