let mocklib = global.mocklib,
    fs = mocklib.require("fs");

return {
	readlink: function(path) {
		mocklib.trace_call("fs", "readlink", { path });

		return path + "-link";
	},

	stat: function(path) {
		let file = sprintf("fs/stat~%s.json", replace(path, /[^A-Za-z0-9_-]+/g, '_')),
		    mock = mocklib.read_json_file(file);

		if (!mock || mock != mock) {
			mocklib.I("No stat result fixture defined for fs.stat() call on %s.", path);
			mocklib.I("Provide a mock result through the following JSON file:\n%s\n", file);

			if (match(path, /\/$/))
				mock = { type: "directory" };
			else
				mock = { type: "file" };
		}

		mocklib.trace_call("fs", "stat", { path });

		return mock;
	},

	unlink: function(path) {
		printf("fs.unlink() path <%s>\n", path);

		return true;
	},

	popen: (cmdline, mode) => {
		let read = (!mode || index(mode, "r") != -1),
		    path = sprintf("fs/popen~%s.txt", replace(cmdline, /[^A-Za-z0-9_-]+/g, '_')),
		    mock = mocklib.read_data_file(path);

		if (read && !mock) {
			mocklib.I("No stdout fixture defined for fs.popen() command %s.", cmdline);
			mocklib.I("Provide a mock output through the following text file:\n%s\n", path);

			return null;
		}

		mocklib.trace_call("fs", "popen", { cmdline, mode });

		return {
			read: function(amount) {
				let rv;

				switch (amount) {
				case "all":
					rv = mock;
					mock = "";
					break;

				case "line":
					let i = index(mock, "\n");
					i = (i > -1) ? i + 1 : mock.length;
					rv = substr(mock, 0, i);
					mock = substr(mock, i);
					break;

				default:
					let n = +amount;
					n = (n > 0) ? n : 0;
					rv = substr(mock, 0, n);
					mock = substr(mock, n);
					break;
				}

				return rv;
			},

			write: function() {},
			close: function() {},

			error: function() {
				return null;
			}
		};
	},

	open: (fpath, mode) => {
		let read = (!mode || index(mode, "r") != -1 || index(mode, "+") != -1),
		    path = sprintf("fs/open~%s.txt", replace(fpath, /[^A-Za-z0-9_-]+/g, '_')),
		    mock = read ? mocklib.read_data_file(path) : null;

		if (read && !mock) {
			mocklib.I("No stdout fixture defined for fs.open() path %s.", fpath);
			mocklib.I("Provide a mock output through the following text file:\n%s\n", path);

			return null;
		}

		mocklib.trace_call("fs", "open", { path: fpath, mode });

		return {
			read: function(amount) {
				let rv;

				switch (amount) {
				case "all":
					rv = mock;
					mock = "";
					break;

				case "line":
					let i = index(mock, "\n");
					i = (i > -1) ? i + 1 : length(mock);
					rv = substr(mock, 0, i);
					mock = length(mock) ? substr(mock, i) : null;
					break;

				default:
					let n = +amount;
					n = (n > 0) ? n : 0;
					rv = substr(mock, 0, n);
					mock = substr(mock, n);
					break;
				}

				return rv;
			},

			write: function() {},
			close: function() {},

			error: function() {
				return null;
			}
		};
	},

	opendir: (path) => {
		let file = sprintf("fs/opendir~%s.json", replace(path, /[^A-Za-z0-9_-]+/g, '_')),
		    mock = mocklib.read_json_file(file),
		    index = 0;

		if (!mock || mock != mock) {
			mocklib.I("No stat result fixture defined for fs.opendir() call on %s.", path);
			mocklib.I("Provide a mock result through the following JSON file:\n%s\n", file);

			mock = [];
		}

		mocklib.trace_call("fs", "opendir", { path });

		return {
			read: function() {
				return mock[index++];
			},

			tell: function() {
				return index;
			},

			seek: function(i) {
				index = i;
			},

			close: function() {},

			error: function() {
				return null;
			}
		};
	},

	error: () => "Unspecified error"
};