//----------------------------------------------------------------------------
//  Copyright (C) 2008-2012  The IPython Development Team
//
//  Distributed under the terms of the BSD License.  The full license is in
//  the file COPYING, distributed as part of this software.
//----------------------------------------------------------------------------

//============================================================================
// Utilities
//============================================================================
IPython.namespace('IPython.utils');

IPython.utils = (function (IPython) {
    "use strict";

    //============================================================================
    // Cross-browser RegEx Split
    //============================================================================

    // This code has been MODIFIED from the code licensed below to not replace the
    // default browser split.  The license is reproduced here.

    // see http://blog.stevenlevithan.com/archives/cross-browser-split for more info:
    /*!
     * Cross-Browser Split 1.1.1
     * Copyright 2007-2012 Steven Levithan <stevenlevithan.com>
     * Available under the MIT License
     * ECMAScript compliant, uniform cross-browser split method
     */

    /**
     * Splits a string into an array of strings using a regex or string
     * separator. Matches of the separator are not included in the result array.
     * However, if `separator` is a regex that contains capturing groups,
     * backreferences are spliced into the result each time `separator` is
     * matched. Fixes browser bugs compared to the native
     * `String.prototype.split` and can be used reliably cross-browser.
     * @param {String} str String to split.
     * @param {RegExp|String} separator Regex or string to use for separating
     *     the string.
     * @param {Number} [limit] Maximum number of items to include in the result
     *     array.
     * @returns {Array} Array of substrings.
     * @example
     *
     * // Basic use
     * regex_split('a b c d', ' ');
     * // -> ['a', 'b', 'c', 'd']
     *
     * // With limit
     * regex_split('a b c d', ' ', 2);
     * // -> ['a', 'b']
     *
     * // Backreferences in result array
     * regex_split('..word1 word2..', /([a-z]+)(\d+)/i);
     * // -> ['..', 'word', '1', ' ', 'word', '2', '..']
     */
    var regex_split = function (str, separator, limit) {
        // If `separator` is not a regex, use `split`
        if (Object.prototype.toString.call(separator) !== "[object RegExp]") {
            return split.call(str, separator, limit);
        }
        var output = [],
            flags = (separator.ignoreCase ? "i" : "") +
                    (separator.multiline  ? "m" : "") +
                    (separator.extended   ? "x" : "") + // Proposed for ES6
                    (separator.sticky     ? "y" : ""), // Firefox 3+
            lastLastIndex = 0,
            // Make `global` and avoid `lastIndex` issues by working with a copy
            separator = new RegExp(separator.source, flags + "g"),
            separator2, match, lastIndex, lastLength;
        str += ""; // Type-convert

        var compliantExecNpcg = typeof(/()??/.exec("")[1]) === "undefined";
        if (!compliantExecNpcg) {
            // Doesn't need flags gy, but they don't hurt
            separator2 = new RegExp("^" + separator.source + "$(?!\\s)", flags);
        }
        /* Values for `limit`, per the spec:
         * If undefined: 4294967295 // Math.pow(2, 32) - 1
         * If 0, Infinity, or NaN: 0
         * If positive number: limit = Math.floor(limit); if (limit > 4294967295) limit -= 4294967296;
         * If negative number: 4294967296 - Math.floor(Math.abs(limit))
         * If other: Type-convert, then use the above rules
         */
        limit = typeof(limit) === "undefined" ?
            -1 >>> 0 : // Math.pow(2, 32) - 1
            limit >>> 0; // ToUint32(limit)
        while (match = separator.exec(str)) {
            // `separator.lastIndex` is not reliable cross-browser
            lastIndex = match.index + match[0].length;
            if (lastIndex > lastLastIndex) {
                output.push(str.slice(lastLastIndex, match.index));
                // Fix browsers whose `exec` methods don't consistently return `undefined` for
                // nonparticipating capturing groups
                if (!compliantExecNpcg && match.length > 1) {
                    match[0].replace(separator2, function () {
                        for (var i = 1; i < arguments.length - 2; i++) {
                            if (typeof(arguments[i]) === "undefined") {
                                match[i] = undefined;
                            }
                        }
                    });
                }
                if (match.length > 1 && match.index < str.length) {
                    Array.prototype.push.apply(output, match.slice(1));
                }
                lastLength = match[0].length;
                lastLastIndex = lastIndex;
                if (output.length >= limit) {
                    break;
                }
            }
            if (separator.lastIndex === match.index) {
                separator.lastIndex++; // Avoid an infinite loop
            }
        }
        if (lastLastIndex === str.length) {
            if (lastLength || !separator.test("")) {
                output.push("");
            }
        } else {
            output.push(str.slice(lastLastIndex));
        }
        return output.length > limit ? output.slice(0, limit) : output;
    };

    //============================================================================
    // End contributed Cross-browser RegEx Split
    //============================================================================


    var uuid = function () {
        // http://www.ietf.org/rfc/rfc4122.txt
        var s = [];
        var hexDigits = "0123456789ABCDEF";
        for (var i = 0; i < 32; i++) {
            s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1);
        }
        s[12] = "4";  // bits 12-15 of the time_hi_and_version field to 0010
        s[16] = hexDigits.substr((s[16] & 0x3) | 0x8, 1);  // bits 6-7 of the clock_seq_hi_and_reserved to 01

        var uuid = s.join("");
        return uuid;
    };


    //Fix raw text to parse correctly in crazy XML
    function xmlencode(string) {
        return string.replace(/\&/g,'&'+'amp;')
            .replace(/</g,'&'+'lt;')
            .replace(/>/g,'&'+'gt;')
            .replace(/\'/g,'&'+'apos;')
            .replace(/\"/g,'&'+'quot;')
            .replace(/`/g,'&'+'#96;');
    }


    //Map from terminal commands to CSS classes
    var ansi_colormap = {
        "01":"ansibold",
        
        "30":"ansiblack",
        "31":"ansired",
        "32":"ansigreen",
        "33":"ansiyellow",
        "34":"ansiblue",
        "35":"ansipurple",
        "36":"ansicyan",
        "37":"ansigray",
        
        "40":"ansibgblack",
        "41":"ansibgred",
        "42":"ansibggreen",
        "43":"ansibgyellow",
        "44":"ansibgblue",
        "45":"ansibgpurple",
        "46":"ansibgcyan",
        "47":"ansibggray"
    };
    
    function _process_numbers(attrs, numbers) {
        // process ansi escapes
        var n = numbers.shift();
        if (ansi_colormap[n]) {
            if ( ! attrs["class"] ) {
                attrs["class"] = ansi_colormap[n];
            } else {
                attrs["class"] += " " + ansi_colormap[n];
            }
        } else if (n == "38" || n == "48") {
            // VT100 256 color or 24 bit RGB
            if (numbers.length < 2) {
                console.log("Not enough fields for VT100 color", numbers);
                return;
            }
            
            var index_or_rgb = numbers.shift();
            var r,g,b;
            if (index_or_rgb == "5") {
                // 256 color
                var idx = parseInt(numbers.shift());
                if (idx < 16) {
                    // indexed ANSI
                    // ignore bright / non-bright distinction
                    idx = idx % 8;
                    var ansiclass = ansi_colormap[n[0] + (idx % 8).toString()];
                    if ( ! attrs["class"] ) {
                        attrs["class"] = ansiclass;
                    } else {
                        attrs["class"] += " " + ansiclass;
                    }
                    return;
                } else if (idx < 232) {
                    // 216 color 6x6x6 RGB
                    idx = idx - 16;
                    b = idx % 6;
                    g = Math.floor(idx / 6) % 6;
                    r = Math.floor(idx / 36) % 6;
                    // convert to rgb
                    r = (r * 51);
                    g = (g * 51);
                    b = (b * 51);
                } else {
                    // grayscale
                    idx = idx - 231;
                    // it's 1-24 and should *not* include black or white,
                    // so a 26 point scale
                    r = g = b = Math.floor(idx * 256 / 26);
                }
            } else if (index_or_rgb == "2") {
                // Simple 24 bit RGB
                if (numbers.length > 3) {
                    console.log("Not enough fields for RGB", numbers);
                    return;
                }
                r = numbers.shift();
                g = numbers.shift();
                b = numbers.shift();
            } else {
                console.log("unrecognized control", numbers);
                return;
            }
            if (r !== undefined) {
                // apply the rgb color
                var line;
                if (n == "38") {
                    line = "color: ";
                } else {
                    line = "background-color: ";
                }
                line = line + "rgb(" + r + "," + g + "," + b + ");"
                if ( !attrs["style"] ) {
                    attrs["style"] = line;
                } else {
                    attrs["style"] += " " + line;
                }
            }
        }
    }

    function ansispan(str) {
        // ansispan function adapted from github.com/mmalecki/ansispan (MIT License)
        // regular ansi escapes (using the table above)
        return str.replace(/\033\[(0?[01]|22|39)?([;\d]+)?m/g, function(match, prefix, pattern) {
            if (!pattern) {
                // [(01|22|39|)m close spans
                return "</span>";
            }
            // consume sequence of color escapes
            var numbers = pattern.match(/\d+/g);
            var attrs = {};
            while (numbers.length > 0) {
                _process_numbers(attrs, numbers);
            }
            
            var span = "<span ";
            for (var attr in attrs) {
                var value = attrs[attr];
                span = span + " " + attr + '="' + attrs[attr] + '"';
            }
            return span + ">";
        });
    };
    
    // Transform ANSI color escape codes into HTML <span> tags with css
    // classes listed in the above ansi_colormap object. The actual color used
    // are set in the css file.
    function fixConsole(txt) {
        txt = xmlencode(txt);
        var re = /\033\[([\dA-Fa-f;]*?)m/;
        var opened = false;
        var cmds = [];
        var opener = "";
        var closer = "";

        // Strip all ANSI codes that are not color related.  Matches
        // all ANSI codes that do not end with "m".
        var ignored_re = /(?=(\033\[[\d;=]*[a-ln-zA-Z]{1}))\1(?!m)/g;
        txt = txt.replace(ignored_re, "");
        
        // color ansi codes
        txt = ansispan(txt);
        return txt;
    }

    // Remove chunks that should be overridden by the effect of
    // carriage return characters
    function fixCarriageReturn(txt) {
        var tmp = txt;
        do {
            txt = tmp;
            tmp = txt.replace(/\r+\n/gm, '\n'); // \r followed by \n --> newline
            tmp = tmp.replace(/^.*\r+/gm, '');  // Other \r --> clear line
        } while (tmp.length < txt.length);
        return txt;
    }

    // Locate any URLs and convert them to a anchor tag
    function autoLinkUrls(txt) {
        return txt.replace(/(^|\s)(https?|ftp)(:[^'">\s]+)/gi,
            "$1<a target=\"_blank\" href=\"$2$3\">$2$3</a>");
    }

    // some keycodes that seem to be platform/browser independent
    var keycodes = {
                BACKSPACE:  8,
                TAB      :  9,
                ENTER    : 13,
                SHIFT    : 16,
                CTRL     : 17,
                CONTROL  : 17,
                ALT      : 18,
                CAPS_LOCK: 20,
                ESC      : 27,
                SPACE    : 32,
                PGUP     : 33,
                PGDOWN   : 34,
                END      : 35,
                HOME     : 36,
                LEFT_ARROW: 37,
                LEFTARROW: 37,
                LEFT     : 37,
                UP_ARROW : 38,
                UPARROW  : 38,
                UP       : 38,
                RIGHT_ARROW:39,
                RIGHTARROW:39,
                RIGHT    : 39,
                DOWN_ARROW: 40,
                DOWNARROW: 40,
                DOWN     : 40,
                I        : 73,
                M        : 77,
                // all three of these keys may be COMMAND on OS X:
                LEFT_SUPER : 91,
                RIGHT_SUPER : 92,
                COMMAND  : 93,
    };
    
    // trigger a key press event
    var press = function (key) {
        var key_press =  $.Event('keydown', {which: key});
        $(document).trigger(key_press);
    }

    var press_up = function() { press(keycodes.UP); };
    var press_down = function() { press(keycodes.DOWN); };

    var press_ctrl_enter = function() {
        $(document).trigger($.Event('keydown', {which: keycodes.ENTER, ctrlKey: true}));
    };

    var press_shift_enter = function() {
        $(document).trigger($.Event('keydown', {which: keycodes.ENTER, shiftKey: true}));
    };

    // trigger the ctrl-m shortcut followed by one of our keys
    var press_ghetto = function(key) {
        $(document).trigger($.Event('keydown', {which: keycodes.M, ctrlKey: true}));
        press(key);
    };


    var points_to_pixels = function (points) {
        // A reasonably good way of converting between points and pixels.
        var test = $('<div style="display: none; width: 10000pt; padding:0; border:0;"></div>');
        $(body).append(test);
        var pixel_per_point = test.width()/10000;
        test.remove();
        return Math.floor(points*pixel_per_point);
    };
    
    var always_new = function (constructor) {
        // wrapper around contructor to avoid requiring `var a = new constructor()`
        // useful for passing constructors as callbacks,
        // not for programmer laziness.
        // from http://programmers.stackexchange.com/questions/118798
        return function () {
            var obj = Object.create(constructor.prototype);
            constructor.apply(obj, arguments);
            return obj;
        };
    };


    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 splitext = function (filename) {
        // mimic Python os.path.splitext
        // Returns ['base', '.ext']
        var idx = filename.lastIndexOf('.');
        if (idx > 0) {
            return [filename.slice(0, idx), filename.slice(idx)];
        } else {
            return [filename, ''];
        }
    };


    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 is_or_has = function (a, b) {
        // Is b a child of a or a itself?
        return a.has(b).length !==0 || a.is(b);
    }

    var is_focused = function (e) {
        // Is element e, or one of its children focused?
        e = $(e);
        var target = $(document.activeElement);
        if (target.length > 0) {
            if (is_or_has(e, target)) {
                return true;
            } else {
                return false;
            }
        } else {
            return false;
        }
    }


    return {
        regex_split : regex_split,
        uuid : uuid,
        fixConsole : fixConsole,
        keycodes : keycodes,
        press : press,
        press_up : press_up,
        press_down : press_down,
        press_ctrl_enter : press_ctrl_enter,
        press_shift_enter : press_shift_enter,
        press_ghetto : press_ghetto,
        fixCarriageReturn : fixCarriageReturn,
        autoLinkUrls : autoLinkUrls,
        points_to_pixels : points_to_pixels,
        get_body_data : get_body_data,
        parse_url : parse_url,
        url_path_join : url_path_join,
        url_join_encode : url_join_encode,
        encode_uri_components : encode_uri_components,
        splitext : splitext,
        escape_html : escape_html,
        always_new : always_new,
        browser : browser,
        platform: platform,
        is_or_has : is_or_has,
        is_focused : is_focused
    };

}(IPython));