FEATURE: move posts to new/existing PM (#6802)

app/assets/javascripts/discourse/components/choose-message.js.es6

@@ -0,0 +1,64 @@
+import debounce from "discourse/lib/debounce";
+import { searchForTerm } from "discourse/lib/search";
+import { observes } from "ember-addons/ember-computed-decorators";
+
+export default Ember.Component.extend({
+  loading: null,
+  noResults: null,
+  messages: null,
+
+  @observes("messageTitle")
+  messageTitleChanged() {
+    this.setProperties({
+      loading: true,
+      noResults: true,
+      selectedTopicId: null
+    });
+    this.search(this.get("messageTitle"));
+  },
+
+  @observes("messages")
+  messagesChanged() {
+    const messages = this.get("messages");
+    if (messages) {
+      this.set("noResults", messages.length === 0);
+    }
+    this.set("loading", false);
+  },
+
+  search: debounce(function(title) {
+    const currentTopicId = this.get("currentTopicId");
+
+    if (Em.isEmpty(title)) {
+      this.setProperties({ messages: null, loading: false });
+      return;
+    }
+
+    searchForTerm(title, {
+      typeFilter: "private_messages",
+      searchForId: true
+    }).then(results => {
+      if (results && results.posts && results.posts.length > 0) {
+        this.set(
+          "messages",
+          results.posts
+            .mapBy("topic")
+            .filter(t => t.get("id") !== currentTopicId)
+        );
+      } else {
+        this.setProperties({ messages: null, loading: false });
+      }
+    });
+  }, 300),
+
+  actions: {
+    chooseMessage(message) {
+      const messageId = Em.get(message, "id");
+      this.set("selectedTopicId", messageId);
+      Ember.run.next(() =>
+        $(`#choose-message-${messageId}`).prop("checked", "true")
+      );
+      return false;
+    }
+  }
+});

app/assets/javascripts/discourse/controllers/merge-topic.js.es6

@@ -1,59 +0,0 @@
-import ModalFunctionality from "discourse/mixins/modal-functionality";
-import { movePosts, mergeTopic } from "discourse/models/topic";
-import DiscourseURL from "discourse/lib/url";
-import computed from "ember-addons/ember-computed-decorators";
-
-export default Ember.Controller.extend(ModalFunctionality, {
-  topicController: Ember.inject.controller("topic"),
-
-  saving: false,
-  selectedTopicId: null,
-
-  selectedPostsCount: Ember.computed.alias(
-    "topicController.selectedPostsCount"
-  ),
-
-  @computed("saving", "selectedTopicId")
-  buttonDisabled(saving, selectedTopicId) {
-    return saving || Ember.isEmpty(selectedTopicId);
-  },
-
-  @computed("saving")
-  buttonTitle(saving) {
-    return saving ? I18n.t("saving") : I18n.t("topic.merge_topic.title");
-  },
-
-  onShow() {
-    this.set("modal.modalClass", "split-modal");
-  },
-
-  actions: {
-    movePostsToExistingTopic() {
-      const topicId = this.get("model.id");
-
-      this.set("saving", true);
-
-      let promise = this.get("topicController.selectedAllPosts")
-        ? mergeTopic(topicId, this.get("selectedTopicId"))
-        : movePosts(topicId, {
-            destination_topic_id: this.get("selectedTopicId"),
-            post_ids: this.get("topicController.selectedPostIds")
-          });
-
-      promise
-        .then(result => {
-          this.send("closeModal");
-          this.get("topicController").send("toggleMultiSelect");
-          Ember.run.next(() => DiscourseURL.routeTo(result.url));
-        })
-        .catch(() => {
-          this.flash(I18n.t("topic.merge_topic.error"));
-        })
-        .finally(() => {
-          this.set("saving", false);
-        });
-
-      return false;
-    }
-  }
-});

app/assets/javascripts/discourse/controllers/move-to-topic.js.es6

@@ -0,0 +1,155 @@
+import ModalFunctionality from "discourse/mixins/modal-functionality";
+import { movePosts, mergeTopic } from "discourse/models/topic";
+import DiscourseURL from "discourse/lib/url";
+import { default as computed } from "ember-addons/ember-computed-decorators";
+import { extractError } from "discourse/lib/ajax-error";
+
+export default Ember.Controller.extend(ModalFunctionality, {
+  topicName: null,
+  saving: false,
+  categoryId: null,
+  tags: null,
+  canAddTags: Ember.computed.alias("site.can_create_tag"),
+  canTagMessages: Ember.computed.alias("site.can_tag_pms"),
+  selectedTopicId: null,
+  newTopic: Ember.computed.equal("selection", "new_topic"),
+  existingTopic: Ember.computed.equal("selection", "existing_topic"),
+  newMessage: Ember.computed.equal("selection", "new_message"),
+  existingMessage: Ember.computed.equal("selection", "existing_message"),
+  moveTypes: ["newTopic", "existingTopic", "newMessage", "existingMessage"],
+  participants: null,
+
+  topicController: Ember.inject.controller("topic"),
+  selectedPostsCount: Ember.computed.alias(
+    "topicController.selectedPostsCount"
+  ),
+  selectedAllPosts: Ember.computed.alias("topicController.selectedAllPosts"),
+  selectedPosts: Ember.computed.alias("topicController.selectedPosts"),
+
+  @computed("saving", "selectedTopicId", "topicName")
+  buttonDisabled(saving, selectedTopicId, topicName) {
+    return (
+      saving || (Ember.isEmpty(selectedTopicId) && Ember.isEmpty(topicName))
+    );
+  },
+
+  @computed(
+    "saving",
+    "newTopic",
+    "existingTopic",
+    "newMessage",
+    "existingMessage"
+  )
+  buttonTitle(saving, newTopic, existingTopic, newMessage, existingMessage) {
+    if (newTopic) {
+      return I18n.t("topic.split_topic.title");
+    } else if (existingTopic) {
+      return I18n.t("topic.merge_topic.title");
+    } else if (newMessage) {
+      return I18n.t("topic.move_to_new_message.title");
+    } else if (existingMessage) {
+      return I18n.t("topic.move_to_existing_message.title");
+    } else {
+      return I18n.t("saving");
+    }
+  },
+
+  onShow() {
+    this.setProperties({
+      "modal.modalClass": "move-to-modal",
+      saving: false,
+      selection: "new_topic",
+      categoryId: null,
+      topicName: "",
+      tags: null,
+      participants: null
+    });
+
+    const isPrivateMessage = this.get("model.isPrivateMessage");
+    const canSplitTopic = this.get("canSplitTopic");
+    if (isPrivateMessage) {
+      this.set("selection", canSplitTopic ? "new_message" : "existing_message");
+    } else if (!canSplitTopic) {
+      this.set("selection", "existing_topic");
+    }
+  },
+
+  @computed("selectedAllPosts", "selectedPosts", "selectedPosts.[]")
+  canSplitTopic(selectedAllPosts, selectedPosts) {
+    return (
+      !selectedAllPosts &&
+      selectedPosts.length > 0 &&
+      selectedPosts.sort((a, b) => a.post_number - b.post_number)[0]
+        .post_type === this.site.get("post_types.regular")
+    );
+  },
+
+  actions: {
+    performMove() {
+      this.get("moveTypes").forEach(type => {
+        if (this.get(type)) {
+          this.send("movePostsTo", type);
+        }
+      });
+    },
+
+    movePostsTo(type) {
+      this.set("saving", true);
+      const topicId = this.get("model.id");
+      let mergeOptions, moveOptions;
+
+      if (type === "existingTopic") {
+        mergeOptions = { destination_topic_id: this.get("selectedTopicId") };
+        moveOptions = Object.assign(
+          { post_ids: this.get("topicController.selectedPostIds") },
+          mergeOptions
+        );
+      } else if (type === "existingMessage") {
+        mergeOptions = {
+          destination_topic_id: this.get("selectedTopicId"),
+          participants: this.get("participants"),
+          archetype: "private_message"
+        };
+        moveOptions = Object.assign(
+          { post_ids: this.get("topicController.selectedPostIds") },
+          mergeOptions
+        );
+      } else if (type === "newTopic") {
+        mergeOptions = {};
+        moveOptions = {
+          title: this.get("topicName"),
+          post_ids: this.get("topicController.selectedPostIds"),
+          category_id: this.get("categoryId"),
+          tags: this.get("tags")
+        };
+      } else {
+        mergeOptions = {};
+        moveOptions = {
+          title: this.get("topicName"),
+          post_ids: this.get("topicController.selectedPostIds"),
+          tags: this.get("tags"),
+          archetype: "private_message"
+        };
+      }
+
+      const promise = this.get("topicController.selectedAllPosts")
+        ? mergeTopic(topicId, mergeOptions)
+        : movePosts(topicId, moveOptions);
+
+      promise
+        .then(result => {
+          this.send("closeModal");
+          this.get("topicController").send("toggleMultiSelect");
+          DiscourseURL.routeTo(result.url);
+        })
+        .catch(xhr => {
+          this.flash(extractError(xhr, I18n.t("topic.move_to.error")));
+        })
+        .finally(() => {
+          this.set("saving", false);
+        });
+
+      return false;
+    }
+  }
+});

app/assets/javascripts/discourse/controllers/split-topic.js.es6

@@ -1,66 +0,0 @@
-import ModalFunctionality from "discourse/mixins/modal-functionality";
-import { extractError } from "discourse/lib/ajax-error";
-import { movePosts } from "discourse/models/topic";
-import DiscourseURL from "discourse/lib/url";
-import { default as computed } from "ember-addons/ember-computed-decorators";
-
-export default Ember.Controller.extend(ModalFunctionality, {
-  topicName: null,
-  saving: false,
-  categoryId: null,
-  tags: null,
-  canAddTags: Ember.computed.alias("site.can_create_tag"),
-
-  topicController: Ember.inject.controller("topic"),
-  selectedPostsCount: Ember.computed.alias(
-    "topicController.selectedPostsCount"
-  ),
-
-  @computed("saving", "topicName")
-  buttonDisabled(saving, topicName) {
-    return saving || Ember.isEmpty(topicName);
-  },
-
-  @computed("saving")
-  buttonTitle(saving) {
-    return saving ? I18n.t("saving") : I18n.t("topic.split_topic.action");
-  },
-
-  onShow() {
-    this.setProperties({
-      "modal.modalClass": "split-modal",
-      saving: false,
-      categoryId: null,
-      topicName: "",
-      tags: null
-    });
-  },
-
-  actions: {
-    movePostsToNewTopic() {
-      this.set("saving", true);
-
-      const options = {
-        title: this.get("topicName"),
-        post_ids: this.get("topicController.selectedPostIds"),
-        category_id: this.get("categoryId"),
-        tags: this.get("tags")
-      };
-
-      movePosts(this.get("model.id"), options)
-        .then(result => {
-          this.send("closeModal");
-          this.get("topicController").send("toggleMultiSelect");
-          Ember.run.next(() => DiscourseURL.routeTo(result.url));
-        })
-        .catch(xhr => {
-          this.flash(extractError(xhr, I18n.t("topic.split_topic.error")));
-        })
-        .finally(() => {
-          this.set("saving", false);
-        });
-
-      return false;
-    }
-  }
-});

app/assets/javascripts/discourse/controllers/topic.js.es6

@@ -1113,22 +1113,6 @@ export default Ember.Controller.extend(BufferedContent, {
     );
   },
 
-  @computed(
-    "canMergeTopic",
-    "selectedAllPosts",
-    "selectedPosts",
-    "selectedPosts.[]"
-  )
-  canSplitTopic(canMergeTopic, selectedAllPosts, selectedPosts) {
-    return (
-      canMergeTopic &&
-      !selectedAllPosts &&
-      selectedPosts.length > 0 &&
-      selectedPosts.sort((a, b) => a.post_number - b.post_number)[0]
-        .post_type === 1
-    );
-  },
-
   @computed("model.details.can_move_posts", "selectedPostsCount")
   canMergeTopic(canMovePosts, selectedPostsCount) {
     return canMovePosts && selectedPostsCount > 0;

app/assets/javascripts/discourse/models/topic.js.es6

@@ -752,11 +752,10 @@ export function movePosts(topicId, data) {
   );
 }
 
-export function mergeTopic(topicId, destinationTopicId) {
+export function mergeTopic(topicId, data) {
-  return ajax("/t/" + topicId + "/merge-topic", {
+  return ajax("/t/" + topicId + "/merge-topic", { type: "POST", data }).then(
-    type: "POST",
+    moveResult
-    data: { destination_topic_id: destinationTopicId }
+  );
-  }).then(moveResult);
 }
 
 export default Topic;

app/assets/javascripts/discourse/routes/topic.js.es6

@@ -114,17 +114,13 @@ const TopicRoute = Discourse.Route.extend({
       this.controllerFor("raw_email").loadRawEmail(model.get("id"));
     },
 
-    mergeTopic() {
+    moveToTopic() {
-      showModal("merge-topic", {
+      showModal("move-to-topic", {
         model: this.modelFor("topic"),
-        title: "topic.merge_topic.title"
+        title: "topic.move_to.title"
       });
     },
 
-    splitTopic() {
-      showModal("split-topic", { model: this.modelFor("topic") });
-    },
-
     changeOwner() {
       showModal("change-owner", {
         model: this.modelFor("topic"),

app/assets/javascripts/discourse/templates/components/choose-message.hbs

@@ -0,0 +1,22 @@
+<label for='choose-message-title'>{{i18n 'choose_message.title.search'}}</label>
+
+{{text-field value=messageTitle placeholderKey="choose_message.title.placeholder" id="choose-message-title"}}
+
+{{#if loading}}
+  <p>{{i18n 'loading'}}</p>
+{{else}}
+  {{#if noResults}}
+    <p>{{i18n 'choose_message.none_found'}}</p>
+  {{else}}
+    {{#each messages as |m|}}
+      <div class='controls existing-message'>
+        <label class='radio'>
+          <input type='radio' id="choose-message-{{unbound m.id}}" name='choose_message_id' {{action "chooseMessage" m}}>
+          <span class="message-title">
+            {{m.title}}
+          </span>
+       </label>
+      </div>
+    {{/each}}
+  {{/if}}
+{{/if}}

app/assets/javascripts/discourse/templates/modal/merge-topic.hbs

@@ -1,13 +0,0 @@
-{{#d-modal-body id='move-selected'}}
-  <p>{{{i18n 'topic.merge_topic.instructions' count=selectedPostsCount}}}</p>
-
-  <form>
-    {{choose-topic currentTopicId=model.id selectedTopicId=selectedTopicId}}
-  </form>
-{{/d-modal-body}}
-
-<div class="modal-footer">
-  {{#d-button class="btn-primary" disabled=buttonDisabled action="movePostsToExistingTopic"}}
-    {{d-icon 'sign-out'}} {{buttonTitle}}
-  {{/d-button}}
-</div>

app/assets/javascripts/discourse/templates/modal/move-to-topic.hbs

@@ -0,0 +1,112 @@
+{{#d-modal-body id='move-selected'}}
+
+  {{#if model.isPrivateMessage}}
+    <div class="radios">
+      {{#if canSplitTopic}}
+        <label class="radio-label" for="move-to-new-message">
+          {{radio-button id='move-to-new-message' name="move-to-entity" value="new_message" selection=selection}}
+          <b>{{i18n 'topic.move_to_new_message.radio_label'}}</b>
+        </label>
+      {{/if}}
+
+        <label class="radio-label" for="move-to-existing-message">
+          {{radio-button id='move-to-existing-message' name="move-to-entity" value="existing_message" selection=selection}}
+          <b>{{i18n 'topic.move_to_existing_message.radio_label'}}</b>
+        </label>
+    </div>
+
+    {{#if canSplitTopic}}
+      {{#if newMessage}}
+        <p>{{{i18n 'topic.move_to_new_message.instructions' count=selectedPostsCount}}}</p>
+        <form>
+          <label>{{i18n 'topic.move_to_new_message.message_title'}}</label>
+          {{text-field value=topicName placeholderKey="composer.title_placeholder" elementId='split-topic-name'}}
+
+          {{#if canTagMessages}}
+            <label>{{i18n 'tagging.tags'}}</label>
+            {{tag-chooser tags=tags filterable=true}}
+          {{/if}}
+        </form>
+      {{/if}}
+    {{/if}}
+
+    {{#if existingMessage}}
+      <p>{{{i18n 'topic.move_to_existing_message.instructions' count=selectedPostsCount}}}</p>
+      <form>
+        {{choose-message currentTopicId=model.id selectedTopicId=selectedTopicId}}
+
+        <label>{{i18n 'topic.move_to_new_message.participants'}}</label>
+        {{user-selector usernames=participants class="participant-selector"}}
+      </form>
+    {{/if}}
+
+  {{else}}
+
+    <div class="radios">
+      {{#if canSplitTopic}}
+        <label class="radio-label" for="move-to-new-topic">
+          {{radio-button id='move-to-new-topic' name="move-to-entity" value="new_topic" selection=selection}}
+          <b>{{i18n 'topic.split_topic.radio_label'}}</b>
+        </label>
+      {{/if}}
+
+      <label class="radio-label" for="move-to-existing-topic">
+        {{radio-button id='move-to-existing-topic' name="move-to-entity" value="existing_topic" selection=selection}}
+        <b>{{i18n 'topic.merge_topic.radio_label'}}</b>
+      </label>
+
+      {{#if canSplitTopic}}
+        <label class="radio-label" for="move-to-new-message">
+          {{radio-button id='move-to-new-message' name="move-to-entity" value="new_message" selection=selection}}
+          <b>{{i18n 'topic.move_to_new_message.radio_label'}}</b>
+        </label>
+      {{/if}}
+    </div>
+
+    {{#if existingTopic}}
+      <p>{{{i18n 'topic.merge_topic.instructions' count=selectedPostsCount}}}</p>
+      <form>
+        {{choose-topic currentTopicId=model.id selectedTopicId=selectedTopicId}}
+      </form>
+    {{/if}}
+
+    {{#if canSplitTopic}}
+      {{#if newTopic}}
+        <p>{{{i18n 'topic.split_topic.instructions' count=selectedPostsCount}}}</p>
+        <form>
+          <label>{{i18n 'topic.split_topic.topic_name'}}</label>
+          {{text-field value=topicName placeholderKey="composer.title_placeholder" elementId='split-topic-name'}}
+
+          <label>{{i18n 'categories.category'}}</label>
+          {{category-chooser value=categoryId class="small"}}
+          {{#if canAddTags}}
+            <label>{{i18n 'tagging.tags'}}</label>
+            {{tag-chooser tags=tags filterable=true categoryId=categoryId}}
+          {{/if}}
+        </form>
+      {{/if}}
+    {{/if}}
+
+    {{#if canSplitTopic}}
+      {{#if newMessage}}
+        <p>{{{i18n 'topic.move_to_new_message.instructions' count=selectedPostsCount}}}</p>
+        <form>
+          <label>{{i18n 'topic.move_to_new_message.message_title'}}</label>
+          {{text-field value=topicName placeholderKey="composer.title_placeholder" elementId='split-topic-name'}}
+
+          {{#if canTagMessages}}
+            <label>{{i18n 'tagging.tags'}}</label>
+            {{tag-chooser tags=tags filterable=true}}
+          {{/if}}
+        </form>
+      {{/if}}
+    {{/if}}
+  {{/if}}
+
+{{/d-modal-body}}
+
+<div class="modal-footer">
+  {{#d-button class="btn-primary" disabled=buttonDisabled action=(action "performMove")}}
+    {{d-icon 'sign-out'}} {{buttonTitle}}
+  {{/d-button}}
+</div>

app/assets/javascripts/discourse/templates/modal/split-topic.hbs

@@ -1,21 +0,0 @@
-{{#d-modal-body id="move-selected" title="topic.split_topic.title"}}
-  {{{i18n 'topic.split_topic.instructions' count=selectedPostsCount}}}
-
-  <form>
-    <label>{{i18n 'topic.split_topic.topic_name'}}</label>
-    {{text-field value=topicName placeholderKey="composer.title_placeholder" elementId='split-topic-name'}}
-
-    <label>{{i18n 'categories.category'}}</label>
-    {{category-chooser value=categoryId class="small"}}
-    {{#if canAddTags}}
-      <label>{{i18n 'tagging.tags'}}</label>
-      {{tag-chooser tags=tags filterable=true categoryId=categoryId}}
-    {{/if}}
-  </form>
-{{/d-modal-body}}
-
-<div class="modal-footer">
-  {{#d-button class="btn-primary" disabled=buttonDisabled action="movePostsToNewTopic"}}
-    {{d-icon 'sign-out'}} {{buttonTitle}}
-  {{/d-button}}
-</div>

app/assets/javascripts/discourse/templates/selected-posts.hbs

@@ -12,12 +12,8 @@
   {{d-button action="deleteSelected" icon="trash-o" label="topic.multi_select.delete" class="btn-danger"}}
 {{/if}}
 
-{{#if canSplitTopic}}
-  {{d-button action="splitTopic" icon="sign-out" label="topic.split_topic.action"}}
-{{/if}}
-
 {{#if canMergeTopic}}
-  {{d-button action="mergeTopic" icon="sign-out" label="topic.merge_topic.action"}}
+  {{d-button action=(route-action "moveToTopic") icon="sign-out" label="topic.move_to.action" class="move-to-topic"}}
 {{/if}}
 
 {{#if canChangeOwner}}

app/assets/stylesheets/desktop/modal.scss

@@ -113,19 +113,28 @@
   }
 }
 
-.split-modal {
+.move-to-modal {
   .modal-body {
     position: relative;
     height: 350px;
   }
 
   #move-selected {
+    width: 475px;
+
     p {
       margin-top: 0;
     }
 
-    input[type="radio"] {
+    .radios {
-      margin-right: 10px;
+      margin-bottom: 10px;
+      display: flex;
+      flex-direction: row;
+
+      .radio-label {
+        display: inline-block;
+        padding-right: 15px;
+      }
     }
 
     button {
@@ -142,9 +151,19 @@
       width: 95%;
       margin-top: 20px;
       #split-topic-name,
-      #choose-topic-title {
+      #choose-topic-title,
+      #choose-message-title {
         width: 100%;
       }
+
+      .participant-selector {
+        width: 100%;
+      }
+
+      div.ac-wrap {
+        width: 100%;
+        margin-bottom: 9px;
+      }
     }
   }
 }

app/controllers/topics_controller.rb

@@ -607,13 +607,26 @@ class TopicsController < ApplicationController
   end
 
   def merge_topic
-    params.require(:destination_topic_id)
+    topic_id = params.require(:topic_id)
+    destination_topic_id = params.require(:destination_topic_id)
+    params.permit(:participants)
+    params.permit(:archetype)
 
-    topic = Topic.find_by(id: params[:topic_id])
+    raise Discourse::InvalidAccess if params[:archetype] == "private_message" && !guardian.is_staff?
+
+    topic = Topic.find_by(id: topic_id)
     guardian.ensure_can_move_posts!(topic)
 
-    dest_topic = topic.move_posts(current_user, topic.posts.pluck(:id), destination_topic_id: params[:destination_topic_id].to_i)
+    args = {}
-    render_topic_changes(dest_topic)
+    args[:destination_topic_id] = destination_topic_id.to_i
+
+    if params[:archetype].present?
+      args[:archetype] = params[:archetype]
+      args[:participants] = params[:participants] if params[:participants].present? && params[:archetype] == "private_message"
+    end
+
+    destination_topic = topic.move_posts(current_user, topic.posts.pluck(:id), args)
+    render_topic_changes(destination_topic)
   end
 
   def move_posts
@@ -621,6 +634,10 @@ class TopicsController < ApplicationController
     topic_id = params.require(:topic_id)
     params.permit(:category_id)
     params.permit(:tags)
+    params.permit(:participants)
+    params.permit(:archetype)
+
+    raise Discourse::InvalidAccess if params[:archetype] == "private_message" && !guardian.is_staff?
 
     topic = Topic.with_deleted.find_by(id: topic_id)
     guardian.ensure_can_move_posts!(topic)
@@ -630,8 +647,8 @@ class TopicsController < ApplicationController
       return render_json_error("When moving posts to a new topic, the first post must be a regular post.")
     end
 
-    dest_topic = move_posts_to_destination(topic)
+    destination_topic = move_posts_to_destination(topic)
-    render_topic_changes(dest_topic)
+    render_topic_changes(destination_topic)
   rescue ActiveRecord::RecordInvalid => ex
     render_json_error(ex)
   end
@@ -893,9 +910,15 @@ class TopicsController < ApplicationController
     args = {}
     args[:title] = params[:title] if params[:title].present?
     args[:destination_topic_id] = params[:destination_topic_id].to_i if params[:destination_topic_id].present?
-    args[:category_id] = params[:category_id].to_i if params[:category_id].present?
     args[:tags] = params[:tags] if params[:tags].present?
 
+    if params[:archetype].present?
+      args[:archetype] = params[:archetype]
+      args[:participants] = params[:participants] if params[:participants].present? && params[:archetype] == "private_message"
+    else
+      args[:category_id] = params[:category_id].to_i if params[:category_id].present?
+    end
+
     topic.move_posts(current_user, post_ids_including_replies, args)
   end
 

app/models/post_mover.rb

@@ -5,18 +5,24 @@ class PostMover
     @move_types ||= Enum.new(:new_topic, :existing_topic)
   end
 
-  def initialize(original_topic, user, post_ids)
+  def initialize(original_topic, user, post_ids, move_to_pm: false)
     @original_topic = original_topic
     @user = user
     @post_ids = post_ids
+    @move_to_pm = move_to_pm
   end
 
-  def to_topic(id)
+  def to_topic(id, participants: nil)
     @move_type = PostMover.move_types[:existing_topic]
 
+    topic = Topic.find_by_id(id)
+    raise Discourse::InvalidParameters unless topic.archetype == @original_topic.archetype
+
     Topic.transaction do
-      move_posts_to Topic.find_by_id(id)
+      move_posts_to topic
     end
+    add_allowed_users(participants) if participants.present? && @move_to_pm
+    topic
   end
 
   def to_new_topic(title, category_id = nil, tags = nil)
@@ -24,13 +30,15 @@ class PostMover
 
     post = Post.find_by(id: post_ids.first)
     raise Discourse::InvalidParameters unless post
+    archetype = @move_to_pm ? Archetype.private_message : Archetype.default
 
     Topic.transaction do
       new_topic = Topic.create!(
         user: post.user,
         title: title,
         category_id: category_id,
-        created_at: post.created_at
+        created_at: post.created_at,
+        archetype: archetype
       )
       DiscourseTagging.tag_topic_by_names(new_topic, Guardian.new(user), tags)
       move_posts_to new_topic
@@ -79,7 +87,11 @@ class PostMover
 
     posts.each do |post|
       post.is_first_post? ? create_first_post(post) : move(post)
+      if @move_to_pm
+        destination_topic.topic_allowed_users.build(user_id: post.user_id) unless destination_topic.topic_allowed_users.where(user_id: post.user_id).exists?
+      end
     end
+    destination_topic.save! if @move_to_pm
 
     PostReply.where("reply_id IN (:post_ids) OR post_id IN (:post_ids)", post_ids: post_ids).each do |post_reply|
       if post_reply.post && post_reply.reply && post_reply.reply.topic_id != post_reply.post.topic_id
@@ -189,6 +201,7 @@ class PostMover
       I18n.t(
         "move_posts.#{move_type_str}_moderator_post",
         count: posts.length,
+        entity: @move_to_pm ? "message" : "topic",
         topic_link: posts.first.is_first_post? ?
           "[#{destination_topic.title}](#{destination_topic.relative_url})" :
           "[#{destination_topic.title}](#{posts.first.url})"
@@ -234,4 +247,14 @@ class PostMover
       notifications_reason_id: TopicUser.notification_reasons[:created_topic]
     )
   end
+
+  def add_allowed_users(usernames)
+    return unless usernames.present?
+
+    names = usernames.split(',').flatten
+    User.where(username: names).find_each do |user|
+      destination_topic.topic_allowed_users.build(user_id: user.id) unless destination_topic.topic_allowed_users.where(user_id: user.id).exists?
+    end
+    destination_topic.save!
+  end
 end

app/models/topic.rb

@@ -896,10 +896,10 @@ class Topic < ActiveRecord::Base
   end
 
   def move_posts(moved_by, post_ids, opts)
-    post_mover = PostMover.new(self, moved_by, post_ids)
+    post_mover = PostMover.new(self, moved_by, post_ids, move_to_pm: opts[:archetype].present? && opts[:archetype] == "private_message")
 
     if opts[:destination_topic_id]
-      topic = post_mover.to_topic(opts[:destination_topic_id])
+      topic = post_mover.to_topic(opts[:destination_topic_id], participants: opts[:participants])
 
       DiscourseEvent.trigger(:topic_merged,
         post_mover.original_topic,

config/locales/client.en.yml

@@ -347,9 +347,15 @@ en:
     choose_topic:
       none_found: "No topics found."
       title:
-        search: "Search for a Topic by name, url or id:"
+        search: "Search for a Topic by title, url or id:"
         placeholder: "type the topic title here"
 
+    choose_message:
+      none_found: "No messages found."
+      title:
+        search: "Search for a Message by title:"
+        placeholder: "type the message title here"
+
     queue:
       topic: "Topic:"
       approve: 'Approve'
@@ -2004,10 +2010,16 @@ en:
           other: "{{count}} posts"
         cancel: "Remove filter"
 
+      move_to:
+        title: "Move to"
+        action: "move to"
+        error: "There was an error moving posts."
+
       split_topic:
         title: "Move to New Topic"
         action: "move to new topic"
-        topic_name: "New Topic Name"
+        topic_name: "New Topic Title"
+        radio_label: "New Topic"
         error: "There was an error moving posts to the new topic."
         instructions:
           one: "You are about to create a new topic and populate it with the post you've selected."
@@ -2017,10 +2029,30 @@ en:
         title: "Move to Existing Topic"
         action: "move to existing topic"
         error: "There was an error moving posts into that topic."
+        radio_label: "Existing Topic"
         instructions:
           one: "Please choose the topic you'd like to move that post to."
           other: "Please choose the topic you'd like to move those <b>{{count}}</b> posts to."
 
+      move_to_new_message:
+        title: "Move to New Message"
+        action: "move to new message"
+        message_title: "New Message Title"
+        radio_label: "New Message"
+        participants: "Participants"
+        instructions:
+          one: "You are about to create a new message and populate it with the post you've selected."
+          other: "You are about to create a new message and populate it with the <b>{{count}}</b> posts you've selected."
+
+      move_to_existing_message:
+        title: "Move to Existing Message"
+        action: "move to existing message"
+        radio_label: "Existing Message"
+        participants: "Participants"
+        instructions:
+          one: "Please choose the message you'd like to move that post to."
+          other: "Please choose the message you'd like to move those <b>{{count}}</b> posts to."
+
       merge_posts:
         title: "Merge Selected Posts"
         action: "merge selected posts"

config/locales/server.en.yml

@@ -1988,11 +1988,11 @@ en:
 
   move_posts:
     new_topic_moderator_post:
-      one: "A post was split to a new topic: %{topic_link}"
+      one: "A post was split to a new %{entity}: %{topic_link}"
-      other: "%{count} posts were split to a new topic: %{topic_link}"
+      other: "%{count} posts were split to a new %{entity}: %{topic_link}"
     existing_topic_moderator_post:
-      one: "A post was merged into an existing topic: %{topic_link}"
+      one: "A post was merged into an existing %{entity}: %{topic_link}"
-      other: "%{count} posts were merged into an existing topic: %{topic_link}"
+      other: "%{count} posts were merged into an existing %{entity}: %{topic_link}"
 
   change_owner:
     post_revision_text: "Ownership transferred"

spec/requests/topics_controller_spec.rb

@@ -241,6 +241,140 @@ RSpec.describe TopicsController do
         end
       end
     end
+
+    describe 'moving to a new message' do
+      let(:user) { Fabricate(:user) }
+      let(:trust_level_4) { Fabricate(:trust_level_4) }
+      let(:moderator) { Fabricate(:moderator) }
+      let!(:message) { Fabricate(:private_message_topic) }
+      let!(:p1) { Fabricate(:post, user: user, post_number: 1, topic: message) }
+      let!(:p2) { Fabricate(:post, user: user, post_number: 2, topic: message) }
+
+      it "raises an error without post_ids" do
+        sign_in(moderator)
+        post "/t/#{message.id}/move-posts.json", params: { title: 'blah', archetype: 'private_message' }
+        expect(response.status).to eq(400)
+      end
+
+      it "raises an error when the user doesn't have permission to move the posts" do
+        sign_in(trust_level_4)
+
+        post "/t/#{message.id}/move-posts.json", params: {
+          title: 'blah', post_ids: [p1.post_number, p2.post_number], archetype: 'private_message'
+        }
+
+        expect(response.status).to eq(403)
+        result = ::JSON.parse(response.body)
+        expect(result['errors']).to be_present
+      end
+
+      context 'success' do
+        before { sign_in(Fabricate(:admin)) }
+
+        it "returns success" do
+          SiteSetting.allow_staff_to_tag_pms = true
+
+          expect do
+            post "/t/#{message.id}/move-posts.json", params: {
+              title: 'Logan is a good movie',
+              post_ids: [p2.id],
+              archetype: 'private_message',
+              tags: ["tag1", "tag2"]
+            }
+          end.to change { Topic.count }.by(1)
+
+          expect(response.status).to eq(200)
+
+          result = ::JSON.parse(response.body)
+
+          expect(result['success']).to eq(true)
+          expect(result['url']).to eq(Topic.last.relative_url)
+          expect(Tag.all.pluck(:name)).to contain_exactly("tag1", "tag2")
+        end
+
+        describe 'when message has been deleted' do
+          it 'should still be able to move posts' do
+            PostDestroyer.new(Fabricate(:admin), message.first_post).destroy
+
+            expect(message.reload.deleted_at).to_not be_nil
+
+            expect do
+              post "/t/#{message.id}/move-posts.json", params: {
+                title: 'Logan is a good movie',
+                post_ids: [p2.id],
+                archetype: 'private_message'
+              }
+            end.to change { Topic.count }.by(1)
+
+            expect(response.status).to eq(200)
+
+            result = JSON.parse(response.body)
+
+            expect(result['success']).to eq(true)
+            expect(result['url']).to eq(Topic.last.relative_url)
+          end
+        end
+      end
+
+      context 'failure' do
+        it "returns JSON with a false success" do
+          sign_in(moderator)
+          post "/t/#{message.id}/move-posts.json", params: {
+            post_ids: [p2.id],
+            archetype: 'private_message'
+          }
+          expect(response.status).to eq(200)
+          result = ::JSON.parse(response.body)
+          expect(result['success']).to eq(false)
+          expect(result['url']).to be_blank
+        end
+      end
+    end
+
+    describe 'moving to an existing message' do
+      let!(:user) { sign_in(Fabricate(:admin)) }
+      let(:trust_level_4) { Fabricate(:trust_level_4) }
+      let(:evil_trout) { Fabricate(:evil_trout) }
+      let(:message) { Fabricate(:private_message_topic) }
+      let(:p1) { Fabricate(:post, user: user, post_number: 1, topic: message) }
+      let(:p2) { Fabricate(:post, user: evil_trout, post_number: 2, topic: message) }
+
+      let(:dest_message) do
+        Fabricate(:private_message_topic, user: trust_level_4, topic_allowed_users: [
+          Fabricate.build(:topic_allowed_user, user: evil_trout)
+        ])
+      end
+
+      context 'success' do
+        it "returns success" do
+          user
+          post "/t/#{message.id}/move-posts.json", params: {
+            post_ids: [p2.id],
+            destination_topic_id: dest_message.id,
+            archetype: 'private_message'
+          }
+
+          expect(response.status).to eq(200)
+          result = ::JSON.parse(response.body)
+          expect(result['success']).to eq(true)
+          expect(result['url']).to be_present
+        end
+      end
+
+      context 'failure' do
+        it "returns JSON with a false success" do
+          post "/t/#{message.id}/move-posts.json", params: {
+            post_ids: [p2.id],
+            archetype: 'private_message'
+          }
+
+          expect(response.status).to eq(200)
+          result = ::JSON.parse(response.body)
+          expect(result['success']).to eq(false)
+          expect(result['url']).to be_blank
+        end
+      end
+    end
   end
 
   describe '#merge_topic' do
@@ -251,7 +385,7 @@ RSpec.describe TopicsController do
       expect(response.status).to eq(403)
     end
 
-    describe 'moving to a new topic' do
+    describe 'merging into another topic' do
       let(:moderator) { Fabricate(:moderator) }
       let(:user) { Fabricate(:user) }
       let(:p1) { Fabricate(:post, user: user) }
@@ -285,6 +419,53 @@ RSpec.describe TopicsController do
         end
       end
     end
+
+    describe 'merging into another message' do
+      let(:moderator) { Fabricate(:moderator) }
+      let(:user) { Fabricate(:user) }
+      let(:trust_level_4) { Fabricate(:trust_level_4) }
+      let(:message) { Fabricate(:private_message_topic, user: user) }
+      let!(:p1) { Fabricate(:post, topic: message, user: trust_level_4) }
+      let!(:p2) { Fabricate(:post, topic: message, reply_to_post_number: p1.post_number, user: user) }
+
+      it "raises an error without destination_topic_id" do
+        sign_in(moderator)
+        post "/t/#{message.id}/merge-topic.json", params: {
+          archetype: 'private_message'
+        }
+        expect(response.status).to eq(400)
+      end
+
+      it "raises an error when the user doesn't have permission to merge" do
+        sign_in(trust_level_4)
+        post "/t/#{message.id}/merge-topic.json", params: {
+          destination_topic_id: 345,
+          archetype: 'private_message'
+        }
+        expect(response).to be_forbidden
+      end
+
+      let(:dest_message) do
+        Fabricate(:private_message_topic, user: trust_level_4, topic_allowed_users: [
+          Fabricate.build(:topic_allowed_user, user: moderator)
+        ])
+      end
+
+      context 'moves all the posts to the destination message' do
+        it "returns success" do
+          sign_in(moderator)
+          post "/t/#{message.id}/merge-topic.json", params: {
+            destination_topic_id: dest_message.id,
+            archetype: 'private_message'
+          }
+
+          expect(response.status).to eq(200)
+          result = ::JSON.parse(response.body)
+          expect(result['success']).to eq(true)
+          expect(result['url']).to be_present
+        end
+      end
+    end
   end
 
   describe '#change_post_owners' do

test/javascripts/acceptance/topic-move-posts-test.js.es6

@@ -0,0 +1,121 @@
+import { acceptance } from "helpers/qunit-helpers";
+acceptance("Topic move posts", { loggedIn: true });
+
+QUnit.test("default", async assert => {
+  await visit("/t/internationalization-localization");
+  await click(".toggle-admin-menu");
+  await click(".topic-admin-multi-select .btn");
+  await click("#post_11 .select-below");
+
+  assert.equal(
+    find(".selected-posts .move-to-topic")
+      .text()
+      .trim(),
+    I18n.t("topic.move_to.action"),
+    "it should show the move to button"
+  );
+
+  await click(".selected-posts .move-to-topic");
+
+  assert.ok(
+    find(".move-to-modal .title")
+      .html()
+      .includes(I18n.t("topic.move_to.title")),
+    "it opens move to modal"
+  );
+
+  assert.ok(
+    find(".move-to-modal .radios")
+      .html()
+      .includes(I18n.t("topic.split_topic.radio_label")),
+    "it shows an option to move to new topic"
+  );
+
+  assert.ok(
+    find(".move-to-modal .radios")
+      .html()
+      .includes(I18n.t("topic.merge_topic.radio_label")),
+    "it shows an option to move to existing topic"
+  );
+
+  assert.ok(
+    find(".move-to-modal .radios")
+      .html()
+      .includes(I18n.t("topic.move_to_new_message.radio_label")),
+    "it shows an option to move to new message"
+  );
+});
+
+QUnit.test("moving all posts", async assert => {
+  await visit("/t/internationalization-localization");
+  await click(".toggle-admin-menu");
+  await click(".topic-admin-multi-select .btn");
+  await click(".select-all");
+  await click(".selected-posts .move-to-topic");
+
+  assert.ok(
+    find(".move-to-modal .title")
+      .html()
+      .includes(I18n.t("topic.move_to.title")),
+    "it opens move to modal"
+  );
+
+  assert.not(
+    find(".move-to-modal .radios")
+      .html()
+      .includes(I18n.t("topic.split_topic.radio_label")),
+    "it does not show an option to move to new topic"
+  );
+
+  assert.ok(
+    find(".move-to-modal .radios")
+      .html()
+      .includes(I18n.t("topic.merge_topic.radio_label")),
+    "it shows an option to move to existing topic"
+  );
+
+  assert.not(
+    find(".move-to-modal .radios")
+      .html()
+      .includes(I18n.t("topic.move_to_new_message.radio_label")),
+    "it does not show an option to move to new message"
+  );
+});
+
+QUnit.test("moving posts from personal message", async assert => {
+  await visit("/t/pm-for-testing/12");
+  await click(".toggle-admin-menu");
+  await click(".topic-admin-multi-select .btn");
+  await click("#post_1 .select-post");
+
+  assert.equal(
+    find(".selected-posts .move-to-topic")
+      .text()
+      .trim(),
+    I18n.t("topic.move_to.action"),
+    "it should show the move to button"
+  );
+
+  await click(".selected-posts .move-to-topic");
+
+  assert.ok(
+    find(".move-to-modal .title")
+      .html()
+      .includes(I18n.t("topic.move_to.title")),
+    "it opens move to modal"
+  );
+
+  assert.ok(
+    find(".move-to-modal .radios")
+      .html()
+      .includes(I18n.t("topic.move_to_new_message.radio_label")),
+    "it shows an option to move to new message"
+  );
+
+  assert.ok(
+    find(".move-to-modal .radios")
+      .html()
+      .includes(I18n.t("topic.move_to_existing_message.radio_label")),
+    "it shows an option to move to existing message"
+  );
+});

test/javascripts/controllers/topic-test.js.es6

@@ -281,10 +281,6 @@ QUnit.test("Can split/merge topic", function(assert) {
   const controller = this.subject({ model });
   const selectedPostIds = controller.get("selectedPostIds");
 
-  assert.not(
-    controller.get("canSplitTopic"),
-    "can't split topic when no posts are selected"
-  );
   assert.not(
     controller.get("canMergeTopic"),
     "can't merge topic when no posts are selected"
@@ -292,10 +288,6 @@ QUnit.test("Can split/merge topic", function(assert) {
 
   selectedPostIds.pushObject(1);
 
-  assert.not(
-    controller.get("canSplitTopic"),
-    "can't split topic when can't move posts"
-  );
   assert.not(
     controller.get("canMergeTopic"),
     "can't merge topic when can't move posts"
@@ -303,16 +295,11 @@ QUnit.test("Can split/merge topic", function(assert) {
 
   model.set("details.can_move_posts", true);
 
-  assert.ok(controller.get("canSplitTopic"), "can split topic");
   assert.ok(controller.get("canMergeTopic"), "can merge topic");
 
   selectedPostIds.removeObject(1);
   selectedPostIds.pushObject(2);
 
-  assert.not(
-    controller.get("canSplitTopic"),
-    "can't split topic when 1st post is not a regular post"
-  );
   assert.ok(
     controller.get("canMergeTopic"),
     "can merge topic when 1st post is not a regular post"
@@ -320,10 +307,6 @@ QUnit.test("Can split/merge topic", function(assert) {
 
   selectedPostIds.pushObject(3);
 
-  assert.not(
-    controller.get("canSplitTopic"),
-    "can't split topic when all posts are selected"
-  );
   assert.ok(
     controller.get("canMergeTopic"),
     "can merge topic when all posts are selected"