Use a configurable period limit

environments/local.toml

@@ -1,4 +1,4 @@
-[upstream]
+[registry]
   rpcEndpoint = "http://localhost:26657"
   chainId = "laconic_9000-1"
   denom = "photon"
@@ -8,6 +8,7 @@
 
 [server]
   port = 3000
+  periodInSecs = 60
   transferAmount = 1000000
   periodTransferLimit = 3000000
   dbDir = "db"

src/index.ts

@@ -12,10 +12,10 @@ import KeyvSqlite from '@keyv/sqlite';
 
 const CONFIG_PATH = 'environments/local.toml';
 const FAUCET_DATA_FILE = 'faucet_data.sqlite';
-const FAUCET_DATA_TTL = 86400000; // 24 hrs
+const TTL_MULTIPLIER = 1.5; // 1.5 times the configured period
 
 interface Config {
-  upstream: {
+  registry: {
     rpcEndpoint: string
     chainId: string
     denom: string
@@ -25,12 +25,18 @@ interface Config {
   },
   server: {
     port: number
+    periodInSecs: number
     transferAmount: string
     periodTransferLimit: string
     dbDir: string
   }
 }
 
+interface FaucetStoreValue {
+  periodStart: string
+  amountSent: string
+}
+
 async function main (): Promise<void> {
   // Read and parse the configuration
   const configFile = fs.readFileSync(CONFIG_PATH, 'utf-8');
@@ -50,26 +56,44 @@ async function main (): Promise<void> {
       return res.status(400).json({ error: 'address is required' });
     }
 
-    if (!isValidAddress(accountAddress, config.upstream.prefix)) {
+    if (!isValidAddress(accountAddress, config.registry.prefix)) {
       return res.status(400).json({ error: 'invalid address' });
     }
 
-    // Check rate limit
-    const now = Date.now();
-    const today = new Date(now).toISOString().split('T')[0];
-    const faucetStoreKey = `${accountAddress}:${today}`;
-    const amountSentToAddress = await faucetDataStore.get(faucetStoreKey) || '0';
+    const currentTimeInSeconds = Math.floor(Date.now() / 1000);
+    let amountSentToAccount = BigInt(0);
+    let accountPeriodStart = currentTimeInSeconds;
 
-    if (BigInt(amountSentToAddress) + BigInt(config.server.transferAmount) > BigInt(config.server.periodTransferLimit)) {
+    // Get accounts data from faucet data store
+    const accountFaucetData: FaucetStoreValue = await faucetDataStore.get(accountAddress);
+
+    // Check rate limit
+    if (accountFaucetData !== undefined) {
+      const elapsedTime = currentTimeInSeconds - Number(accountFaucetData.periodStart);
+
+      // Check if saved entry is still within configured period
+      // Else, create a fresh entry
+      if (elapsedTime < config.server.periodInSecs) {
+        amountSentToAccount = BigInt(accountFaucetData.amountSent);
+        accountPeriodStart = Number(accountFaucetData.periodStart);
+
+        // Check if limit has been reached
+        if (amountSentToAccount + BigInt(config.server.transferAmount) > BigInt(config.server.periodTransferLimit)) {
           return res.status(429).json({ error: 'Limit exceeded' });
         }
+      }
+    }
 
     try {
       const txHash = await sendTokens(config, accountAddress, String(config.server.transferAmount));
       console.log(`Sent tokens to address: ${accountAddress}, txHash: ${txHash}`);
 
       // Update rate limit
-      await faucetDataStore.set(faucetStoreKey, (BigInt(amountSentToAddress) + BigInt(config.server.transferAmount)).toString(), FAUCET_DATA_TTL);
+      const updatedAccountFaucetData: FaucetStoreValue = {
+        periodStart: accountPeriodStart.toString(),
+        amountSent: amountSentToAccount.toString()
+      };
+      await faucetDataStore.set(accountAddress, updatedAccountFaucetData, config.server.periodInSecs * TTL_MULTIPLIER * 1000);
 
       res.json({ success: true, txHash });
     } catch (error) {
@@ -108,27 +132,27 @@ async function initKVStore (dbDir: string): Promise<Keyv> {
 }
 
 async function sendTokens (config: Config, recipientAddress: string, amount: string): Promise<string> {
-  let faucetKey = config.upstream.faucetKey;
+  let faucetKey = config.registry.faucetKey;
   if (faucetKey.startsWith('0x')) {
     faucetKey = faucetKey.slice(2);
   }
 
   const wallet = await DirectSecp256k1Wallet.fromKey(
     Buffer.from(faucetKey, 'hex'),
-    config.upstream.prefix
+    config.registry.prefix
   );
   const [faucetAccount] = await wallet.getAccounts();
 
   const client = await SigningStargateClient.connectWithSigner(
-    config.upstream.rpcEndpoint,
+    config.registry.rpcEndpoint,
     wallet,
-    { gasPrice: GasPrice.fromString(`${config.upstream.gasPrice}${config.upstream.denom}`) }
+    { gasPrice: GasPrice.fromString(`${config.registry.gasPrice}${config.registry.denom}`) }
   );
 
   const result = await client.sendTokens(
     faucetAccount.address,
     recipientAddress,
-    [{ denom: config.upstream.denom, amount: amount }],
+    [{ denom: config.registry.denom, amount: amount }],
     'auto',
     'Faucet transfer'
   );