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define(function(require, exports, module) {
"use strict";
var Range = require("./range").Range;
var comparePoints = Range.comparePoints;

var RangeList = function() {
    this.ranges = [];
};

(function() {
    this.comparePoints = comparePoints;

    this.pointIndex = function(pos, excludeEdges, startIndex) {
        var list = this.ranges;

        for (var i = startIndex || 0; i < list.length; i++) {
            var range = list[i];
            var cmpEnd = comparePoints(pos, range.end);
            if (cmpEnd > 0)
                continue;
            var cmpStart = comparePoints(pos, range.start);
            if (cmpEnd === 0)
                return excludeEdges && cmpStart !== 0 ? -i-2 : i;
            if (cmpStart > 0 || (cmpStart === 0 && !excludeEdges))
                return i;

            return -i-1;
        }
        return -i - 1;
    };

    this.add = function(range) {
        var excludeEdges = !range.isEmpty();
        var startIndex = this.pointIndex(range.start, excludeEdges);
        if (startIndex < 0)
            startIndex = -startIndex - 1;

        var endIndex = this.pointIndex(range.end, excludeEdges, startIndex);

        if (endIndex < 0)
            endIndex = -endIndex - 1;
        else
            endIndex++;
        return this.ranges.splice(startIndex, endIndex - startIndex, range);
    };

    this.addList = function(list) {
        var removed = [];
        for (var i = list.length; i--; ) {
            removed.push.apply(removed, this.add(list[i]));
        }
        return removed;
    };

    this.substractPoint = function(pos) {
        var i = this.pointIndex(pos);

        if (i >= 0)
            return this.ranges.splice(i, 1);
    };

    // merge overlapping ranges
    this.merge = function() {
        var removed = [];
        var list = this.ranges;
        
        list = list.sort(function(a, b) {
            return comparePoints(a.start, b.start);
        });
        
        var next = list[0], range;
        for (var i = 1; i < list.length; i++) {
            range = next;
            next = list[i];
            var cmp = comparePoints(range.end, next.start);
            if (cmp < 0)
                continue;

            if (cmp == 0 && !range.isEmpty() && !next.isEmpty())
                continue;

            if (comparePoints(range.end, next.end) < 0) {
                range.end.row = next.end.row;
                range.end.column = next.end.column;
            }

            list.splice(i, 1);
            removed.push(next);
            next = range;
            i--;
        }
        
        this.ranges = list;

        return removed;
    };

    this.contains = function(row, column) {
        return this.pointIndex({row: row, column: column}) >= 0;
    };

    this.containsPoint = function(pos) {
        return this.pointIndex(pos) >= 0;
    };

    this.rangeAtPoint = function(pos) {
        var i = this.pointIndex(pos);
        if (i >= 0)
            return this.ranges[i];
    };


    this.clipRows = function(startRow, endRow) {
        var list = this.ranges;
        if (list[0].start.row > endRow || list[list.length - 1].start.row < startRow)
            return [];

        var startIndex = this.pointIndex({row: startRow, column: 0});
        if (startIndex < 0)
            startIndex = -startIndex - 1;
        var endIndex = this.pointIndex({row: endRow, column: 0}, startIndex);
        if (endIndex < 0)
            endIndex = -endIndex - 1;

        var clipped = [];
        for (var i = startIndex; i < endIndex; i++) {
            clipped.push(list[i]);
        }
        return clipped;
    };

    this.removeAll = function() {
        return this.ranges.splice(0, this.ranges.length);
    };

    this.attach = function(session) {
        if (this.session)
            this.detach();

        this.session = session;
        this.onChange = this.$onChange.bind(this);

        this.session.on('change', this.onChange);
    };

    this.detach = function() {
        if (!this.session)
            return;
        this.session.removeListener('change', this.onChange);
        this.session = null;
    };

    this.$onChange = function(delta) {
        if (delta.action == "insert"){
            var start = delta.start;
            var end = delta.end;
        } else {
            var end = delta.start;
            var start = delta.end;
        }
        var startRow = start.row;
        var endRow = end.row;
        var lineDif = endRow - startRow;

        var colDiff = -start.column + end.column;
        var ranges = this.ranges;

        for (var i = 0, n = ranges.length; i < n; i++) {
            var r = ranges[i];
            if (r.end.row < startRow)
                continue;
            if (r.start.row > startRow)
                break;

            if (r.start.row == startRow && r.start.column >= start.column ) {
                if (r.start.column == start.column && this.$insertRight) {
                    // do nothing
                } else {
                    r.start.column += colDiff;
                    r.start.row += lineDif;
                }
            }
            if (r.end.row == startRow && r.end.column >= start.column) {
                if (r.end.column == start.column && this.$insertRight) {
                    continue;
                }
                // special handling for the case when two ranges share an edge
                if (r.end.column == start.column && colDiff > 0 && i < n - 1) {                
                    if (r.end.column > r.start.column && r.end.column == ranges[i+1].start.column)
                        r.end.column -= colDiff;
                }
                r.end.column += colDiff;
                r.end.row += lineDif;
            }
        }

        if (lineDif != 0 && i < n) {
            for (; i < n; i++) {
                var r = ranges[i];
                r.start.row += lineDif;
                r.end.row += lineDif;
            }
        }
    };

}).call(RangeList.prototype);

exports.RangeList = RangeList;
});
