// 例: 位置情報を共有

function dbLOC() {
    var nTrial=10, interval=5000;
    var locationmap = L.map("locationmap").setView([38.891, 139.824], 16);
    L.tileLayer('//cyberjapandata.gsi.go.jp/xyz/std/{z}/{x}/{y}.png', {
	attribution:
   '<a href="http://maps.gsi.go.jp/development/ichiran.html">国土地理院</a>'
}).addTo(locationmap);
    var mymarker = L.marker(locationmap.getCenter()).addTo(locationmap);
    var othermarker = {};
    var locTimer;
    var info = document.getElementById('info'),
	name = document.getElementById('name');
    function respondLOC() {
	if (this.readyState == 4) {
	    var resp = JSON.parse(this.responseText); // 受信文字列取得(JSON)
	    if (resp['uid'])
		localStorage.setItem('uid', resp['uid']);
	    if (resp['answer']) {
		alert('ゴール!:\n正解は「' + resp['answer'] + '」です');
		mymarker.bindPopup(resp['answer']).openPopup();
		stop();
	    } else if (resp['distance']) {
		info.textContent = 'あと'+resp['distance']+'mです'
	    }
	}
    }
    function submitLOC(pos) {		// CGIにデータ送出
	// uid vs. name を送らないとだめ ->6/13
	var latlng = L.latLng([pos.coords.latitude, pos.coords.longitude]);
	var uid = localStorage.getItem('uid');
	info.textContent = 'Found'+latlng+'('+nTrial+'回残)';
	locationmap.panTo(latlng);
	mymarker.setLatLng(latlng);
	if (latlng) {
	    var conn = new XMLHttpRequest();
	    // POSTデータを作成する: 変数1=値1&変数2=値2... という形式で
	    // 値の部分に&などが入ってもよいよう encodeURIComponent() する
	    var lat = encodeURIComponent(latlng.lat),
		lng = encodeURIComponent(latlng.lng),
		eui = encodeURIComponent(uid),
		enm = encodeURIComponent(name.value);
	    var post = 'lat='+lat + '&' + 'lng='+lng+'&'+ 'name='+enm;
	    if (uid) post += '&'+ 'uid='+eui;
	    conn.open('POST', './db-loc.cgi');	// POSTメソッドでCGIへ送る
	    conn.setRequestHeader(		// 送信ヘッダを定義
		'Content-Type', 'application/x-www-form-urlencoded');
	    conn.send(post);
	    conn.onreadystatechange = respondLOC;	// イベントリスナ登録
	}
	restart();
    }
    function restart() {
	if (--nTrial > 0) {
	    locTimer = setTimeout(start, interval);
	}
    }
    function onError() {
	info.textContent = 'Cannot capture';
	restart;
    }
    function start() {
	if (name.value == '') {
	    alert('name欄を埋めてください')
	    return;
	}
	localStorage.setItem('name', name.value);
	navigator.geolocation.getCurrentPosition(
	    submitLOC, onError,
	    {maximumAge: 0, enableHighAccuracy: true, timeout: 10000});
    }
    function stop() {
	if (locTimer) {
	    clearTimeout(locTimer);
	}
	info.textContent = 'Stopped';
    }
    function view() {
	alert(localStorage.getItem('uid')+', '+localStorage.getItem('name'));
	// localStorage.clear();
    }
    document.getElementById("start").addEventListener('click', start);
    document.getElementById("stop").addEventListener('click', stop);
    document.getElementById("view").addEventListener('click', view);
    if (localStorage.getItem('name'))
	name.value = localStorage.getItem('name');
}
document.addEventListener('DOMContentLoaded', dbLOC)