1 files changed, 96 insertions, 0 deletions
diff --git a/src/blockchain.rs b/src/blockchain.rs
new file mode 100644
index 0000000..2f5014b
--- /dev/null
+++ b/src/blockchain.rs
@@ -0,0 +1,96 @@
+use anyhow::{Context, Result};
+use bdk::{
+    bitcoin::Network,
+    blockchain::{ElectrumBlockchain, GetHeight},
+    electrum_client::{Client, ConfigBuilder, Socks5Config},
+};
+use serde::Deserialize;
+
+fn get_default_electrum_server(network: Network) -> &'static str {
+    match network {
+        Network::Bitcoin => "ssl://fulcrum.sethforprivacy.com:50002",
+        Network::Testnet => "ssl://electrum.blockstream.info:60002",
+        Network::Signet => "ssl://mempool.space:60602",
+        _ => panic!("unsupported network"),
+    }
+}
+
+#[derive(Deserialize, Default, Debug)]
+pub struct ElectrumConfig {
+    url: Option<String>,
+
+    network: Option<Network>,
+
+    socks5: Option<String>,
+
+    #[serde(default)]
+    certificate_validation: bool,
+}
+
+impl ElectrumConfig {
+    pub fn url(&self) -> &str {
+        self.url
+            .as_deref()
+            .unwrap_or(get_default_electrum_server(self.network()))
+    }
+
+    pub fn network(&self) -> Network {
+        self.network.unwrap_or(Network::Bitcoin)
+    }
+
+    pub fn certificate_validation(&self) -> bool {
+        self.certificate_validation
+    }
+
+    pub fn socks5(&self) -> Option<Socks5Config> {
+        self.socks5.as_ref().map(Socks5Config::new)
+    }
+}
+
+pub fn get_blockchain(electrum_cfg: &ElectrumConfig) -> Result<ElectrumBlockchain> {
+    let server_cfg = ConfigBuilder::new()
+        .validate_domain(electrum_cfg.certificate_validation())
+        .socks5(electrum_cfg.socks5())
+        .build();
+    let electrum_url = electrum_cfg.url();
+    let client = Client::from_config(electrum_url, server_cfg)
+        .with_context(|| "could not configure electrum client".to_string())?;
+    Ok(ElectrumBlockchain::from(client))
+}
+
+pub struct BlockchainState {
+    height: Option<u32>,
+    url: String,
+    blockchain: ElectrumBlockchain,
+}
+
+impl BlockchainState {
+    pub fn new(electrum_cfg: &ElectrumConfig) -> Result<Self> {
+        Ok(Self {
+            height: Default::default(),
+            url: String::from(electrum_cfg.url()),
+            blockchain: get_blockchain(electrum_cfg)?,
+        })
+    }
+
+    pub fn update_height(&mut self) {
+        match self.blockchain.get_height() {
+            Ok(polled_height) => {
+                match self.height {
+                    Some(h) => {
+                        if polled_height != h {
+                            self.height = Some(polled_height);
+                            debug!("current block height: {}", polled_height);
+                        }
+                    }
+                    None => {
+                        self.height = Some(polled_height);
+                        info!("connected to '{}'", self.url);
+                        info!("current block height: {}", polled_height);
+                    }
+                };
+            }
+            Err(e) => warn!("could not reach '{}': {}", self.url, e),
+        };
+    }
+}