/**
 * Usage:
 * var x = new SNTripleLocation( a, b, c, [ d, e, f ]);
 *
 * a        ID of country pulldown
 * b        ID of province pulldown
 * c        ID of city pulldown
 * [d]      country abbreviation of logged in member's country
 * [e]      province abbreviation of logged in member's country
 * [f]      city name of logged in member's country
 *
 * d, e, and f are optional and can be null;
 *
 ***** Note this package assumes AMAX is included and available to call
 */
function SNTripleLocation()
{
    var me = this;
    
    var cntrFld = document.getElementById(arguments[0]);
    var provFld = document.getElementById(arguments[1]);
    var ctyFld = document.getElementById(arguments[2]);
    
    var memCntr = arguments[3];
    var memProv = arguments[4];
    var memCity = arguments[5];
    
    var am;
    
    init();
    
    function init()
    {
        provFld.style.display = displayProvince(cntrFld.value);
        cntrFld.onchange = function() { me.cntrFldOnChange(); }
        provFld.onchange = function() { me.provFldOnChange(); }
        ctyFld.onchange = function() { me.onCityChange(); }
        
        clearField(provFld, 0); clearField(ctyFld, 0);
        ctyFld.options[0] = new Option("Select City", "");
        populateProvince();
        
        if (memCntr) selectField(cntrFld, memCntr);
        if (memProv) selectField(provFld, memProv);
        if (memCity) selectField(ctyFld, memCity);
    }
    
    
    function selectField(fld, val)
    {
        for (i=0; i<fld.options.length;i++) if (fld.options[i].value == val)
        {
            fld.selectedIndex = i; return;
        }
    }
    
    
    function isNorthAmerican(str)
    {
        return str == "CA" || str == "US";
    }
    
    function displayProvince(str)
    {
        return isNorthAmerican(str) || (str == "" && memProv) || cntrFld.selectedIndex == 0 ? "inline" : "none";
    }
    
    
    function clearField(ff, n)
    {
        ff.options.length = n;
    }
    
    
    
    function populateProvince()
    {
        clearField(provFld,0); clearField(ctyFld,1);
        provFld.options[0] = new Option("Please wait ...", "");
        am = new AMAX("/App_Info/GetStates.aspx",
                      true);
        am.onLoad = function()
        {
            if (this.success)
            {
                clearField(provFld,0);
                provFld.options[0] = new Option("Select " + (cntrFld.value == "CA" ? "Province" : "State"), "");
                var root = this.data.getElementsByTagName('Table');
                for (i = 0; i < root.length; i++)
                    provFld.options[provFld.options.length] = new Option( 
                        root[i].getElementsByTagName("prov")[0].firstChild.nodeValue,
                        root[i].getElementsByTagName("provAbbr")[0].firstChild.nodeValue
                    );
                provFld.selectedIndex = 0;
                me.onProvinceLoad();
            }
        }
        am.send("cn="+cntrFld.value, "get");
    }
    
    
    
    
    
    function populateCity()
    {
        am = new AMAX("/App_Info/GetCities.aspx",
                      true);
        clearField(ctyFld,0);
        ctyFld.options[0] = new Option( "Please wait ..." , "");
        am.onLoad = function() 
        {
            if (this.success)
            {
                clearField(ctyFld,0);
                ctyFld.options[0] = new Option( "Select City" , "");
                var root = this.data.getElementsByTagName('Table');
                for (i = 0; i < root.length; i++)
                    ctyFld.options[ctyFld.options.length] = new Option( 
                        root[i].getElementsByTagName("city")[0].firstChild.nodeValue,
                        root[i].getElementsByTagName("city")[0].firstChild.nodeValue
                    );
                ctyFld.selectedIndex = 0;
                me.onCityLoad()
            }
        }
        am.send('cn=' + cntrFld.value + '&pn=' + (isNorthAmerican(cntrFld.value)?provFld.value:"") ,'get');
    }
    
    
    
    
    
    this.cntrFldOnChange = function()
    {
        provFld.style.display = displayProvince(cntrFld.value);
        if (cntrFld.value == "")
        {
            provFld.selectedIndex = ctyFld.selectedIndex = 0;
            clearField(provFld,1);
            clearField(ctyFld,1);
            return;
        }
        if (isNorthAmerican(cntrFld.value))
            populateProvince();
        else
            populateCity();
        me.onCountryChange();
    }
    
    
    
    
    
    this.provFldOnChange = function()
    {
        if (provFld.value == "")
        {
            ctyFld.selectedIndex = 0;
            clearField(ctyFld,1);
            return;
        };
        populateCity();
        me.onProvinceChange();
    }
    
    
    
    // built in handlers you can use to address
    // change events, or load events
    this.onCountryChange = function() { }
    this.onProvinceChange = function() { }
    this.onCityChange = function() { }
    this.onProvinceLoad = function() { }
    this.onCityLoad = function() { }
    
    
    // the following get the values of the select boxes
    this.getCountryValue = function()
    {
        return cntrFld.value;
    }
    
    this.getProvinceValue = function()
    {
        return provFld.value;
    }
    
    this.getCityValue = function()
    {
        return ctyFld.value;
    }
    
}