fix(metrics): num of validators that didn't sign is always 0 (#905)

* fix(metrics): no of validators that didn't sign is always 0

* Update internal/consensus/state_apply_commit.go

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

---------

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

internal/consensus/state_apply_commit.go

@@ -108,13 +108,33 @@ func (c *ApplyCommitAction) Execute(ctx context.Context, stateEvent StateEvent)
 }
 
 func (c *ApplyCommitAction) RecordMetrics(stateData *StateData, height int64, block *types.Block, lastBlockMeta *types.BlockMeta) {
-	c.metrics.Validators.Set(float64(stateData.Validators.Size()))
-	c.metrics.ValidatorsPower.Set(float64(stateData.Validators.TotalVotingPower()))
+	totalValidators := stateData.Validators.Size()
+	totalValidatorsPower := stateData.Validators.TotalVotingPower()
+
+	c.metrics.Validators.Set(float64(totalValidators))
+	c.metrics.ValidatorsPower.Set(float64(totalValidatorsPower))
+
+	// Calculate validators that didn't sign
+
+	// We initialize with total validators count and power, and then decrement as we find the validators
+	// who have signed the precommit
+	missingValidators := totalValidators
+	missingValidatorsPower := totalValidatorsPower
+	precommits := stateData.Votes.Precommits(stateData.CommitRound)
+
+	for _, vote := range precommits.List() {
+		if val := stateData.Validators.GetByIndex(vote.ValidatorIndex); val != nil {
+			missingValidators--
+			missingValidatorsPower -= val.VotingPower
+		} else {
+			c.logger.Error("precommit received from invalid validator",
+				"val", val,
+				"vote", vote,
+				"height", vote.Height,
+				"round", vote.Round)
+		}
+	}
 
-	var (
-		missingValidators      int
-		missingValidatorsPower int64
-	)
 	c.metrics.MissingValidators.Set(float64(missingValidators))
 	c.metrics.MissingValidatorsPower.Set(float64(missingValidatorsPower))