import spawn from "cross-spawn";

function getGitFirstAddedTimeStamp(filePath) {
	return (
		parseInt(
			spawn
				.sync(
					"git",
					// Formats https://www.git-scm.com/docs/git-log#_pretty_formats
					// %at author date, UNIX timestamp
					["log", "--diff-filter=A", "--follow", "-1", "--format=%at", filePath],
				)
				.stdout.toString("utf-8"),
		) * 1000
	);
}

// return a Date
export default function (inputPath) {
	let timestamp = getGitFirstAddedTimeStamp(inputPath);
	if (timestamp) {
		return new Date(timestamp);
	}
}