import * as pg from "pg";

const pool = new pg.Pool({
  database: "postgres"
});

export const insert = async (
  tableName: string,
  data: {},
  returning?: string
) => {
  const db = await pool.connect();
  const result = await db.query(
    `INSERT into ${tableName} (${Object.keys(data).join(
      ", "
    )}) VALUES (${Object.keys(data)
      .map((item, i) => `$${i + 1}`)
      .join(", ")}) ${returning ? `RETURNING ${returning}` : ""};`,
    Object.values(data)
  );
  await db.release();
  return result;
};

export const query = async (query: string, values?: {}[]) => {
  const db = await pool.connect();
  const result = await db.query(query, values);
  await db.release();
  return result;
};

export const update = async (
  tableName: string,
  data: {},
  where: string[],
  values: {}[]
) => {
  const db = await pool.connect();
  const result = await db.query(
    `UPDATE ${tableName}
      SET ${Object.keys(data)
        .map((item, i) => `${item} = $${i + 1 + values.length}`)
        .join(", ")}
        WHERE ${whereClause(where)};`,
    values.concat(Object.values(data))
  );
  await db.release();
  return result;
};

export const select = async (
  tableName: string,
  where?: string[],
  selection?: string,
  values?: any[]
) => {
  const db = await pool.connect();
  const result = db.query(
    `SELECT ${selection || "*"} FROM ${tableName} ${
      where ? `WHERE ${whereClause(where)}` : ""
    }`,
    values
  );
  await db.release();
  return result;
};

export const deletee = async (
  tableName: string,
  where?: string[],
  values?: any[]
) => {
  const db = await pool.connect();
  const result = db.query(
    `DELETE FROM ${tableName} ${where ? `WHERE ${whereClause(where)}` : ""}`,
    values
  );
  await db.release();
  return result;
};

const whereClause = (conditions: string[]) => {
  return conditions.join(" AND ");
};