From f9e032129f01a9c632891d1efbe375f948a5255d Mon Sep 17 00:00:00 2001
From: Sai Kumar <17549398+gsk967@users.noreply.github.com>
Date: Tue, 5 Apr 2022 15:31:13 +0530
Subject: [PATCH] feat: Cancel unbonding delegation entry (#10885)

## Description


Closes: #577

This pull request contains `Canceling unbonding delegation entry` and `delegate back to previous validator`

### `Msg` Service
```protobuf=
package cosmos.staking.v1beta1;

service Msg {
    // CancelUnbondingDelegation
    rpc CancelUnbondingDelegation(MsgCancelUnbondingDelegation) returns (MsgCancelUnbondingDelegationResponse);
}

// MsgCancelUnbondingDelegation
message MsgCancelUnbondingDelegation {
  option (gogoproto.equal)           = false;
  option (gogoproto.goproto_getters) = false;

  string                   delegator_address = 1 [(cosmos_proto.scalar) = "cosmos.AddressString"];
  string                   validator_address = 2 [(cosmos_proto.scalar) = "cosmos.AddressString"];
  cosmos.base.v1beta1.Coin amount            = 3 [(gogoproto.nullable) = false];
  // creation_height is the height which the unbonding took place.
  int64 creation_height = 4;
}

// MsgCancelUnbondingDelegationResponse
message MsgCancelUnbondingDelegationResponse{
}
```

### `Msg` Method Implementation
```go=
func (k msgServer) CancelUnbondingDelegation(goCtx context.Context, msg *types.MsgCancelUnbondingDelegation) (*types.MsgCancelUnbondingDelegationResponse, error) {
    /*
    // checking the unbonding delegation at creation_height
         // get the unbonding delegations of delegatorAddress
        if ubdEntry balance is equal to msg.Amount
            remove the entry from ubd
        else
            update the specific entry with new balance

        if len(ubd.Entries) == 0 {
            k.RemoveUnbondingDelegation(ctx, ubd)
        } else {
            k.SetUnbondingDelegation(ctx, ubd)
        }
    */


    // update the delegation back to validator
    // get validator
        validator, found := k.GetValidator(ctx, valAddr)
        if !found {
            return nil, types.ErrNoValidatorFound
        }

        // delegate the unbonding amount to validator back
        _, err = k.Keeper.Delegate(ctx, delegatorAddress, msg.Amount.Amount, types.Unbonding, validator, false)
        if err != nil {
            return nil, err
        }


        _, err := ms.Keeper.CancelUnbondingDelegation(ctx,delegatorAddress,validatorAddress,amount,creation_height)
        if err != nil {
            return nil, err
        }


        return &types.MsgCancelUnbondingDelegationResponse{}, nil
}
```

#### `cli tx` Method
```bash=
simd tx staking cancel-unbond [validator-address] [amount] [creation_height] --from [user] --chain-id [chain-id]
Example:
simd tx staking cancel-unbond cosmosvaloper1mqtyv4qux68r26mql2hjhgrvz72snjwpulq22m 100000stake 10280 --from test1 --chain-id test-chain
```

---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)
---
 params/weights.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/params/weights.go b/params/weights.go
index 746e304de2be..340de0b24818 100644
--- a/params/weights.go
+++ b/params/weights.go
@@ -17,6 +17,7 @@ const (
 	DefaultWeightMsgDelegate                    int = 100
 	DefaultWeightMsgUndelegate                  int = 100
 	DefaultWeightMsgBeginRedelegate             int = 100
+	DefaultWeightMsgCancelUnbondingDelegation   int = 100
 
 	DefaultWeightCommunitySpendProposal int = 5
 	DefaultWeightTextProposal           int = 5