feat: middleware class

src/Middleware.ts

@@ -0,0 +1,102 @@
+import BigNumber from 'bignumber.js';
+
+import { Context } from '~/base';
+import { eventByIndexedArgs } from '~/middleware/queries';
+import { EventIdEnum, ModuleIdEnum, Query } from '~/middleware/types';
+import { Ensured, EventIdentifier, ResultSet } from '~/types';
+
+/**
+ * Handles all Middleware related functionality
+ */
+export class Middleware {
+  private context: Context;
+
+  /**
+   * @hidden
+   */
+  constructor(context: Context) {
+    this.context = context;
+  }
+
+  /**
+   * Retrieve a single event by any of its indexed arguments Can be filtered using parameters
+   *
+   * @param opts.moduleId - type of the module to fetch
+   * @param opts.eventId - type of the event to fetch
+   * @param opts.eventArg0 - event value to filter in position 0
+   * @param opts.eventArg1 - event value to filter in position 1
+   * @param opts.eventArg2 - event value to filter in position 2
+   */
+  public async getEventByIndexedArgs(opts: {
+    moduleId: ModuleIdEnum;
+    eventId: EventIdEnum;
+    eventArg0?: string;
+    eventArg1?: string;
+    eventArg2?: string;
+  }): Promise<EventIdentifier | null> {
+    const { context } = this;
+
+    const { moduleId, eventId, eventArg0, eventArg1, eventArg2 } = opts;
+
+    const result = await context.queryMiddleware<Ensured<Query, 'eventByIndexedArgs'>>(
+      eventByIndexedArgs({
+        moduleId,
+        eventId,
+        eventArg0,
+        eventArg1,
+        eventArg2,
+      })
+    );
+
+    if (result.data.eventByIndexedArgs) {
+      /* eslint-disable @typescript-eslint/no-non-null-assertion */
+      return {
+        blockNumber: new BigNumber(result.data.eventByIndexedArgs.block_id),
+        blockDate: result.data.eventByIndexedArgs.block!.datetime,
+        eventIndex: result.data.eventByIndexedArgs.event_idx,
+      };
+      /* eslint-enabled @typescript-eslint/no-non-null-assertion */
+    }
+
+    return null;
+  }
+
+  /**
+   * Retrieve a list of event indentifiers. Can be filtered using parameters
+   *
+   * @param opts.moduleId - type of the module to fetch
+   * @param opts.eventId - type of the event to fetch
+   * @param opts.eventArg0 - event value to filter in position 0
+   * @param opts.eventArg1 - event value to filter in position 1
+   * @param opts.eventArg2 - event value to filter in position 2
+   * @param opts.size - page size
+   * @param opts.start - page offset
+   */
+  public async getEventsByIndexedArgs(opts: {
+    moduleId: ModuleIdEnum;
+    eventId: EventIdEnum;
+    eventArg0?: string;
+    eventArg1?: string;
+    eventArg2?: string;
+    size?: number;
+    start?: number;
+  }): Promise<ResultSet<EventIdentifier> | null> {
+    const { context } = this;
+
+    const { moduleId, eventId, eventArg0, eventArg1, eventArg2, size, start } = opts;
+
+    const result = await context.queryMiddleware<Ensured<Query, 'eventsByIndexedArgs'>>(
+      eventsByIndexedArgs({
+        moduleId,
+        eventId,
+        eventArg0,
+        eventArg1,
+        eventArg2,
+        count: size,
+        skip: start,
+      })
+    );
+
+    //
+  }
+}

src/Polymesh.ts

@@ -47,6 +47,7 @@ import { getDid, stringIsClean } from '~/utils/internal';
 
 import { Claims } from './Claims';
 // import { Governance } from './Governance';
+import { Middleware } from './Middleware';
 import { TREASURY_MODULE_ADDRESS } from './utils/constants';
 
 interface ConnectParamsBase {
@@ -75,6 +76,7 @@ export class Polymesh {
   // NOTE uncomment in Governance v2 upgrade
   // public governance: Governance;
   public claims: Claims;
+  public middleware: Middleware;
 
   /**
    * @hidden
@@ -85,6 +87,7 @@ export class Polymesh {
     // NOTE uncomment in Governance v2 upgrade
     // this.governance = new Governance(context);
     this.claims = new Claims(context);
+    this.middleware = new Middleware(context);
   }
 
   /**

src/middleware/queries.ts

@@ -140,6 +140,49 @@ export function eventByIndexedArgs(
   };
 }
 
+/**
+ * @hidden
+ *
+ * Get all events by any of its indexed arguments
+ */
+export function eventsByIndexedArgs(
+  variables: QueryEventsByIndexedArgsArgs
+): GraphqlQuery<QueryEventsByIndexedArgsArgs> {
+  const query = gql`
+    query EventsByIndexedArgsQuery(
+      $moduleId: ModuleIdEnum!
+      $eventId: EventIdEnum!
+      $eventArg0: String
+      $eventArg1: String
+      $eventArg2: String
+      $count: Int
+      $skip: Int
+    ) {
+      eventsByIndexedArgs(
+        moduleId: $moduleId
+        eventId: $eventId
+        eventArg0: $eventArg0
+        eventArg1: $eventArg1
+        eventArg2: $eventArg2
+        count: $count
+        skip: $skip
+      ) {
+        block_id
+        event_idx
+        extrinsic_idx
+        block {
+          datetime
+        }
+      }
+    }
+  `;
+
+  return {
+    query,
+    variables,
+  };
+}
+
 /**
  * @hidden
  *