import * as dotenv from 'dotenv';
dotenv.config({ quiet: true });

/**
 * Get the environmental string from .env.
 * Supports rewriting names to UPPER_SNAKE_CASE if isGlobal is set.
 *
 * @param      {string}              key              The key
 * @param      {boolean}             [isGlobal=true]  Indicates if global
 * @return     {(string|undefined)}  The environment string.
 */
export function getString(
	key: string,
	isGlobal: boolean = true
): string | undefined {
	let keyName: string = '';

	if (isGlobal) {
		// Global values are DECLARED_LIKE_THIS=...
		for (let i: number = 0; i < key.length; i++) {
			if (key[i].toLowerCase() === key[i]) {
				// If is lowercase, skip.
				keyName += key[i];
			} else {
				// If is uppercase, convert to snake case.
				keyName += `_${key[i].toLowerCase()}`;
			}
		}
		keyName = keyName.toUpperCase();
	} else {
		// Non-global keys are parsed as passed
		keyName = key;
	}

	return process.env[keyName];
}

/**
 * Get the environmental boolean from .env.
 * Supports rewriting names to UPPER_SNAKE_CASE if isGlobal is set.
 *
 * @param      {string}               key              The key
 * @param      {boolean}              [isGlobal=true]  Indicates if global
 * @return     {(boolean|undefined)}  The environment boolean.
 */
export function getBool(
	key: string,
	isGlobal: boolean = true
): boolean | undefined {
	
	const valueRead: string | undefined = getString(key, isGlobal);
	if (valueRead === undefined) return undefined;
	if (valueRead.toLowerCase() === 'true')
		return true;

	return false;
}

/**
 * Processes public url, returning protocol, fqdn and path.
 * proto://fqdn/path/ = fullPublicUrl
 * @return     {RewriteStrings}  The rewrite strings.
 */
export function getRewriteStrings(): RewriteStrings {
	const fullPublicUrl: string = getString('publicUrl', true)!;

	const url = new URL(fullPublicUrl);
	const proto = url.protocol.slice(0, -1); // https: -> https
	const fqdn = url.host;
	const path = url.pathname.replace(/\/+$/, '') + '/'; // /abc -> /abc/

	const result: RewriteStrings = {
		fullPublicUrl,
		proto,
		fqdn,
		path
	};

	return result;
};

export type RewriteStrings = {
	fullPublicUrl: string;
	proto: string;
	fqdn: string;
	path: string;
};