var
    /** @type {SlackMessage|null} */
    REPLYING_TO = null
;

/**
 * @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 onNetworkStateUpdated(isNetworkWorking) {
    isNetworkWorking ? document.body.classList.remove(R.klass.noNetwork) : document.body.classList.add(R.klass.noNetwork);
}

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(", ");
    }
    var roomLi = document.getElementById(SELECTED_ROOM.id);
    document.getElementById(R.id.currentRoom.title).textContent = name;
    onRoomUpdated();
    focusInput();

    document.getElementById(R.id.message.file.formContainer).classList.add(R.klass.hidden);
    markRoomAsRead(SELECTED_ROOM);
    if (REPLYING_TO) {
        REPLYING_TO = null;
        onReplyingToUpdated();
    }
}

function onReplyingToUpdated() {
    if (REPLYING_TO) {
        document.body.classList.add(R.klass.replyingTo);
        var domParent = document.getElementById(R.id.message.replyTo)
            ,closeLink = document.createElement("a");
        closeLink.addEventListener("click", function() {
            REPLYING_TO = null;
            onReplyingToUpdated();
        });
        closeLink.className = R.klass.msg.replyTo.close;
        closeLink.textContent = 'x';
        domParent.textContent = "";
        domParent.appendChild(closeLink);
        domParent.appendChild(createMessageDom("reply_" +SELECTED_ROOM.id, REPLYING_TO));
    } else {
        document.body.classList.remove(R.klass.replyingTo);
    }
}

/**
 * @param {string} channelId
 * @param {SlackMessage} msg
 * @return {Element}
**/
function doCreateMessageDom(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();
    var msgContents = msg.raw["text"] || "";
    msgContents = msgContents
        .replace(new RegExp('<([@#]?)([^>]*)>', 'g'),
            function(_, type, entity) {
                var sub = entity.split('|');

                if (type === '@') {
                    if (!sub[1]) {
                        var user = SLACK.context.getMember(sub[0]);
                        sub[1] = user ? ('@' +user.name) : "Unknown member"; // TODO locale
                    } else if ('@' !== sub[1][0]) {
                        sub[1] = '@' +sub[1];
                    }
                    sub[0] = '#' +sub[0];
                    sub[2] = R.klass.msg.link +' ' +R.klass.msg.linkuser;
                } else if (type === '#') {
                    if (!sub[1]) {
                        var chan = SLACK.context.getChannel(sub[0]);
                        sub[1] = chan ? ('#' +chan.name) : "Unknown channel"; // TODO locale
                    } else if ('#' !== sub[1][0]) {
                        sub[1] = '#' +sub[1];
                    }
                    sub[0] = '#' +sub[0];
                    sub[2] = R.klass.msg.link +' ' +R.klass.msg.linkchan;
                } else {
                    if (!sub[1])
                        sub[1] = sub[0];
                    sub[2] = R.klass.msg.link;
                }
                return '<a href="' +sub[0] +'" class="' +sub[2] +'"' +(!type ? ' target="_blank"' : '') +'>' +sub[1] +'</a>';
            })
        .split(/\r?\n/g);
    ;
    for (var msgContentIndex=0, nbMsgContents = msgContents.length; msgContentIndex < nbMsgContents; msgContentIndex++) {
        var msgContent = msgContents[msgContentIndex]
            ,_msgContent = ""
            ,currentMods = {}
            ,quote = false
            ,i =0
            ,msgLength = msgContent.length;

        var checkEnd = function(str, pos, c) {
            while (str[pos]) {
                if (str[pos] != ' ' && str[pos] != c && str[pos +1] == c) {
                    return true;
                }
                pos++;
            }
            return false;
        } ,appendMod = function(mods) {
            if (!Object.keys(currentMods).length)
                return "";
            return '<span class="' +Object.keys(mods).join(' ') +'">';
        };
        // Skip trailing
        while (i < msgLength && (msgContent[i] === ' ' || msgContent[i] === '\t'))
            i++;
        if (msgContent.substr(i, 4) === '&gt;') {
            quote = true;
            i += 4;
        }
        for (; i < msgLength; i++) {
            var c = msgContent[i];

            if (!(currentMods[R.klass.msg.style.bold]) && c === '*' && msgContent[i +1] && checkEnd(msgContent, i, c)) {
                if (Object.keys(currentMods).length)
                    _msgContent += '</span>';
                currentMods[R.klass.msg.style.bold] = true;
                _msgContent += appendMod(currentMods);
            } else if (!(currentMods[R.klass.msg.style.strike]) && c === '~' && msgContent[i +1] && checkEnd(msgContent, i, c)) {
                if (Object.keys(currentMods).length)
                    _msgContent += '</span>';
                currentMods[R.klass.msg.style.strike] = true;
                _msgContent += appendMod(currentMods);
            } else if (!(currentMods[R.klass.msg.style.code]) && c === '`' && msgContent[i +1] && checkEnd(msgContent, i, c)) {
                if (Object.keys(currentMods).length)
                    _msgContent += '</span>';
                currentMods[R.klass.msg.style.code] = true;
                _msgContent += appendMod(currentMods);
            } else if (!(currentMods[R.klass.msg.style.italic]) && c === '_' && msgContent[i +1] && checkEnd(msgContent, i, c)) {
                if (Object.keys(currentMods).length)
                    _msgContent += '</span>';
                currentMods[R.klass.msg.style.italic] = true;
                _msgContent += appendMod(currentMods);
            } else {
                var finalFound = false;
                _msgContent += c;

                do {
                    if ((currentMods[R.klass.msg.style.bold]) && c !== '*' && msgContent[i +1] === '*') {
                        delete currentMods[R.klass.msg.style.bold];
                        finalFound = true;
                    } else if ((currentMods[R.klass.msg.style.strike]) && c !== '~' && msgContent[i +1] === '~') {
                        delete currentMods[R.klass.msg.style.strike];
                        finalFound = true;
                    } else if ((currentMods[R.klass.msg.style.code]) && c !== '`' && msgContent[i +1] === '`') {
                        delete currentMods[R.klass.msg.style.code];
                        finalFound = true;
                    } else if ((currentMods[R.klass.msg.style.italic]) && c !== '_' && msgContent[i +1] === '_') {
                        delete currentMods[R.klass.msg.style.italic];
                        finalFound = true;
                    } else {
                        break;
                    }
                    c = msgContent[++i];
                } while (i < msgLength);
                if (finalFound)
                    _msgContent += '</span>' +appendMod(currentMods);
            }
        }
        if (currentMods) {
            // Should not append
            _msgContent += '</span>';
        }
        if (quote)
            msgContents[msgContentIndex] = '<span class="' +R.klass.msg.style.quote +'">' +_msgContent +'</span>';
        else
            msgContents[msgContentIndex] = _msgContent;
    }
    text.innerHTML = msgContents.join('<br/>');
    authorName.textContent = sender ? sender.name : (msg.raw["username"] || "?");
    if (!sender && !msg.raw["username"])
        text.textContent = msg.raw["subtype"] || JSON.stringify(msg.raw);
    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;
}

/**
 * @param {string} channelId
 * @param {SlackMessage} msg
 * @return {Element}
**/
function doCreateMeMessageDom(channelId, msg) {
    var dom = doCreateMessageDom(channelId, msg);
    dom.classList.add(R.klass.msg.meMessage);
    return dom;
}

/**
 * @param {string} channelId
 * @param {SlackMessage} msg
 * @return {Element}
**/
function createMessageDom(channelId, msg) {
    if (msg.subtype === "me_message") {
        return doCreateMeMessageDom(channelId, msg);
    }
    return doCreateMessageDom(channelId, msg);
}

function updateTitle() {
    var hasUnread = 0
        ,hasHl = 0
        ,title;

    for (var i in UNREAD_CHANS) {
        if (UNREAD_CHANS.hasOwnProperty(i)) {
            hasUnread += UNREAD_CHANS[i].unread;
            hasHl += UNREAD_CHANS[i].hl;
        }
    }
    if (hasHl) {
        title = "(!" +hasHl;
    }
    if (hasUnread) {
        title = (title ? (title+" - ") : "(") +hasUnread;
    }
    if (title)
        title += ") " +SLACK.context.team.name;
    else
        title = SLACK.context.team.name;
    document.title = title;
}

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) {
            if (msg.type === "message") {
                var dom = createMessageDom(currentRoomId, msg);
                chatFrag.appendChild(dom);
            }
        });
    var content = document.getElementById(R.id.currentRoom.content);
    content.appendChild(chatFrag);
    //TODO scroll lock
    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 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) {
                        if (REPLYING_TO !== history[i]) {
                            REPLYING_TO = history[i];
                            onReplyingToUpdated();
                        }
                        return;
                    }
                }
            }
            return;
        }
        target = target.parentElement;
    }
}

function focusInput() {
    document.getElementById(R.id.message.input).focus();
}

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.file.cancel).addEventListener("click", function(e) {
        e.preventDefault();
        document.getElementById(R.id.message.file.error).classList.add(R.klass.hidden);
        document.getElementById(R.id.message.file.formContainer).classList.add(R.klass.hidden);
        document.getElementById(R.id.message.file.fileInput).value = "";
        return false;
    });
    document.getElementById(R.id.message.file.form).addEventListener("submit", function(e) {
        e.preventDefault();
        var fileInput = document.getElementById(R.id.message.file.fileInput)
            ,filename = fileInput.value;

        if (filename) {
            filename = filename.substr(filename.lastIndexOf('\\') +1);
            uploadFile(SELECTED_ROOM, filename, fileInput.files[0], function(errorMsg) {
                var error = document.getElementById(R.id.message.file.error);
                if (errorMsg) {
                    error.textContent = errorMsg;
                    error.classList.remove(R.klass.hidden);
                } else {
                    error.classList.add(R.klass.hidden);
                    document.getElementById(R.id.message.file.fileInput).value = "";
                    document.getElementById(R.id.message.file.formContainer).classList.add(R.klass.hidden);
                }
            });
        }
        return false;
    });
    document.getElementById(R.id.message.file.bt).addEventListener("click", function(e) {
        e.preventDefault();
        if (SELECTED_ROOM) {
            document.getElementById(R.id.message.file.formContainer).classList.remove(R.klass.hidden);
        }
        return false;
    });
    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, REPLYING_TO);
            input.value = "";
            if (REPLYING_TO) {
                REPLYING_TO = null;
                onReplyingToUpdated();
            }
        }
        focusInput();
        return false;
    });
    window.addEventListener('blur', function() {
        window.hasFocus = false;
    });
    window.addEventListener('focus', function() {
        window.hasFocus = true;
        if (SELECTED_ROOM)
            markRoomAsRead(SELECTED_ROOM);
        focusInput();
    });
    window.hasFocus = true;

    startPolling();
});