/* eslint-disable @typescript-eslint/no-unused-vars */
/* eslint-disable no-prototype-builtins */
/*---------------------------------------------------------
 * Copyright (C) Microsoft Corporation. All rights reserved.
 * Licensed under the MIT License. See LICENSE in the project root for license information.
 *--------------------------------------------------------*/

'use strict';

import path = require('path');
import vscode = require('vscode');
import { getGoConfig } from './config';
import { parseProgramArgSync } from './goDebugFactory';
import { toolExecutionEnvironment } from './goEnv';
import {
	declinedToolInstall,
	installTools,
	promptForMissingTool,
	promptForUpdatingTool,
	shouldUpdateTool
} from './goInstallTools';
import { packagePathToGoModPathMap } from './goModules';
import { getTool, getToolAtVersion } from './goTools';
import { pickGoProcess, pickProcess, pickProcessByName } from './pickProcess';
import { getFromGlobalState, updateGlobalState } from './stateUtils';
import { getBinPath, getGoVersion } from './util';
import { parseEnvFiles } from './utils/envUtils';
import { resolveHomeDir } from './utils/pathUtils';

let dlvDAPVersionCurrent = false;

export class GoDebugConfigurationProvider implements vscode.DebugConfigurationProvider {
	constructor(private defaultDebugAdapterType: string = 'go') {}

	public async provideDebugConfigurations(
		folder: vscode.WorkspaceFolder | undefined,
		token?: vscode.CancellationToken
	): Promise<vscode.DebugConfiguration[] | undefined> {
		return await this.pickConfiguration();
	}

	public async pickConfiguration(): Promise<vscode.DebugConfiguration[]> {
		const debugConfigurations = [
			{
				label: 'Go: Launch Package',
				description: 'Debug/test the package of the open file',
				config: {
					name: 'Launch Package',
					type: this.defaultDebugAdapterType,
					request: 'launch',
					mode: 'auto',
					program: '${fileDirname}'
				}
			},
			{
				label: 'Go: Attach to local process',
				description: 'Attach to an existing process by process ID',
				config: {
					name: 'Attach to Process',
					type: 'go',
					request: 'attach',
					mode: 'local',
					processId: 0
				}
			},
			{
				label: 'Go: Connect to server',
				description: 'Connect to a remote headless debug server',
				config: {
					name: 'Connect to server',
					type: 'go',
					request: 'attach',
					mode: 'remote',
					remotePath: '${workspaceFolder}',
					port: 2345,
					host: '127.0.0.1'
				},
				fill: async (config: vscode.DebugConfiguration) => {
					const host = await vscode.window.showInputBox({
						prompt: 'Enter hostname',
						value: '127.0.0.1'
					});
					if (host) {
						config.host = host;
					}
					const port = Number(
						await vscode.window.showInputBox({
							prompt: 'Enter port',
							value: '2345',
							validateInput: (value: string) => {
								if (isNaN(Number(value))) {
									return 'Please enter a number.';
								}
								return '';
							}
						})
					);
					if (port) {
						config.port = port;
					}
				}
			}
		];

		const choice = await vscode.window.showQuickPick(debugConfigurations, {
			placeHolder: 'Choose debug configuration'
		});
		if (!choice) {
			return [];
		}

		if (choice.fill) {
			await choice.fill(choice.config);
		}
		return [choice.config];
	}

	public async resolveDebugConfiguration(
		folder: vscode.WorkspaceFolder | undefined,
		debugConfiguration: vscode.DebugConfiguration,
		token?: vscode.CancellationToken
	): Promise<vscode.DebugConfiguration> {
		const activeEditor = vscode.window.activeTextEditor;
		if (!debugConfiguration || !debugConfiguration.request) {
			// if 'request' is missing interpret this as a missing launch.json
			if (!activeEditor || activeEditor.document.languageId !== 'go') {
				return;
			}

			debugConfiguration = Object.assign(debugConfiguration || {}, {
				name: 'Launch',
				type: this.defaultDebugAdapterType,
				request: 'launch',
				mode: 'auto',
				program: path.dirname(activeEditor.document.fileName) // matches ${fileDirname}
			});
		}

		if (!debugConfiguration.type) {
			debugConfiguration['type'] = this.defaultDebugAdapterType;
		}

		debugConfiguration['packagePathToGoModPathMap'] = packagePathToGoModPathMap;

		const goConfig = getGoConfig(folder && folder.uri);
		const dlvConfig = goConfig['delveConfig'];

		// Figure out which debugAdapter is being used first, so we can use this to send warnings
		// for properties that don't apply.
		if (!debugConfiguration.hasOwnProperty('debugAdapter') && dlvConfig.hasOwnProperty('debugAdapter')) {
			const { globalValue, workspaceValue } = goConfig.inspect('delveConfig.debugAdapter');
			// user configured the default debug adapter through settings.json.
			if (globalValue !== undefined || workspaceValue !== undefined) {
				debugConfiguration['debugAdapter'] = dlvConfig['debugAdapter'];
			}
		}
		if (!debugConfiguration['debugAdapter']) {
			// for local mode, default to dlv-dap.
			debugConfiguration['debugAdapter'] = debugConfiguration['mode'] !== 'remote' ? 'dlv-dap' : 'legacy';
		}
		if (debugConfiguration['debugAdapter'] === 'dlv-dap' && debugConfiguration['port']) {
			this.showWarning(
				'ignorePortInDlvDapWarning',
				"`port` is ignored with the 'dlv-dap' debugAdapter, which does not yet support remote debugging. Please file an issue if you have a use case that requires port."
			);
		}
		if (debugConfiguration['debugAdapter'] === 'dlv-dap' && debugConfiguration['mode'] === 'remote') {
			this.showWarning(
				'ignoreDlvDAPInRemoteModeWarning',
				"debugAdapter type of 'dlv-dap' with mode 'remote' is unsupported. Fall back to the 'legacy' debugAdapter for 'remote' mode."
			);
			debugConfiguration['debugAdapter'] = 'legacy';
		}

		const debugAdapter = debugConfiguration['debugAdapter'] === 'dlv-dap' ? 'dlv-dap' : 'dlv';

		let useApiV1 = false;
		if (debugConfiguration.hasOwnProperty('useApiV1')) {
			useApiV1 = debugConfiguration['useApiV1'] === true;
		} else if (dlvConfig.hasOwnProperty('useApiV1')) {
			useApiV1 = dlvConfig['useApiV1'] === true;
		}
		if (useApiV1) {
			debugConfiguration['apiVersion'] = 1;
		}
		if (!debugConfiguration.hasOwnProperty('apiVersion') && dlvConfig.hasOwnProperty('apiVersion')) {
			debugConfiguration['apiVersion'] = dlvConfig['apiVersion'];
		}
		if (
			debugAdapter === 'dlv-dap' &&
			(debugConfiguration.hasOwnProperty('dlvLoadConfig') ||
				goConfig.inspect('delveConfig.dlvLoadConfig').globalValue !== undefined ||
				goConfig.inspect('delveConfig.dlvLoadConfig').workspaceValue !== undefined)
		) {
			this.showWarning(
				'ignoreDebugDlvConfigWithDlvDapWarning',
				"'dlvLoadConfig' is deprecated with dlv-dap debug adapter.\n\nDlv-dap loads composite data on demand and uses increased string limits on source code hover, in Debug Console and via Copy Value. Please file an issue if these are not sufficient for your use case."
			);
		}
		if (!debugConfiguration.hasOwnProperty('dlvLoadConfig') && dlvConfig.hasOwnProperty('dlvLoadConfig')) {
			debugConfiguration['dlvLoadConfig'] = dlvConfig['dlvLoadConfig'];
		}
		if (
			!debugConfiguration.hasOwnProperty('showGlobalVariables') &&
			dlvConfig.hasOwnProperty('showGlobalVariables')
		) {
			debugConfiguration['showGlobalVariables'] = dlvConfig['showGlobalVariables'];
		}
		if (!debugConfiguration.hasOwnProperty('substitutePath') && dlvConfig.hasOwnProperty('substitutePath')) {
			debugConfiguration['substitutePath'] = dlvConfig['substitutePath'];
		}
		if (debugAdapter !== 'dlv-dap' && debugConfiguration.request === 'attach' && !debugConfiguration['cwd']) {
			debugConfiguration['cwd'] = '${workspaceFolder}';
			if (vscode.workspace.workspaceFolders?.length > 1) {
				debugConfiguration['cwd'] = '${fileWorkspaceFolder}';
			}
		}
		if (debugConfiguration['cwd']) {
			// expand 'cwd' folder path containing '~', which would cause dlv to fail
			debugConfiguration['cwd'] = resolveHomeDir(debugConfiguration['cwd']);
		}

		// Remove any '--gcflags' entries and show a warning
		if (debugConfiguration['buildFlags']) {
			const resp = this.removeGcflags(debugConfiguration['buildFlags']);
			if (resp.removed) {
				debugConfiguration['buildFlags'] = resp.args;
				this.showWarning(
					'ignoreDebugGCFlagsWarning',
					"User specified build flag '--gcflags' in 'buildFlags' is being ignored (see [debugging with build flags](https://github.com/golang/vscode-go/blob/master/docs/debugging.md#specifying-other-build-flags) documentation)"
				);
			}
		}
		if (debugConfiguration['env'] && debugConfiguration['env']['GOFLAGS']) {
			const resp = this.removeGcflags(debugConfiguration['env']['GOFLAGS']);
			if (resp.removed) {
				debugConfiguration['env']['GOFLAGS'] = resp.args;
				this.showWarning(
					'ignoreDebugGCFlagsWarning',
					"User specified build flag '--gcflags' in 'GOFLAGS' is being ignored (see [debugging with build flags](https://github.com/golang/vscode-go/blob/master/docs/debugging.md#specifying-other-build-flags) documentation)"
				);
			}
		}

		const dlvToolPath = getBinPath(debugAdapter);
		if (!path.isAbsolute(dlvToolPath)) {
			// If user has not already declined to install this tool,
			// prompt for it. Otherwise continue and have the lack of
			// dlv binary be caught later.
			if (!declinedToolInstall(debugAdapter)) {
				await promptForMissingTool(debugAdapter);
				return;
			}
		}
		debugConfiguration['dlvToolPath'] = dlvToolPath;

		if (debugAdapter === 'dlv-dap' && !dlvDAPVersionCurrent) {
			const tool = getToolAtVersion('dlv-dap');
			if (await shouldUpdateTool(tool, dlvToolPath)) {
				// If the user has opted in to automatic tool updates, we can update
				// without prompting.
				const toolsManagementConfig = getGoConfig()['toolsManagement'];
				if (toolsManagementConfig && toolsManagementConfig['autoUpdate'] === true) {
					const goVersion = await getGoVersion();
					const toolVersion = { ...tool, version: tool.latestVersion }; // ToolWithVersion
					await installTools([toolVersion], goVersion, true);
				} else {
					// If we are prompting the user to update, we do not want to continue
					// with this debug session.
					promptForUpdatingTool(tool.name);
					return;
				}
			}
			dlvDAPVersionCurrent = true;
		}

		if (debugConfiguration['mode'] === 'auto') {
			let filename = activeEditor?.document?.fileName;
			if (debugConfiguration['program'] && debugConfiguration['program'].endsWith('.go')) {
				// If the 'program' attribute is a file, not a directory, then we will determine the mode from that
				// file path instead of the currently active file.
				filename = debugConfiguration['program'];
			}
			debugConfiguration['mode'] = filename?.endsWith('_test.go') ? 'test' : 'debug';
		}

		if (debugConfiguration['mode'] === 'test' && debugConfiguration['program'].endsWith('_test.go')) {
			// Running a test file in file mode does not make sense, so change the program
			// to the directory.
			debugConfiguration['program'] = path.dirname(debugConfiguration['program']);
		}

		if (debugConfiguration.request === 'launch' && debugConfiguration['mode'] === 'remote') {
			this.showWarning(
				'ignoreDebugLaunchRemoteWarning',
				"Request type of 'launch' with mode 'remote' is deprecated, please use request type 'attach' with mode 'remote' instead."
			);
		}

		if (
			debugAdapter !== 'dlv-dap' &&
			debugConfiguration.request === 'attach' &&
			debugConfiguration['mode'] === 'remote' &&
			debugConfiguration['program']
		) {
			this.showWarning(
				'ignoreUsingRemotePathAndProgramWarning',
				"Request type of 'attach' with mode 'remote' does not work with 'program' attribute, please use 'cwd' attribute instead."
			);
		}

		if (debugConfiguration.request === 'attach' && debugConfiguration['mode'] === 'local') {
			if (!debugConfiguration['processId'] || debugConfiguration['processId'] === 0) {
				// The processId is not valid, offer a quickpick menu of all processes.
				debugConfiguration['processId'] = await pickProcess();
			} else if (
				typeof debugConfiguration['processId'] === 'string' &&
				debugConfiguration['processId'] !== '${command:pickProcess}' &&
				debugConfiguration['processId'] !== '${command:pickGoProcess}'
			) {
				debugConfiguration['processId'] = await pickProcessByName(debugConfiguration['processId']);
			}
		}
		return debugConfiguration;
	}

	public removeGcflags(args: string): { args: string; removed: boolean } {
		// From `go help build`
		// ...
		// -gcflags '[pattern=]arg list'
		// 	 arguments to pass on each go tool compile invocation.
		//
		// The -asmflags, -gccgoflags, -gcflags, and -ldflags flags accept a
		// space-separated list of arguments to pass to an underlying tool
		// during the build. To embed spaces in an element in the list, surround
		// it with either single or double quotes. The argument list may be
		// preceded by a package pattern and an equal sign, which restricts
		// the use of that argument list to the building of packages matching
		// that pattern (see 'go help packages' for a description of package
		// patterns). Without a pattern, the argument list applies only to the
		// packages named on the command line. The flags may be repeated
		// with different patterns in order to specify different arguments for
		// different sets of packages. If a package matches patterns given in
		// multiple flags, the latest match on the command line wins.
		// For example, 'go build -gcflags=-S fmt' prints the disassembly
		// only for package fmt, while 'go build -gcflags=all=-S fmt'
		// prints the disassembly for fmt and all its dependencies.

		// Regexp Explanation:
		// 	1. (^|\s): the flag is preceded by a white space or is at the start of the line.
		//  2. -gcflags: the name of the flag.
		//  3. (=| ): the name of the flag is followed by = or a space.
		//  4. ('[^']*'|"[^"]*"|[^'"\s]+)+: the value of the flag is a combination of nonwhitespace
		//       characters and quoted strings which may contain white space.
		const gcflagsRegexp = /(^|\s)(-gcflags)(=| )('[^']*'|"[^"]*"|[^'"\s]+)+/;
		let removed = false;
		while (args.search(gcflagsRegexp) >= 0) {
			args = args.replace(gcflagsRegexp, '');
			removed = true;
		}
		return { args, removed };
	}

	public resolveDebugConfigurationWithSubstitutedVariables(
		folder: vscode.WorkspaceFolder | undefined,
		debugConfiguration: vscode.DebugConfiguration,
		token?: vscode.CancellationToken
	): vscode.DebugConfiguration {
		// Reads debugConfiguration.envFile and
		// combines the environment variables from all the env files and
		// debugConfiguration.env, on top of the tools execution environment variables.
		// It also unsets 'envFile' from the user-suppled debugConfiguration
		// because it is already applied.
		const goToolsEnvVars = toolExecutionEnvironment(folder?.uri); // also includes GOPATH: getCurrentGoPath().
		const fileEnvs = parseEnvFiles(debugConfiguration['envFile']);
		const env = debugConfiguration['env'] || {};

		debugConfiguration['env'] = Object.assign(goToolsEnvVars, fileEnvs, env);
		debugConfiguration['envFile'] = undefined; // unset, since we already processed.

		const entriesWithRelativePaths = ['cwd', 'output', 'program'].filter(
			(attr) => debugConfiguration[attr] && !path.isAbsolute(debugConfiguration[attr])
		);
		if (debugConfiguration['debugAdapter'] === 'dlv-dap') {
			// relative paths -> absolute paths
			if (entriesWithRelativePaths.length > 0) {
				const workspaceRoot = folder?.uri.fsPath;
				if (workspaceRoot) {
					entriesWithRelativePaths.forEach((attr) => {
						debugConfiguration[attr] = path.join(workspaceRoot, debugConfiguration[attr]);
					});
				} else {
					this.showWarning(
						'relativePathsWithoutWorkspaceFolder',
						'Behavior when using relative paths without a workspace folder for `cwd`, `program`, or `output` is undefined.'
					);
				}
			}
			// compute build dir, and translate the dirname in program to a path relative to buildDir.
			if (debugConfiguration.request === 'launch') {
				const mode = debugConfiguration['mode'] || 'debug';
				if (['debug', 'test', 'auto'].includes(mode)) {
					// Massage config to build the target from the package directory
					// with a relative path. (https://github.com/golang/vscode-go/issues/1713)
					try {
						const { program, dirname, programIsDirectory } = parseProgramArgSync(debugConfiguration);
						if (dirname) {
							debugConfiguration['__buildDir'] = dirname;
							debugConfiguration['program'] = programIsDirectory
								? '.'
								: '.' + path.sep + path.relative(dirname, program);
						}
					} catch (e) {
						this.showWarning('invalidProgramArg', `Invalid 'program': ${e}`);
						// keep going - just in case dlv knows how to handle this better.
					}
				}
			}
		}
		if (debugConfiguration.request === 'attach' && debugConfiguration['mode'] === 'local') {
			// processId needs to be an int, but the substituted variables from pickGoProcess and pickProcess
			// become a string. Convert any strings to integers.
			if (typeof debugConfiguration['processId'] === 'string') {
				debugConfiguration['processId'] = parseInt(debugConfiguration['processId'], 10);
			}
		}
		return debugConfiguration;
	}

	private showWarning(ignoreWarningKey: string, warningMessage: string) {
		const ignoreWarning = getFromGlobalState(ignoreWarningKey);
		if (ignoreWarning) {
			return;
		}

		const neverAgain = { title: "Don't Show Again" };
		vscode.window.showWarningMessage(warningMessage, neverAgain).then((result) => {
			if (result === neverAgain) {
				updateGlobalState(ignoreWarningKey, true);
			}
		});
	}
}