Fixes for rpc request error handler, root list default empty values, …

…prev delegate fetching (#175)

* Fixes issue from #131 where "rpc_request" was not changed to `payload_id` in the error handler.

* Correctly use default empty values to avoid None issues.

* Previous delegates fetching fix for non-archive nodes.

bittensor_cli/src/bittensor/async_substrate_interface.py

@@ -1708,7 +1708,7 @@ async def rpc_request(
         result = await self._make_rpc_request(payloads, runtime=runtime)
         if "error" in result[payload_id][0]:
             raise SubstrateRequestException(
-                result["rpc_request"][0]["error"]["message"]
+                result[payload_id][0]["error"]["message"]
             )
         if "result" in result[payload_id][0]:
             return result[payload_id][0]

bittensor_cli/src/commands/root.py

@@ -11,9 +11,10 @@
 from rich.table import Column, Table
 from rich.text import Text
 from scalecodec import GenericCall, ScaleType
+from substrateinterface.exceptions import SubstrateRequestException
 import typer
 
-from bittensor_cli.src import Constants, DelegatesDetails
+from bittensor_cli.src import DelegatesDetails
 from bittensor_cli.src.bittensor.balances import Balance
 from bittensor_cli.src.bittensor.chain_data import (
     DelegateInfo,
@@ -721,7 +722,7 @@ async def _get_list() -> tuple:
 
         rn: list[NeuronInfoLite] = await subtensor.neurons_lite(netuid=0)
         if not rn:
-            return None, None, None, None
+            return [], [], {}, {}
 
         di: dict[str, DelegatesDetails] = await subtensor.get_delegate_identities()
         ts: dict[str, ScaleType] = await subtensor.substrate.query_multiple(
@@ -1539,16 +1540,24 @@ async def list_delegates(subtensor: SubtensorInterface):
             subtensor.get_delegates(block_hash=block_hash),
         )
 
-        # TODO keep an eye on this, was not working at one point
         print_verbose("Fetching previous delegates info from chain", status)
-        prev_block_hash = await subtensor.substrate.get_block_hash(
-            max(0, block_number - 1200)
-        )
-        prev_delegates = await subtensor.get_delegates(block_hash=prev_block_hash)
+
+        async def get_prev_delegates(fallback_offsets=(1200, 200)):
+            for offset in fallback_offsets:
+                try:
+                    prev_block_hash = await subtensor.substrate.get_block_hash(
+                        max(0, block_number - offset)
+                    )
+                    return await subtensor.get_delegates(block_hash=prev_block_hash)
+                except SubstrateRequestException:
+                    continue
+            return None
+
+        prev_delegates = await get_prev_delegates()
 
     if prev_delegates is None:
         err_console.print(
-            ":warning: [yellow]Could not fetch delegates history[/yellow]"
+            ":warning: [yellow]Could not fetch delegates history. [/yellow]"
         )
 
     delegates.sort(key=lambda d: d.total_stake, reverse=True)