/**
 * @param {SlackChan|SlackGroup} chan
 * @return {Element}
**/
function createChanListItem(chan) {
    var dom = document.createElement("li");
    dom.id = chan.id;
    if (chan.id[0] === 'D')
        dom.className = R.klass.chatList.entry + " " +R.klass.chatList.typeDirect;
    else if (chan.id[0] === 'G')
        dom.className = R.klass.chatList.entry + " " +R.klass.chatList.typeGroup;
    else if (chan.id[0] === 'C')
        dom.className = R.klass.chatList.entry + " " +R.klass.chatList.typeChannel;
    dom.textContent = chan.name;
    return dom;
}

/**
 * @param {SlackIms} ims
 * @return {Element}
**/
function createImsListItem(ims) {
    var dom = document.createElement("li");
    dom.id = ims.id;
    dom.className = R.klass.chatList.entry;
    dom.textContent = ims.user.name;
    return dom;
}

function onContextUpdated() {
    var chanListFram = document.createDocumentFragment();

    var sortedChans = SLACK.context.self ? Object.keys(SLACK.context.self.channels) : [];
    sortedChans.sort(function(a, b) {
        if (a[0] !== b[0]) {
            return a[0] - b[0];
        }
        return (SLACK.context.channels[a] || SLACK.context.groups[a]).name.localeCompare((SLACK.context.channels[b] || SLACK.context.groups[b]).name);
    });
    sortedChans.forEach(function(chanId) {
        var chan = SLACK.context.channels[chanId] || SLACK.context.groups[chanId]
            ,chanListItem = createChanListItem(chan);
        if (chanListItem) {
            chanListFram.appendChild(chanListItem);
        }
    });
    var sortedUsers = SLACK.context.users ? Object.keys(SLACK.context.users) : [];
    sortedUsers.sort(function(a, b) {
        return SLACK.context.users[a].name.localeCompare(SLACK.context.users[b].name);
    });
    sortedUsers.forEach(function(userId) {
        var ims = SLACK.context.users[userId].ims
            ,imsListItem = createImsListItem(ims);

        if (imsListItem) {
            chanListFram.appendChild(imsListItem);
        }
    });
    document.getElementById(R.id.chanList).textContent = "";
    document.getElementById(R.id.chanList).appendChild(chanListFram);
}

function onRoomSelected() {
    var name = SELECTED_ROOM.name || (SELECTED_ROOM.user ? SELECTED_ROOM.user.name : undefined);
    if (!name) {
        var members = [];
        for (var i in SELECTED_ROOM.members) {
            members.push(SELECTED_ROOM.members[i].name);
        }
        name = members.join(", ");
    }
    document.getElementById(R.id.currentRoom.title).textContent = name;
    onRoomUpdated();
}

function createMessageDom(channelId, msg) {
    var dom = document.createElement("div")
        ,ts = document.createElement("div")
        ,text = document.createElement("div")
        ,author = document.createElement("div")
        ,authorImg = document.createElement("img")
        ,authorName = document.createElement("span")
        ,hover = document.createElement("ul")
        ,hoverReply = document.createElement("li")
        ,sender = msg.raw["user"] ?
            SLACK.context.users[msg.raw["user"]] :
            SLACK.context.bots[msg.raw["bot_id"]];

    dom.id = channelId +"_" +msg.ts;
    dom.className = R.klass.msg.item;
    ts.className = R.klass.msg.ts;
    text.className = R.klass.msg.msg;
    author.className = R.klass.msg.author;
    authorImg.className = R.klass.msg.authorAvatar;
    authorName.className = R.klass.msg.authorname;
    hover.className = R.klass.msg.hover.container;
    hoverReply.className = R.klass.msg.hover.reply;
    ts.textContent = (new Date(msg.ts * 1000)).toLocaleTimeString();
    text.textContent = msg.raw["text"];
    authorName.textContent = sender ? sender.name : (msg.raw["username"] || "?");
    authorImg.src = sender ? sender.icons.image_48 : "";
    author.appendChild(authorImg);
    author.appendChild(authorName);
    hover.appendChild(hoverReply);
    dom.appendChild(author);
    dom.appendChild(text);
    dom.appendChild(ts);
    dom.appendChild(hover);
    return dom;
}

function onRoomUpdated() {
    var chatFrag = document.createDocumentFragment()
        ,currentRoomId = SELECTED_ROOM.id;

    document.getElementById(R.id.currentRoom.content).textContent = "";
    if (SLACK.history[currentRoomId])
        SLACK.history[currentRoomId].messages.forEach(function(msg) {
            chatFrag.appendChild(createMessageDom(currentRoomId, msg));
        });
    var content = document.getElementById(R.id.currentRoom.content);
    content.appendChild(chatFrag);
    //TODO scroll lock
    console.log(content.scrollTop = content.scrollHeight -content.clientHeight);
}

function onChanClick(e) {
    while (e.target !== e.currentTarget && e.target) {
        if (e.target.classList.contains(R.klass.chatList.entry)) {
            var room = (SLACK.context.channels[e.target.id] ||
                SLACK.context.ims[e.target.id] ||
                SLACK.context.groups[e.target.id]);

            if (room && room !== SELECTED_ROOM) {
                selectRoom(room);
            }
            return;
        }
        e.target = e.target.parentElement;
    }
}

function replyTo(msg) {
    console.log("Replying to ", msg);
}

function chatClickDelegate(e) {
    var target = e.target
        ,getMessageId = function(e, target) {
            target = target || e.target;
            while (target !== e.currentTarget && target) {
                if (target.classList.contains(R.klass.msg.item)) {
                    return target.id;
                }
                target = target.parentElement;
            }
        };
    while (target !== e.currentTarget && target) {
        if (target.classList.contains(R.klass.msg.hover.container)) {
            return;
        } else if (target.classList.contains(R.klass.msg.hover.reply)) {
            var messageId = getMessageId(e, target);
            if (messageId) {
                messageId = parseFloat(messageId.split("_")[1]);
                var history = SLACK.history[SELECTED_ROOM.id].messages;

                for (var i =0, histLen =history.length; i < histLen && history[i].ts <= messageId; i++) {
                    if (history[i].ts === messageId) {
                        replyTo(history[i]);
                        return;
                    }
                }
            }
            return;
        }
        target = target.parentElement;
    }
}

document.addEventListener('DOMContentLoaded', function() {
    document.getElementById(R.id.chatList).addEventListener("click", onChanClick);
    document.getElementById(R.id.currentRoom.content).addEventListener("click", chatClickDelegate);
    document.getElementById(R.id.message.form).addEventListener("submit", function(e) {
        e.preventDefault();
        var input =document.getElementById(R.id.message.input);
        if (SELECTED_ROOM && input.value) {
            sendMsg(SELECTED_ROOM, input.value);
            input.value = "";
        }
        return false;
    });

    startPolling();
});