Introduce bitcoin mainnet chain spec (#33)

* Build chain spec for bitcoin mainnet

```
./target/release/subcoin build-spec --chain=bitcoin-mainnet --disable-default-bootnode --raw > chain-spec-raw-bitcoin-mainnet.json
```

* Nits

crates/subcoin-node/src/cli.rs

@@ -29,6 +29,9 @@ pub enum Command {
     #[command(subcommand)]
     Blockchain(Blockchain),
 
+    /// Build a chain specification.
+    BuildSpec(sc_cli::BuildSpecCmd),
+
     /// Validate blocks.
     CheckBlock(Box<sc_cli::CheckBlockCmd>),
 
@@ -148,6 +151,10 @@ pub fn run() -> sc_cli::Result<()> {
                 Ok((cmd.run(client), task_manager))
             })
         }
+        Command::BuildSpec(cmd) => {
+            let runner = SubstrateCli.create_runner(&cmd)?;
+            runner.sync_run(|config| cmd.run(config.chain_spec, config.network))
+        }
         Command::CheckBlock(cmd) => {
             let runner = SubstrateCli.create_runner(&*cmd)?;
             runner.async_run(|config| {

crates/subcoin-node/src/cli/params.rs

@@ -6,22 +6,29 @@ use subcoin_network::PeerId;
 /// Chain.
 ///
 /// Currently only Bitcoin is supported, more chains may be supported in the future.
+// TODO: This clippy warning will be fixed once more chains are supported.
+#[allow(clippy::enum_variant_names)]
 #[derive(Clone, Copy, Default, Debug, clap::ValueEnum)]
 pub enum Chain {
     /// Bitcoin mainnet.
     #[default]
-    Bitcoin,
+    BitcoinMainnet,
+    /// Bitcoin testnet
+    BitcoinTestnet,
+    /// Bitcoin signet.
+    BitcoinSignet,
 }
 
-/// Bitcoin network type.
-#[derive(Clone, Copy, Debug, clap::ValueEnum)]
-pub enum Network {
-    /// Mainnet.
-    Mainnet,
-    /// Testnet.
-    Testnet,
-    /// Signet.
-    Signet,
+impl Chain {
+    /// Returns the value of `id` in `SubstrateCli::load_spec(id)`.
+    fn chain_spec_id(&self) -> &'static str {
+        // Convert to kebab-case for consistency in CLI.
+        match self {
+            Self::BitcoinMainnet => "bitcoin-mainnet",
+            Self::BitcoinTestnet => "bitcoin-testnet",
+            Self::BitcoinSignet => "bitcoin-signet",
+        }
+    }
 }
 
 #[derive(Debug, Clone, Parser)]
@@ -71,14 +78,10 @@ pub enum BlockExecution {
 
 #[derive(Debug, Clone, Parser)]
 pub struct CommonParams {
-    /// Specify the chain network.
-    #[arg(long, value_name = "CHAIN", default_value = "bitcoin")]
+    /// Specify the chain.
+    #[arg(long, value_name = "CHAIN", default_value = "bitcoin-mainnet")]
     pub chain: Chain,
 
-    /// Specify the chain network.
-    #[arg(long, value_name = "NETWORK", default_value = "mainnet")]
-    pub network: Network,
-
     /// Specify the block execution strategy.
     #[clap(long, value_enum, default_value_t = BlockExecution::RuntimeDisk)]
     pub block_execution: BlockExecution,
@@ -116,7 +119,7 @@ impl CommonParams {
     pub fn as_shared_params(&self) -> sc_cli::SharedParams {
         // TODO: expose more flags?
         sc_cli::SharedParams {
-            chain: Some(format!("{:?}", self.chain)),
+            chain: Some(self.chain.chain_spec_id().to_string()),
             dev: false,
             base_path: self.base_path.clone(),
             log: self.log.clone(),
@@ -128,13 +131,12 @@ impl CommonParams {
         }
     }
 
-    /// Determines the Bitcoin network type based on the current chain and network settings.
-    #[allow(unused)]
+    /// Determines the Bitcoin network type based on the current chain setting.
     pub fn bitcoin_network(&self) -> bitcoin::Network {
-        match (self.chain, self.network) {
-            (Chain::Bitcoin, Network::Mainnet) => bitcoin::Network::Bitcoin,
-            (Chain::Bitcoin, Network::Testnet) => bitcoin::Network::Testnet,
-            (Chain::Bitcoin, Network::Signet) => bitcoin::Network::Signet,
+        match self.chain {
+            Chain::BitcoinMainnet => bitcoin::Network::Bitcoin,
+            Chain::BitcoinTestnet => bitcoin::Network::Testnet,
+            Chain::BitcoinSignet => bitcoin::Network::Signet,
         }
     }
 

crates/subcoin-node/src/substrate_cli.rs

@@ -1,3 +1,7 @@
+use subcoin_service::ChainSpec;
+
+const BITCOIN_MAINNET_CHAIN_SPEC: &str = include_str!("../res/chain-spec-raw-bitcoin-mainnet.json");
+
 /// Fake CLI for satisfying the Substrate CLI interface.
 ///
 /// Primarily for creating a Substrate runner.
@@ -29,13 +33,15 @@ impl sc_cli::SubstrateCli for SubstrateCli {
         2024
     }
 
-    fn load_spec(&self, _id: &str) -> Result<Box<dyn sc_service::ChainSpec>, String> {
-        // TODO: different chain spec for different bitcoin network.
-        // parse network from id
-        // The chain spec here does not impact the chain but only for showing the proper
-        // network type on explorer.
-        Ok(Box::new(subcoin_service::chain_spec::config(
-            bitcoin::Network::Bitcoin,
-        )?))
+    fn load_spec(&self, id: &str) -> Result<Box<dyn sc_service::ChainSpec>, String> {
+        let chain_spec = match id {
+            "bitcoin-mainnet" => ChainSpec::from_json_bytes(BITCOIN_MAINNET_CHAIN_SPEC.as_bytes())?,
+            "bitcoin-testnet" | "bitcoin-signet" => {
+                unimplemented!("Bitcoin testnet and signet are unsupported")
+            }
+            path => ChainSpec::from_json_file(std::path::PathBuf::from(path))?,
+        };
+
+        Ok(Box::new(chain_spec))
     }
 }