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

import * as ts from 'typescript';
import { readFileSync, existsSync } from 'fs';
import { resolve, dirname, join } from 'path';
import { match } from 'minimatch';

//
// #############################################################################################
//
// A custom typescript checker for the specific task of detecting the use of certain types in a
// layer that does not allow such use. For example:
// - using DOM globals in common/node/electron-main layer (e.g. HTMLElement)
// - using node.js globals in common/browser layer (e.g. process)
//
// Make changes to below RULES to lift certain files from these checks only if absolutely needed
//
// #############################################################################################
//

// Types we assume are present in all implementations of JS VMs (node.js, browsers)
// Feel free to add more core types as you see needed if present in node.js and browsers
const CORE_TYPES = [
	'setTimeout',
	'clearTimeout',
	'setInterval',
	'clearInterval',
	'console',
	'Console',
	'Error',
	'ErrorConstructor',
	'String',
	'TextDecoder',
	'TextEncoder',
	'self',
	'queueMicrotask',
	'Array',
	'Uint8Array',
	'Uint16Array',
	'Uint32Array',
	'Int8Array',
	'Int16Array',
	'Int32Array',
	'Float32Array',
	'Float64Array',
	'Uint8ClampedArray',
	'BigUint64Array',
	'BigInt64Array',
	'btoa',
	'atob',
	'AbortController',
	'AbortSignal',
	'MessageChannel',
	'MessagePort',
	'URL',
	'URLSearchParams',
	'ReadonlyArray',
	'Event',
	'EventTarget',
	'BroadcastChannel',
	'performance',
	'Blob',
	'crypto',
	'File',
	'fetch',
	'RequestInit',
	'Headers',
	'Response',
	'__global',
	'PerformanceMark',
	'PerformanceObserver',
	'ImportMeta',

	// webcrypto has been available since Node.js 19, but still live in dom.d.ts
	'Crypto',
	'SubtleCrypto'
];

// Types that are defined in a common layer but are known to be only
// available in native environments should not be allowed in browser
const NATIVE_TYPES = [
	'NativeParsedArgs',
	'INativeEnvironmentService',
	'AbstractNativeEnvironmentService',
	'INativeWindowConfiguration',
	'ICommonNativeHostService',
	'INativeHostService',
	'IMainProcessService'
];

const RULES: IRule[] = [

	// Tests: skip
	{
		target: '**/vs/**/test/**',
		skip: true // -> skip all test files
	},

	// Common: vs/base/common/platform.ts
	{
		target: '**/vs/base/common/platform.ts',
		allowedTypes: [
			...CORE_TYPES,

			// Safe access to postMessage() and friends
			'MessageEvent',
		],
		disallowedTypes: NATIVE_TYPES,
		disallowedDefinitions: [
			'lib.dom.d.ts', // no DOM
			'@types/node'	// no node.js
		]
	},

	// Common: vs/base/common/async.ts
	{
		target: '**/vs/base/common/async.ts',
		allowedTypes: [
			...CORE_TYPES,

			// Safe access to requestIdleCallback & cancelIdleCallback
			'requestIdleCallback',
			'cancelIdleCallback'
		],
		disallowedTypes: NATIVE_TYPES,
		disallowedDefinitions: [
			'lib.dom.d.ts', // no DOM
			'@types/node'	// no node.js
		]
	},

	// Common: vs/base/common/performance.ts
	{
		target: '**/vs/base/common/performance.ts',
		allowedTypes: [
			...CORE_TYPES,

			// Safe access to Performance
			'Performance',
			'PerformanceEntry',
			'PerformanceTiming'
		],
		disallowedTypes: NATIVE_TYPES,
		disallowedDefinitions: [
			'lib.dom.d.ts', // no DOM
			'@types/node'	// no node.js
		]
	},

	// Common: vs/platform/environment/common/*
	{
		target: '**/vs/platform/environment/common/*.ts',
		allowedTypes: CORE_TYPES,
		disallowedTypes: [/* Ignore native types that are defined from here */],
		disallowedDefinitions: [
			'lib.dom.d.ts', // no DOM
			'@types/node'	// no node.js
		]
	},

	// Common: vs/platform/window/common/window.ts
	{
		target: '**/vs/platform/window/common/window.ts',
		allowedTypes: CORE_TYPES,
		disallowedTypes: [/* Ignore native types that are defined from here */],
		disallowedDefinitions: [
			'lib.dom.d.ts', // no DOM
			'@types/node'	// no node.js
		]
	},

	// Common: vs/platform/native/common/native.ts
	{
		target: '**/vs/platform/native/common/native.ts',
		allowedTypes: CORE_TYPES,
		disallowedTypes: [/* Ignore native types that are defined from here */],
		disallowedDefinitions: [
			'lib.dom.d.ts', // no DOM
			'@types/node'	// no node.js
		]
	},

	// Common: vs/platform/native/common/nativeHostService.ts
	{
		target: '**/vs/platform/native/common/nativeHostService.ts',
		allowedTypes: CORE_TYPES,
		disallowedTypes: [/* Ignore native types that are defined from here */],
		disallowedDefinitions: [
			'lib.dom.d.ts', // no DOM
			'@types/node'	// no node.js
		]
	},

	// Common: vs/workbench/api/common/extHostExtensionService.ts
	{
		target: '**/vs/workbench/api/common/extHostExtensionService.ts',
		allowedTypes: [
			...CORE_TYPES,

			// Safe access to global
			'global'
		],
		disallowedTypes: NATIVE_TYPES,
		disallowedDefinitions: [
			'lib.dom.d.ts', // no DOM
			'@types/node'	// no node.js
		]
	},

	// Common: vs/base/parts/sandbox/electron-sandbox/preload.ts
	{
		target: '**/vs/base/parts/sandbox/electron-sandbox/preload.ts',
		allowedTypes: [
			...CORE_TYPES,

			// Safe access to a very small subset of node.js
			'process',
			'NodeJS'
		],
		disallowedTypes: NATIVE_TYPES,
		disallowedDefinitions: [
			'@types/node'	// no node.js
		]
	},

	// Common
	{
		target: '**/vs/**/common/**',
		allowedTypes: CORE_TYPES,
		disallowedTypes: NATIVE_TYPES,
		disallowedDefinitions: [
			'lib.dom.d.ts', // no DOM
			'@types/node'	// no node.js
		]
	},

	// Browser
	{
		target: '**/vs/**/browser/**',
		allowedTypes: CORE_TYPES,
		disallowedTypes: NATIVE_TYPES,
		allowedDefinitions: [
			'@types/node/stream/consumers.d.ts' // node.js started to duplicate types from lib.dom.d.ts so we have to account for that
		],
		disallowedDefinitions: [
			'@types/node'	// no node.js
		]
	},

	// Browser (editor contrib)
	{
		target: '**/src/vs/editor/contrib/**',
		allowedTypes: CORE_TYPES,
		disallowedTypes: NATIVE_TYPES,
		disallowedDefinitions: [
			'@types/node'	// no node.js
		]
	},

	// node.js
	{
		target: '**/vs/**/node/**',
		allowedTypes: CORE_TYPES,
		disallowedDefinitions: [
			'lib.dom.d.ts'	// no DOM
		]
	},

	// Electron (sandbox)
	{
		target: '**/vs/**/electron-sandbox/**',
		allowedTypes: CORE_TYPES,
		disallowedDefinitions: [
			'@types/node'	// no node.js
		]
	},

	// Electron (utility)
	{
		target: '**/vs/**/electron-utility/**',
		allowedTypes: [
			...CORE_TYPES,

			// --> types from electron.d.ts that duplicate from lib.dom.d.ts
			'Event',
			'Request'
		],
		disallowedTypes: [
			'ipcMain' // not allowed, use validatedIpcMain instead
		],
		disallowedDefinitions: [
			'lib.dom.d.ts'	// no DOM
		]
	},

	// Electron (main)
	{
		target: '**/vs/**/electron-main/**',
		allowedTypes: [
			...CORE_TYPES,

			// --> types from electron.d.ts that duplicate from lib.dom.d.ts
			'Event',
			'Request'
		],
		disallowedTypes: [
			'ipcMain' // not allowed, use validatedIpcMain instead
		],
		disallowedDefinitions: [
			'lib.dom.d.ts'	// no DOM
		]
	}
];

const TS_CONFIG_PATH = join(__dirname, '../../', 'src', 'tsconfig.json');

interface IRule {
	target: string;
	skip?: boolean;
	allowedTypes?: string[];
	allowedDefinitions?: string[];
	disallowedDefinitions?: string[];
	disallowedTypes?: string[];
}

let hasErrors = false;

function checkFile(program: ts.Program, sourceFile: ts.SourceFile, rule: IRule) {
	checkNode(sourceFile);

	function checkNode(node: ts.Node): void {
		if (node.kind !== ts.SyntaxKind.Identifier) {
			return ts.forEachChild(node, checkNode); // recurse down
		}

		const checker = program.getTypeChecker();
		const symbol = checker.getSymbolAtLocation(node);

		if (!symbol) {
			return;
		}

		let _parentSymbol: any = symbol;

		while (_parentSymbol.parent) {
			_parentSymbol = _parentSymbol.parent;
		}

		const parentSymbol = _parentSymbol as ts.Symbol;
		const text = parentSymbol.getName();

		if (rule.allowedTypes?.some(allowed => allowed === text)) {
			return; // override
		}

		if (rule.disallowedTypes?.some(disallowed => disallowed === text)) {
			const { line, character } = sourceFile.getLineAndCharacterOfPosition(node.getStart());
			console.log(`[build/lib/layersChecker.ts]: Reference to type '${text}' violates layer '${rule.target}' (${sourceFile.fileName} (${line + 1},${character + 1}). Learn more about our source code organization at https://github.com/microsoft/vscode/wiki/Source-Code-Organization.`);

			hasErrors = true;
			return;
		}

		const declarations = symbol.declarations;
		if (Array.isArray(declarations)) {
			DeclarationLoop: for (const declaration of declarations) {
				if (declaration) {
					const parent = declaration.parent;
					if (parent) {
						const parentSourceFile = parent.getSourceFile();
						if (parentSourceFile) {
							const definitionFileName = parentSourceFile.fileName;
							if (rule.allowedDefinitions) {
								for (const allowedDefinition of rule.allowedDefinitions) {
									if (definitionFileName.indexOf(allowedDefinition) >= 0) {
										continue DeclarationLoop;
									}
								}
							}
							if (rule.disallowedDefinitions) {
								for (const disallowedDefinition of rule.disallowedDefinitions) {
									if (definitionFileName.indexOf(disallowedDefinition) >= 0) {
										const { line, character } = sourceFile.getLineAndCharacterOfPosition(node.getStart());

										console.log(`[build/lib/layersChecker.ts]: Reference to symbol '${text}' from '${disallowedDefinition}' violates layer '${rule.target}' (${sourceFile.fileName} (${line + 1},${character + 1}) Learn more about our source code organization at https://github.com/microsoft/vscode/wiki/Source-Code-Organization.`);

										hasErrors = true;
										return;
									}
								}
							}
						}
					}
				}
			}
		}
	}
}

function createProgram(tsconfigPath: string): ts.Program {
	const tsConfig = ts.readConfigFile(tsconfigPath, ts.sys.readFile);

	const configHostParser: ts.ParseConfigHost = { fileExists: existsSync, readDirectory: ts.sys.readDirectory, readFile: file => readFileSync(file, 'utf8'), useCaseSensitiveFileNames: process.platform === 'linux' };
	const tsConfigParsed = ts.parseJsonConfigFileContent(tsConfig.config, configHostParser, resolve(dirname(tsconfigPath)), { noEmit: true });

	const compilerHost = ts.createCompilerHost(tsConfigParsed.options, true);

	return ts.createProgram(tsConfigParsed.fileNames, tsConfigParsed.options, compilerHost);
}

//
// Create program and start checking
//
const program = createProgram(TS_CONFIG_PATH);

for (const sourceFile of program.getSourceFiles()) {
	for (const rule of RULES) {
		if (match([sourceFile.fileName], rule.target).length > 0) {
			if (!rule.skip) {
				checkFile(program, sourceFile, rule);
			}

			break;
		}
	}
}

if (hasErrors) {
	process.exit(1);
}