namespace Owl {
	public delegate bool VisitFileLambda (Owl.Path file);
	public class Path {
		static string ALPHABET_STRING = "abcdefghijklmnopqrstuvwxyz";
		GLib.File file;
		bool is_tmp;

		private static string get_random_string () {
			var random_generator = new GLib.Rand ();
			string final_string = "valatmp-";
			for (uint64 i = 0; i < 12; i++) {
				var random_number = random_generator.next_int () % ALPHABET_STRING.length;
				final_string += ALPHABET_STRING[random_number].to_string ();
			}
			return final_string;
		}

		public Path (GLib.File file) {
			this.file = file;
		}

		public Path.tempdir () throws GLib.Error {
			this.is_tmp = true;
			var file = GLib.File.new_for_path(GLib.Environment.get_tmp_dir () + Config.WS + get_random_string ());
			while (file.query_exists ()) {
				file = GLib.File.new_for_path(GLib.Environment.get_tmp_dir () + Config.WS + get_random_string ());
			}
			file.make_directory ();
			this.file = file;
		}

		~Path () {
			if (this.is_tmp) {
				try {
					this.@delete ();
				} catch (GLib.Error error) {
					GLib.critical (error.message);
				}
			}
		}

		public void spew (string content) throws GLib.Error {
			GLib.FileUtils.set_contents (this.get_path (), content);
		}

		public string slurp () throws GLib.Error {
			string output;
			GLib.FileUtils.get_contents (this.get_path (), out output);
			return output;
		}

		public GLib.FileOutputStream replace () throws GLib.Error {
			return this.file.replace (null, false, GLib.FileCreateFlags.PRIVATE);
		}

		public GLib.FileOutputStream create () throws GLib.Error {
			return this.file.create (GLib.FileCreateFlags.PRIVATE);
		}

		public Owl.Path child (string relative_path) throws GLib.Error {
			GLib.File child_file = this.file.resolve_relative_path (relative_path);
			return new Owl.Path (child_file);
		}

		public void mkpath () throws GLib.Error {
			this.file.make_directory_with_parents ();
		}

		public bool exists () {
			return this.file.query_exists ();
		}

		public Owl.Path parent () {
			return new Owl.Path (this.file.get_parent ());
		}

		public void @delete () throws GLib.Error {
			if (!this.is_dir ()) {
				this.file.delete ();
				return;
			}
			foreach (Owl.Path inner_file in this.children ()) {
				inner_file.delete ();
			}
			this.file.delete ();
		}

		public GLib.File get_file () {
			return this.file;
		}

		public string? get_path () {
			return this.file.get_path ();
		}

		public string basename () {
			return this.file.get_basename ();
		}

		public GLib.List<Owl.Path> children() {
			var children = new GLib.List<Owl.Path> ();
			if (!this.is_dir ()) {
				GLib.critical ("You cannot list children if the target is not a directory.\n");
				return children;
			}
			try {
				GLib.FileEnumerator enumerator = this.file.enumerate_children (
					"standard::*",
					FileQueryInfoFlags.NONE);
				GLib.FileInfo info;
				while ((info = enumerator.next_file (null)) != null) {
					GLib.File inner_file = file.resolve_relative_path (info.get_name ());
					children.append (new Owl.Path (inner_file));
				}
			} catch (GLib.Error error) {
				GLib.critical (error.message);
				return children;
			}
			return children;
		}

		public bool visit (bool recursive, Owl.VisitFileLambda lambda, bool visit_upper_dir = true) {
			if (!this.is_dir ()) {
				GLib.critical ("Unable to visit non directory\n");
				return false;
			}
			if (visit_upper_dir) {
				bool continue_visit = lambda (this);
				if (!continue_visit) {
					return false;
				}
			}
			foreach (Owl.Path inner_file in this.children ()) {
				bool continue_visit = lambda (inner_file);
				if (!continue_visit) {
					return false;
				}
				if (recursive && inner_file.is_dir ()) {
					continue_visit = inner_file.visit (true, lambda, false);
					if (!continue_visit) {
						return false;
					}
				}
			}
			return true;
		}

		public bool is_dir () {
			return this.query () == GLib.FileType.DIRECTORY;
		}

		private GLib.FileType query () {
			return this.file.query_file_type (GLib.FileQueryInfoFlags.NOFOLLOW_SYMLINKS);
		}
	}
}