Add derive for council voting info (#2115)

* Add derive for council voting info

* Update packages/api-derive/src/council/votes.ts

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

@@ -3,3 +3,5 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 export * from './proposals';
+export * from './votes';
+export * from './votesOf';

packages/api-derive/src/council/types.ts

@@ -0,0 +1,12 @@
+// Copyright 2017-2020 @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, Balance } from '@polkadot/types/interfaces';
+
+export interface DeriveCouncilVote {
+  stake: Balance;
+  votes: AccountId[];
+}
+
+export type DeriveCouncilVotes = [AccountId, DeriveCouncilVote][];

packages/api-derive/src/council/votes.ts

@@ -0,0 +1,88 @@
+// Copyright 2017-2020 @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, Balance } from '@polkadot/types/interfaces';
+import { ITuple } from '@polkadot/types/types';
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { DeriveCouncilVote, DeriveCouncilVotes } from '../types';
+
+import { Observable, combineLatest } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { Vec } from '@polkadot/types';
+
+function retrieveStakeOf (api: ApiInterfaceRx): Observable<[AccountId, Balance][]> {
+  const elections = (api.query.electionsPhragmen || api.query.elections);
+
+  return elections.stakeOf.creator.meta.type.asMap.linked.isTrue
+    ? elections.stakeOf<ITuple<[Vec<AccountId>, Vec<Balance>]>>().pipe(
+      map(([voters, stake]) =>
+        voters.map((voter, index): [AccountId, Balance] => [voter, stake[index]])
+      )
+    )
+    : elections.stakeOf.entries<Balance>().pipe(
+      map((entries) =>
+        entries.map(([key, stake]) => [key.args[0] as AccountId, stake])
+      )
+    );
+}
+
+function retrieveVoteOf (api: ApiInterfaceRx): Observable<[AccountId, AccountId[]][]> {
+  const elections = (api.query.electionsPhragmen || api.query.elections);
+
+  return elections.votesOf.creator.meta.type.asMap.linked.isTrue
+    ? elections.votesOf<ITuple<[Vec<AccountId>, Vec<Vec<AccountId>>]>>().pipe(
+      map(([voters, votes]) =>
+        voters.map((voter, index) => [voter, votes[index]])
+      )
+    )
+    : elections.votesOf.entries<Vec<AccountId>>().pipe(
+      map((entries) =>
+        entries.map(([key, votes]) => [key.args[0] as AccountId, votes])
+      )
+    );
+}
+
+function retrievePrev (api: ApiInterfaceRx): Observable<DeriveCouncilVotes> {
+  return combineLatest([retrieveStakeOf(api), retrieveVoteOf(api)]).pipe(
+    map(([stakes, votes]): DeriveCouncilVotes => {
+      const result: DeriveCouncilVotes = [];
+
+      votes.forEach(([voter, votes]): void => {
+        result.push([voter, { stake: api.registry.createType('Balance'), votes }]);
+      });
+
+      stakes.forEach(([staker, stake]): void => {
+        const entry = result.find(([voter]) => voter.eq(staker));
+
+        if (entry) {
+          entry[1].stake = stake;
+        } else {
+          result.push([staker, { stake, votes: [] }]);
+        }
+      });
+
+      return result;
+    })
+  );
+}
+
+function retrieveCurrent (api: ApiInterfaceRx): Observable<DeriveCouncilVotes> {
+  const elections = (api.query.electionsPhragmen || api.query.elections);
+
+  return elections.voting.entries<ITuple<[Balance, Vec<AccountId>]>>().pipe(
+    map((entries): DeriveCouncilVotes =>
+      entries.map(([key, [stake, votes]]): [AccountId, DeriveCouncilVote] =>
+        [key.args[0] as AccountId, { stake, votes }]
+      )
+    )
+  );
+}
+
+export function votes (api: ApiInterfaceRx): () => Observable<DeriveCouncilVotes> {
+  // since we are using entries, we are not adding a memo
+  return (): Observable<DeriveCouncilVotes> =>
+    (api.query.electionsPhragmen || api.query.elections).stakeOf
+      ? retrievePrev(api)
+      : retrieveCurrent(api);
+}

packages/api-derive/src/council/votesOf.ts

@@ -0,0 +1,23 @@
+// Copyright 2017-2020 @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 } from '@polkadot/types/interfaces';
+import { ApiInterfaceRx } from '@polkadot/api/types';
+import { DeriveCouncilVote } from '../types';
+
+import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+
+export function votesOf (api: ApiInterfaceRx): (accountId: string | Uint8Array | AccountId) => Observable<DeriveCouncilVote> {
+  // no memo, votes actually pulls the entries without a memo (using entries)
+  return (accountId: string | Uint8Array | AccountId): Observable<DeriveCouncilVote> =>
+    api.derive.council.votes().pipe(
+      map((votes): DeriveCouncilVote =>
+        (
+          votes.find(([from]) => from.eq(accountId)) ||
+          [null, { stake: api.registry.createType('Balance'), votes: [] as AccountId[] }]
+        )[1]
+      )
+    );
+}