/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the Source EULA. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

'use strict';

import * as vscode from 'vscode';
import * as shelljs from 'shelljs';
import * as path from 'path';
import { getActiveKubeconfig, getToolPath } from '../config/config';
import { host } from '../kubectl/host';

export enum Platform {
	Windows,
	MacOS,
	Linux,
	Unsupported,
}

export interface ExecCallback extends shelljs.ExecCallback { }

export interface Shell {
	isWindows(): boolean;
	isUnix(): boolean;
	platform(): Platform;
	home(): string;
	combinePath(basePath: string, relativePath: string): string;
	fileUri(filePath: string): vscode.Uri;
	execOpts(): any;
	exec(cmd: string, stdin?: string): Promise<ShellResult | undefined>;
	execCore(cmd: string, opts: any, stdin?: string): Promise<ShellResult>;
	unquotedPath(path: string): string;
	which(bin: string): string | null;
	cat(path: string): string;
	ls(path: string): string[];
}

export const shell: Shell = {
	isWindows: isWindows,
	isUnix: isUnix,
	platform: platform,
	home: home,
	combinePath: combinePath,
	fileUri: fileUri,
	execOpts: execOpts,
	exec: exec,
	execCore: execCore,
	unquotedPath: unquotedPath,
	which: which,
	cat: cat,
	ls: ls,
};

const WINDOWS: string = 'win32';

export interface ShellResult {
	readonly code: number;
	readonly stdout: string;
	readonly stderr: string;
}

export type ShellHandler = (code: number, stdout: string, stderr: string) => void;

function isWindows(): boolean {
	return (process.platform === WINDOWS);
}

function isUnix(): boolean {
	return !isWindows();
}

function platform(): Platform {
	switch (process.platform) {
		case 'win32': return Platform.Windows;
		case 'darwin': return Platform.MacOS;
		case 'linux': return Platform.Linux;
		default: return Platform.Unsupported;
	}
}

function concatIfBoth(s1: string | undefined, s2: string | undefined): string | undefined {
	return s1 && s2 ? s1.concat(s2) : undefined;
}

function home(): string {
	return process.env['HOME'] ||
		concatIfBoth(process.env['HOMEDRIVE'], process.env['HOMEPATH']) ||
		process.env['USERPROFILE'] ||
		'';
}

function combinePath(basePath: string, relativePath: string) {
	let separator = '/';
	if (isWindows()) {
		relativePath = relativePath.replace(/\//g, '\\');
		separator = '\\';
	}
	return basePath + separator + relativePath;
}

function isWindowsFilePath(filePath: string) {
	return filePath[1] === ':' && filePath[2] === '\\';
}

function fileUri(filePath: string): vscode.Uri {
	if (isWindowsFilePath(filePath)) {
		return vscode.Uri.parse('file:///' + filePath.replace(/\\/g, '/'));
	}
	return vscode.Uri.parse('file://' + filePath);
}

function execOpts(): any {
	let env = process.env;
	if (isWindows()) {
		env = Object.assign({}, env, { HOME: home() });
	}
	env = shellEnvironment(env);
	const opts = {
		cwd: vscode.workspace.rootPath,
		env: env,
		async: true
	};
	return opts;
}

async function exec(cmd: string, stdin?: string): Promise<ShellResult | undefined> {
	try {
		return await execCore(cmd, execOpts(), stdin);
	} catch (ex) {
		vscode.window.showErrorMessage(ex);
		return undefined;
	}
}

function execCore(cmd: string, opts: any, stdin?: string): Promise<ShellResult> {
	return new Promise<ShellResult>((resolve) => {
		const proc = shelljs.exec(cmd, opts, (code, stdout, stderr) => resolve({ code: code, stdout: stdout, stderr: stderr }));
		if (stdin) {
			proc.stdin.end(stdin);
		}
	});
}

function unquotedPath(path: string): string {
	if (isWindows() && path && path.length > 1 && path.startsWith('"') && path.endsWith('"')) {
		return path.substring(1, path.length - 1);
	}
	return path;
}

export function shellEnvironment(baseEnvironment: any): any {
	const env = Object.assign({}, baseEnvironment);
	const pathVariable = pathVariableName(env);
	for (const tool of ['kubectl']) {
		const toolPath = getToolPath(host, shell, tool);
		if (toolPath) {
			const toolDirectory = path.dirname(toolPath);
			const currentPath = env[pathVariable];
			env[pathVariable] = toolDirectory + (currentPath ? `${pathEntrySeparator()}${currentPath}` : '');
		}
	}

	const kubeconfig = getActiveKubeconfig();
	if (kubeconfig) {
		env['KUBECONFIG'] = kubeconfig;
	}

	return env;
}

function pathVariableName(env: any): string {
	if (isWindows()) {
		for (const v of Object.keys(env)) {
			if (v.toLowerCase() === 'path') {
				return v;
			}
		}
	}
	return 'PATH';
}

function pathEntrySeparator() {
	return isWindows() ? ';' : ':';
}

function which(bin: string): string | null {
	return shelljs.which(bin);
}

function cat(path: string): string {
	return shelljs.cat(path);
}

function ls(path: string): string[] {
	return shelljs.ls(path);
}

export function shellMessage(sr: ShellResult | undefined, invocationFailureMessage: string): string {
	if (!sr) {
		return invocationFailureMessage;
	}
	return sr.code === 0 ? sr.stdout : sr.stderr;
}