export function getHover(model: ITextModel, position: Position, token: CancellationToken): Promise<Hover[]> {

	const supports = HoverProviderRegistry.ordered(model);

	const promises = supports.map(support => {
		return Promise.resolve(support.provideHover(model, position, token)).then(hover => {
			return hover && isValid(hover) ? hover : undefined;
		}, err => {
			onUnexpectedExternalError(err);
			return undefined;
		});
	});

	return Promise.all(promises).then(coalesce);
}

	constructor(
		editor: ICommonCodeEditor,
		contextKeyService: IContextKeyService
	) {
		super();
		this._editor = editor;

		this._langId = EditorContextKeys.languageId.bindTo(contextKeyService);
		this._hasCompletionItemProvider = EditorContextKeys.hasCompletionItemProvider.bindTo(contextKeyService);
		this._hasCodeActionsProvider = EditorContextKeys.hasCodeActionsProvider.bindTo(contextKeyService);
		this._hasCodeLensProvider = EditorContextKeys.hasCodeLensProvider.bindTo(contextKeyService);
		this._hasDefinitionProvider = EditorContextKeys.hasDefinitionProvider.bindTo(contextKeyService);
		this._hasImplementationProvider = EditorContextKeys.hasImplementationProvider.bindTo(contextKeyService);
		this._hasTypeDefinitionProvider = EditorContextKeys.hasTypeDefinitionProvider.bindTo(contextKeyService);
		this._hasHoverProvider = EditorContextKeys.hasHoverProvider.bindTo(contextKeyService);
		this._hasDocumentHighlightProvider = EditorContextKeys.hasDocumentHighlightProvider.bindTo(contextKeyService);
		this._hasDocumentSymbolProvider = EditorContextKeys.hasDocumentSymbolProvider.bindTo(contextKeyService);
		this._hasReferenceProvider = EditorContextKeys.hasReferenceProvider.bindTo(contextKeyService);
		this._hasRenameProvider = EditorContextKeys.hasRenameProvider.bindTo(contextKeyService);
		this._hasDocumentFormattingProvider = EditorContextKeys.hasDocumentFormattingProvider.bindTo(contextKeyService);
		this._hasDocumentSelectionFormattingProvider = EditorContextKeys.hasDocumentSelectionFormattingProvider.bindTo(contextKeyService);
		this._hasSignatureHelpProvider = EditorContextKeys.hasSignatureHelpProvider.bindTo(contextKeyService);
		this._isInWalkThrough = EditorContextKeys.isInEmbeddedEditor.bindTo(contextKeyService);

		const update = () => this._update();

		// update when model/mode changes
		this._register(editor.onDidChangeModel(update));
		this._register(editor.onDidChangeModelLanguage(update));

		// update when registries change
		this._register(modes.SuggestRegistry.onDidChange(update));
		this._register(modes.CodeActionProviderRegistry.onDidChange(update));
		this._register(modes.CodeLensProviderRegistry.onDidChange(update));
		this._register(modes.DefinitionProviderRegistry.onDidChange(update));
		this._register(modes.ImplementationProviderRegistry.onDidChange(update));
		this._register(modes.TypeDefinitionProviderRegistry.onDidChange(update));
		this._register(modes.HoverProviderRegistry.onDidChange(update));
		this._register(modes.DocumentHighlightProviderRegistry.onDidChange(update));
		this._register(modes.DocumentSymbolProviderRegistry.onDidChange(update));
		this._register(modes.ReferenceProviderRegistry.onDidChange(update));
		this._register(modes.RenameProviderRegistry.onDidChange(update));
		this._register(modes.DocumentFormattingEditProviderRegistry.onDidChange(update));
		this._register(modes.DocumentRangeFormattingEditProviderRegistry.onDidChange(update));
		this._register(modes.SignatureHelpProviderRegistry.onDidChange(update));

		update();
	}

export function registerHoverProvider(languageId: string, provider: modes.HoverProvider): IDisposable {
	return modes.HoverProviderRegistry.register(languageId, {
		provideHover: (model: model.ITextModel, position: Position, token: CancellationToken): Thenable<modes.Hover> => {
			let word = model.getWordAtPosition(position);

			return Promise.resolve<modes.Hover>(provider.provideHover(model, position, token)).then((value) => {
				if (!value) {
					return undefined;
				}
				if (!value.range && word) {
					value.range = new Range(position.lineNumber, word.startColumn, position.lineNumber, word.endColumn);
				}
				if (!value.range) {
					value.range = new Range(position.lineNumber, position.column, position.lineNumber, position.column);
				}
				return value;
			});
		}
	});
}

export function provideHover(model: IReadOnlyModel, position: IEditorPosition, cancellationToken = CancellationToken.None): Thenable<Hover[]> {

	const supports = HoverProviderRegistry.ordered(model);
	const values: Hover[] = [];

	const promises = supports.map((support, idx) => {
		return toThenable(support.provideHover(model, position, cancellationToken)).then(result => {
			if (result) {
				let hasRange = (typeof result.range !== 'undefined');
				let hasHtmlContent = (typeof result.htmlContent !== 'undefined' && result.htmlContent && result.htmlContent.length > 0);
				if (hasRange && hasHtmlContent) {
					values[idx]  = result;
				}
			}
		}, err => {
			onUnexpectedError(err);
		});
	});

	return TPromise.join(promises).then(() => coalesce(values));
}

export function getHover(model: ITextModel, position: Position): TPromise<Hover[]> {

	const supports = HoverProviderRegistry.ordered(model);
	const values: Hover[] = [];

	const promises = supports.map((support, idx) => {
		return asWinJsPromise((token) => {
			return support.provideHover(model, position, token);
		}).then((result) => {
			if (result) {
				let hasRange = (typeof result.range !== 'undefined');
				let hasHtmlContent = typeof result.contents !== 'undefined' && result.contents && result.contents.length > 0;
				if (hasRange && hasHtmlContent) {
					values[idx] = result;
				}
			}
		}, err => {
			onUnexpectedExternalError(err);
		});
	});

	return TPromise.join(promises).then(() => coalesce(values));
}

	private _update() {
		const model = this._editor.getModel();
		if (!model) {
			this.reset();
			return;
		}
		this._langId.set(model.getLanguageIdentifier().language);
		this._hasCompletionItemProvider.set(modes.SuggestRegistry.has(model));
		this._hasCodeActionsProvider.set(modes.CodeActionProviderRegistry.has(model));
		this._hasCodeLensProvider.set(modes.CodeLensProviderRegistry.has(model));
		this._hasDefinitionProvider.set(modes.DefinitionProviderRegistry.has(model));
		this._hasImplementationProvider.set(modes.ImplementationProviderRegistry.has(model));
		this._hasTypeDefinitionProvider.set(modes.TypeDefinitionProviderRegistry.has(model));
		this._hasHoverProvider.set(modes.HoverProviderRegistry.has(model));
		this._hasDocumentHighlightProvider.set(modes.DocumentHighlightProviderRegistry.has(model));
		this._hasDocumentSymbolProvider.set(modes.DocumentSymbolProviderRegistry.has(model));
		this._hasReferenceProvider.set(modes.ReferenceProviderRegistry.has(model));
		this._hasRenameProvider.set(modes.RenameProviderRegistry.has(model));
		this._hasSignatureHelpProvider.set(modes.SignatureHelpProviderRegistry.has(model));
		this._hasDocumentFormattingProvider.set(modes.DocumentFormattingEditProviderRegistry.has(model) || modes.DocumentRangeFormattingEditProviderRegistry.has(model));
		this._hasDocumentSelectionFormattingProvider.set(modes.DocumentRangeFormattingEditProviderRegistry.has(model));
		this._isInWalkThrough.set(model.uri.scheme === Schemas.walkThroughSnippet);
	}