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

'use strict';

import vscode = require('vscode');
import { CancellationToken, Hover, HoverProvider, Position, TextDocument, WorkspaceConfiguration } from 'vscode';
import { definitionLocation } from './goDeclaration';
import { getGoConfig } from './util';

export class GoHoverProvider implements HoverProvider {
	private goConfig: WorkspaceConfiguration = null;

	constructor(goConfig?: WorkspaceConfiguration) {
		this.goConfig = goConfig;
	}

	public provideHover(document: TextDocument, position: Position, token: CancellationToken): Thenable<Hover> {
		if (!this.goConfig) {
			this.goConfig = getGoConfig(document.uri);
		}
		let goConfig = this.goConfig;

		// Temporary fix to fall back to godoc if guru is the set docsTool
		if (goConfig['docsTool'] === 'guru') {
			goConfig = Object.assign({}, goConfig, { docsTool: 'godoc' });
		}
		return definitionLocation(document, position, goConfig, true, token).then((definitionInfo) => {
			if (definitionInfo == null) {
				return null;
			}
			const lines = definitionInfo.declarationlines
				.filter((line) => line !== '')
				.map((line) => line.replace(/\t/g, '    '));
			let text;
			text = lines.join('\n').replace(/\n+$/, '');
			const hoverTexts = new vscode.MarkdownString();
			hoverTexts.appendCodeblock(text, 'go');
			if (definitionInfo.doc != null) {
				hoverTexts.appendMarkdown(definitionInfo.doc);
			}
			const hover = new Hover(hoverTexts);
			return hover;
		}, () => {
			return null;
		});
	}
}