import { GetMessagesMessageComposer, ModerateMessageMessageComposer, ModerateThreadMessageComposer, PostMessageMessageComposer, PostMessageMessageEvent, PostThreadMessageEvent, ThreadMessagesMessageEvent, UpdateForumReadMarkerMessageComposer, UpdateForumReadMarkerEntry, UpdateMessageMessageEvent, UpdateThreadMessageComposer, UpdateThreadMessageEvent } from '@nitrots/nitro-renderer';
import { FC, useCallback, useEffect, useRef, useState } from 'react';
import { LocalizeText, SendMessageComposer, GetUserProfile } from '../../../../api';
import { Button, Column, Flex, LayoutAvatarImageView, Text } from '../../../../common';
import { useMessageEvent } from '../../../../hooks';
import { ExtendedForumData, GuildForumThread, MessageData } from '@nitrots/nitro-renderer';

const MESSAGES_PER_PAGE = 20;

// Message states
const STATE_NORMAL = 0;
const STATE_VISIBLE = 1;
const STATE_HIDDEN_BY_ADMIN = 10;
const STATE_DELETED_BY_MODERATOR = 20;

interface GroupForumThreadViewProps
{
    groupId: number;
    threadId: number;
    initialThread?: GuildForumThread;
    forumData: ExtendedForumData;
    onBack: () => void;
}

export const GroupForumThreadView: FC<GroupForumThreadViewProps> = props =>
{
    const { groupId = 0, threadId = 0, initialThread = null, forumData = null, onBack = null } = props;
    const effectiveGroupId = forumData?.groupId || groupId;
    const [ messages, setMessages ] = useState<MessageData[]>([]);
    const [ totalMessages, setTotalMessages ] = useState<number>(0);
    const [ replyText, setReplyText ] = useState<string>('');
    const [ threadInfo, setThreadInfo ] = useState<GuildForumThread>(initialThread);
    const [ isSubmitting, setIsSubmitting ] = useState<boolean>(false);
    const messagesEndRef = useRef<HTMLDivElement>(null);

    useMessageEvent<ThreadMessagesMessageEvent>(ThreadMessagesMessageEvent, event =>
    {
        const parser = event.getParser();

        if(parser.groupId !== effectiveGroupId || parser.threadId !== threadId) return;

        setTotalMessages(parser.amount);

        if(parser.startIndex === 0)
        {
            setMessages(parser.messages);
        }
        else
        {
            setMessages(prev => [ ...prev, ...parser.messages ]);
        }

        // Mark messages as read
        if(parser.messages.length > 0)
        {
            const lastMessage = parser.messages[parser.messages.length - 1];
            SendMessageComposer(new UpdateForumReadMarkerMessageComposer(
                new UpdateForumReadMarkerEntry(effectiveGroupId, lastMessage.messageId, true)
            ));
        }
    });

    useMessageEvent<PostMessageMessageEvent>(PostMessageMessageEvent, event =>
    {
        const parser = event.getParser();

        if(parser.groupId !== effectiveGroupId || parser.threadId !== threadId) return;

        setMessages(prev => [ ...prev, parser.message ]);
    });

    useMessageEvent<PostThreadMessageEvent>(PostThreadMessageEvent, event =>
    {
        const parser = event.getParser();

        if(parser.groupId !== effectiveGroupId) return;

        // Update thread info if this is our thread
        if(parser.thread.threadId === threadId)
        {
            setThreadInfo(parser.thread);
        }
    });

    useMessageEvent<UpdateMessageMessageEvent>(UpdateMessageMessageEvent, event =>
    {
        const parser = event.getParser();

        if(parser.groupId !== effectiveGroupId || parser.threadId !== threadId) return;

        setMessages(prev => prev.map(msg =>
        {
            if(msg.messageId === parser.message.messageId)
            {
                return parser.message;
            }

            return msg;
        }));
    });

    useMessageEvent<UpdateThreadMessageEvent>(UpdateThreadMessageEvent, event =>
    {
        const parser = event.getParser();

        if(parser.groupId !== effectiveGroupId) return;

        if(parser.thread.threadId === threadId)
        {
            setThreadInfo(parser.thread);
        }
    });

    useEffect(() =>
    {
        if(!effectiveGroupId || !threadId) return;

        setMessages([]);
        SendMessageComposer(new GetMessagesMessageComposer(effectiveGroupId, threadId, 0, MESSAGES_PER_PAGE));
    }, [ effectiveGroupId, threadId ]);

    const sendReply = useCallback(() =>
    {
        if(replyText.trim().length < 10 || isSubmitting) return;

        setIsSubmitting(true);
        SendMessageComposer(new PostMessageMessageComposer(effectiveGroupId, threadId, '', replyText.trim()));
        setReplyText('');

        setTimeout(() => setIsSubmitting(false), 1000);
    }, [ effectiveGroupId, threadId, replyText, isSubmitting ]);

    const togglePinThread = useCallback(() =>
    {
        if(!threadInfo) return;

        // UpdateThreadMessageComposer swaps 3rd/4th params internally: (groupId, threadId, isLocked, isPinned)
        SendMessageComposer(new UpdateThreadMessageComposer(effectiveGroupId, threadId, threadInfo.isLocked, !threadInfo.isPinned));
    }, [ effectiveGroupId, threadId, threadInfo ]);

    const toggleLockThread = useCallback(() =>
    {
        if(!threadInfo) return;

        // UpdateThreadMessageComposer swaps 3rd/4th params internally: (groupId, threadId, isLocked, isPinned)
        SendMessageComposer(new UpdateThreadMessageComposer(effectiveGroupId, threadId, !threadInfo.isLocked, threadInfo.isPinned));
    }, [ effectiveGroupId, threadId, threadInfo ]);

    const hideMessage = useCallback((messageId: number) =>
    {
        SendMessageComposer(new ModerateMessageMessageComposer(effectiveGroupId, threadId, messageId, STATE_HIDDEN_BY_ADMIN));
    }, [ effectiveGroupId, threadId ]);

    const restoreMessage = useCallback((messageId: number) =>
    {
        SendMessageComposer(new ModerateMessageMessageComposer(effectiveGroupId, threadId, messageId, STATE_VISIBLE));
    }, [ effectiveGroupId, threadId ]);

    const hideThread = useCallback(() =>
    {
        SendMessageComposer(new ModerateThreadMessageComposer(effectiveGroupId, threadId, STATE_HIDDEN_BY_ADMIN));
        onBack();
    }, [ effectiveGroupId, threadId, onBack ]);

    const deleteThread = useCallback(() =>
    {
        SendMessageComposer(new ModerateThreadMessageComposer(effectiveGroupId, threadId, STATE_DELETED_BY_MODERATOR));
        onBack();
    }, [ effectiveGroupId, threadId, onBack ]);

    const formatTimeAgo = (seconds: number): string =>
    {
        if(seconds < 60) return `${ seconds }s ${ LocalizeText('messageboard.time.ago') }`;
        if(seconds < 3600) return `${ Math.floor(seconds / 60) }m ${ LocalizeText('messageboard.time.ago') }`;
        if(seconds < 86400) return `${ Math.floor(seconds / 3600) }h ${ LocalizeText('messageboard.time.ago') }`;

        return `${ Math.floor(seconds / 86400) }d ${ LocalizeText('messageboard.time.ago') }`;
    };

    const getMessageStateText = (message: MessageData): string =>
    {
        if(message.state === STATE_HIDDEN_BY_ADMIN)
        {
            return LocalizeText('messageboard.message.hidden.by.admin');
        }

        if(message.state === STATE_DELETED_BY_MODERATOR)
        {
            return LocalizeText('messageboard.message.permanently.deleted.by.moderator');
        }

        return null;
    };

    const canModerate = forumData && forumData.hasModeratePermissionError;
    const canPost = forumData && forumData.hasPostMessagePermissionError;
    const isLocked = threadInfo ? threadInfo.isLocked : false;

    // Derive thread info from first message if we don't have explicit thread info
    const threadHeader = (messages.length > 0 && messages[0]) ? messages[0].messageText : '';

    return (
        <Column className="h-full" gap={ 0 }>
            <Flex className="bg-muted p-2 border-b" gap={ 2 } alignItems="center" justifyContent="between">
                <Flex gap={ 2 } alignItems="center">
                    <Text pointer underline onClick={ onBack }>
                        &laquo; { LocalizeText('groupforum.view.back') }
                    </Text>
                </Flex>
                { canModerate &&
                    <Flex gap={ 1 }>
                        <Button variant={ threadInfo?.isPinned ? 'warning' : 'outline-secondary' } className="btn-sm" onClick={ togglePinThread }>
                            { threadInfo?.isPinned ? LocalizeText('groupforum.thread.unpin') : LocalizeText('groupforum.thread.pin') }
                        </Button>
                        <Button variant={ isLocked ? 'danger' : 'outline-secondary' } className="btn-sm" onClick={ toggleLockThread }>
                            { isLocked ? LocalizeText('groupforum.thread.unlock') : LocalizeText('groupforum.thread.lock') }
                        </Button>
                        <Button variant="outline-danger" className="btn-sm" onClick={ hideThread }>
                            { LocalizeText('groupforum.thread.hide') }
                        </Button>
                        <Button variant="danger" className="btn-sm" onClick={ deleteThread }>
                            { LocalizeText('groupforum.thread.delete') }
                        </Button>
                    </Flex> }
            </Flex>
            <Column className="overflow-auto flex-1" gap={ 0 }>
                { messages.map((message, index) =>
                {
                    const stateText = getMessageStateText(message);

                    if(stateText && !canModerate)
                    {
                        return (
                            <Flex key={ message.messageId } className="p-2 border-b bg-danger bg-opacity-10" alignItems="center">
                                <Text small variant="muted">{ stateText }</Text>
                            </Flex>
                        );
                    }

                    return (
                        <Flex key={ message.messageId }
                            className={ `p-3 border-b ${ (message.state !== STATE_NORMAL) ? 'bg-danger bg-opacity-10' : '' }` }
                            gap={ 3 }>
                            <Column className="flex-shrink-0 items-center w-[50px]" gap={ 1 }>
                                <div className="w-[40px] h-[40px] rounded-full mx-auto overflow-hidden bg-[rgba(255,255,255,0.1)] flex justify-center">
                                    <div className="mt-[-25px]">
                                        <LayoutAvatarImageView figure={ message.authorFigure } headOnly={ true } direction={ 2 } />
                                    </div>
                                </div>
                                <Text small bold pointer underline onClick={ () => GetUserProfile(message.authorId) }>
                                    { message.authorName }
                                </Text>
                                <Text small variant="muted">{ message.authorPostCount } { LocalizeText('messageboard.messages') }</Text>
                            </Column>
                            <Column className="flex-1" gap={ 1 }>
                                <Flex justifyContent="between" alignItems="center">
                                    <Text small variant="muted">{ formatTimeAgo(message.creationTime) }</Text>
                                    { canModerate && (message.state !== STATE_NORMAL) &&
                                        <Flex gap={ 1 }>
                                            <Text small variant="muted">{ stateText }</Text>
                                            <Text small pointer underline variant="primary" onClick={ () => restoreMessage(message.messageId) }>
                                                { LocalizeText('groupforum.message.restore') }
                                            </Text>
                                        </Flex> }
                                    { canModerate && (message.state === STATE_NORMAL) &&
                                        <Text small pointer underline variant="danger" onClick={ () => hideMessage(message.messageId) }>
                                            { LocalizeText('groupforum.message.hide') }
                                        </Text> }
                                </Flex>
                                { (message.state === STATE_NORMAL || canModerate) &&
                                    <Text className="whitespace-pre-wrap break-words">{ message.messageText }</Text> }
                            </Column>
                        </Flex>
                    );
                }) }
                { (messages.length < totalMessages) &&
                    <Flex justifyContent="center" className="p-2">
                        <Text pointer underline onClick={ () =>
                        {
                            SendMessageComposer(new GetMessagesMessageComposer(effectiveGroupId, threadId, messages.length, MESSAGES_PER_PAGE));
                        } }>
                            { LocalizeText('groupforum.thread.load_more') }
                        </Text>
                    </Flex> }
                <div ref={ messagesEndRef } />
            </Column>
            { canPost && !isLocked &&
                <Flex className="p-2 border-t bg-light" gap={ 2 }>
                    <textarea
                        className="form-control form-control-sm flex-1"
                        placeholder={ LocalizeText('messageboard.message.replying.to') }
                        rows={ 2 }
                        maxLength={ 4000 }
                        value={ replyText }
                        onChange={ e => setReplyText(e.target.value) }
                        onKeyDown={ e =>
                        {
                            if(e.key === 'Enter' && !e.shiftKey)
                            {
                                e.preventDefault();
                                sendReply();
                            }
                        } }
                    />
                    <Button variant="primary" className="btn-sm align-self-end" onClick={ sendReply } disabled={ replyText.trim().length < 10 || isSubmitting }>
                        { LocalizeText('messageboard.reply.button') }
                    </Button>
                </Flex> }
            { isLocked &&
                <Flex className="p-2 border-t bg-warning bg-opacity-10" justifyContent="center">
                    <Text small variant="muted">{ LocalizeText('groupforum.thread.locked') }</Text>
                </Flex> }
            { !canPost && !isLocked && forumData &&
                <Flex className="p-2 border-t bg-muted" justifyContent="center">
                    <Text small variant="muted">
                        { LocalizeText('groupforum.view.error.' + forumData.postMessagePermissionError) }
                    </Text>
                </Flex> }
        </Column>
    );
};