feat: Add past vote invalidation

database/gov.go

@@ -284,12 +284,20 @@ WHERE proposal_deposit.height <= excluded.height`
 }
 
 // --------------------------------------------------------------------------------------------------------------------
+func (db *Db) CleanVote(proposal_id uint64, voter string) error {
+	flagQuery := `UPDATE proposal_vote SET is_valid=FALSE WHERE proposal_id=$1 AND voter_address=$2`
+	_, err := db.SQL.Exec(flagQuery, proposal_id, voter)
+	if err != nil {
+		return fmt.Errorf("error while updating past vote: %s", err)
+	}
+	return nil
+}
 
 // SaveVote allows to save for the given height and the message vote
 func (db *Db) SaveVote(vote types.Vote) error {
 	query := `
-INSERT INTO proposal_vote (proposal_id, voter_address, option, weight, timestamp, height) 
-VALUES ($1, $2, $3, $4, $5, $6)`
+INSERT INTO proposal_vote (proposal_id, voter_address, is_valid, option, weight, timestamp, height) 
+VALUES ($1, $2, TRUE, $3, $4, $5, $6)`
 
 	// Store the voter account
 	err := db.SaveAccounts([]types.Account{types.NewAccount(vote.Voter)})

database/schema/08-gov.sql

@@ -42,6 +42,7 @@ CREATE TABLE proposal_vote
 (
     proposal_id   INTEGER NOT NULL REFERENCES proposal (id),
     voter_address TEXT    NOT NULL REFERENCES account (address),
+    is_valid         BOOLEAN NOT NULL,
     option        TEXT    NOT NULL,
     weight        TEXT    NOT NULL,
     timestamp     TIMESTAMP,

modules/gov/handle_msg.go

@@ -116,7 +116,10 @@ func (m *Module) handleMsgVote(tx *juno.Tx, msg *govtypes.MsgVote) error {
 	}
 
 	vote := types.NewVote(msg.ProposalId, msg.Voter, msg.Option, "1.0", txTimestamp, tx.Height)
-
+	err = m.db.CleanVote(msg.ProposalId, msg.Voter)
+	if err != nil {
+		return err
+	}
 	return m.db.SaveVote(vote)
 }
 
@@ -125,7 +128,10 @@ func (m *Module) handleMsgVoteWeighted(tx *juno.Tx, msg *govtypes.MsgVoteWeighte
 	if err != nil {
 		return fmt.Errorf("error while parsing time: %s", err)
 	}
-
+	err = m.db.CleanVote(msg.ProposalId, msg.Voter)
+	if err != nil {
+		return err
+	}
 	for _, option := range msg.Options {
 		vote := types.NewVote(msg.ProposalId, msg.Voter, option.Option, option.Weight.String(), txTimestamp, tx.Height)
 		err = m.db.SaveVote(vote)