// Copyright (c) 2006-2008 by Martin Stubenschrott <stubenschrott@vimperator.org>
// Copyright (c) 2007-2009 by Doug Kearns <dougkearns@gmail.com>
// Copyright (c) 2008-2009 by Kris Maglione <maglione.k@gmail.com>
//
// This work is licensed for reuse under an MIT license. Details are
// given in the LICENSE.txt file included with this file.
"use strict";

/** @scope modules */

const XHTML = Namespace("html", "http://www.w3.org/1999/xhtml");
const XUL = Namespace("xul", "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
const NS = Namespace("dactyl", "http://vimperator.org/namespaces/liberator");
default xml namespace = XHTML;

const Util = Module("util", {
    init: function () {
        this.Array = array;
    },

    get activeWindow() services.get("windowWatcher").activeWindow,
    callInMainThread: function (callback, self) {
        let mainThread = services.get("threadManager").mainThread;
        if (!services.get("threadManager").isMainThread)
            mainThread.dispatch({ run: callback.call(self) }, mainThread.DISPATCH_NORMAL);
        else
            callback.call(self);
    },

    /**
     * Returns a shallow copy of <b>obj</b>.
     *
     * @param {Object} obj
     * @returns {Object}
     */
    cloneObject: function cloneObject(obj) {
        if (isarray(obj))
            return obj.slice();
        let newObj = {};
        for (let [k, v] in Iterator(obj))
            newObj[k] = v;
        return newObj;
    },

    /**
     * Clips a string to a given length. If the input string is longer
     * than <b>length</b>, an ellipsis is appended.
     *
     * @param {string} str The string to truncate.
     * @param {number} length The length of the returned string.
     * @returns {string}
     */
    clip: function clip(str, length) {
        return str.length <= length ? str : str.substr(0, length - 3) + "...";
    },

    /**
     * Compares two strings, case insensitively. Return values are as
     * in String#localeCompare.
     *
     * @param {string} a
     * @param {string} b
     * @returns {number}
     */
    compareIgnoreCase: function compareIgnoreCase(a, b) String.localeCompare(a.toLowerCase(), b.toLowerCase()),

    /**
     * Returns an object representing a Node's computed CSS style.
     *
     * @param {Node} node
     * @returns {Object}
     */
    computedStyle: function computedStyle(node) {
        while (node instanceof Ci.nsIDOMText && node.parentNode)
            node = node.parentNode;
        return node.ownerDocument.defaultView.getComputedStyle(node, null);
    },

    /**
     * Copies a string to the system clipboard. If <b>verbose</b> is specified
     * the copied string is also echoed to the command line.
     *
     * @param {string} str
     * @param {boolean} verbose
     */
    copyToClipboard: function copyToClipboard(str, verbose) {
        const clipboardHelper = Cc["@mozilla.org/widget/clipboardhelper;1"].getService(Ci.nsIClipboardHelper);
        clipboardHelper.copyString(str);

        if (verbose)
            dactyl.echo("Yanked " + str, commandline.FORCE_SINGLELINE);
    },

    /**
     * Converts any arbitrary string into an URI object.
     *
     * @param {string} str
     * @returns {Object}
     */
    // FIXME: newURI needed too?
    createURI: function createURI(str) {
        const fixup = Cc["@mozilla.org/docshell/urifixup;1"].getService(Ci.nsIURIFixup);
        return fixup.createFixupURI(str, fixup.FIXUP_FLAG_ALLOW_KEYWORD_LOOKUP);
    },

    /**
     * Expands brace globbing patterns in a string.
     *
     * Example:
     *     "a{b,c}d" => ["abd", "acd"]
     *
     * @param {string} pattern The pattern to deglob.
     * @returns [string] The resulting strings.
     */
    debrace: function deglobBrace(pattern) {
        function split(pattern, re, fn, dequote) {
            let end = 0, match, res = [];
            while (match = re.exec(pattern)) {
                end = match.index + match[0].length;
                res.push(match[1]);
                if (fn)
                    fn(match);
            }
            res.push(pattern.substr(end));
            return res.map(function (s) util.dequote(s, dequote));
        }
        let patterns = [], res = [];
        let substrings = split(pattern, /((?:[^\\{]|\\.)*)\{((?:[^\\}]|\\.)*)\}/gy,
            function (match) {
                patterns.push(split(match[2], /((?:[^\\,]|\\.)*),/gy,
                    null, ",{}"));
            }, "{}");
        function rec(acc) {
            if (acc.length == patterns.length)
                res.push(util.Array.zip(substrings, acc).join(""));
            else 
                for (let [, pattern] in Iterator(patterns[acc.length]))
                    rec(acc.concat(pattern));
        }
        rec([]);
        return res;
    },

    /**
     * Removes certain backslash-quoted characters while leaving other
     * backslash-quoting sequences untouched.
     *
     * @param {string} pattern The string to unquote.
     * @param {string} chars The characters to unquote.
     * @returns {string}
     */
    dequote: function dequote(pattern, chars)
        pattern.replace(/\\(.)/, function (m0, m1) chars.indexOf(m1) >= 0 ? m1 : m0),

    /**
     * Converts HTML special characters in <b>str</b> to the equivalent HTML
     * entities.
     *
     * @param {string} str
     * @returns {string}
     */
    escapeHTML: function escapeHTML(str) {
        return str.replace(/&/g, "&amp;").replace(/</g, "&lt;");
    },

    /**
     * Escapes Regular Expression special characters in <b>str</b>.
     *
     * @param {string} str
     * @returns {string}
     */
    escapeRegex: function escapeRegex(str) {
        return str.replace(/([\\{}()[\].?*+])/g, "\\$1");
    },

    /**
     * Escapes quotes, newline and tab characters in <b>str</b>. The returned
     * string is delimited by <b>delimiter</b> or " if <b>delimiter</b> is not
     * specified. {@see String#quote}.
     *
     * @param {string} str
     * @param {string} delimiter
     * @returns {string}
     */
    escapeString: function escapeString(str, delimiter) {
        if (delimiter == undefined)
            delimiter = '"';
        return delimiter + str.replace(/([\\'"])/g, "\\$1").replace("\n", "\\n", "g").replace("\t", "\\t", "g") + delimiter;
    },

    /**
     * Evaluates an XPath expression in the current or provided
     * document. It provides the xhtml, xhtml2 and dactyl XML
     * namespaces. The result may be used as an iterator.
     *
     * @param {string} expression The XPath expression to evaluate.
     * @param {Document} doc The document to evaluate the expression in.
     * @default The current document.
     * @param {Node} elem The context element.
     * @default <b>doc</b>
     * @param {boolean} asIterator Whether to return the results as an
     *     XPath iterator.
     */
    evaluateXPath: function (expression, doc, elem, asIterator) {
        if (!doc)
            doc = content.document;
        if (!elem)
            elem = doc;
        if (isarray(expression))
            expression = util.makeXPath(expression);

        let result = doc.evaluate(expression, elem,
            function lookupNamespaceURI(prefix) {
                return {
                    xul: XUL.uri,
                    xhtml: XHTML.uri,
                    xhtml2: "http://www.w3.org/2002/06/xhtml2",
                    dactyl: NS.uri
                }[prefix] || null;
            },
            asIterator ? Ci.nsIDOMXPathResult.ORDERED_NODE_ITERATOR_TYPE : Ci.nsIDOMXPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
            null
        );

        return {
                __proto__: result,
                __iterator__: asIterator
                            ? function () { let elem; while ((elem = this.iterateNext())) yield elem; }
                            : function () { for (let i = 0; i < this.snapshotLength; i++) yield this.snapshotItem(i); }
        }
    },

    extend: function extend(dest) {
        Array.slice(arguments, 1).filter(util.identity).forEach(function (src) {
            for (let [k, v] in Iterator(src)) {
                let get = src.__lookupGetter__(k),
                    set = src.__lookupSetter__(k);
                if (!get && !set)
                    dest[k] = v;
                if (get)
                    dest.__defineGetter__(k, get);
                if (set)
                    dest.__defineSetter__(k, set);
            }
        });
        return dest;
    },

    /**
     * Returns the selection controller for the given window.
     *
     * @param {Window} window
     * @returns {nsISelectionController}
     */
    selectionController: function (win)
        win.QueryInterface(Ci.nsIInterfaceRequestor)
           .getInterface(Ci.nsIWebNavigation)
           .QueryInterface(Ci.nsIDocShell)
           .QueryInterface(Ci.nsIInterfaceRequestor)
           .getInterface(Ci.nsISelectionDisplay)
           .QueryInterface(Ci.nsISelectionController),

    /**
     * Converts <b>bytes</b> to a pretty printed data size string.
     *
     * @param {number} bytes The number of bytes.
     * @param {string} decimalPlaces The number of decimal places to use if
     *     <b>humanReadable</b> is true.
     * @param {boolean} humanReadable Use byte multiples.
     * @returns {string}
     */
    formatBytes: function formatBytes(bytes, decimalPlaces, humanReadable) {
        const unitVal = ["Bytes", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"];
        let unitIndex = 0;
        let tmpNum = parseInt(bytes, 10) || 0;
        let strNum = [tmpNum + ""];

        if (humanReadable) {
            while (tmpNum >= 1024) {
                tmpNum /= 1024;
                if (++unitIndex > (unitVal.length - 1))
                    break;
            }

            let decPower = Math.pow(10, decimalPlaces);
            strNum = ((Math.round(tmpNum * decPower) / decPower) + "").split(".", 2);

            if (!strNum[1])
                strNum[1] = "";

            while (strNum[1].length < decimalPlaces) // pad with "0" to the desired decimalPlaces)
                strNum[1] += "0";
        }

        for (let u = strNum[0].length - 3; u > 0; u -= 3) // make a 10000 a 10,000
            strNum[0] = strNum[0].substr(0, u) + "," + strNum[0].substr(u);

        if (unitIndex) // decimalPlaces only when > Bytes
            strNum[0] += "." + strNum[1];

        return strNum[0] + " " + unitVal[unitIndex];
    },

    /**
     * Sends a synchronous or asynchronous HTTP request to <b>url</b> and
     * returns the XMLHttpRequest object. If <b>callback</b> is specified the
     * request is asynchronous and the <b>callback</b> is invoked with the
     * object as its argument.
     *
     * @param {string} url
     * @param {function(XMLHttpRequest)} callback
     * @returns {XMLHttpRequest}
     */
    httpGet: function httpGet(url, callback) {
        try {
            let xmlhttp = services.create("xmlhttp");
            xmlhttp.mozBackgroundRequest = true;
            if (callback) {
                xmlhttp.onreadystatechange = function () {
                    if (xmlhttp.readyState == 4)
                        callback(xmlhttp);
                };
            }
            xmlhttp.open("GET", url, !!callback);
            xmlhttp.send(null);
            return xmlhttp;
        }
        catch (e) {
            dactyl.log("Error opening " + String.quote(url) + ": " + e, 1);
            return null;
        }
    },

    /**
     * The identity function.
     *
     * @param {Object} k
     * @returns {Object}
     */
    identity: function identity(k) k,

    /**
     * Returns the intersection of two rectangles.
     *
     * @param {Object} r1
     * @param {Object} r2
     * @returns {Object}
     */
    intersection: function (r1, r2) ({
        get width()  this.right - this.left,
        get height() this.bottom - this.top,
        left: Math.max(r1.left, r2.left),
        right: Math.min(r1.right, r2.right),
        top: Math.max(r1.top, r2.top),
        bottom: Math.min(r1.bottom, r2.bottom)
    }),

    /**
     * Returns an XPath union expression constructed from the specified node
     * tests. An expression is built with node tests for both the null and
     * XHTML namespaces. See {@link Buffer#evaluateXPath}.
     *
     * @param nodes {Array(string)}
     * @returns {string}
     */
    makeXPath: function makeXPath(nodes) {
        return util.Array(nodes).map(util.debrace).flatten()
                                .map(function (node) [node, "xhtml:" + node]).flatten()
                                .map(function (node) "//" + node).join(" | ");
    },

    /**
     * Returns the array that results from applying <b>func</b> to each
     * property of <b>obj</b>.
     *
     * @param {Object} obj
     * @param {function} func
     * @returns {Array}
     */
    map: function map(obj, func) {
        let ary = [];
        for (let i in Iterator(obj))
            ary.push(func(i));
        return ary;
    },

    /**
     * Memoize the lookup of a property in an object.
     *
     * @param {object} obj The object to alter.
     * @param {string} key The name of the property to memoize.
     * @param {function} getter A function of zero to two arguments which
     *          will return the property's value. <b>obj</b> is
     *          passed as the first argument, <b>key</b> as the
     *          second.
     */
    memoize: memoize,

    /**
     * Converts a URI string into a URI object.
     *
     * @param {string} uri
     * @returns {nsIURI}
     */
    // FIXME: createURI needed too?
    newURI: function (uri) {
        return services.get("io").newURI(uri, null, null);
    },

    /**
     * Pretty print a JavaScript object. Use HTML markup to color certain items
     * if <b>color</b> is true.
     *
     * @param {Object} object The object to pretty print.
     * @param {boolean} color Whether the output should be colored.
     * @returns {string}
     */
    objectToString: function objectToString(object, color) {
        // Use E4X literals so html is automatically quoted
        // only when it's asked for. No one wants to see &lt;
        // on their console or :map :foo in their buffer
        // when they expect :map <C-f> :foo.
        XML.prettyPrinting = false;
        XML.ignoreWhitespace = false;

        if (object === null)
            return "null\n";

        if (typeof object != "object")
            return false;

        const NAMESPACES = util.Array.toObject([
            [NS, 'dactyl'],
            [XHTML, 'html'],
            [XUL, 'xul']
        ]);
        if (object instanceof Ci.nsIDOMElement) {
            let elem = object;
            if (elem.nodeType == elem.TEXT_NODE)
                return elem.data;
            function namespaced(node) {
                var ns = NAMESPACES[node.namespaceURI];
                if (ns)
                    return ns + ":" + node.localName;
                return node.localName.toLowerCase();
            }
            try {
                let tag = "<" + [namespaced(elem)].concat(
                    [namespaced(a) + "=" +  template.highlight(a.value, true)
                     for ([i, a] in util.Array.iteritems(elem.attributes))]).join(" ");

                if (!elem.firstChild || /^\s*$/.test(elem.firstChild) && !elem.firstChild.nextSibling)
                    tag += '/>';
                else
                    tag += '>...</' + namespaced(elem) + '>';
                return tag;
            }
            catch (e) {
                return {}.toString.call(elem);
            }
        }

        try { // for window.JSON
            var obj = String(object);
        }
        catch (e) {
            obj = "[Object]";
        }
        obj = template.highlightFilter(util.clip(obj, 150), "\n", !color ? function () "^J" : function () <span highlight="NonText">^J</span>);
        let string = <><span highlight="Title Object">{obj}</span>::<br/>&#xa;</>;

        let keys = [];
        try { // window.content often does not want to be queried with "var i in object"
            let hasValue = !("__iterator__" in object);
            /*
            if (modules.isPrototypeOf(object)) {
                object = Iterator(object);
                hasValue = false;
            }
            */
            for (let i in object) {
                let value = <![CDATA[<no value>]]>;
                try {
                    value = object[i];
                }
                catch (e) {}
                if (!hasValue) {
                    if (isarray(i) && i.length == 2)
                        [i, value] = i;
                    else
                        var noVal = true;
                }

                value = template.highlight(value, true, 150);
                let key = <span highlight="Key">{i}</span>;
                if (!isNaN(i))
                    i = parseInt(i);
                else if (/^[A-Z_]+$/.test(i))
                    i = "";
                keys.push([i, <>{key}{noVal ? "" : <>: {value}</>}<br/>&#xa;</>]);
            }
        }
        catch (e) {}

        function compare(a, b) {
            if (!isNaN(a[0]) && !isNaN(b[0]))
                return a[0] - b[0];
            return String.localeCompare(a[0], b[0]);
        }
        string += template.map(keys.sort(compare), function (f) f[1]);
        return color ? string : [s for each (s in string)].join("");
    },

    /**
     * A generator that returns the values between <b>start</b> and <b>end</b>,
     * in <b>step</b> increments.
     *
     * @param {number} start The interval's start value.
     * @param {number} end The interval's end value.
     * @param {boolean} step The value to step the range by. May be
     *     negative. @default 1
     * @returns {Iterator(Object)}
     */
    range: function range(start, end, step) {
        if (!step)
            step = 1;
        if (step > 0) {
            for (; start < end; start += step)
                yield start;
        }
        else {
            while (start > end)
                yield start += step;
        }
    },

    /**
     * An interruptible generator that returns all values between <b>start</b>
     * and <b>end</b>. The thread yields every <b>time</b> milliseconds.
     *
     * @param {number} start The interval's start value.
     * @param {number} end The interval's end value.
     * @param {number} time The time in milliseconds between thread yields.
     * @returns {Iterator(Object)}
     */
    interruptibleRange: function interruptibleRange(start, end, time) {
        let endTime = Date.now() + time;
        while (start < end) {
            if (Date.now() > endTime) {
                util.threadYield(true, true);
                endTime = Date.now() + time;
            }
            yield start++;
        }
    },

    /**
     * Reads a string from the system clipboard.
     *
     * This is same as Firefox's readFromClipboard function, but is needed for
     * apps like Thunderbird which do not provide it.
     *
     * @returns {string}
     */
    readFromClipboard: function readFromClipboard() {
        let str;

        try {
            const clipboard = Cc["@mozilla.org/widget/clipboard;1"].getService(Ci.nsIClipboard);
            const transferable = Cc["@mozilla.org/widget/transferable;1"].createInstance(Ci.nsITransferable);

            transferable.addDataFlavor("text/unicode");

            if (clipboard.supportsSelectionClipboard())
                clipboard.getData(transferable, clipboard.kSelectionClipboard);
            else
                clipboard.getData(transferable, clipboard.kGlobalClipboard);

            let data = {};
            let dataLen = {};

            transferable.getTransferData("text/unicode", data, dataLen);

            if (data) {
                data = data.value.QueryInterface(Ci.nsISupportsString);
                str = data.data.substring(0, dataLen.value / 2);
            }
        }
        catch (e) {}

        return str;
    },

    /**
     * Scrolls an element into view if and only if it's not already
     * fully visible.
     *
     * @param {Node} elem The element to make visible.
     */
    scrollIntoView: function scrollIntoView(elem) {
        let win = elem.ownerDocument.defaultView;
        let rect = elem.getBoundingClientRect();
        if (!(rect && rect.top < win.innerHeight && rect.bottom >= 0 && rect.left < win.innerWidth && rect.right >= 0))
            elem.scrollIntoView();
    },

    sleep: function (delay) {
        let mainThread = services.get("threadManager").mainThread;

        let end = Date.now() + delay;
        while (Date.now() < end)
            mainThread.processNextEvent(true);
        return true;
    },

    /**
     * Split a string on literal occurrences of a marker.
     *
     * Specifically this ignores occurrences preceded by a backslash, or
     * contained within 'single' or "double" quotes.
     *
     * It assumes backslash escaping on strings, and will thus not count quotes
     * that are preceded by a backslash or within other quotes as starting or
     * ending quoted sections of the string.
     *
     * @param {string} str
     * @param {RegExp} marker
     */
    splitLiteral: function splitLiteral(str, marker) {
        let results = [];
        let resep = RegExp(/^(([^\\'"]|\\.|'([^\\']|\\.)*'|"([^\\"]|\\.)*")*?)/.source + marker.source);
        let cont = true;

        while (cont) {
            cont = false;
            str = str.replace(resep, function (match, before) {
                results.push(before);
                cont = true;
                return "";
            });
        }

        results.push(str);
        return results;
    },

    threadYield: function (flush, interruptable) {
        let mainThread = services.get("threadManager").mainThread;
        /* FIXME */
        util.interrupted = false;
        do {
            mainThread.processNextEvent(!flush);
            if (util.interrupted)
                throw new Error("Interrupted");
        }
        while (flush === true && mainThread.hasPendingEvents());
    },

    /**
     * Converts an E4X XML literal to a DOM node.
     *
     * @param {Node} node
     * @param {Document} doc
     * @param {Object} nodes If present, nodes with the "key" attribute are
     *     stored here, keyed to the value thereof.
     * @returns {Node}
     */
    xmlToDom: function xmlToDom(node, doc, nodes) {
        XML.prettyPrinting = false;
        if (node.length() != 1) {
            let domnode = doc.createDocumentFragment();
            for each (let child in node)
                domnode.appendChild(arguments.callee(child, doc, nodes));
            return domnode;
        }
        switch (node.nodeKind()) {
        case "text":
            return doc.createTextNode(String(node));
        case "element":
            let domnode = doc.createElementNS(node.namespace(), node.localName());
            for each (let attr in node.@*)
                domnode.setAttributeNS(attr.name() == "highlight" ? NS.uri : attr.namespace(), attr.name(), String(attr));
            for each (let child in node.*)
                domnode.appendChild(arguments.callee(child, doc, nodes));
            if (nodes && node.@key)
                nodes[node.@key] = domnode;
            return domnode;
        default:
            return null;
        }
    }
}, {
    Array: array
});

/**
 * Math utility methods.
 * @singleton
 */
var Math = {
    __proto__: window.Math,

    /**
     * Returns the specified <b>value</b> constrained to the range <b>min</b> -
     * <b>max</b>.
     *
     * @param {number} value The value to constrain.
     * @param {number} min The minimum constraint.
     * @param {number} max The maximum constraint.
     * @returns {number}
     */
    constrain: function constrain(value, min, max) Math.min(Math.max(min, value), max)
};

// vim: set fdm=marker sw=4 ts=4 et: