import * as vm from "node:vm";
import { convertCode } from "@power-doctest/core";
import type { ParsedCode } from "@power-doctest/types";
// @ts-expect-error: no types
import assert from "power-assert";

export interface PowerDoctestRunnerOptions {
	// pseudo file path for code
	filePath?: string;
	// sandbox context for code
	// context defined global variables
	context?: {
		[index: string]: any;
	};
	// sandbox require mock for code
	requireMock?: {
		[index: string]: any;
	};
	// If it is true, console.log output to console
	// If you want to mock console, please pass `console` to `context: { console: consoleMock }`
	//
	// Exception:
	// Always suppress console and assertion, because it is converted to assert function
	// ```
	// console.log(1); // => 1
	// ```
	console?: boolean;
	// Timeout millisecond
	// Default: 2000
	timeout?: number;
	// Default: all
	// If runMode is all, all assertions are finished and resolve it
	// If runMode is any, anyone assertion is finished and resolve it
	// In Both, anyone is failed and reject it
	runMode?: "any" | "all";
	// Internal Option
	powerDoctestCallbackFunctionName?: string;
}

const CALLBACK_FUNCTION_NAME = "__power_doctest_runner_callback__";

export interface testOptions {
	// if it is true and Each testOptions.state is "none", run the test
	// if it is false and Each testOptions.state is "none", do not run the test
	// Default: false
	disableRunning: boolean;
	// default values for doctestRunnerOptions
	// It is override by test case's `doctestRunnerOptions`.
	defaultDoctestRunnerOptions?: PowerDoctestRunnerOptions;
}

export type PowerDocTestError = Error & {
	// file path of the code
	fileName?: string;
	// line number of the code
	lineNumber?: number;
	// column number of the code
	columnNumber?: number;
	// metadata of the code
	meta?: {
		[index: string]: unknown;
	};
};
export function test(parsedCode: ParsedCode, oprions?: testOptions): Promise<void> {
	if (parsedCode.state === "disabled") {
		return Promise.resolve();
	}
	if (oprions?.disableRunning && parsedCode.state === "none") {
		return Promise.resolve();
	}
	return run(parsedCode.code, {
		...(oprions?.defaultDoctestRunnerOptions ? oprions.defaultDoctestRunnerOptions : {}),
		...parsedCode.doctestOptions,
	}).catch((error) => {
		// if it is expected error, resolve it
		if (parsedCode.expectedError && error.name === parsedCode.expectedError) {
			return Promise.resolve();
		}
		const doctestOptions: PowerDoctestRunnerOptions | undefined = parsedCode.doctestOptions;
		error.fileName = doctestOptions?.filePath ? doctestOptions.filePath : error.fileName;
		error.lineNumber = parsedCode.location.start.line;
		error.columnNumber = parsedCode.location.start.column;
		const metadata = parsedCode.metadata;
		if (metadata) {
			error.meta = metadata;
		}
		return Promise.reject(error);
	});
}

export function run(code: string, options: PowerDoctestRunnerOptions = {}): Promise<void> {
	const filePath = options.filePath || "default.js";
	const runMode = options.runMode || "all";
	const timeout = options.timeout !== undefined ? options.timeout : 2000;
	const postCallbackName = options.powerDoctestCallbackFunctionName || CALLBACK_FUNCTION_NAME;
	const context = options.context || {};
	// total count of assert
	let totalAssertionCount = 0;
	// current count of assert
	let countOfExecutedAssertion = 0;
	return new Promise((resolve, reject) => {
		let isSettled = false;

		const timeoutId = setTimeout(() => {
			if (isSettled) {
				return;
			}
			restoreListener();
			reject(
				new Error(`Timeout error

${
	runMode === "all"
		? `If you use { "runMode": "all" }, you should check all condition flow is passed.

Total Assertion: ${totalAssertionCount}
Executed Assertion: ${countOfExecutedAssertion}

Also, you should consider to use { "runMode": "any" }`
		: ""
}`),
			);
		}, timeout);
		// Test Runner like mocha listen unhandledRejection and uncaughtException
		// Disable these listener before running code
		const originalUnhandledRejection = process.listeners("unhandledRejection");
		const originalUncaughtException = process.listeners("uncaughtException");
		process.removeAllListeners("uncaughtException");
		process.removeAllListeners("unhandledRejection");
		const unhandledRejection = (reason: {}, _promise: Promise<void>): void => {
			restoreListener();
			reject(reason);
		};
		const uncaughtException = (error: Error): void => {
			restoreListener();
			reject(error);
		};
		const restoreListener = () => {
			isSettled = true;
			process.removeListener("uncaughtException", uncaughtException);
			process.removeListener("unhandledRejection", unhandledRejection);
			// restore
			const currentUncaughtException = process.listeners("uncaughtException");
			const currentUnhandledRejection = process.listeners("unhandledRejection");
			originalUncaughtException
				.filter((listener) => {
					// remove duplicated
					return !currentUncaughtException.includes(listener);
				})
				.forEach((listener) => {
					process.addListener("uncaughtException", listener);
				});
			originalUnhandledRejection
				.filter((listener) => {
					// remove duplicated
					return !currentUnhandledRejection.includes(listener);
				})
				.forEach((listener) => {
					process.addListener("unhandledRejection", listener);
				});
			// clearTimeout
			clearTimeout(timeoutId);
		};
		process.on("uncaughtException", uncaughtException);
		process.on("unhandledRejection", unhandledRejection as any);
		const poweredCode = convertCode(code, {
			assertAfterCallbackName: postCallbackName,
			filePath: filePath,
		});
		// total count of assert
		totalAssertionCount = poweredCode.split(CALLBACK_FUNCTION_NAME).length - 1;
		// current count of assert
		countOfExecutedAssertion = 0;
		try {
			const HostBuildIns = Object.freeze({
				__proto__: null,
				version: parseInt(process.versions.node.split(".")[0]),
				process,
				console,
				setTimeout,
				setInterval,
				setImmediate,
				clearTimeout,
				clearInterval,
				clearImmediate,
			});
			const script = new vm.Script(poweredCode, {
				filename: options.filePath,
			});
			const vmContext = vm.createContext({
				require: (moduleName: string) => {
					if (moduleName === "power-assert") {
						return assert;
					}
					// options.requireMock
					if (options.requireMock && Object.hasOwn(options.requireMock, moduleName)) {
						return options.requireMock[moduleName];
					}
					return require(moduleName);
				},
				[postCallbackName]: (_id: string) => {
					countOfExecutedAssertion++;
					if (runMode === "all" && countOfExecutedAssertion === totalAssertionCount) {
						// when all finish
						restoreListener();
						resolve();
					} else if (runMode === "any") {
						// when anyone finish
						restoreListener();
						resolve();
					}
				},
				...HostBuildIns,
				...context,
			});
			script.runInNewContext(vmContext, {
				timeout,
			});
		} catch (error) {
			restoreListener();
			reject(error);
		}
		// No assertion code
		if (totalAssertionCount === 0) {
			restoreListener();
			resolve();
		}
	});
}