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

import * as nls from 'vs/nls';
import * as dom from 'vs/base/browser/dom';
import { CancellationToken } from 'vs/base/common/cancellation';
import { Color, RGBA } from 'vs/base/common/color';
import { IMarkdownString, MarkdownString, isEmptyMarkdownString, markedStringsEquals } from 'vs/base/common/htmlContent';
import { IDisposable, toDisposable, DisposableStore, combinedDisposable, MutableDisposable } from 'vs/base/common/lifecycle';
import { ICodeEditor } from 'vs/editor/browser/editorBrowser';
import { Position } from 'vs/editor/common/core/position';
import { IRange, Range } from 'vs/editor/common/core/range';
import { ModelDecorationOptions } from 'vs/editor/common/model/textModel';
import { DocumentColorProvider, Hover as MarkdownHover, HoverProviderRegistry, IColor, TokenizationRegistry, CodeActionTriggerType } from 'vs/editor/common/modes';
import { getColorPresentations } from 'vs/editor/contrib/colorPicker/color';
import { ColorDetector } from 'vs/editor/contrib/colorPicker/colorDetector';
import { ColorPickerModel } from 'vs/editor/contrib/colorPicker/colorPickerModel';
import { ColorPickerWidget } from 'vs/editor/contrib/colorPicker/colorPickerWidget';
import { getHover } from 'vs/editor/contrib/hover/getHover';
import { HoverOperation, HoverStartMode, IHoverComputer } from 'vs/editor/contrib/hover/hoverOperation';
import { ContentHoverWidget } from 'vs/editor/contrib/hover/hoverWidgets';
import { MarkdownRenderer } from 'vs/editor/contrib/markdown/markdownRenderer';
import { IThemeService, registerThemingParticipant } from 'vs/platform/theme/common/themeService';
import { coalesce, isNonEmptyArray, asArray } from 'vs/base/common/arrays';
import { IMarker, IMarkerData, MarkerSeverity } from 'vs/platform/markers/common/markers';
import { basename } from 'vs/base/common/resources';
import { IMarkerDecorationsService } from 'vs/editor/common/services/markersDecorationService';
import { onUnexpectedError } from 'vs/base/common/errors';
import { IOpenerService, NullOpenerService } from 'vs/platform/opener/common/opener';
import { MarkerController, NextMarkerAction } from 'vs/editor/contrib/gotoError/gotoError';
import { IKeybindingService } from 'vs/platform/keybinding/common/keybinding';
import { CancelablePromise, createCancelablePromise } from 'vs/base/common/async';
import { getCodeActions, CodeActionSet } from 'vs/editor/contrib/codeAction/codeAction';
import { QuickFixAction, QuickFixController } from 'vs/editor/contrib/codeAction/codeActionCommands';
import { CodeActionKind, CodeActionTrigger } from 'vs/editor/contrib/codeAction/types';
import { IModeService } from 'vs/editor/common/services/modeService';
import { IIdentifiedSingleEditOperation } from 'vs/editor/common/model';
import { EditorOption } from 'vs/editor/common/config/editorOptions';
import { Constants } from 'vs/base/common/uint';
import { textLinkForeground } from 'vs/platform/theme/common/colorRegistry';
import { Progress } from 'vs/platform/progress/common/progress';
import { IContextKey } from 'vs/platform/contextkey/common/contextkey';

const $ = dom.$;

class ColorHover {

	constructor(
		public readonly range: IRange,
		public readonly color: IColor,
		public readonly provider: DocumentColorProvider
	) { }
}

class MarkerHover {

	constructor(
		public readonly range: IRange,
		public readonly marker: IMarker,
	) { }
}

type HoverPart = MarkdownHover | ColorHover | MarkerHover;

class ModesContentComputer implements IHoverComputer<HoverPart[]> {

	private readonly _editor: ICodeEditor;
	private _result: HoverPart[];
	private _range?: Range;

	constructor(
		editor: ICodeEditor,
		private readonly _markerDecorationsService: IMarkerDecorationsService
	) {
		this._editor = editor;
		this._result = [];
	}

	setRange(range: Range): void {
		this._range = range;
		this._result = [];
	}

	clearResult(): void {
		this._result = [];
	}

	computeAsync(token: CancellationToken): Promise<HoverPart[]> {
		if (!this._editor.hasModel() || !this._range) {
			return Promise.resolve([]);
		}

		const model = this._editor.getModel();

		if (!HoverProviderRegistry.has(model)) {
			return Promise.resolve([]);
		}

		return getHover(model, new Position(
			this._range.startLineNumber,
			this._range.startColumn
		), token);
	}

	computeSync(): HoverPart[] {
		if (!this._editor.hasModel() || !this._range) {
			return [];
		}

		const model = this._editor.getModel();
		const lineNumber = this._range.startLineNumber;

		if (lineNumber > this._editor.getModel().getLineCount()) {
			// Illegal line number => no results
			return [];
		}

		const colorDetector = ColorDetector.get(this._editor);
		const maxColumn = model.getLineMaxColumn(lineNumber);
		const lineDecorations = this._editor.getLineDecorations(lineNumber);
		let didFindColor = false;

		const hoverRange = this._range;
		const result = lineDecorations.map((d): HoverPart | null => {
			const startColumn = (d.range.startLineNumber === lineNumber) ? d.range.startColumn : 1;
			const endColumn = (d.range.endLineNumber === lineNumber) ? d.range.endColumn : maxColumn;

			if (startColumn > hoverRange.startColumn || hoverRange.endColumn > endColumn) {
				return null;
			}

			const range = new Range(hoverRange.startLineNumber, startColumn, hoverRange.startLineNumber, endColumn);
			const marker = this._markerDecorationsService.getMarker(model, d);
			if (marker) {
				return new MarkerHover(range, marker);
			}

			const colorData = colorDetector.getColorData(d.range.getStartPosition());

			if (!didFindColor && colorData) {
				didFindColor = true;

				const { color, range } = colorData.colorInfo;
				return new ColorHover(range, color, colorData.provider);
			} else {
				if (isEmptyMarkdownString(d.options.hoverMessage)) {
					return null;
				}

				const contents: IMarkdownString[] = d.options.hoverMessage ? asArray(d.options.hoverMessage) : [];
				return { contents, range };
			}
		});

		return coalesce(result);
	}

	onResult(result: HoverPart[], isFromSynchronousComputation: boolean): void {
		// Always put synchronous messages before asynchronous ones
		if (isFromSynchronousComputation) {
			this._result = result.concat(this._result.sort((a, b) => {
				if (a instanceof ColorHover) { // sort picker messages at to the top
					return -1;
				} else if (b instanceof ColorHover) {
					return 1;
				}
				return 0;
			}));
		} else {
			this._result = this._result.concat(result);
		}
	}

	getResult(): HoverPart[] {
		return this._result.slice(0);
	}

	getResultWithLoadingMessage(): HoverPart[] {
		return this._result.slice(0).concat([this._getLoadingMessage()]);
	}

	private _getLoadingMessage(): HoverPart {
		return {
			range: this._range,
			contents: [new MarkdownString().appendText(nls.localize('modesContentHover.loading', "Loading..."))]
		};
	}
}

const markerCodeActionTrigger: CodeActionTrigger = {
	type: CodeActionTriggerType.Manual,
	filter: { include: CodeActionKind.QuickFix }
};

export class ModesContentHoverWidget extends ContentHoverWidget {

	static readonly ID = 'editor.contrib.modesContentHoverWidget';

	private _messages: HoverPart[];
	private _lastRange: Range | null;
	private readonly _computer: ModesContentComputer;
	private readonly _hoverOperation: HoverOperation<HoverPart[]>;
	private _highlightDecorations: string[];
	private _isChangingDecorations: boolean;
	private _shouldFocus: boolean;
	private _colorPicker: ColorPickerWidget | null;

	private _codeLink?: HTMLElement;

	private readonly renderDisposable = this._register(new MutableDisposable<IDisposable>());

	constructor(
		editor: ICodeEditor,
		_hoverVisibleKey: IContextKey<boolean>,
		markerDecorationsService: IMarkerDecorationsService,
		keybindingService: IKeybindingService,
		private readonly _themeService: IThemeService,
		private readonly _modeService: IModeService,
		private readonly _openerService: IOpenerService = NullOpenerService,
	) {
		super(ModesContentHoverWidget.ID, editor, _hoverVisibleKey, keybindingService);

		this._messages = [];
		this._lastRange = null;
		this._computer = new ModesContentComputer(this._editor, markerDecorationsService);
		this._highlightDecorations = [];
		this._isChangingDecorations = false;
		this._shouldFocus = false;
		this._colorPicker = null;

		this._hoverOperation = new HoverOperation(
			this._computer,
			result => this._withResult(result, true),
			null,
			result => this._withResult(result, false),
			this._editor.getOption(EditorOption.hover).delay
		);

		this._register(dom.addStandardDisposableListener(this.getDomNode(), dom.EventType.FOCUS, () => {
			if (this._colorPicker) {
				dom.addClass(this.getDomNode(), 'colorpicker-hover');
			}
		}));
		this._register(dom.addStandardDisposableListener(this.getDomNode(), dom.EventType.BLUR, () => {
			dom.removeClass(this.getDomNode(), 'colorpicker-hover');
		}));
		this._register(editor.onDidChangeConfiguration((e) => {
			this._hoverOperation.setHoverTime(this._editor.getOption(EditorOption.hover).delay);
		}));
		this._register(TokenizationRegistry.onDidChange((e) => {
			if (this.isVisible && this._lastRange && this._messages.length > 0) {
				this._hover.contentsDomNode.textContent = '';
				this._renderMessages(this._lastRange, this._messages);
			}
		}));
	}

	dispose(): void {
		this._hoverOperation.cancel();
		super.dispose();
	}

	onModelDecorationsChanged(): void {
		if (this._isChangingDecorations) {
			return;
		}
		if (this.isVisible) {
			// The decorations have changed and the hover is visible,
			// we need to recompute the displayed text
			this._hoverOperation.cancel();
			this._computer.clearResult();

			if (!this._colorPicker) { // TODO@Michel ensure that displayed text for other decorations is computed even if color picker is in place
				this._hoverOperation.start(HoverStartMode.Delayed);
			}
		}
	}

	startShowingAt(range: Range, mode: HoverStartMode, focus: boolean): void {
		if (this._lastRange && this._lastRange.equalsRange(range)) {
			// We have to show the widget at the exact same range as before, so no work is needed
			return;
		}

		this._hoverOperation.cancel();

		if (this.isVisible) {
			// The range might have changed, but the hover is visible
			// Instead of hiding it completely, filter out messages that are still in the new range and
			// kick off a new computation
			if (!this._showAtPosition || this._showAtPosition.lineNumber !== range.startLineNumber) {
				this.hide();
			} else {
				let filteredMessages: HoverPart[] = [];
				for (let i = 0, len = this._messages.length; i < len; i++) {
					const msg = this._messages[i];
					const rng = msg.range;
					if (rng && rng.startColumn <= range.startColumn && rng.endColumn >= range.endColumn) {
						filteredMessages.push(msg);
					}
				}
				if (filteredMessages.length > 0) {
					if (hoverContentsEquals(filteredMessages, this._messages)) {
						return;
					}
					this._renderMessages(range, filteredMessages);
				} else {
					this.hide();
				}
			}
		}

		this._lastRange = range;
		this._computer.setRange(range);
		this._shouldFocus = focus;
		this._hoverOperation.start(mode);
	}

	hide(): void {
		this._lastRange = null;
		this._hoverOperation.cancel();
		super.hide();
		this._isChangingDecorations = true;
		this._highlightDecorations = this._editor.deltaDecorations(this._highlightDecorations, []);
		this._isChangingDecorations = false;
		this.renderDisposable.clear();
		this._colorPicker = null;
	}

	isColorPickerVisible(): boolean {
		if (this._colorPicker) {
			return true;
		}
		return false;
	}

	private _withResult(result: HoverPart[], complete: boolean): void {
		this._messages = result;

		if (this._lastRange && this._messages.length > 0) {
			this._renderMessages(this._lastRange, this._messages);
		} else if (complete) {
			this.hide();
		}
	}

	private _renderMessages(renderRange: Range, messages: HoverPart[]): void {
		this.renderDisposable.dispose();
		this._colorPicker = null;

		// update column from which to show
		let renderColumn = Constants.MAX_SAFE_SMALL_INTEGER;
		let highlightRange: Range | null = messages[0].range ? Range.lift(messages[0].range) : null;
		let fragment = document.createDocumentFragment();
		let isEmptyHoverContent = true;

		let containColorPicker = false;
		const markdownDisposeables = new DisposableStore();
		const markerMessages: MarkerHover[] = [];
		messages.forEach((msg) => {
			if (!msg.range) {
				return;
			}

			renderColumn = Math.min(renderColumn, msg.range.startColumn);
			highlightRange = highlightRange ? Range.plusRange(highlightRange, msg.range) : Range.lift(msg.range);

			if (msg instanceof ColorHover) {
				containColorPicker = true;

				const { red, green, blue, alpha } = msg.color;
				const rgba = new RGBA(Math.round(red * 255), Math.round(green * 255), Math.round(blue * 255), alpha);
				const color = new Color(rgba);

				if (!this._editor.hasModel()) {
					return;
				}

				const editorModel = this._editor.getModel();
				let range = new Range(msg.range.startLineNumber, msg.range.startColumn, msg.range.endLineNumber, msg.range.endColumn);
				let colorInfo = { range: msg.range, color: msg.color };

				// create blank olor picker model and widget first to ensure it's positioned correctly.
				const model = new ColorPickerModel(color, [], 0);
				const widget = new ColorPickerWidget(fragment, model, this._editor.getOption(EditorOption.pixelRatio), this._themeService);

				getColorPresentations(editorModel, colorInfo, msg.provider, CancellationToken.None).then(colorPresentations => {
					model.colorPresentations = colorPresentations || [];
					if (!this._editor.hasModel()) {
						// gone...
						return;
					}
					const originalText = this._editor.getModel().getValueInRange(msg.range);
					model.guessColorPresentation(color, originalText);

					const updateEditorModel = () => {
						let textEdits: IIdentifiedSingleEditOperation[];
						let newRange: Range;
						if (model.presentation.textEdit) {
							textEdits = [model.presentation.textEdit as IIdentifiedSingleEditOperation];
							newRange = new Range(
								model.presentation.textEdit.range.startLineNumber,
								model.presentation.textEdit.range.startColumn,
								model.presentation.textEdit.range.endLineNumber,
								model.presentation.textEdit.range.endColumn
							);
							newRange = newRange.setEndPosition(newRange.endLineNumber, newRange.startColumn + model.presentation.textEdit.text.length);
						} else {
							textEdits = [{ identifier: null, range, text: model.presentation.label, forceMoveMarkers: false }];
							newRange = range.setEndPosition(range.endLineNumber, range.startColumn + model.presentation.label.length);
						}

						this._editor.pushUndoStop();
						this._editor.executeEdits('colorpicker', textEdits);

						if (model.presentation.additionalTextEdits) {
							textEdits = [...model.presentation.additionalTextEdits as IIdentifiedSingleEditOperation[]];
							this._editor.executeEdits('colorpicker', textEdits);
							this.hide();
						}
						this._editor.pushUndoStop();
						range = newRange;
					};

					const updateColorPresentations = (color: Color) => {
						return getColorPresentations(editorModel, {
							range: range,
							color: {
								red: color.rgba.r / 255,
								green: color.rgba.g / 255,
								blue: color.rgba.b / 255,
								alpha: color.rgba.a
							}
						}, msg.provider, CancellationToken.None).then((colorPresentations) => {
							model.colorPresentations = colorPresentations || [];
						});
					};

					const colorListener = model.onColorFlushed((color: Color) => {
						updateColorPresentations(color).then(updateEditorModel);
					});
					const colorChangeListener = model.onDidChangeColor(updateColorPresentations);

					this._colorPicker = widget;
					this.showAt(range.getStartPosition(), range, this._shouldFocus);
					this.updateContents(fragment);
					this._colorPicker.layout();

					this.renderDisposable.value = combinedDisposable(colorListener, colorChangeListener, widget, markdownDisposeables);
				});
			} else {
				if (msg instanceof MarkerHover) {
					markerMessages.push(msg);
					isEmptyHoverContent = false;
				} else {
					msg.contents
						.filter(contents => !isEmptyMarkdownString(contents))
						.forEach(contents => {
							const markdownHoverElement = $('div.hover-row.markdown-hover');
							const hoverContentsElement = dom.append(markdownHoverElement, $('div.hover-contents'));
							const renderer = markdownDisposeables.add(new MarkdownRenderer(this._editor, this._modeService, this._openerService));
							markdownDisposeables.add(renderer.onDidRenderCodeBlock(() => {
								hoverContentsElement.className = 'hover-contents code-hover-contents';
								this._hover.onContentsChanged();
							}));
							const renderedContents = markdownDisposeables.add(renderer.render(contents));
							hoverContentsElement.appendChild(renderedContents.element);
							fragment.appendChild(markdownHoverElement);
							isEmptyHoverContent = false;
						});
				}
			}
		});

		if (markerMessages.length) {
			markerMessages.forEach(msg => fragment.appendChild(this.renderMarkerHover(msg)));
			const markerHoverForStatusbar = markerMessages.length === 1 ? markerMessages[0] : markerMessages.sort((a, b) => MarkerSeverity.compare(a.marker.severity, b.marker.severity))[0];
			fragment.appendChild(this.renderMarkerStatusbar(markerHoverForStatusbar));
		}

		// show

		if (!containColorPicker && !isEmptyHoverContent) {
			this.showAt(new Position(renderRange.startLineNumber, renderColumn), highlightRange, this._shouldFocus);
			this.updateContents(fragment);
		}

		this._isChangingDecorations = true;
		this._highlightDecorations = this._editor.deltaDecorations(this._highlightDecorations, highlightRange ? [{
			range: highlightRange,
			options: ModesContentHoverWidget._DECORATION_OPTIONS
		}] : []);
		this._isChangingDecorations = false;
	}

	private renderMarkerHover(markerHover: MarkerHover): HTMLElement {
		const hoverElement = $('div.hover-row');
		const markerElement = dom.append(hoverElement, $('div.marker.hover-contents'));
		const { source, message, code, relatedInformation } = markerHover.marker;

		this._editor.applyFontInfo(markerElement);
		const messageElement = dom.append(markerElement, $('span'));
		messageElement.style.whiteSpace = 'pre-wrap';
		messageElement.innerText = message;

		if (source || code) {
			// Code has link
			if (code && typeof code !== 'string') {
				const sourceAndCodeElement = $('span');
				if (source) {
					const sourceElement = dom.append(sourceAndCodeElement, $('span'));
					sourceElement.innerText = source;
				}
				this._codeLink = dom.append(sourceAndCodeElement, $('a.code-link'));
				this._codeLink.setAttribute('href', code.target.toString());

				this._codeLink.onclick = (e) => {
					this._openerService.open(code.target);
					e.preventDefault();
					e.stopPropagation();
				};

				const codeElement = dom.append(this._codeLink, $('span'));
				codeElement.innerText = code.value;

				const detailsElement = dom.append(markerElement, sourceAndCodeElement);
				detailsElement.style.opacity = '0.6';
				detailsElement.style.paddingLeft = '6px';
			} else {
				const detailsElement = dom.append(markerElement, $('span'));
				detailsElement.style.opacity = '0.6';
				detailsElement.style.paddingLeft = '6px';
				detailsElement.innerText = source && code ? `${source}(${code})` : source ? source : `(${code})`;
			}
		}

		if (isNonEmptyArray(relatedInformation)) {
			for (const { message, resource, startLineNumber, startColumn } of relatedInformation) {
				const relatedInfoContainer = dom.append(markerElement, $('div'));
				relatedInfoContainer.style.marginTop = '8px';
				const a = dom.append(relatedInfoContainer, $('a'));
				a.innerText = `${basename(resource)}(${startLineNumber}, ${startColumn}): `;
				a.style.cursor = 'pointer';
				a.onclick = e => {
					e.stopPropagation();
					e.preventDefault();
					if (this._openerService) {
						this._openerService.open(resource.with({ fragment: `${startLineNumber},${startColumn}` }), { fromUserGesture: true }).catch(onUnexpectedError);
					}
				};
				const messageElement = dom.append<HTMLAnchorElement>(relatedInfoContainer, $('span'));
				messageElement.innerText = message;
				this._editor.applyFontInfo(messageElement);
			}
		}

		return hoverElement;
	}

	private renderMarkerStatusbar(markerHover: MarkerHover): HTMLElement {
		const hoverElement = $('div.hover-row.status-bar');
		const disposables = new DisposableStore();
		const actionsElement = dom.append(hoverElement, $('div.actions'));
		if (markerHover.marker.severity === MarkerSeverity.Error || markerHover.marker.severity === MarkerSeverity.Warning || markerHover.marker.severity === MarkerSeverity.Info) {
			disposables.add(this._renderAction(actionsElement, {
				label: nls.localize('peek problem', "Peek Problem"),
				commandId: NextMarkerAction.ID,
				run: () => {
					this.hide();
					MarkerController.get(this._editor).showAtMarker(markerHover.marker);
					this._editor.focus();
				}
			}));
		}

		const quickfixPlaceholderElement = dom.append(actionsElement, $('div'));
		quickfixPlaceholderElement.style.opacity = '0';
		quickfixPlaceholderElement.style.transition = 'opacity 0.2s';
		setTimeout(() => quickfixPlaceholderElement.style.opacity = '1', 200);
		quickfixPlaceholderElement.textContent = nls.localize('checkingForQuickFixes', "Checking for quick fixes...");
		disposables.add(toDisposable(() => quickfixPlaceholderElement.remove()));

		const codeActionsPromise = this.getCodeActions(markerHover.marker);
		disposables.add(toDisposable(() => codeActionsPromise.cancel()));
		codeActionsPromise.then(actions => {
			quickfixPlaceholderElement.style.transition = '';
			quickfixPlaceholderElement.style.opacity = '1';

			if (!actions.validActions.length) {
				actions.dispose();
				quickfixPlaceholderElement.textContent = nls.localize('noQuickFixes', "No quick fixes available");
				return;
			}
			quickfixPlaceholderElement.remove();

			let showing = false;
			disposables.add(toDisposable(() => {
				if (!showing) {
					actions.dispose();
				}
			}));

			disposables.add(this._renderAction(actionsElement, {
				label: nls.localize('quick fixes', "Quick Fix..."),
				commandId: QuickFixAction.Id,
				run: (target) => {
					showing = true;
					const controller = QuickFixController.get(this._editor);
					const elementPosition = dom.getDomNodePagePosition(target);
					// Hide the hover pre-emptively, otherwise the editor can close the code actions
					// context menu as well when using keyboard navigation
					this.hide();
					controller.showCodeActions(markerCodeActionTrigger, actions, {
						x: elementPosition.left + 6,
						y: elementPosition.top + elementPosition.height + 6
					});
				}
			}));
		});

		this.renderDisposable.value = disposables;
		return hoverElement;
	}

	private getCodeActions(marker: IMarker): CancelablePromise<CodeActionSet> {
		return createCancelablePromise(cancellationToken => {
			return getCodeActions(
				this._editor.getModel()!,
				new Range(marker.startLineNumber, marker.startColumn, marker.endLineNumber, marker.endColumn),
				markerCodeActionTrigger,
				Progress.None,
				cancellationToken);
		});
	}

	private static readonly _DECORATION_OPTIONS = ModelDecorationOptions.register({
		className: 'hoverHighlight'
	});
}

function hoverContentsEquals(first: HoverPart[], second: HoverPart[]): boolean {
	if ((!first && second) || (first && !second) || first.length !== second.length) {
		return false;
	}
	for (let i = 0; i < first.length; i++) {
		const firstElement = first[i];
		const secondElement = second[i];
		if (firstElement instanceof MarkerHover && secondElement instanceof MarkerHover) {
			return IMarkerData.makeKey(firstElement.marker) === IMarkerData.makeKey(secondElement.marker);
		}
		if (firstElement instanceof ColorHover || secondElement instanceof ColorHover) {
			return false;
		}
		if (firstElement instanceof MarkerHover || secondElement instanceof MarkerHover) {
			return false;
		}
		if (!markedStringsEquals(firstElement.contents, secondElement.contents)) {
			return false;
		}
	}
	return true;
}

registerThemingParticipant((theme, collector) => {
	const linkFg = theme.getColor(textLinkForeground);
	if (linkFg) {
		collector.addRule(`.monaco-hover .hover-contents a.code-link span:hover { color: ${linkFg}; }`);
	}
});
