// Copyright (c) Microsoft Corporation. All rights reserved.

// Licensed under the MIT License.

'use strict';

import { EnvironmentVariables } from '../variables/types';

export enum Architecture {

Unknown = 1,

x86 = 2,

x64 = 3,

}

export enum OSType {

Unknown = 'Unknown',

Windows = 'Windows',

OSX = 'OSX',

Linux = 'Linux',

}

// Return the OS type for the given platform string.

export function getOSType(platform: string = process.platform): OSType {

if (/^win/.test(platform)) {

return OSType.Windows;

} else if (/^darwin/.test(platform)) {

return OSType.OSX;

} else if (/^linux/.test(platform)) {

return OSType.Linux;

} else {

return OSType.Unknown;

}

}

const architectures: Record<string, Architecture> = {

x86: Architecture.x86, // 32-bit

x64: Architecture.x64, // 64-bit

'': Architecture.Unknown,

};

/**

* Identify the host's native architecture/bitness.

*/

export function getArchitecture(): Architecture {

const fromProc = architectures[process.arch];

if (fromProc !== undefined) {

return fromProc;

}

const arch = require('arch');

return architectures[arch()] || Architecture.Unknown;

}

/**

* Look up the requested env var value (or undefined` if not set).

*/

export function getEnvironmentVariable(key: string): string | undefined {

return ((process.env as any) as EnvironmentVariables)[key];

}

/**

* Get the current user's home directory.

*

* The lookup is limited to environment variables.

*/

export function getUserHomeDir(): string | undefined {

if (getOSType() === OSType.Windows) {

return getEnvironmentVariable('USERPROFILE');

}

return getEnvironmentVariable('HOME') || getEnvironmentVariable('HOMEPATH');

}