LoRaWAN-Signal-Mapping/server/Repos.SQLite/GatewayRepo.mjs

"use strict";

class GatewayRepo {
	constructor({ database }) {
		this.db = database;
	}
	
	add(...gateways) {
		if(typeof this.query_insert == "undefined")
			this.query_insert = this.db.prepare(`INSERT INTO gateways (
				id,
				lat, long,
				altitude
			) VALUES (
				:id,
				:latitude, :longitude,
				:altitude
			)`);
		
		for(let gateway of gateways)
			this.insert_query.run(gateway);
	}
	
	/**
	 * Determines whether a gateway exists in the dayabase with the given name.
	 * @param	{string}	id	The id of the gateway.
	 * @return	{bool}		Whether a gateway with the given name exists in the database.
	 */
	exists(id) {
		// Note that normally a count wouldn't be appropriate here just to test for existence, but it's ok because it's guaranteed that there will only ever be a single entry with a given id.
		let statement = this.db.prepare(`SELECT COUNT(id) AS count
		FROM gateways
		WHERE id = :id`);
		
		let count = statement.get({ id }).count;
		
		return count > 0;
	}
	
	/**
	 * Iterates over all the gateways in the table.
	 * TODO: Use Symbol.iterator here?
 	 * @return	{Generator}	A generator that can be used with for..of
	 */
	iterate() {
		return this.db.prepare(`SELECT * FROM gateways`).iterate();
	}
}

export default GatewayRepo;