import { existsSync } from "fs";
import Knex from "knex";
import { Knex as KnexConfig } from "./config";
import { get_setting } from "./SettingConfig";

export async function connectDB() {
	const env = get_setting().mode;
	const config = KnexConfig.config[env];
	if (!config.connection) {
		throw new Error("connection options required.");
	}
	const connection = config.connection;
	if (typeof connection === "string") {
		throw new Error("unknown connection options");
	}
	if (typeof connection === "function") {
		throw new Error("connection provider not supported...");
	}
	if (!("filename" in connection)) {
		throw new Error("sqlite3 config need");
	}
	const init_need = !existsSync(connection.filename);
	const knex = Knex(config);
	let tries = 0;
	for (;;) {
		try {
			console.log("try to connect db");
			await knex.raw("select 1 + 1;");
			console.log("connect success");
		} catch (err) {
			if (tries < 3) {
				tries++;
				console.error(`connection fail ${err} retry...`);
				continue;
			} else {
				throw err;
			}
		}
		break;
	}
	if (init_need) {
		console.log("first execute: initialize database...");
		const migrate = await import("../migrations/initial");
		await migrate.up(knex);
	}
	return knex;
}