hunk.code_window:     loadMorePostsTop(id, true);
   }
   export function loadMorePostsTop(id, isFocusPost) {
       const earliestPostId = PostStore.getEarliestPost(id).id;
       if (PostStore.requestVisibilityIncrease(id, Constants.POST_CHUNK_SIZE)) {
           loadPostsBefore(earliestPostId, 0, Constants.POST_CHUNK_SIZE, isFocusPost);
       }
  
hunk.labels: keep keep keep keep replace keep keep keep
hunk.after_edit:     const earliestPostId = PostStore.getEarliestPostFromPage(id).id;
  
hunk.file_path: webapp/actions/global_actions.jsx
hunk.type: replace
file: // Copyright (c) 2015 Mattermost, Inc. All Rights Reserved.
  // See License.txt for license information.
  
  import AppDispatcher from '../dispatcher/app_dispatcher.jsx';
  import EventEmitter from 'events';
  
  import ChannelStore from 'stores/channel_store.jsx';
  import BrowserStore from 'stores/browser_store.jsx';
  import UserStore from 'stores/user_store.jsx';
  
  import Constants from 'utils/constants.jsx';
  const ActionTypes = Constants.ActionTypes;
  
  const CHANGE_EVENT = 'change';
  const FOCUSED_POST_CHANGE = 'focused_post_change';
  const EDIT_POST_EVENT = 'edit_post';
  const POSTS_VIEW_JUMP_EVENT = 'post_list_jump';
  const SELECTED_POST_CHANGE_EVENT = 'selected_post_change';
  
  class PostStoreClass extends EventEmitter {
      constructor() {
          super();
          this.selectedPostId = null;
          this.postsInfo = {};
          this.latestPageTime = {};
          this.currentFocusedPostId = null;
      }
      emitChange() {
          this.emit(CHANGE_EVENT);
      }
  
      addChangeListener(callback) {
          this.on(CHANGE_EVENT, callback);
      }
  
      removeChangeListener(callback) {
          this.removeListener(CHANGE_EVENT, callback);
      }
  
      emitPostFocused() {
          this.emit(FOCUSED_POST_CHANGE);
      }
  
      addPostFocusedListener(callback) {
          this.on(FOCUSED_POST_CHANGE, callback);
      }
  
      removePostFocusedListener(callback) {
          this.removeListener(FOCUSED_POST_CHANGE, callback);
      }
  
      emitEditPost(post) {
          this.emit(EDIT_POST_EVENT, post);
      }
  
      addEditPostListener(callback) {
          this.on(EDIT_POST_EVENT, callback);
      }
  
      removeEditPostListner(callback) {
          this.removeListener(EDIT_POST_EVENT, callback);
      }
  
      emitPostsViewJump(type, post) {
          this.emit(POSTS_VIEW_JUMP_EVENT, type, post);
      }
  
      addPostsViewJumpListener(callback) {
          this.on(POSTS_VIEW_JUMP_EVENT, callback);
      }
  
      removePostsViewJumpListener(callback) {
          this.removeListener(POSTS_VIEW_JUMP_EVENT, callback);
      }
  
      jumpPostsViewToBottom() {
          this.emitPostsViewJump(Constants.PostsViewJumpTypes.BOTTOM, null);
      }
  
      jumpPostsViewToPost(post) {
          this.emitPostsViewJump(Constants.PostsViewJumpTypes.POST, post);
      }
  
      jumpPostsViewSidebarOpen() {
          this.emitPostsViewJump(Constants.PostsViewJumpTypes.SIDEBAR_OPEN, null);
      }
  
      // All this does is makes sure the postsInfo is not null for the specified channel
      makePostsInfo(id) {
          if (!this.postsInfo.hasOwnProperty(id)) {
              this.postsInfo[id] = {};
          }
      }
  
      getPost(channelId, postId) {
          const postInfo = this.postsInfo[channelId];
          if (postInfo == null) {
              return null;
          }
  
          const posts = postInfo.postList;
          let post = null;
  
          if (posts.posts.hasOwnProperty(postId)) {
              post = posts.posts[postId];
          }
  
          return post;
      }
  
      getAllPosts(id) {
          if (this.postsInfo.hasOwnProperty(id)) {
              return this.postsInfo[id].postList;
          }
  
          return null;
      }
  
      getEarliestPost(id) {
          if (this.postsInfo.hasOwnProperty(id)) {
              const postList = this.postsInfo[id].postList;
  
              for (let i = postList.order.length - 1; i >= 0; i--) {
                  const postId = postList.order[i];
  
                  if (postList.posts[postId].state !== Constants.POST_DELETED) {
                      return postList.posts[postId];
                  }
              }
          }
  
          return null;
      }
  
      getLatestPost(id) {
          if (this.postsInfo.hasOwnProperty(id)) {
              const postList = this.postsInfo[id].postList;
  
              for (const postId of postList.order) {
                  if (postList.posts[postId].state !== Constants.POST_DELETED) {
                      return postList.posts[postId];
                  }
              }
          }
  
          return null;
      }
  
      getLatestPostFromPageTime(id) {
          if (this.latestPageTime.hasOwnProperty(id)) {
              return this.latestPageTime[id];
          }
  
          return 0;
      }
  
      getVisiblePosts(id) {
          if (this.postsInfo.hasOwnProperty(id) && this.postsInfo[id].hasOwnProperty('postList')) {
              const postList = JSON.parse(JSON.stringify(this.postsInfo[id].postList));
  
              // Only limit visibility if we are not focused on a post
              if (this.currentFocusedPostId === null) {
                  postList.order = postList.order.slice(0, this.postsInfo[id].endVisible);
              }
  
              // Add pending posts
              if (this.postsInfo[id].hasOwnProperty('pendingPosts')) {
                  Object.assign(postList.posts, this.postsInfo[id].pendingPosts.posts);
                  postList.order = this.postsInfo[id].pendingPosts.order.concat(postList.order);
              }
  
              return postList;
          }
  
          return null;
      }
  
      getVisibilityAtTop(id) {
          if (this.postsInfo.hasOwnProperty(id)) {
              return this.postsInfo[id].atTop && this.postsInfo[id].endVisible >= this.postsInfo[id].postList.order.length;
          }
  
          return false;
      }
  
      getVisibilityAtBottom(id) {
          if (this.postsInfo.hasOwnProperty(id)) {
              return this.postsInfo[id].atBottom;
          }
  
          return false;
      }
  
      // Returns true if posts need to be fetched
      requestVisibilityIncrease(id, amount) {
          const endVisible = this.postsInfo[id].endVisible;
          const postList = this.postsInfo[id].postList;
          if (this.getVisibilityAtTop(id)) {
              return false;
          }
          this.postsInfo[id].endVisible += amount;
          this.emitChange();
          return endVisible + amount > postList.order.length;
      }
  
      getFocusedPostId() {
          return this.currentFocusedPostId;
      }
  
      storePosts(id, newPosts, checkLatest) {
          if (isPostListNull(newPosts)) {
              return;
          }
  
          if (checkLatest) {
              const currentLatest = this.latestPageTime[id] || 0;
              if (newPosts.order.length >= 1) {
                  const newLatest = newPosts.posts[newPosts.order[0]].create_at || 0;
                  if (newLatest > currentLatest) {
                      this.latestPageTime[id] = newLatest;
                  }
              } else if (currentLatest === 0) {
                  // Mark that an empty page was received
                  this.latestPageTime[id] = 1;
              }
          }
  
          const combinedPosts = makePostListNonNull(this.getAllPosts(id));
  
          for (const pid in newPosts.posts) {
              if (newPosts.posts.hasOwnProperty(pid)) {
                  const np = newPosts.posts[pid];
                  if (np.delete_at === 0) {
                      combinedPosts.posts[pid] = np;
                      if (combinedPosts.order.indexOf(pid) === -1 && newPosts.order.indexOf(pid) !== -1) {
                          combinedPosts.order.push(pid);
                      }
                  } else if (combinedPosts.posts.hasOwnProperty(pid)) {
                      combinedPosts.posts[pid] = Object.assign({}, np, {
                          state: Constants.POST_DELETED,
                          fileIds: []
                      });
                  }
              }
          }
  
          combinedPosts.order.sort((a, b) => {
              if (combinedPosts.posts[a].create_at > combinedPosts.posts[b].create_at) {
                  return -1;
              }
              if (combinedPosts.posts[a].create_at < combinedPosts.posts[b].create_at) {
                  return 1;
              }
  
              return 0;
          });
  
          this.makePostsInfo(id);
          this.postsInfo[id].postList = combinedPosts;
      }
  
      storePost(post, isNewPost = false) {
          const postList = makePostListNonNull(this.getAllPosts(post.channel_id));
  
          if (post.pending_post_id !== '') {
              this.removePendingPost(post.channel_id, post.pending_post_id);
          }
  
          post.pending_post_id = '';
  
          postList.posts[post.id] = post;
          if (isNewPost && postList.order.indexOf(post.id) === -1) {
              postList.order.unshift(post.id);
          }
  
          this.makePostsInfo(post.channel_id);
          this.postsInfo[post.channel_id].postList = postList;
      }
  
      storeFocusedPost(postId, channelId, postList) {
          const focusedPost = postList.posts[postId];
          if (!focusedPost) {
              return;
          }
          this.currentFocusedPostId = postId;
          this.storePosts(postId, postList);
          this.storePosts(channelId, postList);
      }
  
      checkBounds(id, numRequested, postList, before) {
          if (numRequested > postList.order.length) {
              if (before) {
                  this.postsInfo[id].atTop = true;
              } else {
                  this.postsInfo[id].atBottom = true;
              }
          }
      }
  
      clearFocusedPost() {
          if (this.currentFocusedPostId != null) {
              Reflect.deleteProperty(this.postsInfo, this.currentFocusedPostId);
              this.currentFocusedPostId = null;
          }
      }
  
      clearChannelVisibility(id, atBottom) {
          this.makePostsInfo(id);
          this.postsInfo[id].endVisible = Constants.POST_CHUNK_SIZE;
          if (this.postsInfo[id].postList) {
              this.postsInfo[id].atTop = this.postsInfo[id].atTop && Constants.POST_CHUNK_SIZE >= this.postsInfo[id].postList.order.length;
          } else {
              this.postsInfo[id].atTop = false;
          }
          this.postsInfo[id].atBottom = atBottom;
      }
  
      deletePost(post) {
          let postInfo = null;
          if (this.currentFocusedPostId == null) {
              postInfo = this.postsInfo[post.channel_id];
          } else {
              postInfo = this.postsInfo[this.currentFocusedPostId];
          }
          if (!postInfo) {
              // the post that has been deleted is in a channel that we haven't seen so just ignore it
              return;
          }
  
          const postList = postInfo.postList;
  
          if (isPostListNull(postList)) {
              return;
          }
  
          if (post.id in postList.posts) {
              // make sure to copy the post so that component state changes work properly
              postList.posts[post.id] = Object.assign({}, post, {
                  state: Constants.POST_DELETED,
                  file_ids: [],
                  has_reactions: false
              });
          }
      }
  
      removePost(post) {
          const channelId = post.channel_id;
          this.makePostsInfo(channelId);
          const postList = this.postsInfo[channelId].postList;
          if (isPostListNull(postList)) {
              return;
          }
  
          if (post.id in postList.posts) {
              Reflect.deleteProperty(postList.posts, post.id);
          }
  
          const index = postList.order.indexOf(post.id);
          if (index !== -1) {
              postList.order.splice(index, 1);
          }
  
          for (const pid in postList.posts) {
              if (!postList.posts.hasOwnProperty(pid)) {
                  continue;
              }
  
              if (postList.posts[pid].root_id === post.id) {
                  Reflect.deleteProperty(postList.posts, pid);
                  const commentIndex = postList.order.indexOf(pid);
                  if (commentIndex !== -1) {
                      postList.order.splice(commentIndex, 1);
                  }
              }
          }
  
          this.postsInfo[channelId].postList = postList;
      }
  
      getPendingPosts(channelId) {
          if (this.postsInfo.hasOwnProperty(channelId)) {
              return this.postsInfo[channelId].pendingPosts;
          }
  
          return null;
      }
  
      storePendingPost(post) {
          const copyPost = JSON.parse(JSON.stringify(post));
          copyPost.state = Constants.POST_LOADING;
  
          const postList = makePostListNonNull(this.getPendingPosts(copyPost.channel_id));
  
          postList.posts[copyPost.pending_post_id] = copyPost;
          postList.order.unshift(copyPost.pending_post_id);
  
          this.makePostsInfo(copyPost.channel_id);
          this.postsInfo[copyPost.channel_id].pendingPosts = postList;
          this.emitChange();
      }
  
      removePendingPost(channelId, pendingPostId) {
          const postList = makePostListNonNull(this.getPendingPosts(channelId));
  
          Reflect.deleteProperty(postList.posts, pendingPostId);
          const index = postList.order.indexOf(pendingPostId);
          if (index === -1) {
              return;
          }
  
          postList.order.splice(index, 1);
  
          this.postsInfo[channelId].pendingPosts = postList;
          this.emitChange();
      }
  
      clearPendingPosts(channelId) {
          if (this.postsInfo.hasOwnProperty(channelId)) {
              Reflect.deleteProperty(this.postsInfo[channelId], 'pendingPosts');
          }
      }
  
      updatePendingPost(post) {
          const copyPost = JSON.parse(JSON.stringify(post));
          const postList = makePostListNonNull(this.getPendingPosts(copyPost.channel_id));
  
          if (postList.order.indexOf(copyPost.pending_post_id) === -1) {
              return;
          }
  
          postList.posts[copyPost.pending_post_id] = copyPost;
          this.postsInfo[copyPost.channel_id].pendingPosts = postList;
          this.emitChange();
      }
  
      storeSelectedPostId(postId) {
          this.selectedPostId = postId;
      }
  
      getSelectedPostId() {
          return this.selectedPostId;
      }
  
      getSelectedPost() {
          if (this.selectedPostId == null) {
              return null;
          }
  
          for (const k in this.postsInfo) {
              if (this.postsInfo[k].postList.posts.hasOwnProperty(this.selectedPostId)) {
                  return this.postsInfo[k].postList.posts[this.selectedPostId];
              }
          }
  
          return null;
      }
  
      getSelectedPostThread() {
          if (this.selectedPostId == null) {
              return null;
          }
  
          const posts = {};
          let pendingPosts;
          for (const k in this.postsInfo) {
              if (this.postsInfo[k].postList && this.postsInfo[k].postList.posts.hasOwnProperty(this.selectedPostId)) {
                  Object.assign(posts, this.postsInfo[k].postList.posts);
                  if (this.postsInfo[k].pendingPosts != null) {
                      pendingPosts = this.postsInfo[k].pendingPosts.posts;
                  }
              }
          }
  
          const threadPosts = {};
          const rootId = this.selectedPostId;
          for (const k in posts) {
              if (posts[k].root_id === rootId) {
                  threadPosts[k] = JSON.parse(JSON.stringify(posts[k]));
              }
          }
  
          for (const k in pendingPosts) {
              if (pendingPosts[k].root_id === rootId) {
                  threadPosts[k] = JSON.parse(JSON.stringify(pendingPosts[k]));
              }
          }
  
          return threadPosts;
      }
  
      emitSelectedPostChange(fromSearch, fromFlaggedPosts) {
          this.emit(SELECTED_POST_CHANGE_EVENT, fromSearch, fromFlaggedPosts);
      }
  
      addSelectedPostChangeListener(callback) {
          this.on(SELECTED_POST_CHANGE_EVENT, callback);
      }
  
      removeSelectedPostChangeListener(callback) {
          this.removeListener(SELECTED_POST_CHANGE_EVENT, callback);
      }
  
      getCurrentUsersLatestPost(channelId, rootId) {
          const userId = UserStore.getCurrentId();
  
          const postList = makePostListNonNull(this.getAllPosts(channelId));
          const len = postList.order.length;
  
          let lastPost = null;
  
          for (let i = 0; i < len; i++) {
              const post = postList.posts[postList.order[i]];
  
              // don't edit webhook posts, deleted posts, or system messages
              if (post.user_id !== userId ||
                  (post.props && post.props.from_webhook) ||
                  post.state === Constants.POST_DELETED ||
                  (post.type && post.type.startsWith(Constants.SYSTEM_MESSAGE_PREFIX))) {
                  continue;
              }
  
              if (rootId) {
                  if (post.root_id === rootId || post.id === rootId) {
                      lastPost = post;
                      break;
                  }
              } else {
                  lastPost = post;
                  break;
              }
          }
  
          return lastPost;
      }
  
      normalizeDraft(originalDraft) {
          let draft = {
              message: '',
              uploadsInProgress: [],
              fileInfos: []
          };
  
          // Make sure that the post draft is non-null and has all the required fields
          if (originalDraft) {
              draft = {
                  message: originalDraft.message || draft.message,
                  uploadsInProgress: originalDraft.uploadsInProgress || draft.uploadsInProgress,
                  fileInfos: originalDraft.fileInfos || draft.fileInfos
              };
          }
  
          return draft;
      }
  
      storeCurrentDraft(draft) {
          var channelId = ChannelStore.getCurrentId();
          BrowserStore.setGlobalItem('draft_' + channelId, draft);
      }
  
      getCurrentDraft() {
          var channelId = ChannelStore.getCurrentId();
          return this.getDraft(channelId);
      }
  
      storeDraft(channelId, draft) {
          BrowserStore.setGlobalItem('draft_' + channelId, draft);
      }
  
      getDraft(channelId) {
          return this.normalizeDraft(BrowserStore.getGlobalItem('draft_' + channelId));
      }
  
      storeCommentDraft(parentPostId, draft) {
          BrowserStore.setGlobalItem('comment_draft_' + parentPostId, draft);
      }
  
      getCommentDraft(parentPostId) {
          return this.normalizeDraft(BrowserStore.getGlobalItem('comment_draft_' + parentPostId));
      }
  
      clearDraftUploads() {
          BrowserStore.actionOnGlobalItemsWithPrefix('draft_', (key, value) => {
              if (value) {
                  value.uploadsInProgress = [];
                  BrowserStore.setGlobalItem(key, value);
              }
          });
      }
  
      clearCommentDraftUploads() {
          BrowserStore.actionOnGlobalItemsWithPrefix('comment_draft_', (key, value) => {
              if (value) {
                  value.uploadsInProgress = [];
                  BrowserStore.setGlobalItem(key, value);
              }
          });
      }
  
      getCommentCount(post) {
          const posts = this.getAllPosts(post.channel_id).posts;
  
          let commentCount = 0;
          for (const id in posts) {
              if (posts.hasOwnProperty(id)) {
                  if (posts[id].root_id === post.id) {
                      commentCount += 1;
                  }
              }
          }
  
          return commentCount;
      }
  
      filterPosts(channelId, joinLeave) {
          const postsList = JSON.parse(JSON.stringify(this.getVisiblePosts(channelId)));
  
          if (!joinLeave && postsList) {
              postsList.order = postsList.order.filter((id) => {
                  if (postsList.posts[id].type === Constants.POST_TYPE_JOIN_LEAVE) {
                      Reflect.deleteProperty(postsList.posts, id);
  
                      return false;
                  }
  
                  return true;
              });
          }
  
          return postsList;
      }
  }
  
  var PostStore = new PostStoreClass();
  
  PostStore.dispatchToken = AppDispatcher.register((payload) => {
      var action = payload.action;
  
      switch (action.type) {
      case ActionTypes.RECEIVED_POSTS: {
          if (PostStore.currentFocusedPostId !== null && action.isPost) {
              PostStore.storePosts(PostStore.currentFocusedPostId, makePostListNonNull(action.post_list), action.checkLatest);
              PostStore.checkBounds(PostStore.currentFocusedPostId, action.numRequested, makePostListNonNull(action.post_list), action.before);
          }
          PostStore.storePosts(action.id, makePostListNonNull(action.post_list), action.checkLatest);
          PostStore.checkBounds(action.id, action.numRequested, makePostListNonNull(action.post_list), action.before);
          PostStore.emitChange();
          break;
      }
      case ActionTypes.RECEIVED_FOCUSED_POST:
          PostStore.clearChannelVisibility(action.postId, false);
          PostStore.storeFocusedPost(action.postId, action.channelId, makePostListNonNull(action.post_list));
          PostStore.emitChange();
          break;
      case ActionTypes.RECEIVED_POST:
          PostStore.storePost(action.post, true);
          PostStore.emitChange();
          break;
      case ActionTypes.RECEIVED_EDIT_POST:
          PostStore.emitEditPost(action);
          PostStore.emitChange();
          break;
      case ActionTypes.CLICK_CHANNEL:
          PostStore.clearFocusedPost();
          PostStore.clearChannelVisibility(action.id, true);
          break;
      case ActionTypes.CREATE_POST:
          PostStore.storePendingPost(action.post);
          PostStore.storeDraft(action.post.channel_id, null);
          PostStore.jumpPostsViewToBottom();
          break;
      case ActionTypes.CREATE_COMMENT:
          PostStore.storePendingPost(action.post);
          PostStore.storeCommentDraft(action.post.root_id, null);
          break;
      case ActionTypes.POST_DELETED:
          PostStore.deletePost(action.post);
          PostStore.emitChange();
          break;
      case ActionTypes.REMOVE_POST:
          PostStore.removePost(action.post);
          PostStore.emitChange();
          break;
      case ActionTypes.RECEIVED_POST_SELECTED:
          PostStore.storeSelectedPostId(action.postId);
          PostStore.emitSelectedPostChange(action.from_search, action.from_flagged_posts);
          break;
      default:
      }
  });
  
  export default PostStore;
  
  function makePostListNonNull(pl) {
      var postList = pl;
      if (postList == null) {
          postList = {order: [], posts: {}};
      }
  
      if (postList.order == null) {
          postList.order = [];
      }
  
      if (postList.posts == null) {
          postList.posts = {};
      }
  
      return postList;
  }
  
  function isPostListNull(pl) {
      if (pl == null) {
          return true;
      }
  
      if (pl.posts == null) {
          return true;
      }
  
      if (pl.order == null) {
          return true;
      }
  
      return false;
  }
  