Merge pull request #154 from makerdao/delegates-sorted-by-type

Add sorting rules to sort delegates by type and by expiration

migrations/071-delegates-sorted-by-type.sql

@@ -0,0 +1,88 @@
+-- Dropping function as the amount of parameters changed.
+drop function if exists api.delegates;
+
+-- Same function, but adding support to passing an array of addresses to sort the table by those addresses first.
+create or replace function api.delegates(_first int, order_by delegate_order_by_type default 'DATE', order_direction order_direction_type default 'DESC', include_expired boolean default false, seed double precision default random(), constitutional_delegates char[] default '{}')
+returns setof delegate_entry as $$
+declare
+  max_page_size_value int := (select api.max_page_size());
+begin
+  if _first > max_page_size_value then
+    raise exception 'Parameter FIRST cannot be greater than %.', max_page_size_value;
+  elsif seed > 1 or seed < -1 then
+    raise exception 'Parameter SEED must have a value between -1 and 1';
+  else
+    return query
+      -- Merge poll votes from Mainnet and Arbitrum and attach the timestamp to them
+      with merged_vote_events as (
+        select voter, vote_timestamp
+        from (
+          select voter, timestamp as vote_timestamp
+          from polling.voted_event A
+          left join vulcan2x.block B
+          on A.block_id = B.id
+        ) AB
+        union all
+        select voter, vote_timestamp
+        from (
+          select voter, timestamp as vote_timestamp
+          from polling.voted_event_arbitrum C
+          left join vulcan2xarbitrum.block D
+          on C.block_id = D.id
+        ) CD
+      ),
+      delegates_table as (
+        select E.delegate, E.vote_delegate, F.timestamp as creation_date, F.timestamp + '1 year' as expiration_date, now() > F.timestamp + '1 year' as expired
+        from dschief.vote_delegate_created_event E
+        left join vulcan2x.block F
+        on E.block_id = F.id
+        -- Filter out expired delegates if include_expired is false
+        where include_expired or now() < F.timestamp + '1 year'
+      ),
+      -- Merge delegates with their last votes
+      delegates_with_last_vote as (
+        select G.*, max(H.vote_timestamp) as last_voted
+        from delegates_table G
+        left join merged_vote_events H
+        on G.vote_delegate = H.voter
+        group by G.vote_delegate, G.delegate, G.creation_date, G.expiration_date, G.expired
+      ),
+      delegations_table as (
+        select contract_address, count(immediate_caller) as delegators, sum(delegations) as delegations
+        from (
+          select immediate_caller, sum(lock) as delegations, contract_address
+          from dschief.delegate_lock
+          group by contract_address, immediate_caller
+        ) as I
+        where delegations > 0
+        group by contract_address
+      )
+      select delegate::character varying(66), vote_delegate::character varying(66), creation_date, expiration_date, expired, last_voted, coalesce(delegators, 0)::int as delegator_count, coalesce(delegations, 0)::numeric(78,18) as total_mkr
+      from (
+        -- We call setseed here to make sure it's executed before the main select statement and the order by random clause.
+        -- By appending it to the delegates_with_last_vote table and then removing the row with offset 1, we make sure the table remains unmodified.
+        select setseed(seed), null delegate, null vote_delegate, null creation_date, null expiration_date, null expired, null last_voted
+        union all
+        select null, delegate, vote_delegate, creation_date, expiration_date, expired, last_voted from delegates_with_last_vote
+        offset 1
+      ) sd
+      left join delegations_table
+      on sd.vote_delegate::character varying(66) = delegations_table.contract_address
+      order by 
+        -- Ordering first by expiration: expired at the end, second by delegate type: constitutional delegates first
+        -- and third by the sorting criterion selected.
+        case when expired then 1 else 0 end,
+        case when vote_delegate = ANY (constitutional_delegates) then 0 else 1 end,
+        case
+          when order_by = 'DELEGATORS' then
+            case when order_direction = 'ASC' then coalesce(delegators, 0)::int else -coalesce(delegators, 0)::int end
+          when order_by = 'MKR' then
+            case when order_direction = 'ASC' then coalesce(delegations, 0)::numeric(78,18) else -coalesce(delegations, 0)::numeric(78,18) end
+          when order_by = 'DATE' then
+            case when order_direction = 'ASC' then extract(epoch from creation_date) else -extract(epoch from creation_date) end
+          else
+            random()
+        end;
+  end if;
+end;
+$$ language plpgsql stable strict;

queries/delegates.graphql

@@ -7,6 +7,7 @@ query delegates(
   $includeExpired: Boolean
   $seed: Float
   $filter: DelegateEntryFilter
+  $constitutionalDelegates: [String]
 ) {
   delegates(
     first: $first
@@ -18,6 +19,7 @@ query delegates(
     includeExpired: $includeExpired
     seed: $seed
     filter: $filter
+    constitutionalDelegates: $constitutionalDelegates
   ) {
     totalCount
     pageInfo {