/**
 * @license
 * Copyright 2019-2020 Balena Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * THIS MODULE SHOULD NOT IMPORT / REQUIRE ANYTHING AT THE GLOBAL LEVEL.
 * It is meant to contain elementary helper functions or classes that
 * can be used very early on during CLI startup, before anything else
 * like Sentry error reporting, preparser, oclif parser and the like.
 */

export class CliSettings {
	public readonly settings: any;
	constructor() {
		this.settings =
			require('balena-settings-client') as typeof import('balena-settings-client');
	}

	public get<T>(name: string): T {
		return this.settings.get(name);
	}

	/**
	 * Like settings.get(), but return `undefined` instead of throwing an
	 * error if the setting is not found / not defined.
	 */
	public getCatch<T>(name: string): T | undefined {
		try {
			return this.settings.get(name);
		} catch (err) {
			if (!/Setting not found/i.test(err.message)) {
				throw err;
			}
		}
	}
}

export function parseBoolEnvVar(varName: string): boolean {
	return !['0', 'no', 'false', '', undefined].includes(
		process.env[varName]?.toLowerCase(),
	);
}

export function normalizeEnvVar(varName: string) {
	process.env[varName] = parseBoolEnvVar(varName) ? '1' : '';
}

const bootstrapVars = [
	'BALENARC_NO_SENTRY',
	'BALENARC_NO_ANALYTICS',
	'BALENARC_OFFLINE_MODE',
	'BALENARC_UNSUPPORTED',
	'DEBUG',
];

export function normalizeEnvVars(varNames: string[] = bootstrapVars) {
	for (const varName of varNames) {
		normalizeEnvVar(varName);
	}
}

/**
 * Set the individual env vars implied by BALENARC_OFFLINE_MODE.
 */
export function setOfflineModeEnvVars() {
	if (process.env.BALENARC_OFFLINE_MODE) {
		process.env.BALENARC_UNSUPPORTED = '1';
		process.env.BALENARC_NO_SENTRY = '1';
		process.env.BALENARC_NO_ANALYTICS = '1';
	}
}

/**
 * Implements the 'pkgExec' command, used as a way to provide a Node.js
 * interpreter for child_process.spawn()-like operations when the CLI is
 * executing as a standalone zip package (built-in Node interpreter) and
 * the system may not have a separate Node.js installation. A present use
 * case is a patched version of the 'windosu' package that requires a
 * Node.js interpreter to spawn a privileged child process.
 *
 * @param modFunc Path to a JS module that will be executed via require().
 * The modFunc argument may optionally contain a function name separated
 * by '::', for example '::main' in:
 * 'C:\\snapshot\\balena-cli\\node_modules\\windosu\\lib\\pipe.js::main'
 * in which case that function is executed in the require'd module.
 * @param args Optional arguments to passed through process.argv and as
 * arguments to the function specified via modFunc.
 */
export async function pkgExec(modFunc: string, args: string[]) {
	const [modPath, funcName] = modFunc.split('::');
	let replacedModPath = modPath;
	const match = modPath
		.replace(/\\/g, '/')
		.match(/\/snapshot\/balena-cli\/(.+)/);
	if (match) {
		replacedModPath = `../${match[1]}`;
	}
	process.argv = [process.argv[0], process.argv[1], ...args];
	try {
		const mod: any = await import(replacedModPath);
		if (funcName) {
			await mod[funcName](...args);
		}
	} catch (err) {
		console.error(`Error executing pkgExec "${modFunc}" [${args.join()}]`);
		console.error(err);
	}
}

export interface CachedUsername {
	token: string;
	username: string;
}

let cachedUsername: CachedUsername | undefined;

/**
 * Return the parsed contents of the `~/.balena/cachedUsername` file. If the file
 * does not exist, create it with the details from the cloud. If not connected
 * to the internet, return undefined. This function is used by `lib/events.ts`
 * (event tracking) and `lib/utils/device/ssh.ts` and needs to gracefully handle
 * the scenario of not being connected to the internet.
 */
export async function getCachedUsername(): Promise<CachedUsername | undefined> {
	if (cachedUsername) {
		return cachedUsername;
	}
	const [{ getBalenaSdk }, getStorage, settings] = await Promise.all([
		import('./lazy'),
		import('balena-settings-storage'),
		import('balena-settings-client'),
	]);
	const dataDirectory = settings.get<string>('dataDirectory');
	const storage = getStorage({ dataDirectory });
	let token: string | undefined;
	try {
		token = (await storage.get('token')) as string | undefined;
	} catch {
		// ignore
	}
	if (!token) {
		// If we can't get a token then we can't get a username
		return;
	}
	try {
		const result = (await storage.get('cachedUsername')) as
			| CachedUsername
			| undefined;
		if (result && result.token === token && result.username) {
			cachedUsername = result;
			return cachedUsername;
		}
	} catch {
		// ignore
	}
	try {
		const username = await getBalenaSdk().auth.whoami();
		if (username) {
			cachedUsername = { token, username };
			await storage.set('cachedUsername', cachedUsername);
		}
	} catch {
		// ignore (not connected to the internet?)
	}
	return cachedUsername;
}