Problem: Missing CloseChannel command (fixes #71) (#74)

Solution: 

add close-channel command, the ibc-go does not allowed the user to close the channel by default because of this, we need to add a path for it and recompile the chain-maind if we want to use this feature.

@@ -304,8 +304,9 @@ func (am AppModule) OnChanCloseInit(
        portID,
        channelID string,
 ) error {
-       // Disallow user-initiated channel closing for transfer channels
-       return sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "user cannot close channel")
+       // Allow user-initiated channel closing for transfer channels
+       // return sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "user cannot close channel")
+        return nil
 }

solo-machine-core/src/event.rs

@@ -95,6 +95,13 @@ pub enum Event {
         /// Channel ID of solo machine client on IBC enabled chain
         channel_id: ChannelId,
     },
+    /// Close channel on IBC enabled chain
+    CloseChannelInitOnSoloMachine {
+        /// Chain ID of IBC enabled chain
+        chain_id: String,
+        /// Channel ID of IBC enabled chain on solo machine
+        channel_id: ChannelId,
+    },
     /// Initialized channel on solo machine
     InitializedChannelOnSoloMachine {
         /// Channel ID of IBC enabled chain on solo machine

solo-machine-core/src/ibc/core/ics04_channel.rs

@@ -1,4 +1,5 @@
 pub mod msg_acknowledgement;
+pub mod msg_channel_close_init;
 pub mod msg_channel_open_ack;
 pub mod msg_channel_open_init;
 pub mod msg_recv_packet;

solo-machine-core/src/ibc/core/ics04_channel/msg_channel_close_init.rs

@@ -0,0 +1,5 @@
+use cosmos_sdk_proto::ibc::core::channel::v1::MsgChannelCloseInit;
+
+const TYPE_URL: &str = "/ibc.core.channel.v1.MsgChannelCloseInit";
+
+impl_any_conversion!(MsgChannelCloseInit, TYPE_URL);

solo-machine-core/src/model/chain/chain.rs

@@ -49,18 +49,27 @@ pub struct Chain {
 impl Chain {
     /// Returns the IBC denom of given denomination based on connection details. Returns `None` if connection details
     /// are not present.
-    pub fn get_ibc_denom(&self, denom: &Identifier) -> Option<String> {
-        let connection_details = self.connection_details.as_ref()?;
+    pub fn get_ibc_denom(&self, denom: &Identifier) -> Result<String> {
+        let connection_details = self.connection_details.as_ref();
+        ensure!(
+            connection_details.is_some(),
+            "connection is not established with given chain"
+        );
+        let connection_details = connection_details.unwrap();
+        ensure!(
+            connection_details.solo_machine_channel_id.is_some(),
+            "can't find solo machine channel, channel is already closed"
+        );
 
         let denom_trace = DenomTrace::new(
             &self.config.port_id,
-            &connection_details.solo_machine_channel_id,
+            connection_details.solo_machine_channel_id.as_ref().unwrap(),
             denom,
         );
 
         let hash = Sha256::digest(denom_trace.to_string().as_bytes());
 
-        Some(format!("ibc/{}", hex::encode_upper(hash)))
+        Ok(format!("ibc/{}", hex::encode_upper(hash)))
     }
 
     /// Fetches on-chain balance of given denom
@@ -76,9 +85,7 @@ impl Chain {
                 self.config.grpc_addr
             ))?;
 
-        let denom = self
-            .get_ibc_denom(denom)
-            .ok_or_else(|| anyhow!("connection details not found when fetching balance"))?;
+        let denom = self.get_ibc_denom(denom)?;
 
         let request = QueryBalanceRequest {
             address: signer.to_account_address()?,
@@ -170,9 +177,9 @@ pub struct ConnectionDetails {
     /// Connection ID of IBC enabled chain on solo machine
     pub tendermint_connection_id: ConnectionId,
     /// Channel ID of solo machine client on IBC enabled chain
-    pub solo_machine_channel_id: ChannelId,
+    pub solo_machine_channel_id: Option<ChannelId>,
     /// Channel ID of IBC enabled chain on solo machine
-    pub tendermint_channel_id: ChannelId,
+    pub tendermint_channel_id: Option<ChannelId>,
 }
 
 impl From<Chain> for RawChain {

solo-machine-core/src/service/chain_service.rs

@@ -76,9 +76,7 @@ impl ChainService {
             .get(chain_id)
             .await?
             .ok_or_else(|| anyhow!("chain details not found when computing ibc denom"))?;
-        chain
-            .get_ibc_denom(denom)
-            .ok_or_else(|| anyhow!("connection details not found when computing ibc denom"))
+        chain.get_ibc_denom(denom)
     }
 
     /// Fetches details of a chain