On send, pull data from target edit if sending edit

ts/util/editHelpers.ts

@@ -0,0 +1,143 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { isNumber, sortBy } from 'lodash';
+
+import { strictAssert } from './assert';
+import { isSent } from '../messages/MessageSendState';
+
+import type { EditHistoryType } from '../model-types';
+import type { MessageModel } from '../models/messages';
+import type { LoggerType } from '../types/Logging';
+
+export function hasEditBeenSent(message: MessageModel): boolean {
+  const originalTimestamp = message.get('timestamp');
+  const editHistory = message.get('editHistory') || [];
+
+  return Boolean(
+    editHistory.find(item => {
+      if (item.timestamp === originalTimestamp) {
+        return false;
+      }
+      return Object.values(item.sendStateByConversationId || {}).some(
+        sendState => isSent(sendState.status)
+      );
+    })
+  );
+}
+
+// The tricky bit for this function is if we are on our second+ attempt to send a given
+//   edit, we're still sending that edit.
+export function getTargetOfThisEditTimestamp({
+  message,
+  targetTimestamp,
+}: {
+  message: MessageModel;
+  targetTimestamp: number;
+}): number {
+  const originalTimestamp = message.get('timestamp');
+  const editHistory = message.get('editHistory') || [];
+
+  const sentItems = editHistory.filter(item => {
+    return item.timestamp <= targetTimestamp;
+  });
+  const mostRecent = sortBy(
+    sentItems,
+    (item: EditHistoryType) => item.timestamp
+  );
+
+  const { length } = mostRecent;
+
+  // We want the second-to-last item, because we may have partially sent targetTimestamp
+  if (length > 1) {
+    return mostRecent[length - 2].timestamp;
+  }
+  // If there's only one item, we'll use it
+  if (length > 0) {
+    return mostRecent[length - 1].timestamp;
+  }
+
+  // This is a good failover in case we ever stop duplicating data in editHistory
+  return originalTimestamp;
+}
+
+export function getPropForTimestamp<T extends keyof EditHistoryType>({
+  log,
+  message,
+  prop,
+  targetTimestamp,
+}: {
+  log: LoggerType;
+  message: MessageModel;
+  prop: T;
+  targetTimestamp: number;
+}): EditHistoryType[T] {
+  const logId = `getPropForTimestamp(${message.idForLogging()}, target=${targetTimestamp}})`;
+
+  const editHistory = message.get('editHistory');
+  const targetEdit = editHistory?.find(
+    item => item.timestamp === targetTimestamp
+  );
+  if (!targetEdit) {
+    if (editHistory) {
+      log.warn(`${logId}: No edit found, using top-level data`);
+    }
+    return message.get(prop);
+  }
+
+  return targetEdit[prop];
+}
+
+export function setPropForTimestamp<T extends keyof EditHistoryType>({
+  log,
+  message,
+  prop,
+  targetTimestamp,
+  value,
+}: {
+  log: LoggerType;
+  message: MessageModel;
+  prop: T;
+  targetTimestamp: number;
+  value: EditHistoryType[T];
+}): void {
+  const logId = `setPropForTimestamp(${message.idForLogging()}, target=${targetTimestamp}})`;
+
+  const editHistory = message.get('editHistory');
+  const targetEditIndex = editHistory?.findIndex(
+    item => item.timestamp === targetTimestamp
+  );
+  const targetEdit =
+    editHistory && isNumber(targetEditIndex)
+      ? editHistory[targetEditIndex]
+      : undefined;
+
+  if (!targetEdit) {
+    if (editHistory) {
+      log.warn(`${logId}: No edit found, updating top-level data`);
+    }
+    message.set({
+      [prop]: value,
+    });
+    return;
+  }
+
+  strictAssert(editHistory, 'Got targetEdit, but no editHistory');
+  strictAssert(
+    isNumber(targetEditIndex),
+    'Got targetEdit, but no targetEditIndex'
+  );
+
+  const newEditHistory = [...editHistory];
+  newEditHistory[targetEditIndex] = { ...targetEdit, [prop]: value };
+
+  message.set('editHistory', newEditHistory);
+
+  // We always edit the top-level attribute if this is the most recent send
+  const editMessageTimestamp = message.get('editMessageTimestamp');
+  if (!editMessageTimestamp || editMessageTimestamp === targetTimestamp) {
+    message.set({
+      [prop]: value,
+    });
+  }
+}