var request;
var state_name;
var city_name ;
var state;
var route;
var station;

function init(){
    state_name = document.getElementById("state_name");
    state_name.onchange = city_kensaku;
    city_name = document.getElementById("city_name");
    state = document.getElementById("state");
    route = document.getElementById("route");
    station = document.getElementById("station");


    //AJAXで路線情報を取得
    if(window.XMLHttpRequest){
        request = new window.XMLHttpRequest();
    }else if(window.ActiveXObject){
        try{
            request = new window.ActiveXObject('Msxml2.XMLHTTP');
        }catch(e){
            request = new window.ActiveXObject('Microsoft.XMLHTTP');
        }

    }else{
        throw new Error('XMLHttpRequestがサポートされていません');
    }

}


function route_kensaku(){
    //routeとstationの子ノードを全て削除する
    var route_child_num = route.childNodes.length;
    for(var i = 0;i < route_child_num;i++){
        route.removeChild(route.firstChild);
    }

    var station_child_num = station.childNodes.length;
    for(var i = 0;i < station_child_num;i++){
        station.removeChild(station.firstChild);
    }

    request.onreadystatechange = get_route;
    query = "/return_route_info.php?state=" + encodeURI(state.value);
    request.open('GET',query,'true');
    request.send(null);
}


//都道府県と路線名から駅検索を行う
function station_kensaku(){
    //stationの子ノードを削除する
    var station_child_num = station.childNodes.length;
    for(var i = 0;i < station_child_num;i++){
        station.removeChild(station.firstChild);
    }

    if(state.value && route.value){
        request.onreadystatechange = get_station;
        query = "/return_route_info.php?state=" + encodeURI(state.value) + "&route=" + encodeURI(route.value);
        request.open('GET',query,'true');
        request.send(null);
    }

}


//サーバから帰ってきた路線情報を表示する
function get_route(){

    if(request.readyState == 4 && request.status == 200){
        json = request.responseText;
        //document.write(json);
        var route_value = eval('(' + json + ')');

        option = document.createElement("option");
        option.value = "";
        option_value = document.createTextNode("指定しない");
        option.appendChild(option_value);
        route.appendChild(option);

        for(var i = 0;i < route_value.length;i++){
            route_name = route_value[i];
            option = document.createElement("option");
            option.value = route_name;
            option_value = document.createTextNode(route_name);
            option.appendChild(option_value);
            route.appendChild(option);
        }

    }
}


//サーバから帰ってきた駅情報を表示する
function get_station(){
    if(request.readyState == 4 && request.status == 200){
        json = request.responseText;
        //document.write(json);
        var station_value = eval('(' + json + ')');


        //すべての条件の時の設定
        var option1 = document.createElement("option");
        option1_text = document.createTextNode("全ての駅");
        for(var i = 0;i < station_value.length;i++){
            option1.value += station_value[i] + ",";
        }
        option1.appendChild(option1_text);
        station.appendChild(option1);

        for(var i = 0;i < station_value.length;i++){
            station_name1 = station_value[i];
            option = document.createElement("option");
            option.value = station_name1;
            option_value = document.createTextNode(station_name1);
            option.appendChild(option_value);
            station.appendChild(option);
        }

    }

}



//市区町村情報をAJAXで検索する
function city_kensaku(){
    //city_nameの子ノードを削除する
    var city_name_childs_num= city_name.childNodes.length;
    for(var i = 0;i < city_name_childs_num;i++){
        city_name.removeChild(city_name.firstChild);
    }

    if(state_name.value){
        request.onreadystatechange = get_city;
        query = "/return_city.php?state=" + encodeURI(state_name.value);
        request.open('GET',query,'true');
        request.send(null);
    }

}


//市区町村情報のAJAXからのレスポンス関数
function get_city(){
    if(request.readyState == 4 && request.status == 200){
        var json = request.responseText;
        //document.write(json);
        var city_value = eval('(' + json + ')');

        //何も指定しないノードを加える
        var option = document.createElement("option");
        option.value = "";
        option_value = document.createTextNode("指定しない");
        option.appendChild(option_value);
        city_name.appendChild(option);
        for(var i = 0;i < city_value.length;i++){
            city_name1 = city_value[i];
            option = document.createElement("option");
            option.value = city_name1;
            option_value = document.createTextNode(city_name1);
            option.appendChild(option_value);
            city_name.appendChild(option);
        }

    }

}

window.onload = init;