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_DB,
  });
}

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

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

function getShareholderShares(connection, owner_id) {
  return new Promise((resolve, reject) => {
    connection.query(
      `SELECT * FROM Share WHERE owner_id = ${owner_id}`,
      (error, result) => {
        if (error) {
          throw(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

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

function setShareOwner(connection, share_id, owner_id) {
  return new Promise((resolve, reject) => {
    connection.query(
      `UPDATE Share SET owner_id = ${owner_id} WHERE id = ${share_id}`,
      (error, result) => {
        if (error) {
          throw(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

function addShare(connection, price, company_id) {
  return new Promise((resolve, reject) => {
    connection.query(
      `INSERT INTO Share (price, owner_id, company_id) VALUES (${price}, -1, ${company_id})`,
      (error, result) => {
        if (error) {
          throw(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

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

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

function setShareholderCapital(connection, id, capital) {
  return new Promise((resolve, reject) => {
    connection.query(
      `UPDATE Shareholder SET capital = ${capital} WHERE id = ${id}`,
      (error, result) => {
        if (error) {
          throw(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

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

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

function setCompanyCapital(connection, id, capital ) {
  return new Promise((resolve, reject) => {
    connection.query(
      `UPDATE Company SET capital = ${capital} WHERE id = ${id}`,
      (error, result) => {
        if (error) {
          throw(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

function addTransaction(connection, price, seller_id, buyer_id, share_id) {
  return new Promise((resolve, reject) => {
    connection.query(
      `INSERT INTO Transaction (sell_price, seller_id, buyer_id, share_id) VALUES (${price}, ${seller_id}, ${buyer_id}, ${share_id})`,
      (error, result) => {
        if (error) {
          throw(new Error(error));
        }
        resolve(result);
      }
    );
  });
}

module.exports = {
  getConnection,

  getShares,
  getShare,
  getShareholderShares,
  getCompanyShares,
  setShareOwner,
  addShare,

  getShareholders,
  getShareholder,
  setShareholderCapital,

  getCompanies,
  getCompany,
  setCompanyCapital,

  addTransaction,
}