/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/**
 * Get the API endpoint URL for an action
 * @param {String} action
 * @return {String}
 */
function getActionUrl(action) {
    return SETTINGS["server"] + "/" + action;
}

/**
 * Compare two version strings.
 * http://stackoverflow.com/a/16187766/2534036
 * @param {string} a
 * @param {string} b
 * @returns a number < 0 if a < b, a number > 0 if a > b, 0 if a = b
 */
function compareVersions(a, b) {
    var i, diff;
    var regExStrip0 = /(\.0+)+$/;
    var segmentsA = a.replace(regExStrip0, '').split('.');
    var segmentsB = b.replace(regExStrip0, '').split('.');
    var l = Math.min(segmentsA.length, segmentsB.length);

    for (i = 0; i < l; i++) {
        diff = parseInt(segmentsA[i], 10) - parseInt(segmentsB[i], 10);
        if (diff) {
            return diff;
        }
    }
    return segmentsA.length - segmentsB.length;
}

function checkClientVersion(success, failure) {
    return $.ajax({
        type: 'GET',
        url: getActionUrl("version.txt"),
        timeout: 5000,
        success: function (version) {
            $.getJSON("package.json", {}, function (local) {
                if (compareVersions(local.version, version) < 0) {
                    success(false);
                } else {
                    success(true);
                }
            });
        },
        error: function (xhr, textStatus, errorThrown) {
            if (typeof failure != 'function') {
                return;
            }
            switch (textStatus) {
                case "timeout":
                    failure("Couldn't connect to the server (timeout).", xhr);
                    break;
                case "error":
                    failure("Couldn't connect to the server (error).", xhr);
                    break;
                case "parseerror":
                    failure("The server sent a malformed response.", xhr);
                    break;
                default:
                    failure("Couldn't connect to the server.", xhr);
            }
        }
    });
}

/**
 * Call an API function on the server.
 * @param {string} action
 * @param {array} data key: value array of arguments for the server.
 * @param {function} success Called with the JSON response object.
 * @param {function} failure Called with an error message string.
 * @return {undefined}
 */
function callAPI(action, data, success, failure) {
    if (typeof data.username == "undefined" && typeof data.password == "undefined") {
        data.username = localStorage.getItem("username");
        data.password = localStorage.getItem("password");
    }
    return $.ajax({
        type: 'POST',
        dataType: 'json',
        url: getActionUrl(action),
        data: data,
        timeout: 5000,
        success: function (data, textStatus) {
            if (data.status === "OK") {
                success(data);
                return;
            }
            if (typeof failure != 'function') {
                return;
            }
            if (data.status === "ERROR") {
                failure(data.msg);
            } else {
                failure("The server sent an invalid response.");
            }
        },
        error: function (xhr, textStatus, errorThrown) {
            if (typeof failure != 'function') {
                return;
            }
            switch (textStatus) {
                case "timeout":
                    failure("Couldn't connect to the server (timeout).");
                    break;
                case "error":
                    failure("Couldn't connect to the server (error).");
                    break;
                case "parseerror":
                    failure("The server sent a malformed response.");
                    break;
                default:
                    failure("Couldn't connect to the server.");
            }
        }
    });
}

/**
 * Call an API function on the server.  Makes fewer assumptions about what
 * constitutes a success response.
 * @param {string} action
 * @param {array} data key: value array of arguments for the server.
 * @param {function} success Called with the JSON response object.
 * @param {function} failure Called with an error message string.
 * @return {undefined}
 */
function callAPIRawResponse(action, data, success, failure) {
    if (typeof data.username == "undefined" && typeof data.password == "undefined") {
        data.username = localStorage.getItem("username");
        data.password = localStorage.getItem("password");
    }
    return $.ajax({
        type: 'POST',
        url: getActionUrl(action),
        data: data,
        timeout: 5000,
        success: function (data, textStatus) {
            success(data);
        },
        error: function (xhr, textStatus, errorThrown) {
            if (typeof failure != 'function') {
                return;
            }
            switch (textStatus) {
                case "timeout":
                    failure("Couldn't connect to the server (timeout).", xhr);
                    break;
                case "error":
                    failure("Couldn't connect to the server (error).", xhr);
                    break;
                case "parseerror":
                    failure("The server sent a malformed response.", xhr);
                    break;
                default:
                    failure("Couldn't connect to the server.", xhr);
            }
        }
    });
}