package keeper

import (
	"context"

	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"

	"github.com/cosmos/cosmos-sdk/store/prefix"
	sdk "github.com/cosmos/cosmos-sdk/types"
	"github.com/cosmos/cosmos-sdk/types/query"
	"github.com/cosmos/cosmos-sdk/x/bank/types"
)

var _ types.QueryServer = BaseKeeper{}

// Balance implements the Query/Balance gRPC method
func (k BaseKeeper) Balance(ctx context.Context, req *types.QueryBalanceRequest) (*types.QueryBalanceResponse, error) {
	if req == nil {
		return nil, status.Error(codes.InvalidArgument, "empty request")
	}

	if req.Address == "" {
		return nil, status.Error(codes.InvalidArgument, "address cannot be empty")
	}

	if req.Denom == "" {
		return nil, status.Error(codes.InvalidArgument, "invalid denom")
	}

	sdkCtx := sdk.UnwrapSDKContext(ctx)
	address, err := sdk.AccAddressFromBech32(req.Address)
	if err != nil {
		return nil, status.Errorf(codes.InvalidArgument, "invalid address: %s", err.Error())
	}

	balance := k.GetBalance(sdkCtx, address, req.Denom)

	return &types.QueryBalanceResponse{Balance: &balance}, nil
}

// AllBalances implements the Query/AllBalances gRPC method
func (k BaseKeeper) AllBalances(ctx context.Context, req *types.QueryAllBalancesRequest) (*types.QueryAllBalancesResponse, error) {
	if req == nil {
		return nil, status.Error(codes.InvalidArgument, "empty request")
	}

	if req.Address == "" {
		return nil, status.Error(codes.InvalidArgument, "address cannot be empty")
	}

	addr, err := sdk.AccAddressFromBech32(req.Address)
	if err != nil {
		return nil, status.Errorf(codes.InvalidArgument, "invalid address: %s", err.Error())
	}

	sdkCtx := sdk.UnwrapSDKContext(ctx)

	balances := sdk.NewCoins()
	accountStore := k.getAccountStore(sdkCtx, addr)

	pageRes, err := query.Paginate(accountStore, req.Pagination, func(_, value []byte) error {
		var result sdk.Coin
		err := k.cdc.Unmarshal(value, &result)
		if err != nil {
			return err
		}
		balances = append(balances, result)
		return nil
	})

	if err != nil {
		return nil, status.Errorf(codes.InvalidArgument, "paginate: %v", err)
	}

	return &types.QueryAllBalancesResponse{Balances: balances, Pagination: pageRes}, nil
}

// SpendableBalances implements a gRPC query handler for retrieving an account's
// spendable balances.
func (k BaseKeeper) SpendableBalances(ctx context.Context, req *types.QuerySpendableBalancesRequest) (*types.QuerySpendableBalancesResponse, error) {
	if req == nil {
		return nil, status.Error(codes.InvalidArgument, "empty request")
	}

	addr, err := sdk.AccAddressFromBech32(req.Address)
	if err != nil {
		return nil, status.Errorf(codes.InvalidArgument, "invalid address: %s", err.Error())
	}

	sdkCtx := sdk.UnwrapSDKContext(ctx)

	balances := sdk.NewCoins()
	accountStore := k.getAccountStore(sdkCtx, addr)
	zeroAmt := sdk.ZeroInt()

	pageRes, err := query.Paginate(accountStore, req.Pagination, func(key, value []byte) error {
		balances = append(balances, sdk.NewCoin(string(key), zeroAmt))
		return nil
	})
	if err != nil {
		return nil, status.Errorf(codes.InvalidArgument, "paginate: %v", err)
	}

	result := sdk.NewCoins()
	spendable := k.SpendableCoins(sdkCtx, addr)

	for _, c := range balances {
		result = append(result, sdk.NewCoin(c.Denom, spendable.AmountOf(c.Denom)))
	}

	return &types.QuerySpendableBalancesResponse{Balances: result, Pagination: pageRes}, nil
}

// TotalSupply implements the Query/TotalSupply gRPC method
func (k BaseKeeper) TotalSupply(ctx context.Context, req *types.QueryTotalSupplyRequest) (*types.QueryTotalSupplyResponse, error) {
	sdkCtx := sdk.UnwrapSDKContext(ctx)
	totalSupply, pageRes, err := k.GetPaginatedTotalSupply(sdkCtx, req.Pagination)
	if err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	return &types.QueryTotalSupplyResponse{Supply: totalSupply, Pagination: pageRes}, nil
}

// SupplyOf implements the Query/SupplyOf gRPC method
func (k BaseKeeper) SupplyOf(c context.Context, req *types.QuerySupplyOfRequest) (*types.QuerySupplyOfResponse, error) {
	if req == nil {
		return nil, status.Error(codes.InvalidArgument, "empty request")
	}

	if req.Denom == "" {
		return nil, status.Error(codes.InvalidArgument, "invalid denom")
	}

	ctx := sdk.UnwrapSDKContext(c)
	supply := k.GetSupply(ctx, req.Denom)

	return &types.QuerySupplyOfResponse{Amount: sdk.NewCoin(req.Denom, supply.Amount)}, nil
}

// Params implements the gRPC service handler for querying x/bank parameters.
func (k BaseKeeper) Params(ctx context.Context, req *types.QueryParamsRequest) (*types.QueryParamsResponse, error) {
	if req == nil {
		return nil, status.Errorf(codes.InvalidArgument, "empty request")
	}

	sdkCtx := sdk.UnwrapSDKContext(ctx)
	params := k.GetParams(sdkCtx)

	return &types.QueryParamsResponse{Params: params}, nil
}

// DenomsMetadata implements Query/DenomsMetadata gRPC method.
func (k BaseKeeper) DenomsMetadata(c context.Context, req *types.QueryDenomsMetadataRequest) (*types.QueryDenomsMetadataResponse, error) {
	if req == nil {
		return nil, status.Errorf(codes.InvalidArgument, "empty request")
	}

	ctx := sdk.UnwrapSDKContext(c)
	store := prefix.NewStore(ctx.KVStore(k.storeKey), types.DenomMetadataPrefix)

	metadatas := []types.Metadata{}
	pageRes, err := query.Paginate(store, req.Pagination, func(_, value []byte) error {
		var metadata types.Metadata
		k.cdc.MustUnmarshal(value, &metadata)

		metadatas = append(metadatas, metadata)
		return nil
	})

	if err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	return &types.QueryDenomsMetadataResponse{
		Metadatas:  metadatas,
		Pagination: pageRes,
	}, nil
}

// DenomMetadata implements Query/DenomMetadata gRPC method.
func (k BaseKeeper) DenomMetadata(c context.Context, req *types.QueryDenomMetadataRequest) (*types.QueryDenomMetadataResponse, error) {
	if req == nil {
		return nil, status.Errorf(codes.InvalidArgument, "empty request")
	}

	if req.Denom == "" {
		return nil, status.Error(codes.InvalidArgument, "invalid denom")
	}

	ctx := sdk.UnwrapSDKContext(c)

	metadata, found := k.GetDenomMetaData(ctx, req.Denom)
	if !found {
		return nil, status.Errorf(codes.NotFound, "client metadata for denom %s", req.Denom)
	}

	return &types.QueryDenomMetadataResponse{
		Metadata: metadata,
	}, nil
}