From d71e37152b6a79a141cb6795f80d9e75c75cd082 Mon Sep 17 00:00:00 2001
From: Aditya Kulkarni <zcash@adityapk.com>
Date: Thu, 12 Sep 2019 20:32:47 -0700
Subject: [PATCH] Add rescan command

---
 rust-lightclient/src/commands.rs    | 18 +++++++++++++++++-
 rust-lightclient/src/lightclient.rs | 22 +++++++++++++++++++---
 rust-lightclient/src/lightwallet.rs | 10 ++++++++++
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/rust-lightclient/src/commands.rs b/rust-lightclient/src/commands.rs
index c990497..c5b75f7 100644
--- a/rust-lightclient/src/commands.rs
+++ b/rust-lightclient/src/commands.rs
@@ -26,8 +26,23 @@ impl Command for SyncCommand {
     }
 }
 
-struct HelpCommand {}
+struct RescanCommand {}
+impl Command for RescanCommand {
+    fn help(&self) {
+        println!("Rescan the wallet from it's initial state, rescanning and downloading all blocks and transactions.");
+    }
 
+    fn short_help(&self) -> String {
+        "Rescan the wallet, downloading and scanning all blocks and transactions".to_string()
+    }
+
+    fn exec(&self, _args: &[&str], lightclient: &mut LightClient) {
+        lightclient.do_rescan();
+    }
+}
+
+
+struct HelpCommand {}
 impl Command for HelpCommand {
     fn help(&self) {
         println!("Lists all available commands");
@@ -205,6 +220,7 @@ pub fn get_commands() -> Box<HashMap<String, Box<dyn Command>>> {
     let mut map: HashMap<String, Box<dyn Command>> = HashMap::new();
 
     map.insert("sync".to_string(),      Box::new(SyncCommand{}));
+    map.insert("rescan".to_string(),    Box::new(RescanCommand{}));
     map.insert("help".to_string(),      Box::new(HelpCommand{}));
     map.insert("address".to_string(),   Box::new(AddressCommand{}));
     map.insert("info".to_string(),      Box::new(InfoCommand{}));
diff --git a/rust-lightclient/src/lightclient.rs b/rust-lightclient/src/lightclient.rs
index c1998ce..99e3474 100644
--- a/rust-lightclient/src/lightclient.rs
+++ b/rust-lightclient/src/lightclient.rs
@@ -40,6 +40,13 @@ pub struct LightClient {
 
 impl LightClient {
 
+    pub fn set_wallet_initial_state(&self) {
+        self.wallet.set_initial_block(500000,
+                "004fada8d4dbc5e80b13522d2c6bd0116113c9b7197f0c6be69bc7a62f2824cd",
+                "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");
+
+    }
+
     pub fn new(seed_phrase: Option<&str>) -> io::Result<Self> {
         let mut lc = if Path::new("wallet.dat").exists() {
             // Make sure that if a wallet exists, there is no seed phrase being attempted
@@ -63,9 +70,7 @@ impl LightClient {
                 sapling_spend   : vec![]
             };
 
-            l.wallet.set_initial_block(500000,
-                "004fada8d4dbc5e80b13522d2c6bd0116113c9b7197f0c6be69bc7a62f2824cd",
-                "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");
+            l.set_wallet_initial_state();
 
             l
         };
@@ -268,6 +273,17 @@ impl LightClient {
         JsonValue::Array(tx_list)
     }
 
+    pub fn do_rescan(&self) {
+        // First, clear the state from the wallet
+        self.wallet.clear_blocks();
+
+        // Then set the inital block
+        self.set_wallet_initial_state();
+
+        // Then, do a sync, which will force a full rescan from the initial state
+        self.do_sync();
+    }
+
     pub fn do_sync(&self) {
         // Sync is 3 parts
         // 1. Get the latest block
diff --git a/rust-lightclient/src/lightwallet.rs b/rust-lightclient/src/lightwallet.rs
index 8483d61..492a2a1 100644
--- a/rust-lightclient/src/lightwallet.rs
+++ b/rust-lightclient/src/lightwallet.rs
@@ -574,6 +574,16 @@ impl LightWallet {
         Ok(())
     }
 
+    
+
+    // Clears all the downloaded blocks and resets the state back to the inital block.
+    // After this, the wallet's initial state will need to be set
+    // and the wallet will need to be rescanned
+    pub fn clear_blocks(&self) {
+        self.blocks.write().unwrap().clear();
+        self.txs.write().unwrap().clear();
+    }
+
     pub fn set_initial_block(&self, height: i32, hash: &str, sapling_tree: &str) -> bool {
         let mut blocks = self.blocks.write().unwrap();
         if !blocks.is_empty() {