window.app = (function() {
    var that = {},
        coords,
        map,
        marker,
        username = localStorage.username || 'Anonymous',
        color = randomColor(),
        userlist,
        users = [],
        zoomLevel = 23;

    window.onload = setup();
    document.body && window.onload();

    function createUser(data) {
        var user = {
            id: data.id,
            name: data.name,
            color: data.color,
        };
        if (!user.color) {
            user.color = [255, 0, 0];
        }
        users.push(user);
        if(coords) {
            update({
                name: username,
                color: color,
                coords: coords
            });
        }
        updateUserList();
        return user;
    }

    function getUserById(id) {
        return users.filter(function(user) {
            return user.id == id;
        })[0];
    }

    function initMap() {
        navigator.geolocation.watchPosition(updateLocation, locationError, {
            enableHighAccuracy: true
        });
    }

    function joinRoom(room) {
        if(that.room) {
            post(['leave', that.room]);
        }
        users.forEach(function(user) {
            if (user.marker) {
                map.removeLayer(user.marker);
            }
        });
        users = [];
        that.room = room;
        post(['join', that.room]);
        if (coords) {
            update({
                name: username,
                coords: coords
            });
        } else {
            initMap();
        }
        updateUserList();
    }

    function locationError(err) {
        console.log(err);
    }

    function post(data) {
        that.ws.send(JSON.stringify(data));
    }

    function randomColor() {
        var colors = [
                [128, 0, 0],
                [0, 128, 0],
                [0, 0, 128],
                [128, 128, 0],
                [0, 128, 128],
                [128, 0, 128],
                [128, 64, 0],
                [64, 128, 0],
                [0, 128, 64],
                [0, 64, 128],
                [64, 0, 128],
                [128, 0, 64]
            ];
        return colors[Math.floor(Math.random() * 12)];
    }

    function randomName() {
        var name = '';
        while(name.length < 14) {
            name +=  String.fromCharCode('A'.charCodeAt(0) + Math.floor(Math.random() * 25));
        }
        return name;
    }

    function removeUser(id) {
        var user = getUserById(id);
        if (user) {
            if (user.marker) {
                map.removeLayer(user.marker);
            }
            users = users.filter(function(user) {
                user.id != id;
            });
        }
    }

    function setup() {
        var host = (document.location.protocol == 'http:' ? 'ws' : 'wss') + '://' + document.location.host;
        that.ws = new WebSocket(host + '/ws');
        that.ws.onopen = function () {
            window.onhashchange = function() {
                var name = document.location.hash.slice(1);
                if (name) {
                    document.title = '#' + name;
                    joinRoom(name);
                } else {
                    document.location.href = '#' + randomName();
                }
            }
            window.onhashchange();
        };
        that.ws.onmessage = function (event) {
            var data = JSON.parse(event.data);
            if (data[0] == 'leave') {
                removeUser(data[1]);
            } else if (data[0] == 'update') {
                data[2].id = data[1];
                updateUser(data[2]);
            }
        };
        that.ws.onclose = function (event) {
            setTimeout(function() {
                setup();
            }, 1000);
        };
    }

    function update(data) {
        post(['update', that.room, data]);
    }

    function updateLocation(loc) {
        coords = [loc.coords.latitude, loc.coords.longitude];
        var options = {
            title: username,
            icon: L.icon({
                iconUrl: MarkerIcon({
                    label: username[0],
                    color: [255, 255, 255],
                    background: color
                })
            })
        };
        if (!marker) {
            if (!map) {
                L.mapbox.accessToken = config.mapboxAccessToken;
                map = L.mapbox.map('map')
                    .setView(coords, zoomLevel)
                    .addLayer(L.mapbox.styleLayer('mapbox://styles/mapbox/streets-v11'));
            }
            marker = L.marker(coords, options)
                .bindPopup(options.title)
                .addTo(map);
            map.setView(coords, zoomLevel);
            updateUserList();
        } else {
            map.removeLayer(marker);
            marker = L.marker(coords, options)
                .bindPopup(options.title)
                .addTo(map);
        }
        update({
            name: username,
            coords: coords
        });
    }

    function updateUser(data) {
        var user = getUserById(data.id);
        if (!user) {
            user = createUser(data);
        }
        user.coords = data.coords;
        if (user.name != data.name) {
            user.name = data.name;
            updateUserList();
        }
        var options = {
            title: user.name,
            icon: L.icon({
                iconUrl: MarkerIcon({
                    label: user.name[0],
                    background: user.color
                })
            })
        };
        if (user.marker) {
            map.removeLayer(user.marker);
        }
        user.marker = L.marker(user.coords, options)
            .bindPopup(user.name)
            .addTo(map);
    }

    function updateUserList() {
        var list = document.createElement('div');
            list.id = 'users';
        [{
            name: username,
            color: color
        }].concat(users).forEach(function(user) {
            var div = document.createElement('div');
            div.className = 'person';
            div.innerHTML = user.name;
            div.style.background = 'rgb(' + user.color.join(', ') + ')';
            div.style.top = '8px'
            div.onclick = function() {
                if (!user.id) {
                    var name = prompt("What is your name?", username) || 'Anonymous';
                    localStorage.username = username = name;
                    update({
                        name: username,
                        color: color,
                        coords: coords
                    });
                    updateUserList();
                } else if (user.coords) {
                    map.setView(user.coords, zoomLevel);
                }
            }
            list.appendChild(div);
        });
        if (userlist) {
            document.body.replaceChild(list, userlist);
        } else {
            document.body.appendChild(list);
        }
        userlist = list;
    }

    function MarkerIcon(options) {
        options = options || {};
        options.background = options.background || [255, 0, 0];
        options.color = options.color || [255, 255, 255];
        options.label = options.label || 'A';
        var size = 20;
        var canvas = document.createElement('canvas')
        canvas.setAttribute('width', size);
        canvas.setAttribute('height', size);
        var context = canvas.getContext('2d');
        context.fillStyle = 'rgb(' + options.background.join(', ') + ')';
        context.arc(size / 2, size / 2, size / 2 - 2, 0, 360);
        context.fill();
        context.beginPath();
        context.lineWidth = 2;
        context.strokeStyle = 'rgb(' + options.color.join(', ') + ')';
        context.arc(size / 2, size / 2, size / 2 - 1, 0, 360);
        context.stroke();
        context.font = '14px sans-serif';
        context.textAlign = 'center';
        context.fillStyle = 'rgb(' + options.color.join(', ') + ')';
        context.fillText(options.label, size / 2, size * 0.75);
        return canvas.toDataURL();
    }

    return that;
})();