From d51efca9669041927960cacfc8c6d9f317f5d83d Mon Sep 17 00:00:00 2001
From: Jessica McInchak <jessica.mcinchak@gmail.com>
Date: Thu, 7 Dec 2023 12:03:23 +0000
Subject: [PATCH] fix: drop pg function `get_flow_schema` in favor of simpler
 js data munging (#2540)

---
 .../flows/downloadSchema/controller.ts        |  4 +-
 .../modules/flows/downloadSchema/service.ts   | 39 ++++++++-----------
 hasura.planx.uk/metadata/functions.yaml       |  3 --
 hasura.planx.uk/metadata/tables.yaml          | 13 -------
 .../down.sql                                  |  4 ++
 .../up.sql                                    |  2 +
 6 files changed, 23 insertions(+), 42 deletions(-)
 create mode 100644 hasura.planx.uk/migrations/1701881725039_drop_function_get_flow_schema/down.sql
 create mode 100644 hasura.planx.uk/migrations/1701881725039_drop_function_get_flow_schema/up.sql

diff --git a/api.planx.uk/modules/flows/downloadSchema/controller.ts b/api.planx.uk/modules/flows/downloadSchema/controller.ts
index 95113bacc4..f93551817b 100644
--- a/api.planx.uk/modules/flows/downloadSchema/controller.ts
+++ b/api.planx.uk/modules/flows/downloadSchema/controller.ts
@@ -6,8 +6,6 @@ import { ServerError } from "../../../errors";
 
 interface DownloadFlowSchemaResponse {
   message: string;
-  alteredNodes: Node[] | null;
-  description?: string;
 }
 
 export const downloadFlowSchema = z.object({
@@ -34,7 +32,7 @@ export const downloadFlowSchemaController: DownloadFlowSchemaController =
     } catch (error) {
       return next(
         new ServerError({
-          message: `Failed to download flow schema: ${error}`,
+          message: `Failed to download schema for flow ${res.locals.parsedReq.params?.flowId}: ${error}`,
         }),
       );
     }
diff --git a/api.planx.uk/modules/flows/downloadSchema/service.ts b/api.planx.uk/modules/flows/downloadSchema/service.ts
index 8c5ae5211c..32760c4b48 100644
--- a/api.planx.uk/modules/flows/downloadSchema/service.ts
+++ b/api.planx.uk/modules/flows/downloadSchema/service.ts
@@ -1,5 +1,4 @@
-import { $public } from "../../../client";
-import { gql } from "graphql-request";
+import { getFlowData } from "../../../helpers";
 
 interface FlowSchema {
   node: string;
@@ -9,27 +8,21 @@ interface FlowSchema {
 }
 
 export const getFlowSchema = async (flowId: string) => {
-  const { flowSchema } = await $public.client.request<{
-    flowSchema: FlowSchema[];
-  }>(
-    gql`
-      query ($flow_id: String!) {
-        flowSchema: get_flow_schema(args: { published_flow_id: $flow_id }) {
-          node
-          type
-          text
-          planx_variable
-        }
-      }
-    `,
-    { flow_id: flowId },
-  );
+  const flow = await getFlowData(flowId);
 
-  if (!flowSchema.length) {
-    throw Error(
-      "Can't find a schema for this flow. Make sure it's published or try a different flow id.",
-    );
-  }
+  const data: FlowSchema[] = [];
+  Object.entries(flow.data).map(([nodeId, nodeData]) =>
+    data.push({
+      node: nodeId,
+      type: nodeData?.type?.toString() || "_root",
+      text: nodeData.data?.text,
+      planx_variable:
+        nodeData.data?.fn ||
+        nodeData.data?.val ||
+        nodeData.data?.output ||
+        nodeData.data?.dataFieldBoundary,
+    }),
+  );
 
-  return flowSchema;
+  return data;
 };
diff --git a/hasura.planx.uk/metadata/functions.yaml b/hasura.planx.uk/metadata/functions.yaml
index da885f5fc3..401e12cc42 100644
--- a/hasura.planx.uk/metadata/functions.yaml
+++ b/hasura.planx.uk/metadata/functions.yaml
@@ -1,6 +1,3 @@
 - function:
     schema: public
     name: diff_latest_published_flow
-- function:
-    schema: public
-    name: get_flow_schema
diff --git a/hasura.planx.uk/metadata/tables.yaml b/hasura.planx.uk/metadata/tables.yaml
index c69a9345a3..09bbe2a170 100644
--- a/hasura.planx.uk/metadata/tables.yaml
+++ b/hasura.planx.uk/metadata/tables.yaml
@@ -236,19 +236,6 @@
           - document_template
           - flow_id
         filter: {}
-- table:
-    schema: public
-    name: flow_schemas
-  select_permissions:
-    - role: public
-      permission:
-        columns:
-          - flow_id
-          - node
-          - planx_variable
-          - text
-          - type
-        filter: {}
 - table:
     schema: public
     name: flows
diff --git a/hasura.planx.uk/migrations/1701881725039_drop_function_get_flow_schema/down.sql b/hasura.planx.uk/migrations/1701881725039_drop_function_get_flow_schema/down.sql
new file mode 100644
index 0000000000..e3ceaec568
--- /dev/null
+++ b/hasura.planx.uk/migrations/1701881725039_drop_function_get_flow_schema/down.sql
@@ -0,0 +1,4 @@
+-- Could not auto-generate a down migration.
+-- Please write an appropriate down migration for the SQL below:
+-- DROP FUNCTION public.get_flow_schema CASCADE;
+-- DROP TABLE public.flow_schemas CASCADE;
diff --git a/hasura.planx.uk/migrations/1701881725039_drop_function_get_flow_schema/up.sql b/hasura.planx.uk/migrations/1701881725039_drop_function_get_flow_schema/up.sql
new file mode 100644
index 0000000000..a29166de9f
--- /dev/null
+++ b/hasura.planx.uk/migrations/1701881725039_drop_function_get_flow_schema/up.sql
@@ -0,0 +1,2 @@
+DROP FUNCTION public.get_flow_schema CASCADE;
+DROP TABLE public.flow_schemas CASCADE;