// Based on IPython's base.js.utils
// Original Copyright (c) IPython Development Team.
// Distributed under the terms of the Modified BSD License.

// Modifications Copyright (c) Juptyer Development Team.
// Distributed under the terms of the Modified BSD License.

define(['jquery'], function($){
    "use strict";
    
    var url_path_join = function () {
        // join a sequence of url components with '/'
        var url = '';
        for (var i = 0; i < arguments.length; i++) {
            if (arguments[i] === '') {
                continue;
            }
            if (url.length > 0 && url[url.length-1] != '/') {
                url = url + '/' + arguments[i];
            } else {
                url = url + arguments[i];
            }
        }
        url = url.replace(/\/\/+/, '/');
        return url;
    };
    
    var parse_url = function (url) {
        // an `a` element with an href allows attr-access to the parsed segments of a URL
        // a = parse_url("http://localhost:8888/path/name#hash")
        // a.protocol = "http:"
        // a.host     = "localhost:8888"
        // a.hostname = "localhost"
        // a.port     = 8888
        // a.pathname = "/path/name"
        // a.hash     = "#hash"
        var a = document.createElement("a");
        a.href = url;
        return a;
    };
    
    var encode_uri_components = function (uri) {
        // encode just the components of a multi-segment uri,
        // leaving '/' separators
        return uri.split('/').map(encodeURIComponent).join('/');
    };
    
    var url_join_encode = function () {
        // join a sequence of url components with '/',
        // encoding each component with encodeURIComponent
        return encode_uri_components(url_path_join.apply(null, arguments));
    };


    var escape_html = function (text) {
        // escape text to HTML
        return $("<div/>").text(text).html();
    };

    var get_body_data = function(key) {
        // get a url-encoded item from body.data and decode it
        // we should never have any encoded URLs anywhere else in code
        // until we are building an actual request
        return decodeURIComponent($('body').data(key));
    };
    
    
    // http://stackoverflow.com/questions/2400935/browser-detection-in-javascript
    var browser = (function() {
        if (typeof navigator === 'undefined') {
            // navigator undefined in node
            return 'None';
        }
        var N= navigator.appName, ua= navigator.userAgent, tem;
        var M= ua.match(/(opera|chrome|safari|firefox|msie)\/?\s*(\.?\d+(\.\d+)*)/i);
        if (M && (tem= ua.match(/version\/([\.\d]+)/i)) !== null) M[2]= tem[1];
        M= M? [M[1], M[2]]: [N, navigator.appVersion,'-?'];
        return M;
    })();

    // http://stackoverflow.com/questions/11219582/how-to-detect-my-browser-version-and-operating-system-using-javascript
    var platform = (function () {
        if (typeof navigator === 'undefined') {
            // navigator undefined in node
            return 'None';
        }
        var OSName="None";
        if (navigator.appVersion.indexOf("Win")!=-1) OSName="Windows";
        if (navigator.appVersion.indexOf("Mac")!=-1) OSName="MacOS";
        if (navigator.appVersion.indexOf("X11")!=-1) OSName="UNIX";
        if (navigator.appVersion.indexOf("Linux")!=-1) OSName="Linux";
        return OSName;
    })();

    var ajax_error_msg = function (jqXHR) {
        // Return a JSON error message if there is one,
        // otherwise the basic HTTP status text.
        if (jqXHR.responseJSON && jqXHR.responseJSON.message) {
            return jqXHR.responseJSON.message;
        } else {
            return jqXHR.statusText;
        }
    };
    
    var log_ajax_error = function (jqXHR, status, error) {
        // log ajax failures with informative messages
        var msg = "API request failed (" + jqXHR.status + "): ";
        console.log(jqXHR);
        msg += ajax_error_msg(jqXHR);
        console.log(msg);
        return msg;
    };
    
    var ajax_error_dialog = function (jqXHR, status, error) {
        console.log("ajax dialog", arguments);
        var msg = log_ajax_error(jqXHR, status, error);
        var dialog = $("#error-dialog");
        dialog.find(".ajax-error").text(msg);
        dialog.modal();
    };

    var utils = {
        url_path_join : url_path_join,
        url_join_encode : url_join_encode,
        encode_uri_components : encode_uri_components,
        escape_html : escape_html,
        get_body_data : get_body_data,
        parse_url : parse_url,
        browser : browser,
        platform: platform,
        ajax_error_msg : ajax_error_msg,
        log_ajax_error : log_ajax_error,
        ajax_error_dialog : ajax_error_dialog,
    };
    
    return utils;
});