import { parseGoBuildTags } from "../domain/go-build-tags.ts";

export type GoTestPlan = {
	language: "go";
	cwd: string;
	command: "go";
	args: string[];
	displayCommand: string;
};

export type PlanGoTestFromSlashArgsInput = {
	argsTail?: string;
	cwd: string;
};

export function planGoTestFromSlashArgs(
	input: PlanGoTestFromSlashArgsInput,
): GoTestPlan {
	const tags = parseTagsFromSlashArgs(input.argsTail ?? "");
	const args = ["test", "-race"];

	if (tags !== undefined) {
		args.push(`-tags=${tags}`);
	}

	args.push("./...");

	return {
		language: "go",
		cwd: input.cwd,
		command: "go",
		args,
		displayCommand: ["go", ...args].join(" "),
	};
}

function parseTagsFromSlashArgs(argsTail: string): string | undefined {
	const trimmed = argsTail.trim();
	if (trimmed === "") return undefined;

	const tokens = trimmed.split(/\s+/);
	const [first, second, ...rest] = tokens;

	if (first === "--tags") {
		if (second === undefined || second === "") {
			throw new Error("Missing Go build tags value");
		}
		if (rest.length > 0) {
			throw new Error(`Unsupported test arguments: ${rest.join(" ")}`);
		}
		return parseGoBuildTags(second);
	}

	if (first.startsWith("--tags=")) {
		if (tokens.length > 1) {
			throw new Error(
				`Unsupported test arguments: ${tokens.slice(1).join(" ")}`,
			);
		}
		const tags = first.slice("--tags=".length);
		if (tags === "") {
			throw new Error("Missing Go build tags value");
		}
		return parseGoBuildTags(tags);
	}

	if (first.startsWith("-")) {
		throw new Error(`Unsupported test argument: ${first}`);
	}

	return parseGoBuildTags(trimmed);
}