Pass online/offline status indicators with staking accounts (#1265)

* staking online status

* restrict onlineStatus.online to validators

* get onlineStatus for stash/validator only

* tests

* fixes

* Add offline

* Revert stash, change to stashId, linting

* Heartbeat signature

* Make CodeClimate (slightly) happier

* keep compatibility

* change status type

* rv null possible

* cleanup

packages/api-derive/src/imOnline/index.ts

@@ -0,0 +1,5 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+export * from './receivedHeartbeats';

packages/api-derive/src/imOnline/receivedHeartbeats.ts

@@ -0,0 +1,37 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { AccountId, SessionIndex } from '@polkadot/types/interfaces';
+
+import { of, Observable } from 'rxjs';
+import { map, switchMap } from 'rxjs/operators';
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { Bytes } from '@polkadot/types';
+
+import { drr } from '../util/drr';
+
+/**
+ * @description Return a boolean array indicating whether the passed accounts had received heartbeats in the current session
+ */
+export function receivedHeartbeats (api: ApiInterfaceRx): (addresses: (AccountId | string)[]) => Observable<boolean[]> {
+  return (addresses: (AccountId | string)[]): Observable<boolean[]> => {
+    return api.query.imOnline && api.query.imOnline.receivedHeartbeats
+      ? api.query.session
+        .currentIndex<SessionIndex>()
+        .pipe(
+          switchMap((currentIndex): Observable<Bytes[]> =>
+            api.query.imOnline.receivedHeartbeats.multi(
+              addresses.map((address): [SessionIndex, AccountId | string] =>
+                [currentIndex, address]
+              )
+            )
+          ),
+          map((heartbeats): boolean[] =>
+            heartbeats.map((heartbeat): boolean => !heartbeat.isEmpty)
+          ),
+          drr()
+        )
+      : of([...new Array(addresses.length).keys()].map((): boolean => false));
+  };
+}

packages/api-derive/src/index.spec.ts

@@ -61,6 +61,10 @@ describe('derive', (): void => {
     testFunction(api)('session', 'eraLength', []);
     testFunction(api)('session', 'eraProgress', []);
     testFunction(api)('session', 'sessionProgress', []);
+
+    testFunction(api)('staking', 'info', []);
+    testFunction(api)('staking', 'recentlyOffline', []);
+    testFunction(api)('staking', 'controllers', []);
   });
 
   describe('custom', (): void => {

packages/api-derive/src/index.ts

@@ -13,6 +13,7 @@ import * as chain from './chain';
 import * as contracts from './contracts';
 import * as democracy from './democracy';
 import * as elections from './elections';
+import * as imOnline from './imOnline';
 import * as session from './session';
 import * as staking from './staking';
 
@@ -56,7 +57,7 @@ function injectFunctions<AllSections> (api: ApiInterfaceRx, allSections: AllSect
     }, {} as unknown as DeriveSections<AllSections>);
 }
 
-export const derive = { accounts, balances, chain, contracts, democracy, elections, session, staking };
+export const derive = { accounts, balances, chain, contracts, democracy, elections, imOnline, session, staking };
 export type Derive = typeof derive;
 
 // FIXME I have no idea how to get this done

packages/api-derive/src/staking/index.ts

@@ -4,3 +4,4 @@
 
 export * from './controllers';
 export * from './info';
+export * from './recentlyOffline';

packages/api-derive/src/staking/info.ts

@@ -19,6 +19,7 @@ import { isUndefined } from '@polkadot/util';
 
 import { bestNumber } from '../chain/bestNumber';
 import { eraLength } from '../session/eraLength';
+import { recentlyOffline } from './recentlyOffline';
 import { drr } from '../util/drr';
 
 type MultiResult = [Option<Keys>, [
@@ -128,20 +129,20 @@ function retrieveMulti (api: ApiInterfaceRx, stashId: AccountId, controllerId: A
 }
 
 function retrieveInfo (api: ApiInterfaceRx, stashId: AccountId, controllerId: AccountId): Observable<DerivedStaking> {
-  return (
-    combineLatest([
-      eraLength(api)(),
-      bestNumber(api)(),
-      retrieveMulti(api, stashId, controllerId)
-    ])
-  ).pipe(
-    map(([eraLength, bestNumber, [nextKeys, [queuedKeys, _stakingLedger, [nominators], rewardDestination, stakers, [validatorPrefs]]]]): DerivedStaking => {
+  return combineLatest([
+    eraLength(api)(),
+    bestNumber(api)(),
+    recentlyOffline(api)(),
+    retrieveMulti(api, stashId, controllerId)
+  ]).pipe(
+    map(([eraLength, bestNumber, recentlyOffline, [nextKeys, [queuedKeys, _stakingLedger, [nominators], rewardDestination, stakers, [validatorPrefs]]]]): DerivedStaking => {
       const stakingLedger = _stakingLedger.unwrapOr(undefined);
 
       return {
         accountId: stashId,
         controllerId,
         nominators,
+        offline: recentlyOffline[stashId.toString()],
         redeemable: redeemableSum(stakingLedger, eraLength, bestNumber),
         rewardDestination,
         stakers,

packages/api-derive/src/staking/recentlyOffline.ts

@@ -0,0 +1,43 @@
+// Copyright 2017-2019 @polkadot/api-derive authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { AccountId, BlockNumber } from '@polkadot/types/interfaces';
+import { Codec } from '@polkadot/types/types';
+
+import BN from 'bn.js';
+import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { DerivedRecentlyOffline } from '../types';
+
+import { drr } from '../util/drr';
+
+/**
+ * @description Retrieve a keyed record of accounts recently reported to be offline
+ */
+export function recentlyOffline (api: ApiInterfaceRx): () => Observable<DerivedRecentlyOffline> {
+  return (): Observable<DerivedRecentlyOffline> =>
+    api.query.staking
+      .recentlyOffline<[AccountId, BlockNumber, BN][] & Codec>()
+      .pipe(
+        map((recentlyOffline): DerivedRecentlyOffline =>
+          recentlyOffline.reduce((result: DerivedRecentlyOffline, [accountId, blockNumber, count]): DerivedRecentlyOffline => {
+            const key = accountId.toString();
+
+            if (!result[key]) {
+              result[key] = [];
+            }
+
+            result[key].push({
+              blockNumber,
+              count
+            });
+
+            return result;
+          },
+          {})
+        ),
+        drr()
+      );
+}

packages/api-derive/src/types.ts

@@ -51,6 +51,13 @@ export interface DerivedFees {
   transferFee: BN;
 }
 
+export interface RecentlyOffline {
+  blockNumber: BlockNumber;
+  count: BN;
+}
+
+export type DerivedRecentlyOffline = Record<string, RecentlyOffline[]>;
+
 export interface DerivedReferendumVote {
   accountId: AccountId;
   balance: Balance;
@@ -70,7 +77,22 @@ export interface DerivedSessionInfo {
   sessionProgress: BN;
 }
 
-export interface DerivedStaking {
+export type DerivedStakingAccount = [AccountId, DerivedStakingOnlineStatus];
+
+export type DerivedStakingAccounts = DerivedStakingAccount[];
+
+export interface DerivedStakingOnlineStatus {
+  online?: {
+    isOnline: boolean;
+    blockNumber?: BlockNumber;
+  };
+  offline?: {
+    blockNumber: BlockNumber;
+    count: BN;
+  }[];
+}
+
+export interface DerivedStaking extends DerivedStakingOnlineStatus {
   accountId: AccountId;
   controllerId?: AccountId;
   nextSessionId?: AccountId;