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

import * as path from 'path';
import * as fs from 'fs';
import * as nls from 'vscode-nls';
import { xhr, XHRResponse, getErrorStatusDescription } from 'request-light';

const localize = nls.loadMessageBundle();

import {
	workspace, window, languages, commands, ExtensionContext, extensions, Uri, LanguageConfiguration,
	Diagnostic, StatusBarAlignment, TextEditor, TextDocument, FormattingOptions, CancellationToken,
	ProviderResult, TextEdit, Range, Position, Disposable, CompletionItem, CompletionList, CompletionContext
} from 'vscode';
import {
	LanguageClient, LanguageClientOptions, RequestType, ServerOptions, TransportKind, NotificationType,
	DidChangeConfigurationNotification, HandleDiagnosticsSignature, ResponseError, DocumentRangeFormattingParams,
	DocumentRangeFormattingRequest, ProvideCompletionItemsSignature
} from 'vscode-languageclient';
import TelemetryReporter from 'vscode-extension-telemetry';

import { hash } from './utils/hash';

namespace VSCodeContentRequest {
	export const type: RequestType<string, string, any, any> = new RequestType('vscode/content');
}

namespace SchemaContentChangeNotification {
	export const type: NotificationType<string, any> = new NotificationType('json/schemaContent');
}

namespace ForceValidateRequest {
	export const type: RequestType<string, Diagnostic[], any, any> = new RequestType('json/validate');
}

export interface ISchemaAssociations {
	[pattern: string]: string[];
}

export interface ISchemaAssociation {
	fileMatch: string[];
	uri: string;
}

namespace SchemaAssociationNotification {
	export const type: NotificationType<ISchemaAssociations | ISchemaAssociation[], any> = new NotificationType('json/schemaAssociations');
}

namespace ResultLimitReachedNotification {
	export const type: NotificationType<string, any> = new NotificationType('json/resultLimitReached');
}

interface IPackageInfo {
	name: string;
	version: string;
	aiKey: string;
}

interface Settings {
	json?: {
		schemas?: JSONSchemaSettings[];
		format?: { enable: boolean; };
		resultLimit?: number;
	};
	http?: {
		proxy?: string;
		proxyStrictSSL?: boolean;
	};
}

interface JSONSchemaSettings {
	fileMatch?: string[];
	url?: string;
	schema?: any;
}

let telemetryReporter: TelemetryReporter | undefined;

export function activate(context: ExtensionContext) {

	const toDispose = context.subscriptions;

	let rangeFormatting: Disposable | undefined = undefined;

	const packageInfo = getPackageInfo(context);
	telemetryReporter = packageInfo && new TelemetryReporter(packageInfo.name, packageInfo.version, packageInfo.aiKey);

	const serverMain = readJSONFile(context.asAbsolutePath('./server/package.json')).main;
	const serverModule = context.asAbsolutePath(path.join('server', serverMain));

	// The debug options for the server
	const debugOptions = { execArgv: ['--nolazy', '--inspect=' + (9000 + Math.round(Math.random() * 10000))] };

	// If the extension is launch in debug mode the debug server options are use
	// Otherwise the run options are used
	const serverOptions: ServerOptions = {
		run: { module: serverModule, transport: TransportKind.ipc },
		debug: { module: serverModule, transport: TransportKind.ipc, options: debugOptions }
	};

	const documentSelector = ['json', 'jsonc'];

	const schemaResolutionErrorStatusBarItem = window.createStatusBarItem({
		id: 'status.json.resolveError',
		name: localize('json.resolveError', "JSON: Schema Resolution Error"),
		alignment: StatusBarAlignment.Right,
		priority: 0
	});
	schemaResolutionErrorStatusBarItem.command = '_json.retryResolveSchema';
	schemaResolutionErrorStatusBarItem.tooltip = localize('json.schemaResolutionErrorMessage', 'Unable to resolve schema.') + ' ' + localize('json.clickToRetry', 'Click to retry.');
	schemaResolutionErrorStatusBarItem.text = '$(alert)';
	toDispose.push(schemaResolutionErrorStatusBarItem);

	const fileSchemaErrors = new Map<string, string>();

	// Options to control the language client
	const clientOptions: LanguageClientOptions = {
		// Register the server for json documents
		documentSelector,
		initializationOptions: {
			handledSchemaProtocols: ['file'], // language server only loads file-URI. Fetching schemas with other protocols ('http'...) are made on the client.
			provideFormatter: false, // tell the server to not provide formatting capability and ignore the `json.format.enable` setting.
			customCapabilities: { rangeFormatting: { editLimit: 1000 } }
		},
		synchronize: {
			// Synchronize the setting section 'json' to the server
			configurationSection: ['json', 'http'],
			fileEvents: workspace.createFileSystemWatcher('**/*.json')
		},
		middleware: {
			workspace: {
				didChangeConfiguration: () => client.sendNotification(DidChangeConfigurationNotification.type, { settings: getSettings() })
			},
			handleDiagnostics: (uri: Uri, diagnostics: Diagnostic[], next: HandleDiagnosticsSignature) => {
				const schemaErrorIndex = diagnostics.findIndex(candidate => candidate.code === /* SchemaResolveError */ 0x300);

				if (schemaErrorIndex === -1) {
					fileSchemaErrors.delete(uri.toString());
					return next(uri, diagnostics);
				}

				const schemaResolveDiagnostic = diagnostics[schemaErrorIndex];
				fileSchemaErrors.set(uri.toString(), schemaResolveDiagnostic.message);

				if (window.activeTextEditor && window.activeTextEditor.document.uri.toString() === uri.toString()) {
					schemaResolutionErrorStatusBarItem.show();
				}

				next(uri, diagnostics);
			},
			// testing the replace / insert mode
			provideCompletionItem(document: TextDocument, position: Position, context: CompletionContext, token: CancellationToken, next: ProvideCompletionItemsSignature): ProviderResult<CompletionItem[] | CompletionList> {
				function updateRanges(item: CompletionItem) {
					const range = item.range;
					if (range instanceof Range && range.end.isAfter(position) && range.start.isBeforeOrEqual(position)) {
						item.range = { inserting: new Range(range.start, position), replacing: range };
					}
				}
				function updateProposals(r: CompletionItem[] | CompletionList | null | undefined): CompletionItem[] | CompletionList | null | undefined {
					if (r) {
						(Array.isArray(r) ? r : r.items).forEach(updateRanges);
					}
					return r;
				}
				const isThenable = <T>(obj: ProviderResult<T>): obj is Thenable<T> => obj && (<any>obj)['then'];

				const r = next(document, position, context, token);
				if (isThenable<CompletionItem[] | CompletionList | null | undefined>(r)) {
					return r.then(updateProposals);
				}
				return updateProposals(r);
			}
		}
	};

	// Create the language client and start the client.
	const client = new LanguageClient('json', localize('jsonserver.name', 'JSON Language Server'), serverOptions, clientOptions);
	client.registerProposedFeatures();

	const disposable = client.start();
	toDispose.push(disposable);
	client.onReady().then(() => {
		const schemaDocuments: { [uri: string]: boolean } = {};

		// handle content request
		client.onRequest(VSCodeContentRequest.type, (uriPath: string) => {
			const uri = Uri.parse(uriPath);
			if (uri.scheme === 'untitled') {
				return Promise.reject(new Error(localize('untitled.schema', 'Unable to load {0}', uri.toString())));
			}
			if (uri.scheme !== 'http' && uri.scheme !== 'https') {
				return workspace.openTextDocument(uri).then(doc => {
					schemaDocuments[uri.toString()] = true;
					return doc.getText();
				}, error => {
					return Promise.reject(error);
				});
			} else {
				if (telemetryReporter && uri.authority === 'schema.management.azure.com') {
					/* __GDPR__
						"json.schema" : {
							"schemaURL" : { "classification": "SystemMetaData", "purpose": "FeatureInsight" }
						}
					 */
					telemetryReporter.sendTelemetryEvent('json.schema', { schemaURL: uriPath });
				}
				const headers = { 'Accept-Encoding': 'gzip, deflate' };
				return xhr({ url: uriPath, followRedirects: 5, headers }).then(response => {
					return response.responseText;
				}, (error: XHRResponse) => {
					let extraInfo = error.responseText || error.toString();
					if (extraInfo.length > 256) {
						extraInfo = `${extraInfo.substr(0, 256)}...`;
					}
					return Promise.reject(new ResponseError(error.status, getErrorStatusDescription(error.status) + '\n' + extraInfo));
				});
			}
		});

		const handleContentChange = (uriString: string) => {
			if (schemaDocuments[uriString]) {
				client.sendNotification(SchemaContentChangeNotification.type, uriString);
				return true;
			}
			return false;
		};

		const handleActiveEditorChange = (activeEditor?: TextEditor) => {
			if (!activeEditor) {
				return;
			}

			const activeDocUri = activeEditor.document.uri.toString();

			if (activeDocUri && fileSchemaErrors.has(activeDocUri)) {
				schemaResolutionErrorStatusBarItem.show();
			} else {
				schemaResolutionErrorStatusBarItem.hide();
			}
		};

		toDispose.push(workspace.onDidChangeTextDocument(e => handleContentChange(e.document.uri.toString())));
		toDispose.push(workspace.onDidCloseTextDocument(d => {
			const uriString = d.uri.toString();
			if (handleContentChange(uriString)) {
				delete schemaDocuments[uriString];
			}
			fileSchemaErrors.delete(uriString);
		}));
		toDispose.push(window.onDidChangeActiveTextEditor(handleActiveEditorChange));

		const handleRetryResolveSchemaCommand = () => {
			if (window.activeTextEditor) {
				schemaResolutionErrorStatusBarItem.text = '$(watch)';
				const activeDocUri = window.activeTextEditor.document.uri.toString();
				client.sendRequest(ForceValidateRequest.type, activeDocUri).then((diagnostics) => {
					const schemaErrorIndex = diagnostics.findIndex(candidate => candidate.code === /* SchemaResolveError */ 0x300);
					if (schemaErrorIndex !== -1) {
						// Show schema resolution errors in status bar only; ref: #51032
						const schemaResolveDiagnostic = diagnostics[schemaErrorIndex];
						fileSchemaErrors.set(activeDocUri, schemaResolveDiagnostic.message);
					} else {
						schemaResolutionErrorStatusBarItem.hide();
					}
					schemaResolutionErrorStatusBarItem.text = '$(alert)';
				});
			}
		};

		toDispose.push(commands.registerCommand('_json.retryResolveSchema', handleRetryResolveSchemaCommand));

		client.sendNotification(SchemaAssociationNotification.type, getSchemaAssociations(context));

		extensions.onDidChange(_ => {
			client.sendNotification(SchemaAssociationNotification.type, getSchemaAssociations(context));
		});

		// manually register / deregister format provider based on the `html.format.enable` setting avoiding issues with late registration. See #71652.
		updateFormatterRegistration();
		toDispose.push({ dispose: () => rangeFormatting && rangeFormatting.dispose() });
		toDispose.push(workspace.onDidChangeConfiguration(e => e.affectsConfiguration('html.format.enable') && updateFormatterRegistration()));


		client.onNotification(ResultLimitReachedNotification.type, message => {
			window.showInformationMessage(`${message}\nUse setting 'json.maxItemsComputed' to configure the limit.`);
		});

	});

	const languageConfiguration: LanguageConfiguration = {
		wordPattern: /("(?:[^\\\"]*(?:\\.)?)*"?)|[^\s{}\[\],:]+/,
		indentationRules: {
			increaseIndentPattern: /({+(?=([^"]*"[^"]*")*[^"}]*$))|(\[+(?=([^"]*"[^"]*")*[^"\]]*$))/,
			decreaseIndentPattern: /^\s*[}\]],?\s*$/
		}
	};
	languages.setLanguageConfiguration('json', languageConfiguration);
	languages.setLanguageConfiguration('jsonc', languageConfiguration);

	function updateFormatterRegistration() {
		const formatEnabled = workspace.getConfiguration().get('json.format.enable');
		if (!formatEnabled && rangeFormatting) {
			rangeFormatting.dispose();
			rangeFormatting = undefined;
		} else if (formatEnabled && !rangeFormatting) {
			rangeFormatting = languages.registerDocumentRangeFormattingEditProvider(documentSelector, {
				provideDocumentRangeFormattingEdits(document: TextDocument, range: Range, options: FormattingOptions, token: CancellationToken): ProviderResult<TextEdit[]> {
					const params: DocumentRangeFormattingParams = {
						textDocument: client.code2ProtocolConverter.asTextDocumentIdentifier(document),
						range: client.code2ProtocolConverter.asRange(range),
						options: client.code2ProtocolConverter.asFormattingOptions(options)
					};
					return client.sendRequest(DocumentRangeFormattingRequest.type, params, token).then(
						client.protocol2CodeConverter.asTextEdits,
						(error) => {
							client.logFailedRequest(DocumentRangeFormattingRequest.type, error);
							return Promise.resolve([]);
						}
					);
				}
			});
		}
	}
}



export function deactivate(): Promise<any> {
	return telemetryReporter ? telemetryReporter.dispose() : Promise.resolve(null);
}

function getSchemaAssociations(_context: ExtensionContext): ISchemaAssociation[] {
	const associations: ISchemaAssociation[] = [];
	extensions.all.forEach(extension => {
		const packageJSON = extension.packageJSON;
		if (packageJSON && packageJSON.contributes && packageJSON.contributes.jsonValidation) {
			const jsonValidation = packageJSON.contributes.jsonValidation;
			if (Array.isArray(jsonValidation)) {
				jsonValidation.forEach(jv => {
					let { fileMatch, url } = jv;
					if (typeof fileMatch === 'string') {
						fileMatch = [fileMatch];
					}
					if (Array.isArray(fileMatch) && url) {
						if (url[0] === '.' && url[1] === '/') {
							url = Uri.file(path.join(extension.extensionPath, url)).toString();
						}
						fileMatch = fileMatch.map(fm => {
							if (fm[0] === '%') {
								fm = fm.replace(/%APP_SETTINGS_HOME%/, '/User');
								fm = fm.replace(/%MACHINE_SETTINGS_HOME%/, '/Machine');
								fm = fm.replace(/%APP_WORKSPACES_HOME%/, '/Workspaces');
							} else if (!fm.match(/^(\w+:\/\/|\/|!)/)) {
								fm = '/' + fm;
							}
							return fm;
						});
						associations.push({ fileMatch, uri: url });
					}
				});
			}
		}
	});
	return associations;
}

function getSettings(): Settings {
	const httpSettings = workspace.getConfiguration('http');

	const resultLimit: number = Math.trunc(Math.max(0, Number(workspace.getConfiguration().get('json.maxItemsComputed')))) || 5000;

	const settings: Settings = {
		http: {
			proxy: httpSettings.get('proxy'),
			proxyStrictSSL: httpSettings.get('proxyStrictSSL')
		},
		json: {
			schemas: [],
			resultLimit
		}
	};
	const schemaSettingsById: { [schemaId: string]: JSONSchemaSettings } = Object.create(null);
	const collectSchemaSettings = (schemaSettings: JSONSchemaSettings[], folderUri?: Uri, isMultiRoot?: boolean) => {

		let fileMatchPrefix = undefined;
		if (folderUri && isMultiRoot) {
			fileMatchPrefix = folderUri.toString();
			if (fileMatchPrefix[fileMatchPrefix.length - 1] === '/') {
				fileMatchPrefix = fileMatchPrefix.substr(0, fileMatchPrefix.length - 1);
			}
		}
		for (const setting of schemaSettings) {
			const url = getSchemaId(setting, folderUri);
			if (!url) {
				continue;
			}
			let schemaSetting = schemaSettingsById[url];
			if (!schemaSetting) {
				schemaSetting = schemaSettingsById[url] = { url, fileMatch: [] };
				settings.json!.schemas!.push(schemaSetting);
			}
			const fileMatches = setting.fileMatch;
			if (Array.isArray(fileMatches)) {
				const resultingFileMatches = schemaSetting.fileMatch || [];
				schemaSetting.fileMatch = resultingFileMatches;
				const addMatch = (pattern: string) => { //  filter duplicates
					if (resultingFileMatches.indexOf(pattern) === -1) {
						resultingFileMatches.push(pattern);
					}
				};
				for (const fileMatch of fileMatches) {
					if (fileMatchPrefix) {
						if (fileMatch[0] === '/') {
							addMatch(fileMatchPrefix + fileMatch);
							addMatch(fileMatchPrefix + '/*' + fileMatch);
						} else {
							addMatch(fileMatchPrefix + '/' + fileMatch);
							addMatch(fileMatchPrefix + '/*/' + fileMatch);
						}
					} else {
						addMatch(fileMatch);
					}
				}
			}
			if (setting.schema && !schemaSetting.schema) {
				schemaSetting.schema = setting.schema;
			}
		}
	};

	const folders = workspace.workspaceFolders;

	// merge global and folder settings. Qualify all file matches with the folder path.
	const globalSettings = workspace.getConfiguration('json', null).get<JSONSchemaSettings[]>('schemas');
	if (Array.isArray(globalSettings)) {
		if (!folders) {
			collectSchemaSettings(globalSettings);
		}
	}
	if (folders) {
		const isMultiRoot = folders.length > 1;
		for (const folder of folders) {
			const folderUri = folder.uri;

			const schemaConfigInfo = workspace.getConfiguration('json', folderUri).inspect<JSONSchemaSettings[]>('schemas');

			const folderSchemas = schemaConfigInfo!.workspaceFolderValue;
			if (Array.isArray(folderSchemas)) {
				collectSchemaSettings(folderSchemas, folderUri, isMultiRoot);
			}
			if (Array.isArray(globalSettings)) {
				collectSchemaSettings(globalSettings, folderUri, isMultiRoot);
			}

		}
	}
	return settings;
}

function getSchemaId(schema: JSONSchemaSettings, folderUri?: Uri) {
	let url = schema.url;
	if (!url) {
		if (schema.schema) {
			url = schema.schema.id || `vscode://schemas/custom/${encodeURIComponent(hash(schema.schema).toString(16))}`;
		}
	} else if (folderUri && (url[0] === '.' || url[0] === '/')) {
		url = folderUri.with({ path: path.posix.join(folderUri.path, url) }).toString();
	}
	return url;
}

function getPackageInfo(context: ExtensionContext): IPackageInfo | undefined {
	const extensionPackage = readJSONFile(context.asAbsolutePath('./package.json'));
	if (extensionPackage) {
		return {
			name: extensionPackage.name,
			version: extensionPackage.version,
			aiKey: extensionPackage.aiKey
		};
	}
	return undefined;
}

function readJSONFile(location: string) {
	try {
		return JSON.parse(fs.readFileSync(location).toString());
	} catch (e) {
		console.log(`Problems reading ${location}: ${e}`);
		return {};
	}
}