feat: twu proposal polling

src/front-end/typescript/lib/pages/proposal/team-with-us/edit/tab/proposal.tsx

@@ -1,4 +1,7 @@
-import { TWU_PROPOSAL_EVALUATION_CONTENT_ID } from "front-end/config";
+import {
+  PROPOSAL_POLL_DURATION,
+  TWU_PROPOSAL_EVALUATION_CONTENT_ID
+} from "front-end/config";
 import { makeStartLoading, makeStopLoading } from "front-end/lib";
 import { Route } from "front-end/lib/app/types";
 import * as SubmitProposalTerms from "front-end/lib/components/submit-proposal-terms";
@@ -51,7 +54,8 @@ type ModalId =
   | "saveChangesAndSubmit"
   | "withdrawBeforeDeadline"
   | "withdrawAfterDeadline"
-  | "delete";
+  | "delete"
+  | "orgProposalChangeDetected";
 
 export interface State extends Tab.Params {
   organizations: OrganizationSlim[];
@@ -114,7 +118,9 @@ export type InnerMsg =
   | ADT<
       "onDeleteResponse",
       api.ResponseValidation<TWUProposal, DeleteValidationErrors>
-    >;
+    >
+  | ADT<"checkStatus">
+  | ADT<"onCheckStatusResponse", api.ResponseValidation<TWUProposal, string[]>>;
 
 export type Msg = component_.page.Msg<InnerMsg, Route>;
 
@@ -295,7 +301,10 @@ const update: component_.base.Update<State, Msg> = ({ state, msg }) => {
         result.value,
         result.value.status === TWUProposalStatus.Draft
       );
-      return [newState.set("isEditing", true), cmds];
+      return [
+        newState.set("isEditing", true),
+        [...cmds, component_.cmd.dispatch(adt("checkStatus") as Msg)]
+      ];
     }
     case "cancelEditing": {
       const [newState, cmds] = resetProposal(state, state.proposal);
@@ -681,6 +690,46 @@ const update: component_.base.Update<State, Msg> = ({ state, msg }) => {
         ]
       ];
     }
+    case "checkStatus": {
+      return [
+        state,
+        state.isEditing
+          ? [
+              api.proposals.twu.readOne<Msg>(state.proposal.opportunity.id)(
+                state.proposal.id,
+                (result) => adt("onCheckStatusResponse", result)
+              )
+            ]
+          : []
+      ];
+    }
+    case "onCheckStatusResponse": {
+      const incomingProposal = api.getValidValue(msg.value, null);
+      if (!incomingProposal) {
+        return [state, []];
+      }
+
+      if (incomingProposal.updatedAt > state.proposal.updatedAt) {
+        return [
+          state,
+          [
+            component_.cmd.dispatch(
+              adt("showModal", "orgProposalChangeDetected" as const) as Msg
+            )
+          ]
+        ];
+      }
+
+      return [
+        state,
+        [
+          component_.cmd.delayedDispatch(
+            PROPOSAL_POLL_DURATION,
+            adt("checkStatus") as Msg
+          )
+        ]
+      ];
+    }
     default:
       return [state, []];
   }
@@ -911,6 +960,32 @@ export const component: Tab.Component<State, Msg> = {
             }
           ]
         });
+      case "orgProposalChangeDetected":
+        return component_.page.modal.show({
+          title: "Proposal Changes Detected",
+          body: () => (
+            <>
+              <p>
+                Someone else in your organization has submitted changes to this
+                proposal since you started editing it.
+              </p>
+              <p>Your options are:</p>
+              <ol>
+                <li>
+                  Save your changes to a document offline, cancel editing, and
+                  re-enter your changes.
+                </li>
+                <li>
+                  Keep working, and when you submit, your version{" "}
+                  <strong>will</strong> overwrite the previously submitted
+                  changes.
+                </li>
+              </ol>
+            </>
+          ),
+          onCloseMsg: adt("hideModal") as Msg,
+          actions: []
+        });
       case null:
         return component_.page.modal.hide();
     }