From 496e86605401003d63bcf7a90423b1627d915348 Mon Sep 17 00:00:00 2001
From: Manav Desai <manav27202@gmail.com>
Date: Thu, 20 Jul 2023 22:57:46 +0530
Subject: [PATCH] feat<wallet>: Neutrino Integration

---
 lib/wallet/client.js     | 12 +++++++++++
 lib/wallet/nodeclient.js | 19 +++++++++++++++++
 lib/wallet/nullclient.js | 11 ++++++++++
 lib/wallet/walletdb.js   | 44 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 86 insertions(+)

diff --git a/lib/wallet/client.js b/lib/wallet/client.js
index 768f38e50..f60eebbb5 100644
--- a/lib/wallet/client.js
+++ b/lib/wallet/client.js
@@ -71,6 +71,18 @@ class WalletClient extends NodeClient {
     return super.setFilter(filter.toRaw());
   }
 
+  /**
+   * Check filter against wallet key ring
+   * @param {WalletKey} ring
+   * @param {Filter} filter
+   * @returns {Promise}
+   */
+
+  async getBlockFromNode(hash) {
+    // return super.getBlockPeer(hash);
+    console.log('getBlockFromNode');
+  }
+
   async rescan(start) {
     if (Buffer.isBuffer(start))
       start = util.revHex(start);
diff --git a/lib/wallet/nodeclient.js b/lib/wallet/nodeclient.js
index 9f6c43600..bb5bf098c 100644
--- a/lib/wallet/nodeclient.js
+++ b/lib/wallet/nodeclient.js
@@ -37,6 +37,13 @@ class NodeClient extends AsyncEmitter {
 
   init() {
     this.node.chain.on('connect', async (entry, block) => {
+      if (!this.opened || this.node.neutrino)
+        return;
+
+      await this.emitAsync('block connect', entry, block.txs);
+    });
+
+    this.node.chain.on('getblockpeer', async (entry, block) => {
       if (!this.opened)
         return;
 
@@ -50,6 +57,13 @@ class NodeClient extends AsyncEmitter {
       await this.emitAsync('block disconnect', entry);
     });
 
+    this.node.pool.on('cfilter', async (blockHeight, filter) => {
+      if (!this.opened)
+        return;
+
+      await this.emitAsync('cfilter', blockHeight, filter);
+    });
+
     this.node.on('tx', (tx) => {
       if (!this.opened)
         return;
@@ -134,6 +148,11 @@ class NodeClient extends AsyncEmitter {
     return entry;
   }
 
+  async getBlockFromNode(hash) {
+    // await this.node.chain.getBlockPeer(hash);
+    console.log('getBlockFromNode');
+  }
+
   /**
    * Send a transaction. Do not wait for promise.
    * @param {TX} tx
diff --git a/lib/wallet/nullclient.js b/lib/wallet/nullclient.js
index 744629d4b..f08ca5d6d 100644
--- a/lib/wallet/nullclient.js
+++ b/lib/wallet/nullclient.js
@@ -130,6 +130,17 @@ class NullClient extends EventEmitter {
     this.wdb.emit('reset filter');
   }
 
+  /**
+   * Check filter against wallet key ring
+   * @param {WalletKey} ring
+   * @param {Filter} filter
+   * @returns {Promise}
+   */
+
+  async getBlockFromNode(hash) {
+    ;
+  }
+
   /**
    * Esimate smart fee.
    * @param {Number?} blocks
diff --git a/lib/wallet/walletdb.js b/lib/wallet/walletdb.js
index b1f57ebf0..31ef5e04c 100644
--- a/lib/wallet/walletdb.js
+++ b/lib/wallet/walletdb.js
@@ -26,6 +26,8 @@ const Outpoint = require('../primitives/outpoint');
 const layouts = require('./layout');
 const records = require('./records');
 const NullClient = require('./nullclient');
+const Script = require('../script/script');
+const Address = require('../primitives/address');
 const layout = layouts.wdb;
 const tlayout = layouts.txdb;
 
@@ -65,10 +67,12 @@ class WalletDB extends EventEmitter {
     this.state = new ChainState();
     this.confirming = false;
     this.height = 0;
+    this.filterHeight = 0;
     this.wallets = new Map();
     this.depth = 0;
     this.rescanning = false;
     this.filterSent = false;
+    this.isWitness = false;
 
     // Wallet read lock.
     this.readLock = new MapLock();
@@ -169,6 +173,14 @@ class WalletDB extends EventEmitter {
         this.emit('error', e);
       }
     });
+
+    this.client.bind('cfilter', async (blockHeight, filter) => {
+      try {
+        await this.checkFilter(blockHeight, filter);
+      } catch (e) {
+        this.emit('error', e);
+      }
+    });
   }
 
   /**
@@ -201,6 +213,9 @@ class WalletDB extends EventEmitter {
       id: 'primary'
     });
 
+    const account = await wallet.getAccount(wallet.wid);
+    this.isWitness = account.witness;
+
     const addr = await wallet.receiveAddress();
 
     this.logger.info(
@@ -568,6 +583,35 @@ class WalletDB extends EventEmitter {
     return this.client.resetFilter();
   }
 
+  async checkFilter (blockHash, filter) {
+    this.filterHeight = this.filterHeight + 1;
+    const gcsKey = blockHash.slice(0, 16);
+
+    const piter = this.db.iterator({
+      gte: layout.p.min(),
+      lte: layout.p.max()
+    });
+
+    await piter.each(async (key) => {
+      const [data] = layout.p.decode(key);
+      let address = null;
+      if (data.length === 20) {
+        if (this.isWitness)
+          address = Address.fromWitnessPubkeyhash(data);
+        else
+          address = Address.fromPubkeyhash(data);
+      } else if (data.length === 32) {
+        address = Address.fromWitnessScripthash(data);
+      }
+      const script = Script.fromAddress(address);
+      const match = filter.match(gcsKey, script.toRaw());
+      if (match) {
+        await this.client.getBlockFromNode(blockHash);
+        return;
+      }
+    });
+  }
+
   /**
    * Backup the wallet db.
    * @param {String} path