add Etherscan integration to fetch Torch transfer events

Author: pettinarip

src/lib/torch/etherscan.ts

@@ -0,0 +1,66 @@
+import { type Address } from "viem"
+
+import Torch from "@/data/Torch.json"
+
+const TORCH_CONTRACT_ADDRESS = Torch.address as Address
+const TORCH_BLOCK_NUMBER = Torch.blockNumber
+
+export type TransferEvent = {
+  from: Address
+  to: Address
+  blockNumber: number
+  transactionHash: string
+  timestamp: number
+}
+
+// You'll need to get an API key from https://etherscan.io/apis
+const ETHERSCAN_API_KEY = process.env.ETHERSCAN_API_KEY || ""
+
+export const fetchTorchTransfersFromEtherscan = async (): Promise<
+  TransferEvent[]
+> => {
+  if (!ETHERSCAN_API_KEY) {
+    throw new Error("ETHERSCAN_API_KEY environment variable is required")
+  }
+
+  try {
+    // Get contract events from Etherscan
+    const response = await fetch(
+      [
+        "https://api.etherscan.io/api",
+        "?module=logs",
+        "&action=getLogs",
+        `&address=${TORCH_CONTRACT_ADDRESS}`,
+        `&fromBlock=${TORCH_BLOCK_NUMBER}`,
+        "&toBlock=latest",
+        // ERC721 Transfer event signature
+        "&topic0=0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
+        `&apikey=${ETHERSCAN_API_KEY}`,
+      ].join("")
+    )
+
+    const data = await response.json()
+
+    if (data.status !== "1") {
+      throw new Error(`Etherscan API error: ${data.message}`)
+    }
+
+    return data.result.map(
+      (log: {
+        topics: string[]
+        blockNumber: string
+        transactionHash: string
+        timeStamp: string
+      }) => ({
+        from: `0x${log.topics[1].slice(26)}` as Address, // Remove padding from topic1
+        to: `0x${log.topics[2].slice(26)}` as Address, // Remove padding from topic2
+        blockNumber: parseInt(log.blockNumber, 16),
+        transactionHash: log.transactionHash,
+        timestamp: parseInt(log.timeStamp, 16),
+      })
+    )
+  } catch (error) {
+    console.error("Failed to fetch torch transfers from Etherscan:", error)
+    return []
+  }
+}

src/lib/torch/index.ts

@@ -6,10 +6,10 @@ import { getPublicClient } from "@wagmi/core"
 import Torch from "@/data/Torch.json"
 
 import { config } from "./config"
+import { fetchTorchTransfersFromEtherscan } from "./etherscan"
 
 const TORCH_CONTRACT_ADDRESS = Torch.address as Address
 const TORCH_ABI = Torch.abi
-const TORCH_BLOCK_NUMBER = Torch.blockNumber
 
 // Addresses to filter from the UI (show as "Unknown Holder")
 const FILTERED_ADDRESSES: string[] = [
@@ -50,54 +50,7 @@ export type TorchHolderEvent = TorchHolder & {
 
 export const getTransferEvents = cache(
   async () => {
-    const publicClient = getPublicClient(config)
-
-    // Get the current block number to ensure consistent results
-    const currentBlock = await publicClient.getBlockNumber()
-
-    // Get Transfer events from the contract
-    // ERC721 Transfer event signature: Transfer(address indexed from, address indexed to, uint256 indexed tokenId)
-    const logs = await publicClient.getLogs({
-      address: TORCH_CONTRACT_ADDRESS,
-      event: {
-        type: "event",
-        name: "Transfer",
-        inputs: [
-          { name: "from", type: "address", indexed: true },
-          { name: "to", type: "address", indexed: true },
-          { name: "tokenId", type: "uint256", indexed: true },
-        ],
-      },
-      args: {
-        tokenId: BigInt(1), // Torch NFT token ID is always 1
-      },
-      fromBlock: BigInt(TORCH_BLOCK_NUMBER) || "earliest",
-      toBlock: currentBlock,
-    })
-
-    // Process logs and get timestamps
-    const transferEvents: TransferEvent[] = []
-
-    for (const log of logs) {
-      if (log.args?.from && log.args?.to) {
-        // Get block details to get timestamp
-        const block = await publicClient.getBlock({
-          blockNumber: log.blockNumber,
-        })
-
-        transferEvents.push({
-          from: log.args.from as Address,
-          to: log.args.to as Address,
-          blockNumber: Number(log.blockNumber),
-          transactionHash: log.transactionHash,
-          timestamp: Number(block.timestamp),
-        })
-      }
-    }
-
-    // Sort by block number (oldest first)
-    transferEvents.sort((a, b) => a.blockNumber - b.blockNumber)
-
+    const transferEvents = await fetchTorchTransfersFromEtherscan()
     return transferEvents
   },
   ["torch-transfer-events"],