/* ***** BEGIN LICENSE BLOCK *****
 * Distributed under the BSD license:
 *
 * Copyright (c) 2010, Ajax.org B.V.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of Ajax.org B.V. nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL AJAX.ORG B.V. BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * ***** END LICENSE BLOCK ***** */

define(function(require, exports, module) {
"use strict";

var oop = require("../lib/oop");
var dom = require("../lib/dom");
var lang = require("../lib/lang");
var useragent = require("../lib/useragent");
var EventEmitter = require("../lib/event_emitter").EventEmitter;

var Text = function(parentEl) {
    this.element = dom.createElement("div");
    this.element.className = "ace_layer ace_text-layer";
    parentEl.appendChild(this.element);
    this.$updateEolChar = this.$updateEolChar.bind(this);
};

(function() {

    oop.implement(this, EventEmitter);

    this.EOF_CHAR = "\xB6";
    this.EOL_CHAR_LF = "\xAC";
    this.EOL_CHAR_CRLF = "\xa4";
    this.EOL_CHAR = this.EOL_CHAR_LF;
    this.TAB_CHAR = "\u2014"; //"\u21E5";
    this.SPACE_CHAR = "\xB7";
    this.$padding = 0;

    this.$updateEolChar = function() {
        var doc = this.session.doc;
        var unixMode = doc.getNewLineCharacter() == "\n" && doc.getNewLineMode() != "windows";
        var EOL_CHAR = unixMode ? this.EOL_CHAR_LF : this.EOL_CHAR_CRLF;
        if (this.EOL_CHAR != EOL_CHAR) {
            this.EOL_CHAR = EOL_CHAR;
            return true;
        }
    };

    this.setPadding = function(padding) {
        this.$padding = padding;
        this.element.style.padding = "0 " + padding + "px";
    };

    this.getLineHeight = function() {
        return this.$fontMetrics.$characterSize.height || 0;
    };

    this.getCharacterWidth = function() {
        return this.$fontMetrics.$characterSize.width || 0;
    };
    
    this.$setFontMetrics = function(measure) {
        this.$fontMetrics = measure;
        this.$fontMetrics.on("changeCharacterSize", function(e) {
            this._signal("changeCharacterSize", e);
        }.bind(this));
        this.$pollSizeChanges();
    };

    this.checkForSizeChanges = function() {
        this.$fontMetrics.checkForSizeChanges();
    };
    this.$pollSizeChanges = function() {
        return this.$pollSizeChangesTimer = this.$fontMetrics.$pollSizeChanges();
    };
    this.setSession = function(session) {
        this.session = session;
        if (session)
            this.$computeTabString();
    };

    this.showInvisibles = false;
    this.setShowInvisibles = function(showInvisibles) {
        if (this.showInvisibles == showInvisibles)
            return false;

        this.showInvisibles = showInvisibles;
        this.$computeTabString();
        return true;
    };

    this.displayIndentGuides = true;
    this.setDisplayIndentGuides = function(display) {
        if (this.displayIndentGuides == display)
            return false;

        this.displayIndentGuides = display;
        this.$computeTabString();
        return true;
    };

    this.$tabStrings = [];
    this.onChangeTabSize =
    this.$computeTabString = function() {
        var tabSize = this.session.getTabSize();
        this.tabSize = tabSize;
        var tabStr = this.$tabStrings = [0];
        for (var i = 1; i < tabSize + 1; i++) {
            if (this.showInvisibles) {
                tabStr.push("<span class='ace_invisible ace_invisible_tab'>"
                    + lang.stringRepeat(this.TAB_CHAR, i)
                    + "</span>");
            } else {
                tabStr.push(lang.stringRepeat(" ", i));
            }
        }
        if (this.displayIndentGuides) {
            this.$indentGuideRe =  /\s\S| \t|\t |\s$/;
            var className = "ace_indent-guide";
            var spaceClass = "";
            var tabClass = "";
            if (this.showInvisibles) {
                className += " ace_invisible";
                spaceClass = " ace_invisible_space";
                tabClass = " ace_invisible_tab";
                var spaceContent = lang.stringRepeat(this.SPACE_CHAR, this.tabSize);
                var tabContent = lang.stringRepeat(this.TAB_CHAR, this.tabSize);
            } else{
                var spaceContent = lang.stringRepeat(" ", this.tabSize);
                var tabContent = spaceContent;
            }

            this.$tabStrings[" "] = "<span class='" + className + spaceClass + "'>" + spaceContent + "</span>";
            this.$tabStrings["\t"] = "<span class='" + className + tabClass + "'>" + tabContent + "</span>";
        }
    };

    this.updateLines = function(config, firstRow, lastRow) {
        // Due to wrap line changes there can be new lines if e.g.
        // the line to updated wrapped in the meantime.
        if (this.config.lastRow != config.lastRow ||
            this.config.firstRow != config.firstRow) {
            this.scrollLines(config);
        }
        this.config = config;

        var first = Math.max(firstRow, config.firstRow);
        var last = Math.min(lastRow, config.lastRow);

        var lineElements = this.element.childNodes;
        var lineElementsIdx = 0;

        for (var row = config.firstRow; row < first; row++) {
            var foldLine = this.session.getFoldLine(row);
            if (foldLine) {
                if (foldLine.containsRow(first)) {
                    first = foldLine.start.row;
                    break;
                } else {
                    row = foldLine.end.row;
                }
            }
            lineElementsIdx ++;
        }

        var row = first;
        var foldLine = this.session.getNextFoldLine(row);
        var foldStart = foldLine ? foldLine.start.row : Infinity;

        while (true) {
            if (row > foldStart) {
                row = foldLine.end.row+1;
                foldLine = this.session.getNextFoldLine(row, foldLine);
                foldStart = foldLine ? foldLine.start.row :Infinity;
            }
            if (row > last)
                break;

            var lineElement = lineElements[lineElementsIdx++];
            if (lineElement) {
                var html = [];
                this.$renderLine(
                    html, row, !this.$useLineGroups(), row == foldStart ? foldLine : false
                );
                lineElement.style.height = config.lineHeight * this.session.getRowLength(row) + "px";
                lineElement.innerHTML = html.join("");
            }
            row++;
        }
    };

    this.scrollLines = function(config) {
        var oldConfig = this.config;
        this.config = config;

        if (!oldConfig || oldConfig.lastRow < config.firstRow)
            return this.update(config);

        if (config.lastRow < oldConfig.firstRow)
            return this.update(config);

        var el = this.element;
        if (oldConfig.firstRow < config.firstRow)
            for (var row=this.session.getFoldedRowCount(oldConfig.firstRow, config.firstRow - 1); row>0; row--)
                el.removeChild(el.firstChild);

        if (oldConfig.lastRow > config.lastRow)
            for (var row=this.session.getFoldedRowCount(config.lastRow + 1, oldConfig.lastRow); row>0; row--)
                el.removeChild(el.lastChild);

        if (config.firstRow < oldConfig.firstRow) {
            var fragment = this.$renderLinesFragment(config, config.firstRow, oldConfig.firstRow - 1);
            if (el.firstChild)
                el.insertBefore(fragment, el.firstChild);
            else
                el.appendChild(fragment);
        }

        if (config.lastRow > oldConfig.lastRow) {
            var fragment = this.$renderLinesFragment(config, oldConfig.lastRow + 1, config.lastRow);
            el.appendChild(fragment);
        }
    };

    this.$renderLinesFragment = function(config, firstRow, lastRow) {
        var fragment = this.element.ownerDocument.createDocumentFragment();
        var row = firstRow;
        var foldLine = this.session.getNextFoldLine(row);
        var foldStart = foldLine ? foldLine.start.row : Infinity;

        while (true) {
            if (row > foldStart) {
                row = foldLine.end.row+1;
                foldLine = this.session.getNextFoldLine(row, foldLine);
                foldStart = foldLine ? foldLine.start.row : Infinity;
            }
            if (row > lastRow)
                break;

            var container = dom.createElement("div");

            var html = [];
            // Get the tokens per line as there might be some lines in between
            // beeing folded.
            this.$renderLine(html, row, false, row == foldStart ? foldLine : false);

            // don't use setInnerHtml since we are working with an empty DIV
            container.innerHTML = html.join("");
            if (this.$useLineGroups()) {
                container.className = 'ace_line_group';
                fragment.appendChild(container);
                container.style.height = config.lineHeight * this.session.getRowLength(row) + "px";

            } else {
                while(container.firstChild)
                    fragment.appendChild(container.firstChild);
            }

            row++;
        }
        return fragment;
    };

    this.update = function(config) {
        this.config = config;

        var html = [];
        var firstRow = config.firstRow, lastRow = config.lastRow;

        var row = firstRow;
        var foldLine = this.session.getNextFoldLine(row);
        var foldStart = foldLine ? foldLine.start.row : Infinity;

        while (true) {
            if (row > foldStart) {
                row = foldLine.end.row+1;
                foldLine = this.session.getNextFoldLine(row, foldLine);
                foldStart = foldLine ? foldLine.start.row :Infinity;
            }
            if (row > lastRow)
                break;

            if (this.$useLineGroups())
                html.push("<div class='ace_line_group' style='height:", config.lineHeight*this.session.getRowLength(row), "px'>");

            this.$renderLine(html, row, false, row == foldStart ? foldLine : false);

            if (this.$useLineGroups())
                html.push("</div>"); // end the line group

            row++;
        }
        this.element.innerHTML = html.join("");
    };

    this.$textToken = {
        "text": true,
        "rparen": true,
        "lparen": true
    };

    this.$renderToken = function(stringBuilder, screenColumn, token, value) {
        var self = this;
        var replaceReg = /\t|&|<|>|( +)|([\x00-\x1f\x80-\xa0\xad\u1680\u180E\u2000-\u200f\u2028\u2029\u202F\u205F\u3000\uFEFF])|[\u1100-\u115F\u11A3-\u11A7\u11FA-\u11FF\u2329-\u232A\u2E80-\u2E99\u2E9B-\u2EF3\u2F00-\u2FD5\u2FF0-\u2FFB\u3000-\u303E\u3041-\u3096\u3099-\u30FF\u3105-\u312D\u3131-\u318E\u3190-\u31BA\u31C0-\u31E3\u31F0-\u321E\u3220-\u3247\u3250-\u32FE\u3300-\u4DBF\u4E00-\uA48C\uA490-\uA4C6\uA960-\uA97C\uAC00-\uD7A3\uD7B0-\uD7C6\uD7CB-\uD7FB\uF900-\uFAFF\uFE10-\uFE19\uFE30-\uFE52\uFE54-\uFE66\uFE68-\uFE6B\uFF01-\uFF60\uFFE0-\uFFE6]/g;
        var replaceFunc = function(c, a, b, tabIdx, idx4) {
            if (a) {
                return self.showInvisibles
                    ? "<span class='ace_invisible ace_invisible_space'>" + lang.stringRepeat(self.SPACE_CHAR, c.length) + "</span>"
                    : c;
            } else if (c == "&") {
                return "&#38;";
            } else if (c == "<") {
                return "&#60;";
            } else if (c == ">") {
                // normally escaping this is not needed, but xml documents throw error when setting innerHTML to ]]>
                return "&#62;";
            } else if (c == "\t") {
                var tabSize = self.session.getScreenTabSize(screenColumn + tabIdx);
                screenColumn += tabSize - 1;
                return self.$tabStrings[tabSize];
            } else if (c == "\u3000") {
                // U+3000 is both invisible AND full-width, so must be handled uniquely
                var classToUse = self.showInvisibles ? "ace_cjk ace_invisible ace_invisible_space" : "ace_cjk";
                var space = self.showInvisibles ? self.SPACE_CHAR : "";
                screenColumn += 1;
                return "<span class='" + classToUse + "' style='width:" +
                    (self.config.characterWidth * 2) +
                    "px'>" + space + "</span>";
            } else if (b) {
                return "<span class='ace_invisible ace_invisible_space ace_invalid'>" + self.SPACE_CHAR + "</span>";
            } else {
                screenColumn += 1;
                return "<span class='ace_cjk' style='width:" +
                    (self.config.characterWidth * 2) +
                    "px'>" + c + "</span>";
            }
        };

        var output = value.replace(replaceReg, replaceFunc);

        if (!this.$textToken[token.type]) {
            var classes = "ace_" + token.type.replace(/\./g, " ace_");
            var style = "";
            if (token.type == "fold")
                style = " style='width:" + (token.value.length * this.config.characterWidth) + "px;' ";
            stringBuilder.push("<span class='", classes, "'", style, ">", output, "</span>");
        }
        else {
            stringBuilder.push(output);
        }
        return screenColumn + value.length;
    };

    this.renderIndentGuide = function(stringBuilder, value, max) {
        var cols = value.search(this.$indentGuideRe);
        if (cols <= 0 || cols >= max)
            return value;
        if (value[0] == " ") {
            cols -= cols % this.tabSize;
            stringBuilder.push(lang.stringRepeat(this.$tabStrings[" "], cols/this.tabSize));
            return value.substr(cols);
        } else if (value[0] == "\t") {
            stringBuilder.push(lang.stringRepeat(this.$tabStrings["\t"], cols));
            return value.substr(cols);
        }
        return value;
    };

    this.$renderWrappedLine = function(stringBuilder, tokens, splits, onlyContents) {
        var chars = 0;
        var split = 0;
        var splitChars = splits[0];
        var screenColumn = 0;

        for (var i = 0; i < tokens.length; i++) {
            var token = tokens[i];
            var value = token.value;
            if (i == 0 && this.displayIndentGuides) {
                chars = value.length;
                value = this.renderIndentGuide(stringBuilder, value, splitChars);
                if (!value)
                    continue;
                chars -= value.length;
            }

            if (chars + value.length < splitChars) {
                screenColumn = this.$renderToken(stringBuilder, screenColumn, token, value);
                chars += value.length;
            } else {
                while (chars + value.length >= splitChars) {
                    screenColumn = this.$renderToken(
                        stringBuilder, screenColumn,
                        token, value.substring(0, splitChars - chars)
                    );
                    value = value.substring(splitChars - chars);
                    chars = splitChars;

                    if (!onlyContents) {
                        stringBuilder.push("</div>",
                            "<div class='ace_line' style='height:",
                            this.config.lineHeight, "px'>"
                        );
                    }

                    stringBuilder.push(lang.stringRepeat("\xa0", splits.indent));

                    split ++;
                    screenColumn = 0;
                    splitChars = splits[split] || Number.MAX_VALUE;
                }
                if (value.length != 0) {
                    chars += value.length;
                    screenColumn = this.$renderToken(
                        stringBuilder, screenColumn, token, value
                    );
                }
            }
        }
    };

    this.$renderSimpleLine = function(stringBuilder, tokens) {
        var screenColumn = 0;
        var token = tokens[0];
        var value = token.value;
        if (this.displayIndentGuides)
            value = this.renderIndentGuide(stringBuilder, value);
        if (value)
            screenColumn = this.$renderToken(stringBuilder, screenColumn, token, value);
        for (var i = 1; i < tokens.length; i++) {
            token = tokens[i];
            value = token.value;
            screenColumn = this.$renderToken(stringBuilder, screenColumn, token, value);
        }
    };

    // row is either first row of foldline or not in fold
    this.$renderLine = function(stringBuilder, row, onlyContents, foldLine) {
        if (!foldLine && foldLine != false)
            foldLine = this.session.getFoldLine(row);

        if (foldLine)
            var tokens = this.$getFoldLineTokens(row, foldLine);
        else
            var tokens = this.session.getTokens(row);


        if (!onlyContents) {
            stringBuilder.push(
                "<div class='ace_line' style='height:", 
                    this.config.lineHeight * (
                        this.$useLineGroups() ? 1 :this.session.getRowLength(row)
                    ), "px'>"
            );
        }

        if (tokens.length) {
            var splits = this.session.getRowSplitData(row);
            if (splits && splits.length)
                this.$renderWrappedLine(stringBuilder, tokens, splits, onlyContents);
            else
                this.$renderSimpleLine(stringBuilder, tokens);
        }

        if (this.showInvisibles) {
            if (foldLine)
                row = foldLine.end.row

            stringBuilder.push(
                "<span class='ace_invisible ace_invisible_eol'>",
                row == this.session.getLength() - 1 ? this.EOF_CHAR : this.EOL_CHAR,
                "</span>"
            );
        }
        if (!onlyContents)
            stringBuilder.push("</div>");
    };

    this.$getFoldLineTokens = function(row, foldLine) {
        var session = this.session;
        var renderTokens = [];

        function addTokens(tokens, from, to) {
            var idx = 0, col = 0;
            while ((col + tokens[idx].value.length) < from) {
                col += tokens[idx].value.length;
                idx++;

                if (idx == tokens.length)
                    return;
            }
            if (col != from) {
                var value = tokens[idx].value.substring(from - col);
                // Check if the token value is longer then the from...to spacing.
                if (value.length > (to - from))
                    value = value.substring(0, to - from);

                renderTokens.push({
                    type: tokens[idx].type,
                    value: value
                });

                col = from + value.length;
                idx += 1;
            }

            while (col < to && idx < tokens.length) {
                var value = tokens[idx].value;
                if (value.length + col > to) {
                    renderTokens.push({
                        type: tokens[idx].type,
                        value: value.substring(0, to - col)
                    });
                } else
                    renderTokens.push(tokens[idx]);
                col += value.length;
                idx += 1;
            }
        }

        var tokens = session.getTokens(row);
        foldLine.walk(function(placeholder, row, column, lastColumn, isNewRow) {
            if (placeholder != null) {
                renderTokens.push({
                    type: "fold",
                    value: placeholder
                });
            } else {
                if (isNewRow)
                    tokens = session.getTokens(row);

                if (tokens.length)
                    addTokens(tokens, lastColumn, column);
            }
        }, foldLine.end.row, this.session.getLine(foldLine.end.row).length);

        return renderTokens;
    };

    this.$useLineGroups = function() {
        // For the updateLines function to work correctly, it's important that the
        // child nodes of this.element correspond on a 1-to-1 basis to rows in the
        // document (as distinct from lines on the screen). For sessions that are
        // wrapped, this means we need to add a layer to the node hierarchy (tagged
        // with the class name ace_line_group).
        return this.session.getUseWrapMode();
    };

    this.destroy = function() {
        clearInterval(this.$pollSizeChangesTimer);
        if (this.$measureNode)
            this.$measureNode.parentNode.removeChild(this.$measureNode);
        delete this.$measureNode;
    };

}).call(Text.prototype);

exports.Text = Text;

});
