genuinex-screen-sync-server/src/model.js

GenuineX key value sync server

/**
 * @format
 */
"use strict";

const path = require("path");
const sqlite = require("sqlite3");

class Model {
  constructor() {
    let dbPath = ":memory:";
    if (process.env.NODE_ENV === "production") {
      dbPath = path.resolve(__dirname, "../genuinex.sqlite3");
    }

    console.log("connecting to this.db." + dbPath);

    this.db = new sqlite.Database(dbPath);
    this.db.run(
      "CREATE TABLE IF NOT EXISTS trends (id TEXT PRIMARY KEY NOT NULL, value INTEGER DEFAULT 0)"
    );
  }

  list(cb) {
    this.db.all("SELECT * FROM trends", (err, rows) => {
      if (err) {
        return cb(err, []);
      }

      const trends = {};
      rows.forEach(row => {
        trends[row.id] = row.value;
      });

      cb(err, trends);
    });
  }

  create(id, value, cb) {
    if (!id) {
      return cb(new Error("invalid id"));
    }

    if (!this.isValid(value)) {
      return cb(new Error("invalid value"));
    }

    this.db.run(
      "INSERT INTO trends VALUES ($id, $value)",
      {
        $id: id,
        $value: value
      },
      err => {
        if (err) {
          return cb(err, null);
        }

        this.get(id, cb);
      }
    );
  }

  get(id, cb) {
    if (!id) {
      return cb(new Error("invalid id"));
    }

    this.db.get(
      "SELECT * FROM trends WHERE id = $id",
      {
        $id: id
      },
      cb
    );
  }

  update(id, value, cb) {
    if (!id) {
      return cb(new Error("invalid id"));
    }

    if (!this.isValid(value)) {
      return cb(new Error("value must be a number"));
    }

    this.db.run(
      "UPDATE trends SET value = $value WHERE id = $id",
      {
        $id: id,
        $value: value
      },
      err => {
        if (err) {
          return cb(err, null);
        }

        this.get(id, cb);
      }
    );
  }

  increment(id, cb) {
    if (!id) {
      return cb(new Error("invalid id"));
    }

    this.get(id, (err, row) => {
      if (err) {
        return cb(err, null);
      }

      if (!row) {
        this.create(id, 1, cb);
      } else {
        this.db.run(
          "UPDATE trends SET value = value + 1 WHERE id = $id",
          { $id: id },
          err => {
            if (err) {
              return cb(err, null);
            }

            this.get(id, cb);
          }
        );
      }
    });
  }

  delete(id, cb) {
    if (!id) {
      return cb(new Error("invalid id"));
    }

    this.db.run("DELETE FROM trends WHERE id = $id", { $id: id }, cb);
  }

  isValid(value) {
    if (isNaN(value)) {
      return false;
    }

    return true;
  }
}

module.exports = new Model();