// Copyright (c) 2006-2009 by Martin Stubenschrott <stubenschrott@vimperator.org>
//
// This work is licensed for reuse under an MIT license. Details are
// given in the LICENSE.txt file included with this file.

/** @scope modules */

// TODO: proper backwards search - implement our own component?
//     : implement our own highlighter?
//     : <ESC> should cancel search highlighting in 'incsearch' mode and jump
//       back to the presearch page location - can probably use the same
//       solution as marks
//     : 'linksearch' searches should highlight link matches only
//     : changing any search settings should also update the search state including highlighting
//     : incremental searches shouldn't permanently update search modifiers

/**
 * @instance finder
 */
function Finder() //{{{
{
    ////////////////////////////////////////////////////////////////////////////////
    ////////////////////// PRIVATE SECTION /////////////////////////////////////////
    /////////////////////////////////////////////////////////////////////////////{{{

    var found = false;               // true if the last search was successful
    var backwards = false;           // currently searching backwards
    var searchString = "";           // current search string (without modifiers)
    var searchPattern = "";          // current search string (includes modifiers)
    var lastSearchPattern = "";      // the last searched pattern (includes modifiers)
    var lastSearchString = "";       // the last searched string (without modifiers)
    var lastSearchBackwards = false; // like "backwards", but for the last search, so if you cancel a search with <esc> this is not set
    var caseSensitive = false;       // search string is case sensitive
    var linksOnly = false;           // search is limited to link text only

    // Event handlers for search - closure is needed
    commandline.registerCallback("change", modes.SEARCH_FORWARD, function (str) { finder.onKeyPress(str); });
    commandline.registerCallback("submit", modes.SEARCH_FORWARD, function (str) { finder.onSubmit(str); });
    commandline.registerCallback("cancel", modes.SEARCH_FORWARD, function () { finder.onCancel(); });
    // TODO: allow advanced myModes in register/triggerCallback
    commandline.registerCallback("change", modes.SEARCH_BACKWARD, function (str) { finder.onKeyPress(str); });
    commandline.registerCallback("submit", modes.SEARCH_BACKWARD, function (str) { finder.onSubmit(str); });
    commandline.registerCallback("cancel", modes.SEARCH_BACKWARD, function () { finder.onCancel(); });

    // set searchString, searchPattern, caseSensitive, linksOnly
    function processUserPattern(pattern)
    {
        //// strip off pattern terminator and offset
        //if (backwards)
        //    pattern = pattern.replace(/\?.*/, "");
        //else
        //    pattern = pattern.replace(/\/.*/, "");

        searchPattern = pattern;

        // links only search - \l wins if both modifiers specified
        if (/\\l/.test(pattern))
            linksOnly = true;
        else if (/\L/.test(pattern))
            linksOnly = false;
        else if (options["linksearch"])
            linksOnly = true;
        else
            linksOnly = false;

        // strip links-only modifiers
        pattern = pattern.replace(/(\\)?\\[lL]/g, function ($0, $1) { return $1 ? $0 : ""; });

        // case sensitivity - \c wins if both modifiers specified
        if (/\c/.test(pattern))
            caseSensitive = false;
        else if (/\C/.test(pattern))
            caseSensitive = true;
        else if (options["ignorecase"] && options["smartcase"] && /[A-Z]/.test(pattern))
            caseSensitive = true;
        else if (options["ignorecase"])
            caseSensitive = false;
        else
            caseSensitive = true;

        // strip case-sensitive modifiers
        pattern = pattern.replace(/(\\)?\\[cC]/g, function ($0, $1) { return $1 ? $0 : ""; });

        // remove any modifier escape \
        pattern = pattern.replace(/\\(\\[cClL])/g, "$1");

        searchString = pattern;
    }

    /* Stolen from toolkit.jar in Firefox, for the time being. The private
     * methods were unstable, and changed. The new version is not remotely
     * compatible with what we do.
     *   The following only applies to this object, and may not be
     * necessary, or accurate, but, just in case:
     *   The Original Code is mozilla.org viewsource frontend.
     *
     *   The Initial Developer of the Original Code is
     *   Netscape Communications Corporation.
     *   Portions created by the Initial Developer are Copyright (c) 2003
     *   by the Initial Developer. All Rights Reserved.
     *
     *   Contributor(s):
     *       Blake Ross <blake@cs.stanford.edu> (Original Author)
     *       Masayuki Nakano <masayuki@d-toybox.com>
     *       Ben Basson <contact@cusser.net>
     *       Jason Barnabe <jason_barnabe@fastmail.fm>
     *       Asaf Romano <mano@mozilla.com>
     *       Ehsan Akhgari <ehsan.akhgari@gmail.com>
     *       Graeme McCutcheon <graememcc_firefox@graeme-online.co.uk>
     */
    var highlighter = {

        doc: null,

        spans: [],

        search: function (aWord, matchCase)
        {
            var finder = services.create("find");
            if (matchCase !== undefined)
                finder.caseSensitive = matchCase;

            var range;
            while ((range = finder.Find(aWord, this.searchRange, this.startPt, this.endPt)))
                yield range;
        },

        highlightDoc: function highlightDoc(win, aWord)
        {
            this.doc = content.document; // XXX
            Array.forEach(win.frames, function (frame) highlighter.highlightDoc(frame, aWord));

            var doc = win.document;
            if (!doc || !(doc instanceof HTMLDocument))
                return;

            if (!aWord)
            {
                let elems = highlighter.spans;
                for (let i = elems.length; --i >= 0;)
                {
                    let elem = elems[i];
                    let docfrag = doc.createDocumentFragment();
                    let next = elem.nextSibling;
                    let parent = elem.parentNode;

                    let child;
                    while (child = elem.firstChild)
                        docfrag.appendChild(child);

                    parent.removeChild(elem);
                    parent.insertBefore(docfrag, next);
                    parent.normalize();
                }
                return;
            }

            var baseNode = <span highlight="Search"/>;
            baseNode = util.xmlToDom(baseNode, window.content.document);

            var body = doc.body;
            var count = body.childNodes.length;
            this.searchRange = doc.createRange();
            this.startPt = doc.createRange();
            this.endPt = doc.createRange();

            this.searchRange.setStart(body, 0);
            this.searchRange.setEnd(body, count);

            this.startPt.setStart(body, 0);
            this.startPt.setEnd(body, 0);
            this.endPt.setStart(body, count);
            this.endPt.setEnd(body, count);

            liberator.interrupted = false;
            let n = 0;
            for (let retRange in this.search(aWord, caseSensitive))
            {
                // Highlight
                var nodeSurround = baseNode.cloneNode(true);
                var node = this.highlight(retRange, nodeSurround);
                this.startPt = node.ownerDocument.createRange();
                this.startPt.setStart(node, node.childNodes.length);
                this.startPt.setEnd(node, node.childNodes.length);
                if (n++ % 20 == 0)
                    liberator.threadYield(true);
                if (liberator.interrupted)
                    break;
            }
        },

        highlight: function highlight(aRange, aNode)
        {
            var startContainer = aRange.startContainer;
            var startOffset = aRange.startOffset;
            var endOffset = aRange.endOffset;
            var docfrag = aRange.extractContents();
            var before = startContainer.splitText(startOffset);
            var parent = before.parentNode;
            aNode.appendChild(docfrag);
            parent.insertBefore(aNode, before);
            this.spans.push(aNode);
            return aNode;
        },

        /**
         * Clears all search highlighting.
         */
        clear: function ()
        {
            this.spans.forEach(function (span)
            {
                if (span.parentNode)
                {
                    let el = span.firstChild;
                    while (el)
                    {
                        span.removeChild(el);
                        span.parentNode.insertBefore(el, span);
                        el = span.firstChild;
                    }
                    span.parentNode.removeChild(span);
                }
            });
            this.spans = [];
        },

        isHighlighted: function (doc) this.doc == doc && this.spans.length > 0
    };

    /////////////////////////////////////////////////////////////////////////////}}}
    ////////////////////// OPTIONS /////////////////////////////////////////////////
    /////////////////////////////////////////////////////////////////////////////{{{

    options.add(["hlsearch", "hls"],
        "Highlight previous search pattern matches",
        "boolean", "false",
        {
            setter: function (value)
            {
                if (value)
                    finder.highlight();
                else
                    finder.clear();

                return value;
            }
        });

    options.add(["ignorecase", "ic"],
        "Ignore case in search patterns",
        "boolean", true);

    options.add(["incsearch", "is"],
        "Show where the search pattern matches as it is typed",
        "boolean", true);

    options.add(["linksearch", "lks"],
        "Limit the search to hyperlink text",
        "boolean", false);

    options.add(["smartcase", "scs"],
        "Override the 'ignorecase' option if the pattern contains uppercase characters",
        "boolean", true);

    /////////////////////////////////////////////////////////////////////////////}}}
    ////////////////////// MAPPINGS ////////////////////////////////////////////////
    /////////////////////////////////////////////////////////////////////////////{{{

    var myModes = config.browserModes;
    myModes = myModes.concat([modes.CARET]);

    mappings.add(myModes,
        ["/"], "Search forward for a pattern",
        function () { finder.openPrompt(modes.SEARCH_FORWARD); });

    mappings.add(myModes,
        ["?"], "Search backwards for a pattern",
        function () { finder.openPrompt(modes.SEARCH_BACKWARD); });

    mappings.add(myModes,
        ["n"], "Find next",
        function () { finder.findAgain(false); });

    mappings.add(myModes,
        ["N"], "Find previous",
        function () { finder.findAgain(true); });

    mappings.add(myModes.concat([modes.CARET, modes.TEXTAREA]), ["*"],
        "Find word under cursor",
        function ()
        {
            found = false;
            finder.onSubmit(buffer.getCurrentWord(), false);
        });

    mappings.add(myModes.concat([modes.CARET, modes.TEXTAREA]), ["#"],
        "Find word under cursor backwards",
        function ()
        {
            found = false;
            finder.onSubmit(buffer.getCurrentWord(), true);
        });

    /////////////////////////////////////////////////////////////////////////////}}}
    ////////////////////// COMMANDS ////////////////////////////////////////////////
    /////////////////////////////////////////////////////////////////////////////{{{

    commands.add(["noh[lsearch]"],
        "Remove the search highlighting",
        function () { finder.clear(); },
        { argCount: "0" });

    /////////////////////////////////////////////////////////////////////////////}}}
    ////////////////////// PUBLIC SECTION //////////////////////////////////////////
    /////////////////////////////////////////////////////////////////////////////{{{

    return {

        /**
         * Called when the search dialog is requested.
         *
         * @param {number} mode The search mode, either modes.SEARCH_FORWARD or
         *     modes.SEARCH_BACKWARD.
         * @default modes.SEARCH_FORWARD
         */
        openPrompt: function (mode)
        {
            backwards = mode == modes.SEARCH_BACKWARD;
            commandline.open(backwards ? "?" : "/", "", mode);
            // TODO: focus the top of the currently visible screen
        },

        // TODO: backwards seems impossible i fear :(
        /**
         * Searches the current buffer for <b>str</b>.
         *
         * @param {string} str The string to find.
         */
        find: function (str)
        {
            let fastFind = getBrowser().fastFind;

            processUserPattern(str);
            fastFind.caseSensitive = caseSensitive;
            found = fastFind.find(searchString, linksOnly) != Ci.nsITypeAheadFind.FIND_NOTFOUND;

            if (!found)
                setTimeout(function () liberator.echoerr("E486: Pattern not found: " + searchPattern, commandline.FORCE_SINGLELINE), 0);
        },

        /**
         * Searches the current buffer again for the most recently used search
         * string.
         *
         * @param {boolean} reverse Whether to search forwards or backwards.
         * @default false
         */
        findAgain: function (reverse)
        {
            // This hack is needed to make n/N work with the correct string, if
            // we typed /foo<esc> after the original search.  Since searchString is
            // readonly we have to call find() again to update it.
            if (getBrowser().fastFind.searchString != lastSearchString)
                this.find(lastSearchString);

            let up = reverse ? !lastSearchBackwards : lastSearchBackwards;
            let result = getBrowser().fastFind.findAgain(up, linksOnly);

            if (result == Ci.nsITypeAheadFind.FIND_NOTFOUND)
                liberator.echoerr("E486: Pattern not found: " + lastSearchPattern, commandline.FORCE_SINGLELINE);
            else if (result == Ci.nsITypeAheadFind.FIND_WRAPPED)
            {
                // hack needed, because wrapping causes a "scroll" event which clears
                // our command line
                setTimeout(function () {
                    let msg = up ? "search hit TOP, continuing at BOTTOM" : "search hit BOTTOM, continuing at TOP";
                    commandline.echo(msg, commandline.HL_WARNINGMSG, commandline.APPEND_TO_MESSAGES | commandline.FORCE_SINGLELINE);
                }, 0);
            }
            else
            {
                commandline.echo((up ? "?" : "/") + lastSearchPattern, null, commandline.FORCE_SINGLELINE);

                if (options["hlsearch"])
                    this.highlight(lastSearchString);
            }
        },

        /**
         * Called when the user types a key in the search dialog. Triggers a
         * search attempt if 'incsearch' is set.
         *
         * @param {string} str The search string.
         */
        onKeyPress: function (str)
        {
            if (options["incsearch"])
                this.find(str);
        },

        /**
         * Called when the <Enter> key is pressed to trigger a search.
         *
         * @param {string} str The search string.
         * @param {boolean} forcedBackward Whether to search forwards or
         *     backwards. This overrides the direction set in
         *     (@link #openPrompt).
         * @default false
         */
        onSubmit: function (str, forcedBackward)
        {
            if (typeof forcedBackward === "boolean")
                backwards = forcedBackward;

            if (str)
                var pattern = str;
            else
            {
                if (lastSearchPattern)
                    pattern = lastSearchPattern;
                else
                    return void liberator.echoerr("E35: No previous search pattern");
            }

            this.clear();

            if (!options["incsearch"] || !str || !found)
            {
                // prevent any current match from matching again
                if (!window.content.getSelection().isCollapsed)
                    window.content.getSelection().getRangeAt(0).collapse(backwards);

                this.find(pattern);
            }

            lastSearchBackwards = backwards;
            //lastSearchPattern = pattern.replace(backwards ? /\?.*/ : /\/.*/, ""); // XXX
            lastSearchPattern = pattern;
            lastSearchString = searchString;

            // TODO: move to find() when reverse incremental searching is kludged in
            // need to find again for reverse searching
            if (backwards)
                setTimeout(function () { finder.findAgain(false); }, 0);

            if (options["hlsearch"])
                this.highlight(searchString);

            modes.reset();
        },

        /**
         * Called when the search is canceled. For example, if someone presses
         * <Esc> while typing a search.
         */
        onCancel: function ()
        {
            // TODO: code to reposition the document to the place before search started
        },

        /**
         * Highlights all occurances of <b>str</b> in the buffer.
         *
         * @param {string} str The string to highlight.
         */
        highlight: function (str)
        {
            // FIXME: Thunderbird incompatible
            if (config.name == "Muttator")
                return;

            if (highlighter.isHighlighted(content.document))
                return;

            if (!str)
                str = lastSearchString;

            highlighter.highlightDoc(window.content, str);

            // recreate selection since highlightDoc collapses the selection
            if (window.content.getSelection().isCollapsed)
                getBrowser().fastFind.findAgain(backwards, linksOnly);

            // TODO: remove highlighting from non-link matches (HTML - A/AREA with href attribute; XML - Xlink [type="simple"])
        },

        /**
         * Clears all search highlighting.
         */
        clear: function ()
        {
            highlighter.clear();
        }
    };
    //}}}
} //}}}

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