diff --git a/app/assets/javascripts/discourse/app/controllers/flag.js b/app/assets/javascripts/discourse/app/controllers/flag.js
index 671130e4822..8d2f6bbbe9d 100644
--- a/app/assets/javascripts/discourse/app/controllers/flag.js
+++ b/app/assets/javascripts/discourse/app/controllers/flag.js
@@ -1,7 +1,5 @@
 import { schedule } from "@ember/runloop";
-import ActionSummary from "discourse/models/action-summary";
 import Controller from "@ember/controller";
-import EmberObject from "@ember/object";
 import I18n from "I18n";
 import { MAX_MESSAGE_LENGTH } from "discourse/models/post-action-type";
 import ModalFunctionality from "discourse/mixins/modal-functionality";
@@ -10,19 +8,18 @@ import User from "discourse/models/user";
 import discourseComputed, { bind } from "discourse-common/utils/decorators";
 import { not } from "@ember/object/computed";
 import optionalService from "discourse/lib/optional-service";
-import { popupAjaxError } from "discourse/lib/ajax-error";
 import { classify } from "@ember/string";
 
 export default Controller.extend(ModalFunctionality, {
   adminTools: optionalService(),
   userDetails: null,
   selected: null,
-  flagTopic: null,
   message: null,
   isWarning: false,
   topicActionByName: null,
   spammerDetails: null,
   flagActions: null,
+  flagTarget: null,
 
   init() {
     this._super(...arguments);
@@ -76,13 +73,14 @@ export default Controller.extend(ModalFunctionality, {
   _penalize(adminToolMethod, performAction) {
     if (this.adminTools) {
       return User.findByUsername(this.model.username).then((createdBy) => {
-        let postId = this.model.id;
-        let postEdit = this.model.cooked;
-        return this.adminTools[adminToolMethod](createdBy, {
-          postId,
-          postEdit,
-          before: performAction,
-        });
+        const opts = { before: performAction };
+
+        if (this.flagTarget.editable()) {
+          opts.postId = this.model.id;
+          opts.postEdit = this.model.cooked;
+        }
+
+        return this.adminTools[adminToolMethod](createdBy, opts);
       });
     }
   },
@@ -115,47 +113,25 @@ export default Controller.extend(ModalFunctionality, {
     return canDeleteSpammer && nameKey === "spam";
   },
 
-  @discourseComputed("flagTopic")
-  title(flagTopic) {
-    return flagTopic ? "flagging_topic.title" : "flagging.title";
+  @discourseComputed("flagTarget")
+  title(flagTarget) {
+    return flagTarget.title();
   },
 
-  @discourseComputed("post", "flagTopic", "model.actions_summary.@each.can_act")
+  @discourseComputed(
+    "post",
+    "flagTarget",
+    "model.actions_summary.@each.can_act"
+  )
   flagsAvailable() {
-    if (!this.flagTopic) {
-      // flagging post
-      let flagsAvailable = this.get("model.flagsAvailable");
-
-      // "message user" option should be at the top
-      const notifyUserIndex = flagsAvailable.indexOf(
-        flagsAvailable.filterBy("name_key", "notify_user")[0]
-      );
-      if (notifyUserIndex !== -1) {
-        const notifyUser = flagsAvailable[notifyUserIndex];
-        flagsAvailable.splice(notifyUserIndex, 1);
-        flagsAvailable.splice(0, 0, notifyUser);
-      }
-      return flagsAvailable;
-    } else {
-      // flagging topic
-      let lookup = EmberObject.create();
-      let model = this.model;
-      model.get("actions_summary").forEach((a) => {
-        a.flagTopic = model;
-        a.actionType = this.site.topicFlagTypeById(a.id);
-        lookup.set(a.actionType.get("name_key"), ActionSummary.create(a));
-      });
-      this.set("topicActionByName", lookup);
-
-      return this.site.get("topic_flag_types").filter((item) => {
-        return this.get("model.actions_summary").some((a) => {
-          return a.id === item.get("id") && a.can_act;
-        });
-      });
-    }
+    return this.flagTarget.flagsAvailable(this, this.site, this.model);
   },
 
-  @discourseComputed("post", "flagTopic", "model.actions_summary.@each.can_act")
+  @discourseComputed(
+    "post",
+    "flagTarget",
+    "model.actions_summary.@each.can_act"
+  )
   staffFlagsAvailable() {
     return (
       this.get("model.flagsAvailable") &&
@@ -190,9 +166,13 @@ export default Controller.extend(ModalFunctionality, {
   },
 
   // Staff accounts can "take action"
-  @discourseComputed("flagTopic", "selected.is_custom_flag")
-  canTakeAction(flagTopic, isCustomFlag) {
-    return !flagTopic && !isCustomFlag && this.currentUser.get("staff");
+  @discourseComputed("flagTarget", "selected.is_custom_flag")
+  canTakeAction(flagTarget, isCustomFlag) {
+    return (
+      !flagTarget.targetsTopic() &&
+      !isCustomFlag &&
+      this.currentUser.get("staff")
+    );
   },
 
   @discourseComputed("selected.is_custom_flag")
@@ -200,14 +180,13 @@ export default Controller.extend(ModalFunctionality, {
     return isCustomFlag ? "envelope" : "flag";
   },
 
-  @discourseComputed("selected.is_custom_flag", "flagTopic")
-  submitLabel(isCustomFlag, flagTopic) {
+  @discourseComputed("selected.is_custom_flag", "flagTarget")
+  submitLabel(isCustomFlag, flagTarget) {
     if (isCustomFlag) {
-      return flagTopic
-        ? "flagging_topic.notify_action"
-        : "flagging.notify_action";
+      return flagTarget.customSubmitLabel();
     }
-    return flagTopic ? "flagging_topic.action" : "flagging.action";
+
+    return flagTarget.submitLabel();
   },
 
   actions: {
@@ -243,59 +222,13 @@ export default Controller.extend(ModalFunctionality, {
     },
 
     createFlag(opts) {
-      let postAction; // an instance of ActionSummary
+      const params = opts || {};
 
-      if (!this.flagTopic) {
-        postAction = this.get("model.actions_summary").findBy(
-          "id",
-          this.get("selected.id")
-        );
-      } else {
-        postAction = this.get(
-          "topicActionByName." + this.get("selected.name_key")
-        );
+      if (this.get("selected.is_custom_flag")) {
+        params.message = this.message;
       }
 
-      let params = this.get("selected.is_custom_flag")
-        ? { message: this.message }
-        : {};
-
-      if (opts) {
-        params = Object.assign(params, opts);
-      }
-
-      this.appEvents.trigger(
-        this.flagTopic ? "topic:flag-created" : "post:flag-created",
-        this.model,
-        postAction,
-        params
-      );
-
-      this.send("hideModal");
-
-      postAction
-        .act(this.model, params)
-        .then(() => {
-          if (this.isDestroying || this.isDestroyed) {
-            return;
-          }
-
-          if (!params.skipClose) {
-            this.send("closeModal");
-          }
-          if (params.message) {
-            this.set("message", "");
-          }
-          this.appEvents.trigger("post-stream:refresh", {
-            id: this.get("model.id"),
-          });
-        })
-        .catch((error) => {
-          if (!this.isDestroying && !this.isDestroyed) {
-            this.send("closeModal");
-          }
-          popupAjaxError(error);
-        });
+      this.flagTarget.create(this, params);
     },
 
     createFlagAsWarning() {
@@ -304,7 +237,10 @@ export default Controller.extend(ModalFunctionality, {
     },
 
     flagForReview() {
-      this.set("selected", this.get("notifyModeratorsFlag"));
+      if (!this.selected) {
+        this.set("selected", this.get("notifyModeratorsFlag"));
+      }
+
       this.send("createFlag", { queue_for_review: true });
       this.set("model.hidden", true);
     },
@@ -314,10 +250,12 @@ export default Controller.extend(ModalFunctionality, {
     },
   },
 
-  @discourseComputed("flagTopic", "selected.name_key")
-  canSendWarning(flagTopic, nameKey) {
+  @discourseComputed("flagTarget", "selected.name_key")
+  canSendWarning(flagTarget, nameKey) {
     return (
-      !flagTopic && this.currentUser.get("staff") && nameKey === "notify_user"
+      !flagTarget.targetsTopic() &&
+      this.currentUser.get("staff") &&
+      nameKey === "notify_user"
     );
   },
 });
diff --git a/app/assets/javascripts/discourse/app/lib/flag-targets/flag.js b/app/assets/javascripts/discourse/app/lib/flag-targets/flag.js
new file mode 100644
index 00000000000..b2affe83496
--- /dev/null
+++ b/app/assets/javascripts/discourse/app/lib/flag-targets/flag.js
@@ -0,0 +1,49 @@
+import { popupAjaxError } from "discourse/lib/ajax-error";
+
+export default class Flag {
+  targetsTopic() {
+    return false;
+  }
+
+  editable() {
+    return true;
+  }
+
+  create(controller, opts) {
+    // an instance of ActionSummary
+    let postAction = this.postActionFor(controller);
+
+    controller.appEvents.trigger(
+      this.flagCreatedEvent,
+      controller.model,
+      postAction,
+      opts
+    );
+
+    controller.send("hideModal");
+
+    postAction
+      .act(controller.model, opts)
+      .then(() => {
+        if (controller.isDestroying || controller.isDestroyed) {
+          return;
+        }
+
+        if (!opts.skipClose) {
+          controller.send("closeModal");
+        }
+        if (opts.message) {
+          controller.set("message", "");
+        }
+        controller.appEvents.trigger("post-stream:refresh", {
+          id: controller.get("model.id"),
+        });
+      })
+      .catch((error) => {
+        if (!controller.isDestroying && !controller.isDestroyed) {
+          controller.send("closeModal");
+        }
+        popupAjaxError(error);
+      });
+  }
+}
diff --git a/app/assets/javascripts/discourse/app/lib/flag-targets/post-flag.js b/app/assets/javascripts/discourse/app/lib/flag-targets/post-flag.js
new file mode 100644
index 00000000000..f30fd72ba27
--- /dev/null
+++ b/app/assets/javascripts/discourse/app/lib/flag-targets/post-flag.js
@@ -0,0 +1,42 @@
+import Flag from "discourse/lib/flag-targets/flag";
+
+export default class PostFlag extends Flag {
+  title() {
+    return "flagging.title";
+  }
+
+  customSubmitLabel() {
+    return "flagging.notify_action";
+  }
+
+  submitLabel() {
+    return "flagging.action";
+  }
+
+  flagCreatedEvent() {
+    return "post:flag-created";
+  }
+
+  flagsAvailable(_flagController, _site, model) {
+    let flagsAvailable = model.flagsAvailable;
+
+    // "message user" option should be at the top
+    const notifyUserIndex = flagsAvailable.indexOf(
+      flagsAvailable.filterBy("name_key", "notify_user")[0]
+    );
+
+    if (notifyUserIndex !== -1) {
+      const notifyUser = flagsAvailable[notifyUserIndex];
+      flagsAvailable.splice(notifyUserIndex, 1);
+      flagsAvailable.splice(0, 0, notifyUser);
+    }
+
+    return flagsAvailable;
+  }
+
+  postActionFor(controller) {
+    return controller
+      .get("model.actions_summary")
+      .findBy("id", controller.get("selected.id"));
+  }
+}
diff --git a/app/assets/javascripts/discourse/app/lib/flag-targets/topic-flag.js b/app/assets/javascripts/discourse/app/lib/flag-targets/topic-flag.js
new file mode 100644
index 00000000000..e8df5440fd9
--- /dev/null
+++ b/app/assets/javascripts/discourse/app/lib/flag-targets/topic-flag.js
@@ -0,0 +1,46 @@
+import ActionSummary from "discourse/models/action-summary";
+import EmberObject from "@ember/object";
+import Flag from "discourse/lib/flag-targets/flag";
+
+export default class TopicFlag extends Flag {
+  title() {
+    return "flagging_topic.title";
+  }
+
+  targetsTopic() {
+    return true;
+  }
+
+  customSubmitLabel() {
+    return "flagging_topic.notify_action";
+  }
+
+  submitLabel() {
+    return "flagging_topic.action";
+  }
+
+  flagCreatedEvent() {
+    return "topic:flag-created";
+  }
+
+  flagsAvailable(flagController, site, model) {
+    let lookup = EmberObject.create();
+
+    model.actions_summary.forEach((a) => {
+      a.flagTopic = model;
+      a.actionType = site.topicFlagTypeById(a.id);
+      lookup.set(a.actionType.name_key, ActionSummary.create(a));
+    });
+    flagController.set("topicActionByName", lookup);
+
+    return site.topic_flag_types.filter((item) => {
+      return model.actions_summary.some((a) => {
+        return a.id === item.id && a.can_act;
+      });
+    });
+  }
+
+  postActionFor(controller) {
+    return controller.get(`topicActionByName.${controller.selected.name_key}`);
+  }
+}
diff --git a/app/assets/javascripts/discourse/app/lib/transform-post.js b/app/assets/javascripts/discourse/app/lib/transform-post.js
index cd02dc7ca4a..ea7674d9258 100644
--- a/app/assets/javascripts/discourse/app/lib/transform-post.js
+++ b/app/assets/javascripts/discourse/app/lib/transform-post.js
@@ -57,7 +57,7 @@ export function transformBasicPost(post) {
     showFlagDelete: false,
     canRecover: post.can_recover,
     canEdit: post.can_edit,
-    canFlag: !isEmpty(post.get("flagsAvailable")),
+    canFlag: !post.get("topic.deleted") && !isEmpty(post.get("flagsAvailable")),
     canReviewTopic: false,
     reviewableId: post.reviewable_id,
     reviewableScoreCount: post.reviewable_score_count,
diff --git a/app/assets/javascripts/discourse/app/routes/topic.js b/app/assets/javascripts/discourse/app/routes/topic.js
index 89e6e7a1f95..6764143a011 100644
--- a/app/assets/javascripts/discourse/app/routes/topic.js
+++ b/app/assets/javascripts/discourse/app/routes/topic.js
@@ -8,6 +8,8 @@ import { isEmpty } from "@ember/utils";
 import { inject as service } from "@ember/service";
 import { setTopicId } from "discourse/lib/topic-list-tracker";
 import showModal from "discourse/lib/show-modal";
+import TopicFlag from "discourse/lib/flag-targets/topic-flag";
+import PostFlag from "discourse/lib/flag-targets/post-flag";
 
 const SCROLL_DELAY = 500;
 
@@ -94,14 +96,14 @@ const TopicRoute = DiscourseRoute.extend({
   @action
   showFlags(model) {
     let controller = showModal("flag", { model });
-    controller.setProperties({ flagTopic: false });
+    controller.setProperties({ flagTarget: new PostFlag() });
   },
 
   @action
   showFlagTopic() {
     const model = this.modelFor("topic");
     let controller = showModal("flag", { model });
-    controller.setProperties({ flagTopic: true });
+    controller.setProperties({ flagTarget: new TopicFlag() });
   },
 
   @action
diff --git a/app/assets/javascripts/discourse/app/templates/modal/flag.hbs b/app/assets/javascripts/discourse/app/templates/modal/flag.hbs
index 863c4828954..a890ce311ee 100644
--- a/app/assets/javascripts/discourse/app/templates/modal/flag.hbs
+++ b/app/assets/javascripts/discourse/app/templates/modal/flag.hbs
@@ -18,7 +18,7 @@
   {{#if this.canTakeAction}}
     <ReviewableBundledAction @bundle={{this.flagActions}} @performAction={{action "takeAction"}} @reviewableUpdating={{this.submitDisabled}} />
 
-    <DButton @class="btn-danger" @action={{action "flagForReview"}} @disabled={{this.cantFlagForReview}} @icon="exclamation-triangle" @label="flagging.flag_for_review" />
+    <DButton @class="btn-danger" @action={{action "flagForReview"}} @disabled={{or this.submitDisabled this.cantFlagForReview}} @icon="exclamation-triangle" @label="flagging.flag_for_review" />
   {{/if}}
 
   {{#if this.showDeleteSpammer}}
diff --git a/app/assets/javascripts/select-kit/addon/components/select-kit.js b/app/assets/javascripts/select-kit/addon/components/select-kit.js
index 7d1b4003a38..11348538cd8 100644
--- a/app/assets/javascripts/select-kit/addon/components/select-kit.js
+++ b/app/assets/javascripts/select-kit/addon/components/select-kit.js
@@ -294,6 +294,7 @@ export default Component.extend(
       mobilePlacementStrategy: null,
       desktopPlacementStrategy: null,
       hiddenValues: null,
+      disabled: false,
     },
 
     autoFilterable: computed("content.[]", "selectKit.filter", function () {
diff --git a/lib/guardian/post_guardian.rb b/lib/guardian/post_guardian.rb
index a4f9e536ecf..1e884d5e588 100644
--- a/lib/guardian/post_guardian.rb
+++ b/lib/guardian/post_guardian.rb
@@ -232,7 +232,7 @@ module PostGuardian
   def can_delete_post_action?(post_action)
     return false unless is_my_own?(post_action) && !post_action.is_private_message?
 
-    post_action.created_at > SiteSetting.post_undo_action_window_mins.minutes.ago && !post_action.post.topic&.archived?
+    post_action.created_at > SiteSetting.post_undo_action_window_mins.minutes.ago && !post_action.post&.topic&.archived?
   end
 
   def can_see_post?(post)