"use strict";

const path = require("path");
const Database = require("better-sqlite3");

const db = new Database(path.resolve(__dirname, "../data/count.db"));

db.exec(`CREATE TABLE IF NOT EXISTS tb_count (
    id    INTEGER      PRIMARY KEY AUTOINCREMENT
                       NOT NULL
                       UNIQUE,
    name  VARCHAR (32) NOT NULL
                       UNIQUE,
    num   BIGINT       NOT NULL
                       DEFAULT (0) 
);`);

function getNum(name) {
  return new Promise((resolve, reject) => {
    const stmt = db.prepare(
      "SELECT `name`, `num` from tb_count WHERE `name` = ?"
    );
    const row = stmt.get(name);
    resolve(row || { name, num: 0 });
  });
}

function getAll(name) {
  return new Promise((resolve, reject) => {
    const stmt = db.prepare("SELECT * from tb_count");
    const rows = stmt.all();
    resolve(rows);
  });
}

function setNum(name, num) {
  return new Promise((resolve, reject) => {
    db.exec(
      `INSERT INTO tb_count(\`name\`, \`num\`)
            VALUES($name, $num)
            ON CONFLICT(name) DO
            UPDATE SET \`num\` = $num;`,
      { $name: name, $num: num }
    );

    resolve();
  });
}

function setNumMulti(counters) {
  return new Promise((resolve, reject) => {
    const stmt = db.prepare(`INSERT INTO tb_count(\`name\`, \`num\`)
    VALUES($name, $num)
    ON CONFLICT(name) DO
    UPDATE SET \`num\` = $num;`);

    const setMany = db.transaction((counters) => {
      for (const counter of counters) stmt.run(counter);
    });

    setMany(counters);
    resolve();
  });
}

module.exports = {
  getNum,
  getAll,
  setNum,
  setNumMulti,
};