"use strict";

const Promise = require("bluebird");

const execFileAsync = require("./exec-file-async");

module.exports = function ldd(path) {
	return Promise.try(() => {
		return execFileAsync("ldd", [ path ]);
	}).then(({ stdout, stderr }) => {
		return stdout.split("\n").filter((line) => {
			return (line.trim().length > 0);
		}).map((line) => {
			let match = /^\s*(\S+)\s+=>\s+(.+)$/.exec(line);

			if (match == null) {
				if (!line.includes(".so")) {
					throw new Error(`Encountered unexpected output from ldd: ${line}`);
				}
			} else {
				return {
					library: match[1],
					location: (match[2] === "not found")
						? null
						: match[2]
				};
			}
		}).filter((result) => {
			return (result != null);
		});
	});
};