From f9ddd8729ddfa218e5e7e56e5807f8d52e52f515 Mon Sep 17 00:00:00 2001
From: Lucas Menendez <hi@lucasmenendez.me>
Date: Thu, 19 Oct 2023 10:31:03 +0200
Subject: [PATCH] fix to allow to recreate census of strategies

---
 api/censuses.go | 27 +++++++++++++++++++++++++--
 api/types.go    |  5 ++---
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/api/censuses.go b/api/censuses.go
index dbfa45fd..504b17a0 100644
--- a/api/censuses.go
+++ b/api/censuses.go
@@ -11,6 +11,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/vocdoni/census3/census"
 	queries "github.com/vocdoni/census3/db/sqlc"
+	"github.com/vocdoni/census3/state"
 	"go.vocdoni.io/dvote/httprouter"
 	api "go.vocdoni.io/dvote/httprouter/apirest"
 	"go.vocdoni.io/dvote/log"
@@ -134,9 +135,31 @@ func (capi *census3API) createAndPublishCensus(req *CreateCensusRequest, qID str
 	if len(strategyTokens) == 0 {
 		return 0, ErrNoStrategyTokens.WithErr(err)
 	}
-
+	// any census strategy is identified by id created from the concatenation of
+	// the block number, the strategy id and the anonymous flag. The creation of
+	// censuses on specific block is not supported yet, so we need to get the
+	// last block of every token chain id to sum them and get the total block
+	// number, used to create the census id.
+	totalTokensBlockNumber := uint64(0)
+	w3 := state.Web3{}
+	defer cancel()
+	// get correct web3 uri provider
+	for _, token := range strategyTokens {
+		w3uri, exists := capi.w3p[token.ChainID]
+		if !exists {
+			return 0, ErrChainIDNotSupported.With("chain ID not supported")
+		}
+		if err := w3.Init(internalCtx, w3uri, common.BytesToAddress(token.ID), state.TokenType(token.TypeID)); err != nil {
+			return 0, ErrInitializingWeb3.WithErr(err)
+		}
+		currentBlockNumber, err := w3.LatestBlockNumber(internalCtx)
+		if err != nil {
+			return 0, ErrCantGetLastBlockNumber.WithErr(err)
+		}
+		totalTokensBlockNumber += currentBlockNumber
+	}
 	// compute the new censusId and censusType
-	newCensusID := census.InnerCensusID(req.BlockNumber, req.StrategyID, req.Anonymous)
+	newCensusID := census.InnerCensusID(totalTokensBlockNumber, req.StrategyID, req.Anonymous)
 	// check if the census already exists
 	_, err = qtx.CensusByID(internalCtx, newCensusID)
 	if err != nil {
diff --git a/api/types.go b/api/types.go
index 9b625a99..218f6c92 100644
--- a/api/types.go
+++ b/api/types.go
@@ -51,9 +51,8 @@ type TokenHoldersResponse struct {
 }
 
 type CreateCensusRequest struct {
-	StrategyID  uint64 `json:"strategyID"`
-	BlockNumber uint64 `json:"blockNumber"`
-	Anonymous   bool   `json:"anonymous"`
+	StrategyID uint64 `json:"strategyID"`
+	Anonymous  bool   `json:"anonymous"`
 }
 
 type CreateCensusResponse struct {