// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
// See License.txt for license information.

import AppDispatcher from 'dispatcher/app_dispatcher.jsx';

import ChannelStore from 'stores/channel_store.jsx';
import PostStore from 'stores/post_store.jsx';
import TeamStore from 'stores/team_store.jsx';
import UserStore from 'stores/user_store.jsx';

import * as PostUtils from 'utils/post_utils.jsx';
import Constants from 'utils/constants.jsx';
const ActionTypes = Constants.ActionTypes;

import Client from 'utils/web_client.jsx';
import * as AsyncClient from 'utils/async_client.jsx';

export function handleNewPost(post, msg) {
    if (ChannelStore.getCurrentId() === post.channel_id) {
        if (window.isActive) {
            AsyncClient.updateLastViewedAt();
        } else {
            AsyncClient.getChannel(post.channel_id);
        }
    } else if (msg && (TeamStore.getCurrentId() === msg.team_id || msg.props.channel_type === Constants.DM_CHANNEL)) {
        AsyncClient.getChannel(post.channel_id);
    }

    var websocketMessageProps = null;
    if (msg) {
        websocketMessageProps = msg.data;
    }

    if (post.root_id && PostStore.getPost(post.channel_id, post.root_id) == null) {
        Client.getPost(
            post.channel_id,
            post.root_id,
            (data) => {
                AppDispatcher.handleServerAction({
                    type: ActionTypes.RECEIVED_POSTS,
                    id: post.channel_id,
                    numRequested: 0,
                    post_list: data
                });

                // Required to update order
                AppDispatcher.handleServerAction({
                    type: ActionTypes.RECEIVED_POST,
                    post,
                    websocketMessageProps
                });
            },
            (err) => {
                AsyncClient.dispatchError(err, 'getPost');
            }
        );

        return;
    }

    AppDispatcher.handleServerAction({
        type: ActionTypes.RECEIVED_POST,
        post,
        websocketMessageProps
    });
}

export function setUnreadPost(channelId, postId) {
    let lastViewed = 0;
    let ownNewMessage = false;
    const post = PostStore.getPost(channelId, postId);
    const posts = PostStore.getVisiblePosts(channelId).posts;
    var currentUsedId = UserStore.getCurrentId();
    if (currentUsedId === post.user_id || PostUtils.isSystemMessage(post)) {
        for (const otherPostId in posts) {
            if (lastViewed < posts[otherPostId].create_at && currentUsedId !== posts[otherPostId].user_id && !PostUtils.isSystemMessage(posts[otherPostId])) {
                lastViewed = posts[otherPostId].create_at;
            }
        }
        if (lastViewed === 0) {
            lastViewed = Number.MAX_VALUE;
        } else if (lastViewed > post.create_at) {
            lastViewed = post.create_at - 1;
            ownNewMessage = true;
        } else {
            lastViewed -= 1;
        }
    } else {
        lastViewed = post.create_at - 1;
    }

    if (lastViewed === Number.MAX_VALUE) {
        AsyncClient.updateLastViewedAt();
        ChannelStore.resetCounts(ChannelStore.getCurrentId());
        ChannelStore.emitChange();
    } else {
        let unreadPosts = 0;
        for (const otherPostId in posts) {
            if (posts[otherPostId].create_at > lastViewed) {
                unreadPosts += 1;
            }
        }
        const member = ChannelStore.getMember(channelId);
        const channel = ChannelStore.get(channelId);
        member.last_viewed_at = lastViewed;
        member.msg_count = channel.total_msg_count - unreadPosts;
        member.mention_count = 0;
        ChannelStore.setChannelMember(member);
        ChannelStore.setUnreadCount(channelId);
        AsyncClient.setLastViewedAt(lastViewed, channelId);
    }

    if (channelId === ChannelStore.getCurrentId()) {
        ChannelStore.emitLastViewed(lastViewed, ownNewMessage);
    }
}
