Handle chain information in explicit form in invoices

invoice/src/builder.rs

@@ -32,15 +32,16 @@ pub struct RgbInvoiceBuilder(RgbInvoice);
 
 impl RgbInvoiceBuilder {
     pub fn new(beneficiary: impl Into<Beneficiary>) -> Self {
+        let beneficiary = beneficiary.into();
         Self(RgbInvoice {
             transports: vec![RgbTransport::UnspecifiedMeans],
             contract: None,
             iface: None,
             operation: None,
             assignment: None,
-            beneficiary: beneficiary.into(),
+            chain: beneficiary.chain_info().unwrap_or(Chain::Bitcoin),
+            beneficiary,
             owned_state: TypedState::Void,
-            chain: None,
             expiry: None,
             unknown_query: none!(),
         })
@@ -114,9 +115,20 @@ impl RgbInvoiceBuilder {
         self.set_amount(coins as u64, cents as u64, precision)
     }
 
-    pub fn set_chain(mut self, chain: impl Into<Chain>) -> Self {
-        self.0.chain = Some(chain.into());
-        self
+    pub fn set_chain(mut self, chain: impl Into<Chain>) -> Result<Self, Self> {
+        let chain = chain.into();
+        match (self.0.beneficiary.chain_info(), chain) {
+            (None, _) => {}
+            (Some(chain1), chain2) if chain1 == chain2 => {}
+            (Some(chain1), chain2)
+                if chain1.is_testnet() &&
+                    chain2.is_testnet() &&
+                    chain1 != Chain::Regtest &&
+                    chain2 != Chain::Regtest => {}
+            _ => return Err(self),
+        }
+        self.0.chain = chain;
+        Ok(self)
     }
 
     pub fn set_expiry_timestamp(mut self, expiry: i64) -> Self {

invoice/src/invoice.rs

@@ -19,7 +19,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use bp::Address;
+use bp::{Address, AddressNetwork};
 use indexmap::IndexMap;
 use rgb::interface::TypedState;
 use rgb::{AttachId, Chain, ContractId, SecretSeal};
@@ -55,6 +55,28 @@ pub enum Beneficiary {
     WitnessUtxo(Address),
 }
 
+impl Beneficiary {
+    pub fn chain_info(&self) -> Option<Chain> {
+        match self {
+            Beneficiary::BlindedSeal(_) => None,
+            Beneficiary::WitnessUtxo(Address {
+                network: AddressNetwork::Mainnet,
+                ..
+            }) => Some(Chain::Bitcoin),
+            Beneficiary::WitnessUtxo(Address {
+                network: AddressNetwork::Regtest,
+                ..
+            }) => Some(Chain::Regtest),
+            Beneficiary::WitnessUtxo(Address {
+                network: AddressNetwork::Testnet,
+                ..
+            }) => Some(Chain::Testnet3),
+        }
+    }
+
+    pub fn has_chain_info(&self) -> bool { self.chain_info().is_some() }
+}
+
 #[derive(Clone, Eq, PartialEq, Debug)]
 pub struct RgbInvoice {
     pub transports: Vec<RgbTransport>,
@@ -64,7 +86,7 @@ pub struct RgbInvoice {
     pub assignment: Option<FieldName>,
     pub beneficiary: Beneficiary,
     pub owned_state: TypedState,
-    pub chain: Option<Chain>,
+    pub chain: Chain,
     /// UTC unix timestamp
     pub expiry: Option<i64>,
     pub unknown_query: IndexMap<String, String>,