Move fetch messages logic to the store

Move fetchMessages and lookForNewMessages to store actions, including
logic for cancelling them.
Removed store usage for these functions in messagesService and moved it
to the store actions.

Signed-off-by: Vincent Petry <vincent@nextcloud.com>

1 files changed, 174 insertions, 0 deletions

diff --git a/src/store/messagesStore.js b/src/store/messagesStore.js
index 1cb586038..a3b1a3470 100644
--- a/src/store/messagesStore.js
+++ b/src/store/messagesStore.js
@@ -23,9 +23,13 @@ import Vue from 'vue'
 import {
 	deleteMessage,
 	updateLastReadMessage,
+	fetchMessages,
+	lookForNewMessages,
 } from '../services/messagesService'
+
 import SHA1 from 'crypto-js/sha1'
 import Hex from 'crypto-js/enc-hex'
+import CancelableRequest from '../utils/cancelableRequest'
 
 const state = {
 	/**
@@ -45,6 +49,19 @@ const state = {
 	 * Cached last read message id for display.
 	 */
 	visualLastReadMessageId: {},
+
+	/**
+	 * Stores the cancel function returned by `cancelableFetchMessages`,
+	 * which allows to cancel the previous request for old messages
+	 * when quickly switching to a new conversation.
+	 */
+	cancelFetchMessages: null,
+	/**
+	 * Stores the cancel function returned by `cancelableLookForNewMessages`,
+	 * which allows to cancel the previous long polling request for new
+	 * messages before making another one.
+	 */
+	cancelLookForNewMessages: null,
 }
 
 const getters = {
@@ -119,6 +136,14 @@ const getters = {
 }
 
 const mutations = {
+	setCancelFetchMessages(state, cancelFunction) {
+		state.cancelFetchMessages = cancelFunction
+	},
+
+	setCancelLookForNewMessages(state, cancelFunction) {
+		state.cancelLookForNewMessages = cancelFunction
+	},
+
 	/**
 	 * Adds a message to the store.
 	 * @param {object} state current store state;
@@ -466,6 +491,155 @@ const actions = {
 			await updateLastReadMessage(token, id)
 		}
 	},
+
+	/**
+	 * Fetches messages that belong to a particular conversation
+	 * specified with its token.
+	 *
+	 * @param {object} context default store context;
+	 * @param {string} token the conversation token;
+	 * @param {object} requestOptions request options;
+	 * @param {string} lastKnownMessageId last known message id;
+	 * @param {bool} includeLastKnown whether to include the last known message in the response;
+	 */
+	async fetchMessages(context, { token, lastKnownMessageId, includeLastKnown, requestOptions }) {
+		context.dispatch('cancelFetchMessages')
+
+		// Get a new cancelable request function and cancel function pair
+		const { request, cancel } = CancelableRequest(fetchMessages)
+		// Assign the new cancel function to our data value
+		context.commit('setCancelFetchMessages', cancel)
+
+		const response = await request({
+			token,
+			lastKnownMessageId,
+			includeLastKnown,
+		}, requestOptions)
+
+		let newestKnownMessageId = 0
+
+		if ('x-chat-last-common-read' in response.headers) {
+			const lastCommonReadMessage = parseInt(response.headers['x-chat-last-common-read'], 10)
+			context.dispatch('updateLastCommonReadMessage', {
+				token,
+				lastCommonReadMessage,
+			})
+		}
+
+		// Process each messages and adds it to the store
+		response.data.ocs.data.forEach(message => {
+			if (message.actorType === 'guests') {
+				context.dispatch('setGuestNameIfEmpty', message)
+			}
+			context.dispatch('processMessage', message)
+			newestKnownMessageId = Math.max(newestKnownMessageId, message.id)
+		})
+
+		if (response.headers['x-chat-last-given']) {
+			context.dispatch('setFirstKnownMessageId', {
+				token: token,
+				id: parseInt(response.headers['x-chat-last-given'], 10),
+			})
+		}
+
+		// For guests we also need to set the last known message id
+		// after the first grab of the history, otherwise they start loading
+		// the full history with fetchMessages().
+		if (includeLastKnown && newestKnownMessageId
+			&& !context.getters.getLastKnownMessageId(token)) {
+			context.dispatch('setLastKnownMessageId', {
+				token: token,
+				id: newestKnownMessageId,
+			})
+		}
+
+		return response
+	},
+
+	/**
+	 * Cancels a previously running "fetchMessages" action if applicable.
+	 *
+	 * @param {object} context default store context;
+	 * @returns {bool} true if a request got cancelled, false otherwise
+	 */
+	cancelFetchMessages(context) {
+		if (context.state.cancelFetchMessages) {
+			context.state.cancelFetchMessages('canceled')
+			context.commit('setCancelFetchMessages', null)
+			return true
+		}
+		return false
+	},
+
+	/**
+	 * Fetches newly created messages that belong to a particular conversation
+	 * specified with its token.
+	 *
+	 * @param {object} context default store context;
+	 * @param {string} token The conversation token;
+	 * @param {object} requestOptions reuquest options;
+	 * @param {int} lastKnownMessageId The id of the last message in the store.
+	 */
+	async lookForNewMessages(context, { token, lastKnownMessageId, requestOptions }) {
+		context.dispatch('cancelLookForNewMessages')
+
+		// Get a new cancelable request function and cancel function pair
+		const { request, cancel } = CancelableRequest(lookForNewMessages)
+		// Assign the new cancel function to our data value
+		context.commit('setCancelLookForNewMessages', cancel)
+
+		const response = await request({ token, lastKnownMessageId }, requestOptions)
+
+		if ('x-chat-last-common-read' in response.headers) {
+			const lastCommonReadMessage = parseInt(response.headers['x-chat-last-common-read'], 10)
+			context.dispatch('updateLastCommonReadMessage', {
+				token,
+				lastCommonReadMessage,
+			})
+		}
+
+		let lastMessage = null
+		// Process each messages and adds it to the store
+		response.data.ocs.data.forEach(message => {
+			if (message.actorType === 'guests') {
+				context.dispatch('forceGuestName', message)
+			}
+			context.dispatch('processMessage', message)
+			if (!lastMessage || message.id > lastMessage.id) {
+				lastMessage = message
+			}
+		})
+
+		context.dispatch('setLastKnownMessageId', {
+			token: token,
+			id: parseInt(response.headers['x-chat-last-given'], 10),
+		})
+
+		const conversation = context.getters.conversation(token)
+		if (conversation && conversation.lastMessage && lastMessage.id > conversation.lastMessage.id) {
+			context.dispatch('updateConversationLastMessage', {
+				token: token,
+				lastMessage: lastMessage,
+			})
+		}
+
+		return response
+	},
+
+	/**
+	 * Cancels a previously running "lookForNewMessages" action if applicable.
+	 *
+	 * @param {object} context default store context;
+	 * @returns {bool} true if a request got cancelled, false otherwise
+	 */
+	cancelLookForNewMessages(context) {
+		if (context.state.cancelLookForNewMessages) {
+			context.state.cancelLookForNewMessages('canceled')
+			context.commit('setCancelLookForNewMessages', null)
+			return true
+		}
+		return false
+	},
 }
 
 export default { state, mutations, getters, actions }