/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Ajax.org Code Editor (ACE).
 *
 * The Initial Developer of the Original Code is
 * Ajax.org B.V.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *      Fabian Jakobs <fabian AT ajax DOT org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

define(function(require, exports, module) {

var oop = require("pilot/oop");
var EventEmitter = require("pilot/event_emitter").EventEmitter;
var Range = require("ace/range").Range;
var Anchor = require("ace/anchor").Anchor;

var Document = function(text) {
    this.$lines = [];

    if (Array.isArray(text)) {
        this.insertLines(0, text);
    }
    // There has to be one line at least in the document. If you pass an empty
    // string to the insert function, nothing will happen. Workaround.
    else if (text.length == 0) {
        this.$lines = [""];
    } else {
        this.insert({row: 0, column:0}, text);
    }
};

(function() {

    oop.implement(this, EventEmitter);

    this.setValue = function(text) {
        var len = this.getLength();
        this.remove(new Range(0, 0, len, this.getLine(len-1).length));
        this.insert({row: 0, column:0}, text);
    };

    this.getValue = function() {
        return this.getAllLines().join(this.getNewLineCharacter());
    };

    this.createAnchor = function(row, column) {
        return new Anchor(this, row, column);
    };

    // check for IE split bug
    if ("aaa".split(/a/).length == 0)
        this.$split = function(text) {
            return text.replace(/\r\n|\r/g, "\n").split("\n");
        }
    else
        this.$split = function(text) {
            return text.split(/\r\n|\r|\n/);
        };


    this.$detectNewLine = function(text) {
        var match = text.match(/^.*?(\r\n|\r|\n)/m);
        if (match) {
            this.$autoNewLine = match[1];
        } else {
            this.$autoNewLine = "\n";
        }
    };

    this.getNewLineCharacter = function() {
      switch (this.$newLineMode) {
          case "windows":
              return "\r\n";

          case "unix":
              return "\n";

          case "auto":
              return this.$autoNewLine;
      }
    },

    this.$autoNewLine = "\n";
    this.$newLineMode = "auto";
    this.setNewLineMode = function(newLineMode) {
        if (this.$newLineMode === newLineMode)
            return;

        this.$newLineMode = newLineMode;
    };

    this.getNewLineMode = function() {
        return this.$newLineMode;
    };

    this.isNewLine = function(text) {
        return (text == "\r\n" || text == "\r" || text == "\n");
    };

    /**
     * Get a verbatim copy of the given line as it is in the document
     */
    this.getLine = function(row) {
        return this.$lines[row] || "";
    };

    this.getLines = function(firstRow, lastRow) {
        return this.$lines.slice(firstRow, lastRow + 1);
    };

    /**
     * Returns all lines in the document as string array. Warning: The caller
     * should not modify this array!
     */
    this.getAllLines = function() {
        return this.getLines(0, this.getLength());
    };

    this.getLength = function() {
        return this.$lines.length;
    };

    this.getTextRange = function(range) {
        if (range.start.row == range.end.row) {
            return this.$lines[range.start.row].substring(range.start.column,
                                                         range.end.column);
        }
        else {
            var lines = [];
            lines.push(this.$lines[range.start.row].substring(range.start.column));
            lines.push.apply(lines, this.getLines(range.start.row+1, range.end.row-1));
            lines.push(this.$lines[range.end.row].substring(0, range.end.column));
            return lines.join(this.getNewLineCharacter());
        }
    };

    this.$clipPosition = function(position) {
        var length = this.getLength();
        if (position.row >= length) {
            position.row = Math.max(0, length - 1);
            position.column = this.getLine(length-1).length;
        }
        return position;
    }

    this.insert = function(position, text) {
        if (text.length == 0)
            return position;

        position = this.$clipPosition(position);

        if (this.getLength() <= 1)
            this.$detectNewLine(text);

        var lines = this.$split(text);
        var firstLine = lines.splice(0, 1)[0];
        var lastLine = lines.length == 0 ? null : lines.splice(lines.length - 1, 1)[0];

        position = this.insertInLine(position, firstLine);
        if (lastLine !== null) {
            position = this.insertNewLine(position); // terminate first line
            position = this.insertLines(position.row, lines);
            position = this.insertInLine(position, lastLine || "");
        }
        return position;
    };

    this.insertLines = function(row, lines) {
        if (lines.length == 0)
            return {row: row, column: 0};

        var args = [row, 0];
        args.push.apply(args, lines);
        this.$lines.splice.apply(this.$lines, args);

        var range = new Range(row, 0, row + lines.length, 0);
        var delta = {
            action: "insertLines",
            range: range,
            lines: lines
        };
        this._dispatchEvent("change", { data: delta });
        return range.end;
    },

    this.insertNewLine = function(position) {
        position = this.$clipPosition(position);
        var line = this.$lines[position.row] || "";

        this.$lines[position.row] = line.substring(0, position.column);
        this.$lines.splice(position.row + 1, 0, line.substring(position.column, line.length));

        var end = {
            row : position.row + 1,
            column : 0
        };

        var delta = {
            action: "insertText",
            range: Range.fromPoints(position, end),
            text: this.getNewLineCharacter()
        };
        this._dispatchEvent("change", { data: delta });

        return end;
    };

    this.insertInLine = function(position, text) {
        if (text.length == 0)
            return position;

        var line = this.$lines[position.row] || "";

        this.$lines[position.row] = line.substring(0, position.column) + text
                + line.substring(position.column);

        var end = {
            row : position.row,
            column : position.column + text.length
        };

        var delta = {
            action: "insertText",
            range: Range.fromPoints(position, end),
            text: text
        };
        this._dispatchEvent("change", { data: delta });

        return end;
    };

    this.remove = function(range) {
        // clip to document
        range.start = this.$clipPosition(range.start);
        range.end = this.$clipPosition(range.end);

        if (range.isEmpty())
            return range.start;

        var firstRow = range.start.row;
        var lastRow = range.end.row;

        if (range.isMultiLine()) {
            var firstFullRow = range.start.column == 0 ? firstRow : firstRow + 1;
            var lastFullRow = lastRow - 1;

            if (range.end.column > 0)
                this.removeInLine(lastRow, 0, range.end.column);

            if (lastFullRow >= firstFullRow)
                this.removeLines(firstFullRow, lastFullRow);

            if (firstFullRow != firstRow) {
                this.removeInLine(firstRow, range.start.column, this.getLine(firstRow).length);
                this.removeNewLine(range.start.row);
            }
        }
        else {
            this.removeInLine(firstRow, range.start.column, range.end.column);
        }
        return range.start;
    };

    this.removeInLine = function(row, startColumn, endColumn) {
        if (startColumn == endColumn)
            return;

        var range = new Range(row, startColumn, row, endColumn);
        var line = this.getLine(row);
        var removed = line.substring(startColumn, endColumn);
        var newLine = line.substring(0, startColumn) + line.substring(endColumn, line.length);
        this.$lines.splice(row, 1, newLine);

        var delta = {
            action: "removeText",
            range: range,
            text: removed
        };
        this._dispatchEvent("change", { data: delta });
        return range.start;
    };

    /**
     * Removes a range of full lines
     *
     * @param firstRow {Integer} The first row to be removed
     * @param lastRow {Integer} The last row to be removed
     * @return {String[]} The removed lines
     */
    this.removeLines = function(firstRow, lastRow) {
        var range = new Range(firstRow, 0, lastRow + 1, 0);
        var removed = this.$lines.splice(firstRow, lastRow - firstRow + 1);

        var delta = {
            action: "removeLines",
            range: range,
            nl: this.getNewLineCharacter(),
            lines: removed
        };
        this._dispatchEvent("change", { data: delta });
        return removed;
    };

    this.removeNewLine = function(row) {
        var firstLine = this.getLine(row);
        var secondLine = this.getLine(row+1);

        var range = new Range(row, firstLine.length, row+1, 0);
        var line = firstLine + secondLine;

        this.$lines.splice(row, 2, line);

        var delta = {
            action: "removeText",
            range: range,
            text: this.getNewLineCharacter()
        };
        this._dispatchEvent("change", { data: delta });
    };

    this.replace = function(range, text) {
        if (text.length == 0 && range.isEmpty())
            return range.start;

        // Shortcut: If the text we want to insert is the same as it is already
        // in the document, we don't have to replace anything.
        if (text == this.getTextRange(range))
            return range.end;

        this.remove(range);
        if (text) {
            var end = this.insert(range.start, text);
        }
        else {
            end = range.start;
        }

        return end;
    };

    this.applyDeltas = function(deltas) {
        for (var i=0; i<deltas.length; i++) {
            var delta = deltas[i];
            var range = Range.fromPoints(delta.range.start, delta.range.end);

            if (delta.action == "insertLines")
                this.insertLines(range.start.row, delta.lines)
            else if (delta.action == "insertText")
                this.insert(range.start, delta.text)
            else if (delta.action == "removeLines")
                this.removeLines(range.start.row, range.end.row - 1)
            else if (delta.action == "removeText")
                this.remove(range)
        }
    };

    this.revertDeltas = function(deltas) {
        for (var i=deltas.length-1; i>=0; i--) {
            var delta = deltas[i];

            var range = Range.fromPoints(delta.range.start, delta.range.end);

            if (delta.action == "insertLines")
                this.removeLines(range.start.row, range.end.row - 1)
            else if (delta.action == "insertText")
                this.remove(range)
            else if (delta.action == "removeLines")
                this.insertLines(range.start.row, delta.lines)
            else if (delta.action == "removeText")
                this.insert(range.start, delta.text)
        }
    };

}).call(Document.prototype);

exports.Document = Document;
});