From 7263fc19509dbcae510c73b841d51e3ce66e6563 Mon Sep 17 00:00:00 2001
From: Mohammed Sohail <sohailsameja@gmail.com>
Date: Tue, 16 Apr 2024 15:59:21 +0800
Subject: [PATCH] feat: add token index fetcher

---
 internal/chain/token_index.go | 42 +++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 internal/chain/token_index.go

diff --git a/internal/chain/token_index.go b/internal/chain/token_index.go
new file mode 100644
index 0000000..113aa96
--- /dev/null
+++ b/internal/chain/token_index.go
@@ -0,0 +1,42 @@
+package chain
+
+import (
+	"context"
+	"math/big"
+
+	"github.com/celo-org/celo-blockchain/common"
+	"github.com/grassrootseconomics/w3-celo"
+	"github.com/grassrootseconomics/w3-celo/module/eth"
+	"github.com/grassrootseconomics/w3-celo/w3types"
+)
+
+var (
+	entryCountFunc = w3.MustNewFunc("entryCount()", "uint256")
+	entrySig       = w3.MustNewFunc("entry(uint256 _idx)", "address")
+)
+
+func (c *Chain) GetAllTokensFromTokenIndex(ctx context.Context, tokenIndex common.Address) ([]common.Address, error) {
+	var (
+		tokenIndexEntryCount big.Int
+	)
+
+	if err := c.provider.Client.CallCtx(
+		ctx,
+		eth.CallFunc(tokenIndex, entryCountFunc).Returns(&tokenIndexEntryCount),
+	); err != nil {
+		return nil, err
+	}
+
+	calls := make([]w3types.RPCCaller, tokenIndexEntryCount.Int64())
+	tokenAddresses := make([]common.Address, tokenIndexEntryCount.Int64())
+
+	for i := 0; i < int(tokenIndexEntryCount.Int64()); i++ {
+		calls[i] = eth.CallFunc(tokenIndex, entrySig, new(big.Int).SetInt64(int64(i))).Returns(&tokenAddresses[i])
+	}
+
+	if err := c.provider.Client.CallCtx(ctx, calls...); err != nil {
+		return nil, err
+	}
+
+	return tokenAddresses, nil
+}