From 250cd7f1238c04519270f5fb3fa985221fcc76e4 Mon Sep 17 00:00:00 2001
From: Wietse Wind <mail@wietse.com>
Date: Sun, 1 Oct 2023 02:20:56 +0200
Subject: [PATCH] Add ledger file persist

---
 index.mjs        | 16 +++++-----
 lib/onLedger.mjs | 78 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 8 deletions(-)
 create mode 100644 lib/onLedger.mjs

diff --git a/index.mjs b/index.mjs
index 024ef76..f960436 100644
--- a/index.mjs
+++ b/index.mjs
@@ -1,7 +1,7 @@
 import { XrplClient } from 'xrpl-client'
 import { createDirectory } from './lib/createDirectory.mjs'
 import { onValidation } from './lib/onValidation.mjs'
-// import { onLedger } from './lib/onLedger.mjs'
+import { onLedger } from './lib/onLedger.mjs'
 // import { onTransaction } from './lib/onTransaction.mjs'
 import 'dotenv/config'
 import assert from 'assert'
@@ -20,7 +20,7 @@ process.env.NODES.split(',').map(h => h.trim())
 
     c.send({ command: "subscribe", streams: [
       "validations",
-      // "ledger",
+      "ledger",
       // "transactions",
       // "transactions_proposed"
     ] })
@@ -31,12 +31,12 @@ process.env.NODES.split(',').map(h => h.trim())
       validation,
     }))
 
-    // c.on("ledger", ledger => onLedger({
-    //   connectionUrl: c.getState()?.server?.uri,
-    //   networkId: c.getState()?.server?.networkId,
-    //   ledger,
-    //   connection: c,
-    // }))
+    c.on("ledger", ledger => onLedger({
+      connectionUrl: c.getState()?.server?.uri,
+      networkId: c.getState()?.server?.networkId,
+      ledger,
+      connection: c,
+    }))
 
     // c.on("transaction", transaction => onTransaction({
     //   connectionUrl: c.getState()?.server?.uri,
diff --git a/lib/onLedger.mjs b/lib/onLedger.mjs
new file mode 100644
index 0000000..f9aa6c7
--- /dev/null
+++ b/lib/onLedger.mjs
@@ -0,0 +1,78 @@
+import { writeFile } from 'fs'
+import { stat } from 'fs'
+import { ledgerIndexToFolders } from './ledgerIndexToFolders.mjs'
+import 'dotenv/config'
+
+const obtainedHumanReadableLedgers = []
+const obtainedBinaryTxLedgers = []
+
+const onLedger = async ({
+  networkId,
+  ledger,
+  connection,
+}) => {
+  if ((ledger?.type || '').toUpperCase() === 'LEDGERCLOSED') {
+    if (ledger?.txn_count > 0 && ledger?.ledger_index) {
+      const relativeStoreDir = 'store/' + networkId + '/' + ledgerIndexToFolders(ledger.ledger_index)
+      const storeDir = new URL('../' + relativeStoreDir, import.meta.url).pathname
+
+      const dirExists = await new Promise(resolve => stat(storeDir, staterr => resolve(!staterr)))
+
+      if (dirExists) {
+        ;[
+          ...(
+            obtainedBinaryTxLedgers.indexOf(ledger.ledger_index) < 0
+              ? [
+                  connection.send({
+                    command: 'ledger',
+                    ledger_index: ledger.ledger_index,
+                    transactions: true,
+                    expand: true,
+                    binary: true,
+                  })
+                ]
+              : []),
+          ...(
+            obtainedHumanReadableLedgers.indexOf(ledger.ledger_index) < 0
+              ? [
+                  connection.send({
+                    command: 'ledger',
+                    ledger_index: ledger.ledger_index,
+                  })
+                ]
+              : []),
+        ].map(query => query.then(results => {
+          if (results?.validated && results?.ledger_index === ledger?.ledger_index && results?.ledger_hash === ledger?.ledger_hash) {
+            if (results?.ledger?.transactions && obtainedBinaryTxLedgers.indexOf(ledger.ledger_index) < 0) {
+              obtainedBinaryTxLedgers.unshift(results.ledger_index)
+              obtainedBinaryTxLedgers.length = 250
+
+              console.log('Obtained ledger (binary)', results.ledger_index, results.ledger.transactions.length)
+              writeFile(storeDir + '/ledger_binary_transactions.json', Buffer.from(JSON.stringify(results.ledger), 'utf8'), err => {
+                if (err) {
+                  console.log('Error writing file @ ' + storeDir)
+                }
+              })
+            }
+            if (results?.ledger?.parent_hash && obtainedHumanReadableLedgers.indexOf(ledger.ledger_index) < 0) {
+              obtainedHumanReadableLedgers.unshift(results.ledger_index)
+              obtainedHumanReadableLedgers.length = 250
+        
+              console.log('Obtained ledger (JSON object)', results.ledger_index, results.ledger.ledger_hash)
+              writeFile(storeDir + '/ledger.json', Buffer.from(JSON.stringify(results.ledger), 'utf8'), err => {
+                if (err) {
+                  console.log('Error writing file @ ' + storeDir)
+                }
+              })
+            }
+          }
+        }))
+      }
+
+    }
+  }
+}
+
+export {
+  onLedger,
+}