import { config } from "dotenv";
import type { Config } from "@jest/types";
import fs from "fs/promises";
import { pathsToModuleNameMapper } from "ts-jest";
import path from "path";

// Or async function
export default async (): Promise<Config.InitialOptions> => {
	config({ path: path.resolve(process.cwd(), "test.env"), debug: true, override: true });
	return {
		verbose: false,
		clearMocks: true,
		errorOnDeprecated: true,
		preset: "ts-jest",
		testEnvironment: "node",
		rootDir: "./",
		modulePathIgnorePatterns: ["<rootDir>/dist/"],
		cache: false,
		silent: false,
		moduleNameMapper: await getTSConfigPathsToJest(),
	};
};

async function getTSConfigPathsToJest() {
	const tsconfigWithComments = await fs.readFile("./tsconfig.json", { encoding: "utf8" });

	// Remove comments
	const tsconfigText = tsconfigWithComments.replace(/\\"|"(?:\\"|[^"])*"|(\/\/.*|\/\*[\s\S]*?\*\/)/g, (m, g) =>
		g ? "" : m,
	);

	// Get the file with types
	const tsconfig = JSON.parse(tsconfigText);

	// Get all the paths from the compiler and convert them to something that jest understands
	const moduleNameMapper = pathsToModuleNameMapper(tsconfig.compilerOptions.paths, { prefix: "<rootDir>/src/" });

	return moduleNameMapper;
}