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

import { IWorkbenchContribution } from 'vs/workbench/common/contributions';
import { IExtensionService, IResponsiveStateChangeEvent, IExtensionHostProfile, ProfileSession, ExtensionHostKind } from 'vs/workbench/services/extensions/common/extensions';
import { ITelemetryService } from 'vs/platform/telemetry/common/telemetry';
import { Disposable } from 'vs/base/common/lifecycle';
import { ILogService } from 'vs/platform/log/common/log';
import { CancellationTokenSource } from 'vs/base/common/cancellation';
import { onUnexpectedError } from 'vs/base/common/errors';
import { joinPath } from 'vs/base/common/resources';
import { IExtensionHostProfileService } from 'vs/workbench/contrib/extensions/electron-sandbox/runtimeExtensionsEditor';
import { INotificationService, Severity } from 'vs/platform/notification/common/notification';
import { localize } from 'vs/nls';
import { IEditorService } from 'vs/workbench/services/editor/common/editorService';
import { RuntimeExtensionsInput } from 'vs/workbench/contrib/extensions/common/runtimeExtensionsInput';
import { ExtensionIdentifier } from 'vs/platform/extensions/common/extensions';
import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
import { createSlowExtensionAction } from 'vs/workbench/contrib/extensions/electron-sandbox/extensionsSlowActions';
import { ExtensionHostProfiler } from 'vs/workbench/services/extensions/electron-sandbox/extensionHostProfiler';
import { INativeWorkbenchEnvironmentService } from 'vs/workbench/services/environment/electron-sandbox/environmentService';
import { IFileService } from 'vs/platform/files/common/files';
import { VSBuffer } from 'vs/base/common/buffer';
import { timeout } from 'vs/base/common/async';

export class ExtensionsAutoProfiler extends Disposable implements IWorkbenchContribution {

	private readonly _blame = new Set<string>();
	private _session: CancellationTokenSource | undefined;

	constructor(
		@IExtensionService private readonly _extensionService: IExtensionService,
		@IExtensionHostProfileService private readonly _extensionProfileService: IExtensionHostProfileService,
		@ITelemetryService private readonly _telemetryService: ITelemetryService,
		@ILogService private readonly _logService: ILogService,
		@INotificationService private readonly _notificationService: INotificationService,
		@IEditorService private readonly _editorService: IEditorService,
		@IInstantiationService private readonly _instantiationService: IInstantiationService,
		@INativeWorkbenchEnvironmentService private readonly _environmentServie: INativeWorkbenchEnvironmentService,
		@IFileService private readonly _fileService: IFileService
	) {
		super();
		this._register(_extensionService.onDidChangeResponsiveChange(this._onDidChangeResponsiveChange, this));
	}

	private async _onDidChangeResponsiveChange(event: IResponsiveStateChangeEvent): Promise<void> {
		if (event.extensionHostKind !== ExtensionHostKind.LocalProcess) {
			return;
		}

		const port = await this._extensionService.getInspectPort(event.extensionHostId, true);

		if (!port) {
			return;
		}

		if (event.isResponsive && this._session) {
			// stop profiling when responsive again
			this._session.cancel();
			this._logService.info('UNRESPONSIVE extension host: received responsive event and cancelling profiling session');


		} else if (!event.isResponsive && !this._session) {
			// start profiling if not yet profiling
			const cts = new CancellationTokenSource();
			this._session = cts;


			let session: ProfileSession;
			try {
				session = await this._instantiationService.createInstance(ExtensionHostProfiler, port).start();

			} catch (err) {
				this._session = undefined;
				// fail silent as this is often
				// caused by another party being
				// connected already
				return;
			}
			this._logService.info('UNRESPONSIVE extension host: starting to profile NOW');

			// wait 5 seconds or until responsive again
			try {
				await timeout(5e3, cts.token);
			} catch {
				// can throw cancellation error. that is
				// OK, we stop profiling and analyse the
				// profile anyways
			}

			try {
				// stop profiling and analyse results
				this._processCpuProfile(await session.stop());
			} catch (err) {
				onUnexpectedError(err);
			} finally {
				this._session = undefined;
			}
		}
	}

	private async _processCpuProfile(profile: IExtensionHostProfile) {

		interface NamedSlice {
			id: string;
			total: number;
			percentage: number;
		}

		let data: NamedSlice[] = [];
		for (let i = 0; i < profile.ids.length; i++) {
			const id = profile.ids[i];
			const total = profile.deltas[i];
			data.push({ id, total, percentage: 0 });
		}

		// merge data by identifier
		let anchor = 0;
		data.sort((a, b) => a.id.localeCompare(b.id));
		for (let i = 1; i < data.length; i++) {
			if (data[anchor].id === data[i].id) {
				data[anchor].total += data[i].total;
			} else {
				anchor += 1;
				data[anchor] = data[i];
			}
		}
		data = data.slice(0, anchor + 1);

		const duration = profile.endTime - profile.startTime;
		const percentage = duration / 100;
		let top: NamedSlice | undefined;
		for (const slice of data) {
			slice.percentage = Math.round(slice.total / percentage);
			if (!top || top.percentage < slice.percentage) {
				top = slice;
			}
		}

		if (!top) {
			return;
		}

		const extension = await this._extensionService.getExtension(top.id);
		if (!extension) {
			// not an extension => idle, gc, self?
			return;
		}


		// print message to log
		const path = joinPath(this._environmentServie.tmpDir, `exthost-${Math.random().toString(16).slice(2, 8)}.cpuprofile`);
		await this._fileService.writeFile(path, VSBuffer.fromString(JSON.stringify(profile.data)));
		this._logService.warn(`UNRESPONSIVE extension host: '${top.id}' took ${top.percentage}% of ${duration / 1e3}ms, saved PROFILE here: '${path}'`, data);

		type UnresponsiveData = {
			duration: number;
			data: NamedSlice[];
		};
		type UnresponsiveDataClassification = {
			owner: 'jrieken';
			comment: 'Profiling data that was collected while the extension host was unresponsive';
			duration: { classification: 'SystemMetaData'; purpose: 'PerformanceAndHealth'; isMeasurement: true; comment: 'Duration for which the extension host was unresponsive' };
			data: { classification: 'SystemMetaData'; purpose: 'PerformanceAndHealth'; comment: 'Extensions ids and core parts that were active while the extension host was froozen' };
		};
		this._telemetryService.publicLog2<UnresponsiveData, UnresponsiveDataClassification>('exthostunresponsive', {
			duration,
			data,
		});

		// add to running extensions view
		this._extensionProfileService.setUnresponsiveProfile(extension.identifier, profile);

		// prompt: when really slow/greedy
		if (!(top.percentage >= 99 && top.total >= 5e6)) {
			return;
		}

		const action = await this._instantiationService.invokeFunction(createSlowExtensionAction, extension, profile);

		if (!action) {
			// cannot report issues against this extension...
			return;
		}

		// only blame once per extension, don't blame too often
		if (this._blame.has(ExtensionIdentifier.toKey(extension.identifier)) || this._blame.size >= 3) {
			return;
		}
		this._blame.add(ExtensionIdentifier.toKey(extension.identifier));

		// user-facing message when very bad...
		this._notificationService.prompt(
			Severity.Warning,
			localize(
				'unresponsive-exthost',
				"The extension '{0}' took a very long time to complete its last operation and it has prevented other extensions from running.",
				extension.displayName || extension.name
			),
			[{
				label: localize('show', 'Show Extensions'),
				run: () => this._editorService.openEditor(RuntimeExtensionsInput.instance, { pinned: true })
			},
				action
			],
			{ silent: true }
		);
	}
}