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

import path = require('path');
import vscode = require('vscode');
import { lintDiagnosticCollection } from './goMain';
import { diagnosticsStatusBarItem, outputChannel } from './goStatus';
import { getGoConfig, getToolsEnvVars, getToolsGopath, getWorkspaceFolderPath, handleDiagnosticErrors, ICheckResult, resolvePath, runTool } from './util';
/**
 * Runs linter on the current file, package or workspace.
 */
export function lintCode(scope?: string) {
	const editor = vscode.window.activeTextEditor;
	if (!editor && scope !== 'workspace') {
		vscode.window.showInformationMessage('No editor is active, cannot find current package to lint');
		return;
	}
	if (editor.document.languageId !== 'go' && scope !== 'workspace') {
		vscode.window.showInformationMessage('File in the active editor is not a Go file, cannot find current package to lint');
		return;
	}

	const documentUri = editor ? editor.document.uri : null;
	const goConfig = getGoConfig(documentUri);

	outputChannel.clear(); // Ensures stale output from lint on save is cleared
	diagnosticsStatusBarItem.show();
	diagnosticsStatusBarItem.text = 'Linting...';

	goLint(documentUri, goConfig, scope)
		.then((warnings) => {
			handleDiagnosticErrors(editor ? editor.document : null, warnings, lintDiagnosticCollection);
			diagnosticsStatusBarItem.hide();
		})
		.catch((err) => {
			vscode.window.showInformationMessage('Error: ' + err);
			diagnosticsStatusBarItem.text = 'Linting Failed';
		});
}

/**
 * Runs linter and presents the output in the 'Go' channel and in the diagnostic collections.
 *
 * @param fileUri Document uri.
 * @param goConfig Configuration for the Go extension.
 * @param scope Scope in which to run the linter.
 */
export function goLint(fileUri: vscode.Uri, goConfig: vscode.WorkspaceConfiguration, scope?: string): Promise<ICheckResult[]> {
	epoch++;
	const closureEpoch = epoch;
	if (tokenSource) {
		if (running) {
			tokenSource.cancel();
		}
		tokenSource.dispose();
	}
	tokenSource = new vscode.CancellationTokenSource();

	const currentWorkspace = getWorkspaceFolderPath(fileUri);

	const cwd = (scope === 'workspace' && currentWorkspace) ? currentWorkspace : path.dirname(fileUri.fsPath);

	if (!path.isAbsolute(cwd)) {
		return Promise.resolve([]);
	}

	const lintTool = goConfig['lintTool'] || 'golint';
	const lintFlags: string[] = goConfig['lintFlags'] || [];
	const lintEnv = Object.assign({}, getToolsEnvVars());
	const args: string[] = [];

	lintFlags.forEach((flag) => {
		// --json is not a valid flag for golint and in gometalinter, it is used to print output in json which we dont want
		if (flag === '--json') {
			return;
		}
		if (flag.startsWith('--config=') || flag.startsWith('-config=')) {
			let configFilePath = flag.substr(flag.indexOf('=') + 1).trim();
			if (!configFilePath) {
				return;
			}
			configFilePath = resolvePath(configFilePath);
			args.push(`${flag.substr(0, flag.indexOf('=') + 1)}${configFilePath}`);
			return;
		}
		args.push(flag);
	});
	if (lintTool === 'gometalinter') {
		if (args.indexOf('--aggregate') === -1) {
			args.push('--aggregate');
		}
		if (goConfig['toolsGopath']) {
			// gometalinter will expect its linters to be in the GOPATH
			// So add the toolsGopath to GOPATH
			lintEnv['GOPATH'] += path.delimiter + getToolsGopath();
		}
	}
	if (lintTool === 'golangci-lint') {
		if (args.indexOf('run') === -1) {
			args.unshift('run');
		}
		if (args.indexOf('--print-issued-lines=false') === -1) {
			// print only file:number:column
			args.push('--print-issued-lines=false');
		}
	}

	if (scope === 'workspace' && currentWorkspace) {
		args.push('./...');
		outputChannel.appendLine(`Starting linting the current workspace at ${currentWorkspace}`);
	} else if (scope === 'file') {
		args.push(fileUri.fsPath);
		outputChannel.appendLine(`Starting linting the current file at ${fileUri.fsPath}`);
	} else {
		outputChannel.appendLine(`Starting linting the current package at ${cwd}`);
	}

	running = true;
	const lintPromise = runTool(
		args,
		cwd,
		'warning',
		false,
		lintTool,
		lintEnv,
		false,
		tokenSource.token
	).then((result) => {
		if (closureEpoch === epoch) {
			running = false;
		}
		return result;
	});

	return lintPromise;
}

let epoch = 0;
let tokenSource: vscode.CancellationTokenSource;
let running = false;