fix: Ensure staking-payouts depth integrates with the relay chain post AHM (#1718)

* Add backwards era calculating

* Start and end of migration for relay on westend

* Get the logic working

* Update docs

Author: TarikGul

docs/dist/app.bundle.js

@@ -554,14 +554,16 @@ paths:
       tags:
       - staking
       summary: Get payout information for a _Stash_ account.
-      description: Returns payout information for the last specified eras. If
-        specifying both the depth and era query params, this endpoint will
-        return information for (era - depth) through era. (i.e. if depth=5 and
-        era=20 information will be returned for eras 16 through 20). N.B. You
-        cannot query eras less then `current_era - HISTORY_DEPTH`. N.B. The
-        `nominator*` fields correspond to the address being queried, even if it
-        is a validator's _Stash_ address. This is because a validator is technically
-        nominating itself.
+      description: |
+        Returns payout information for the last specified eras. If specifying both the depth and era query params, this endpoint will return information for (era - depth) through era. (i.e. if depth=5 and era=20 information will be returned for eras 16 through 20).
+
+        **Asset Hub Migration Support:**
+        For Asset Hub chains that have migrated staking from the relay chain, this endpoint automatically handles era query routing:
+        - **Pre-migration eras**: Queries historical data from the relay chain
+        - **Post-migration eras**: Queries current data from Asset Hub
+        - **Cross-migration queries**: Automatically splits the era range and combines results from both chains
+
+        **Note:** The `nominator*` fields correspond to the address being queried, even if it is a validator's _Stash_ address. This is because a validator is technically nominating itself.
       operationId: getStakingPayoutsByAccountId
       parameters:
       - name: accountId
@@ -624,7 +626,12 @@ paths:
                   - type: array
                     items:
                       $ref: '#/components/schemas/AccountStakingPayouts'
-                description: Returns a single object when using standard parameters. Returns an array when using 'useRcBlock' parameter (array contains one object per Asset Hub block found, or empty array if none found).
+                description: |
+                  **Standard Mode**: Returns a single object when using standard parameters (without useRcBlock). 
+                  
+                  **Relay Chain Block Mode**: Returns an array when using 'useRcBlock' parameter (array contains one object per Asset Hub block found, or empty array if none found).
+                  
+                  **Asset Hub Migration**: For both modes, when querying eras that span the Asset Hub migration boundary, the endpoint automatically fetches and combines data from both relay chain (pre-migration eras) and Asset Hub (post-migration eras). The migration handling is transparent to the user - you get complete payout information regardless of which chain originally held the data.
         "400":
           description: invalid blockId supplied for at query param, or invalid parameter combination
           content:

docs/src/openapi-v1.yaml

@@ -20,6 +20,7 @@ import BN from 'bn.js';
 import { RequestHandler } from 'express';
 import { BadRequest, InternalServerError } from 'http-errors';
 
+import { ApiPromiseRegistry } from '../../apiRegistry';
 import { validateAddress, validateBoolean, validateUseRcBlock } from '../../middleware';
 import { AccountsStakingPayoutsService } from '../../services';
 import { IEarlyErasBlockInfo } from '../../services/accounts/AccountsStakingPayoutsService';
@@ -118,6 +119,7 @@ export default class AccountsStakingPayoutsController extends AbstractController
 	): Promise<void> => {
 		const { specName } = this;
 		const isKusama = specName.toString().toLowerCase() === 'kusama';
+		const { isAssetHubMigrated } = ApiPromiseRegistry.assetHubInfo;
 
 		if (useRcBlock === 'true') {
 			const rcAtResults = await this.getHashFromRcAt(at);
@@ -154,15 +156,28 @@ export default class AccountsStakingPayoutsController extends AbstractController
 					throw new BadRequest('Staking pallet not found for queried runtime');
 				}
 
-				const result = await this.service.fetchAccountStakingPayout(
-					hash,
-					address,
-					this.verifyAndCastOr('depth', sanitizedDepth, 1) as number,
-					eraArg,
-					unclaimedOnly === 'false' ? false : true,
-					currentEra,
-					apiAt,
-				);
+				let result;
+				if (isAssetHubMigrated) {
+					result = await this.service.fetchAccountStakingPayoutAssetHub(
+						hash,
+						address,
+						this.verifyAndCastOr('depth', sanitizedDepth, 1) as number,
+						eraArg,
+						unclaimedOnly === 'false' ? false : true,
+						currentEra,
+						apiAt,
+					);
+				} else {
+					result = await this.service.fetchAccountStakingPayout(
+						hash,
+						address,
+						this.verifyAndCastOr('depth', sanitizedDepth, 1) as number,
+						eraArg,
+						unclaimedOnly === 'false' ? false : true,
+						currentEra,
+						apiAt,
+					);
+				}
 
 				const finalApiAt = await this.api.at(hash);
 				const ahTimestamp = await finalApiAt.query.timestamp.now();
@@ -201,15 +216,28 @@ export default class AccountsStakingPayoutsController extends AbstractController
 				throw new BadRequest('Staking pallet not found for queried runtime');
 			}
 
-			const result = await this.service.fetchAccountStakingPayout(
-				hash,
-				address,
-				this.verifyAndCastOr('depth', sanitizedDepth, 1) as number,
-				eraArg,
-				unclaimedOnly === 'false' ? false : true,
-				currentEra,
-				apiAt,
-			);
+			let result;
+			if (isAssetHubMigrated) {
+				result = await this.service.fetchAccountStakingPayoutAssetHub(
+					hash,
+					address,
+					this.verifyAndCastOr('depth', sanitizedDepth, 1) as number,
+					eraArg,
+					unclaimedOnly === 'false' ? false : true,
+					currentEra,
+					apiAt,
+				);
+			} else {
+				result = await this.service.fetchAccountStakingPayout(
+					hash,
+					address,
+					this.verifyAndCastOr('depth', sanitizedDepth, 1) as number,
+					eraArg,
+					unclaimedOnly === 'false' ? false : true,
+					currentEra,
+					apiAt,
+				);
+			}
 
 			AccountsStakingPayoutsController.sanitizedSend(res, result);
 		}