feat: add initial logic to precommit stage

src/main/java/com/limechain/grandpa/round/GrandpaRound.java

@@ -248,7 +248,7 @@ private boolean isFinalizable() {
      *
      * @return if the current round is completable
      */
-    private boolean isCompletable() {
+    public boolean isCompletable() {
 
         Map<Vote, Long> votes = getDirectVotes(SubRound.PRE_COMMIT);
         long votesCount = votes.values().stream()

src/main/java/com/limechain/grandpa/round/PreCommitStage.java

@@ -1,13 +1,102 @@
 package com.limechain.grandpa.round;
 
+import lombok.extern.java.Log;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
+@Log
 public class PreCommitStage implements StageState {
 
     @Override
     public void start(GrandpaRound round) {
+        log.fine(String.format("Round %d started pre-commit stage.", round.getRoundNumber()));
+
+        long timeout = round.getStartTime().toEpochMilli() + (4 * GrandpaRound.DURATION);
+
+        round.setOnStageTimerHandler(Executors.newScheduledThreadPool(1));
+        round.getOnStageTimerHandler().scheduleAtFixedRate(() -> {
+            long currentTime = System.currentTimeMillis();
+
+            if (currentTime >= timeout || round.isCompletable()) {
+                log.info("first log msg");
+                round.getOnStageTimerHandler().shutdown();
+            }
+        }, 0, 500, TimeUnit.MILLISECONDS);
+
     }
 
     @Override
     public void end(GrandpaRound round) {
     }
+
+//    void VotingRoundImpl::startPrecommitStage() {
+//        SL_DEBUG(logger_, "Round #{}: Start precommit stage", round_number_);
+//
+//        // Continue to receive messages
+//        // until T>=Tstart + 4 * Duration or round is completable
+//
+//        // spec: Receive-Messages(
+//        //  until Bpv>=Best-Final-Candidate(r-1)
+//        //  and (Time>=Tr+4T or r is completable)
+//        // )
+//
+//        if (completable()) {
+//            SL_DEBUG(logger_, "Round #{} is already completable", round_number_);
+//            stage_ = Stage::PRECOMMIT_RUNS;
+//            endPrecommitStage();
+//            return;
+//        }
+//
+//        stage_timer_handle_ = scheduler_->scheduleWithHandle(
+//                [wself{weak_from_this()}] {
+//            if (auto self = wself.lock()) {
+//                if (self->stage_ == Stage::PRECOMMIT_RUNS) {
+//                    SL_DEBUG(self->logger_,
+//                            "Round #{}: Time of precommit stage is out",
+//                            self->round_number_);
+//                    self->endPrecommitStage();
+//                }
+//            }
+//        },
+//        toMilliseconds(duration_ * 4 - (scheduler_->now() - start_time_)));
+//
+//        on_complete_handler_ = [this] {
+//            if (stage_ == Stage::PRECOMMIT_RUNS) {
+//                SL_DEBUG(logger_, "Round #{}: Became completable", round_number_);
+//                endPrecommitStage();
+//            }
+//        };
+//
+//        stage_ = Stage::PRECOMMIT_RUNS;
+//    }
+//
+//    void VotingRoundImpl::endPrecommitStage() {
+//        if (stage_ == Stage::COMPLETED) {
+//            return;
+//        }
+//        BOOST_ASSERT(stage_ == Stage::PRECOMMIT_RUNS
+//                || stage_ == Stage::PRECOMMIT_WAITS_FOR_PREVOTES);
+//
+//        stage_timer_handle_.reset();
+//
+//        // https://github.com/paritytech/finality-grandpa/blob/8c45a664c05657f0c71057158d3ba555ba7d20de/src/voter/voting_round.rs#L630-L633
+//        if (not prevote_ghost_) {
+//            stage_ = Stage::PRECOMMIT_WAITS_FOR_PREVOTES;
+//            logger_->debug("Round #{}: Precommit waits for prevotes", round_number_);
+//            return;
+//        }
+//
+//        on_complete_handler_ = nullptr;
+//
+//        stage_ = Stage::END_PRECOMMIT;
+//
+//        SL_DEBUG(logger_, "Round #{}: End precommit stage", round_number_);
+//
+//        // Broadcast vote for precommit stage
+//        doPrecommit();
+//
+//        startWaitingStage();
+//    }
 }