Prevent duplicate usage of tool

Author: CarsonF

dbschema/tool.gel

@@ -19,6 +19,7 @@ module Tool {
     overloaded required container: default::Resource {
       on target delete delete source;
     }
+    constraint exclusive on ((.tool, .container));
 
     startDate: cal::local_date;
   }

src/components/tools/tool-usage/tool-usage.gel.repository.ts

@@ -52,4 +52,19 @@ export class ToolUsageRepository
       }));
     },
   );
+
+  async usageFor(container: ID<'Resource'>, tool: ID<'Tool'>) {
+    return await this.db.run(this.usageForQuery, { container, tool });
+  }
+  private readonly usageForQuery = e.params(
+    { container: e.uuid, tool: e.uuid },
+    ($) =>
+      e.select(e.Tool.Usage, (usage) => ({
+        ...this.hydrate(usage),
+        filter_single: {
+          tool: e.cast(e.Tool, $.tool),
+          container: e.cast(e.Resource, $.container),
+        },
+      })),
+  );
 }

src/components/tools/tool-usage/tool-usage.neo4j.repository.ts

@@ -92,6 +92,21 @@ export class ToolUsageRepository extends DtoRepository(ToolUsage) {
     return result;
   }
 
+  async usageFor(container: ID<'Resource'>, tool: ID<'Tool'>) {
+    const res = await this.db
+      .query()
+      .match([
+        node('container', 'BaseNode', { id: container }),
+        relation('out', '', 'uses', ACTIVE),
+        node('node', 'ToolUsage'),
+        relation('out', '', 'tool', ACTIVE),
+        node('tool', 'Tool', { id: tool }),
+      ])
+      .apply(this.hydrate())
+      .first();
+    return res?.dto ?? null;
+  }
+
   async create(input: CreateToolUsage) {
     const initialProps = {
       startDate: input.startDate,

src/components/tools/tool-usage/tool-usage.service.ts

@@ -1,6 +1,7 @@
 import { Injectable } from '@nestjs/common';
 import { mapKeys } from '@seedcompany/common';
 import {
+  DuplicateException,
   type ID,
   InputException,
   isIdLike,
@@ -112,6 +113,13 @@ export class ToolUsageService {
     ) {
       throw new InputException('No recursion');
     }
+    const prev = await this.repo.usageFor(input.container, input.tool);
+    if (prev) {
+      throw new DuplicateException(
+        'tool',
+        'This resource already uses this tool',
+      );
+    }
 
     const dto = await this.repo.create(input);
     this.privileges