/*
 * Copyright(c) 2011
 *     OJC Technologies
 *     all rights reserved
 * @author: Jake Smith
 */

function ClickChooser(event) {
    this.x = event.pageX;
    this.y = event.pageY;
    
    this.getPositionInfo = function(terminalNodes) {
        var clickedTextNode, helper, posInfo, foundIndex;
        helper = new ProximityHelper(this.x, this.y);
        clickedTextNode = this.getClickedTextNode(terminalNodes);
        if (clickedTextNode == null) {
            posInfo = helper.getInfoFromRelation(terminalNodes);
        } else {
            foundIndex = this.specifyIndex(clickedTextNode);
            posInfo = new Array(
                    helper.WITHIN, clickedTextNode, foundIndex);
        }
        return posInfo;
    }
    
    //-----------------------//
    //  "Private" functions  //
    //-----------------------//
    
    this.getClickedTextNode = function(terminalNodes) {
        var i, consideredNode;
        for (i = 0; i < terminalNodes.length; i += 1) {
            consideredNode = terminalNodes[i];
            if (this.clickInBounds(consideredNode)) {
                return consideredNode;
            }
        }
        return null; // not in any of the terminal nodes
    }
    
    this.clickInBounds = function(textNode) {
        var i, rects, tempSpan, flag, parent;
        parent = textNode.parentNode;
        flag = false;
        tempSpan = makeTempSpan(textNode);
        parent.replaceChild(tempSpan, textNode);
        rects = tempSpan.getClientRects();
        for (i = 0; i < rects.length; i += 1) {
            if (rectContains(rects[i], this.x, this.y)) {
                flag = true;
            }
        }
        parent.replaceChild(textNode, tempSpan);
        return flag;
    }
    
    this.specifyIndex = function(node) {
        var textLength, index, ERR;
        ERR = -1;
        textLength = node.nodeValue.length;
        if (textLength < 1) {
            index = ERR; // definitely not here
        } else  if (textLength === 1) {
            index = (this.clickInBounds(node)) ? 0 : ERR;
        } else { // length > 1
            index = this.splitAndSearch(node, textLength);
        }
        return index;
    }
    
    this.splitAndSearch = function(node, textLength) {
        var fence, index, parent;
        parent = node.parentNode
        fence = Math.ceil(textLength / 2);
        var newNode = node.splitText(fence);
        if (this.clickInBounds(node)) {
            index = this.specifyIndex(node);
        } else if (this.clickInBounds(newNode)) {
            index = fence + this.specifyIndex(newNode);
        } else {
            throw new Error("error: specifyIndex search");
        }
        parent.normalize();
        return index;
    }
} // ClickChooser(event)

// standalone 'helper' function
function rectContains(rect, x, y) {
    var bool, l, r, t, b;
    l = rect.left + window.scrollX;
    r = rect.right + window.scrollX;
    t = Math.round(rect.top) + window.scrollY;
    b = Math.round(rect.bottom) + window.scrollY;
    // possibily rounding issues with Firefox (rect.top & bottom)
    if (x < l) {
        bool = false;
    } else if (x > r) {
        bool = false;
    } else if (y < t) {
        bool = false;
    } else if (y > b) {
        bool = false;
    } else {
        bool = true;
    }
    return bool;
}