feat: reverse search links (#793)

## Description
This PR adds the ability to reverse search for app links and chain links owners. The new following queries have been added: 
- search for app link owners using an application name (optional), and username (optional, works only if the application is specified as well)
- search for chain link owners using a chain name (optional), and target address (optional, works only if the chain name is specified as well)  

Closes: #777
Closes: #794

---

### 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/desmos-labs/desmos/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://docs.cosmos.network/v0.44/building-modules/intro.html)
- [ ] included the necessary unit and integration [tests](https://github.com/desmos-labs/desmos/blob/master/CONTRIBUTING.md#testing)
- [x] 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)

.changeset/entries/ed739ae62d392b19a07694f596ae5facae8dbd18ca8eb70bd6be0bc775aee829.yaml

@@ -0,0 +1,6 @@
+type: feat
+module: x/profiles
+pull_request: 793
+description: Added the ability to reverse search application links and chain links
+backward_compatible: true
+date: 2022-03-23T14:27:24.394374729Z

proto/desmos/profiles/v2/query.proto

@@ -36,6 +36,13 @@ service Query {
     option (google.api.http).get = "/desmos/profiles/v2/chain-links";
   }
 
+  // ChainLinkOwners queries for the owners of chain links, optionally searching
+  // for a specific chain name and external address
+  rpc ChainLinkOwners(QueryChainLinkOwnersRequest)
+      returns (QueryChainLinkOwnersResponse) {
+    option (google.api.http).get = "/desmos/profiles/v2/chain-links/owners";
+  }
+
   // ApplicationLinks queries the applications links associated to the given
   // user, if provided. Otherwise, it queries all the application links stored.
   rpc ApplicationLinks(QueryApplicationLinksRequest)
@@ -51,6 +58,13 @@ service Query {
         "/desmos/profiles/v2/app-links/clients/{client_id}";
   }
 
+  // ApplicationLinkOwners queries for the owners of applications links,
+  // optionally searching for a specific application and username.
+  rpc ApplicationLinkOwners(QueryApplicationLinkOwnersRequest)
+      returns (QueryApplicationLinkOwnersResponse) {
+    option (google.api.http).get = "/desmos/profiles/v2/app-links/owners";
+  }
+
   // Params queries the profiles module params
   rpc Params(QueryParamsRequest) returns (QueryParamsResponse) {
     option (google.api.http).get = "/desmos/profiles/v2/params";

proto/desmos/profiles/v2/query_app_links.proto

@@ -49,4 +49,38 @@ message QueryApplicationLinkByClientIDRequest {
 // request allowing to get an application link using a client id
 message QueryApplicationLinkByClientIDResponse {
   ApplicationLink link = 1 [ (gogoproto.nullable) = false ];
+}
+
+// QueryApplicationLinkOwnersRequest contains the data of the request that can
+// be used to get application link owners
+message QueryApplicationLinkOwnersRequest {
+  // (Optional) Application name to search link owners of. If not specified, all
+  // links stored will be searched instead.
+  string application = 1;
+
+  // (Optional) Username to search for. This will only be used if the
+  // application is specified as well
+  string username = 2;
+
+  // Pagination defines an optional pagination for the request
+  cosmos.base.query.v1beta1.PageRequest pagination = 3;
+}
+
+// QueryApplicationLinkOwnersResponse contains the data returned by the request
+// allowing to get application link owners.
+message QueryApplicationLinkOwnersResponse {
+  // ApplicationLinkOwnerDetails contains the details of a single application
+  // link owner
+  message ApplicationLinkOwnerDetails {
+    string user = 1;
+    string application = 2;
+    string username = 3;
+  }
+
+  // Addresses of the application links owners
+  repeated ApplicationLinkOwnerDetails owners = 1
+      [ (gogoproto.nullable) = false ];
+
+  // Pagination defines the pagination response
+  cosmos.base.query.v1beta1.PageResponse pagination = 2;
 }

proto/desmos/profiles/v2/query_chain_links.proto

@@ -38,3 +38,35 @@ message QueryChainLinksResponse {
   // Pagination defines the pagination response
   cosmos.base.query.v1beta1.PageResponse pagination = 2;
 }
+
+// QueryChainLinkOwnersRequest contains the data of the request that can
+// be used to get chain link owners
+message QueryChainLinkOwnersRequest {
+  // (Optional) Chain name to search link owners of. If not specified, all
+  // links stored will be searched instead.
+  string chain_name = 1;
+
+  // (Optional) External address to search for. This will only be used if the
+  // chain name is specified as well
+  string target = 2;
+
+  // Pagination defines an optional pagination for the request
+  cosmos.base.query.v1beta1.PageRequest pagination = 3;
+}
+
+// QueryChainLinkOwnersResponse contains the data returned by the request
+// allowing to get chain link owners.
+message QueryChainLinkOwnersResponse {
+  // ChainLinkOwnerDetails contains the details of a single chain link owner
+  message ChainLinkOwnerDetails {
+    string user = 1;
+    string chain_name = 2;
+    string target = 3;
+  }
+
+  // Addresses of the chain links owners
+  repeated ChainLinkOwnerDetails owners = 1 [ (gogoproto.nullable) = false ];
+
+  // Pagination defines the pagination response
+  cosmos.base.query.v1beta1.PageResponse pagination = 2;
+}

testutil/profiles.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/cosmos/cosmos-sdk/codec"
+
 	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
 	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -48,6 +50,15 @@ func PubKeyFromBech32(pubKey string) cryptotypes.PubKey {
 	return publicKey
 }
 
+func PubKeyFromJSON(cdc codec.Codec, pubKey string) cryptotypes.PubKey {
+	var publicKey cryptotypes.PubKey
+	err := cdc.UnmarshalInterfaceJSON([]byte(pubKey), &publicKey)
+	if err != nil {
+		panic(err)
+	}
+	return publicKey
+}
+
 func ProfileFromAddr(address string) *types.Profile {
 	profile, err := types.NewProfile(
 		fmt.Sprintf("%s-dtag", address),

x/profiles/keeper/grpc_query.go

@@ -122,6 +122,42 @@ func (k Keeper) ChainLinks(ctx context.Context, request *types.QueryChainLinksRe
 	return &types.QueryChainLinksResponse{Links: links, Pagination: pageRes}, nil
 }
 
+// ChainLinkOwners implements the Query/ChainLinkOwners gRPC method
+func (k Keeper) ChainLinkOwners(ctx context.Context, request *types.QueryChainLinkOwnersRequest) (*types.QueryChainLinkOwnersResponse, error) {
+	sdkCtx := sdk.UnwrapSDKContext(ctx)
+	store := sdkCtx.KVStore(k.storeKey)
+
+	ownersPrefix := types.ChainLinkChainPrefix
+	switch {
+	case request.ChainName != "" && request.Target != "":
+		ownersPrefix = types.ChainLinkChainAddressKey(request.ChainName, request.Target)
+	case request.ChainName != "":
+		ownersPrefix = types.ChainLinkChainKey(request.ChainName)
+	}
+
+	var owners []types.QueryChainLinkOwnersResponse_ChainLinkOwnerDetails
+	ownersStore := prefix.NewStore(store, ownersPrefix)
+	pageRes, err := query.Paginate(ownersStore, request.Pagination, func(key []byte, value []byte) error {
+		// Re-add the prefix because the prefix store trims it out, and we need it to get the data
+		keyWithPrefix := append(ownersPrefix, key...)
+		chainName, target, user := types.GetChainLinkOwnerData(keyWithPrefix)
+
+		owners = append(owners, types.QueryChainLinkOwnersResponse_ChainLinkOwnerDetails{
+			User:      user,
+			ChainName: chainName,
+			Target:    target,
+		})
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+
+	return &types.QueryChainLinkOwnersResponse{Owners: owners, Pagination: pageRes}, nil
+}
+
 // ApplicationLinks implements the Query/ApplicationLinks gRPC method
 func (k Keeper) ApplicationLinks(ctx context.Context, request *types.QueryApplicationLinksRequest) (*types.QueryApplicationLinksResponse, error) {
 	sdkCtx := sdk.UnwrapSDKContext(ctx)
@@ -174,6 +210,42 @@ func (k Keeper) ApplicationLinkByClientID(ctx context.Context, request *types.Qu
 	return &types.QueryApplicationLinkByClientIDResponse{Link: link}, nil
 }
 
+// ApplicationLinkOwners implements the Query/ApplicationLinkOwners gRPC method
+func (k Keeper) ApplicationLinkOwners(ctx context.Context, request *types.QueryApplicationLinkOwnersRequest) (*types.QueryApplicationLinkOwnersResponse, error) {
+	sdkCtx := sdk.UnwrapSDKContext(ctx)
+	store := sdkCtx.KVStore(k.storeKey)
+
+	ownersPrefix := types.ApplicationLinkAppPrefix
+	switch {
+	case request.Application != "" && request.Username != "":
+		ownersPrefix = types.ApplicationLinkAppUsernameKey(request.Application, request.Username)
+	case request.Application != "":
+		ownersPrefix = types.ApplicationLinkAppKey(request.Application)
+	}
+
+	var owners []types.QueryApplicationLinkOwnersResponse_ApplicationLinkOwnerDetails
+	ownersStore := prefix.NewStore(store, ownersPrefix)
+	pageRes, err := query.Paginate(ownersStore, request.Pagination, func(key []byte, value []byte) error {
+		// Re-add the prefix because the prefix store trims it out, and we need it to get the data
+		keyWithPrefix := append(ownersPrefix, key...)
+		application, username, user := types.GetApplicationLinkOwnerData(keyWithPrefix)
+
+		owners = append(owners, types.QueryApplicationLinkOwnersResponse_ApplicationLinkOwnerDetails{
+			User:        user,
+			Application: application,
+			Username:    username,
+		})
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+
+	return &types.QueryApplicationLinkOwnersResponse{Owners: owners, Pagination: pageRes}, nil
+}
+
 // Params implements the Query/Params gRPC method
 func (k Keeper) Params(ctx context.Context, _ *types.QueryParamsRequest) (*types.QueryParamsResponse, error) {
 	sdkCtx := sdk.UnwrapSDKContext(ctx)