package keeper

import (
	"context"

	"github.com/armon/go-metrics"

	"github.com/cosmos/cosmos-sdk/telemetry"
	sdk "github.com/cosmos/cosmos-sdk/types"
	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
	"github.com/cosmos/cosmos-sdk/x/bank/types"
)

type msgServer struct {
	Keeper
}

// NewMsgServerImpl returns an implementation of the bank MsgServer interface
// for the provided Keeper.
func NewMsgServerImpl(keeper Keeper) types.MsgServer {
	return &msgServer{Keeper: keeper}
}

var _ types.MsgServer = msgServer{}

func (k msgServer) Send(goCtx context.Context, msg *types.MsgSend) (*types.MsgSendResponse, error) {
	ctx := sdk.UnwrapSDKContext(goCtx)

	if err := k.SendEnabledCoins(ctx, msg.Amount...); err != nil {
		return nil, err
	}

	from, err := sdk.AccAddressFromBech32(msg.FromAddress)
	if err != nil {
		return nil, err
	}
	to, err := sdk.AccAddressFromBech32(msg.ToAddress)
	if err != nil {
		return nil, err
	}

	if k.BlockedAddr(to) {
		return nil, sdkerrors.Wrapf(sdkerrors.ErrUnauthorized, "%s is not allowed to receive funds", msg.ToAddress)
	}

	err = k.SendCoins(ctx, from, to, msg.Amount)
	if err != nil {
		return nil, err
	}

	defer func() {
		for _, a := range msg.Amount {
			if a.Amount.IsInt64() {
				telemetry.SetGaugeWithLabels(
					[]string{"tx", "msg", "send"},
					float32(a.Amount.Int64()),
					[]metrics.Label{telemetry.NewLabel("denom", a.Denom)},
				)
			}
		}
	}()

	ctx.EventManager().EmitEvent(
		sdk.NewEvent(
			sdk.EventTypeMessage,
			sdk.NewAttribute(sdk.AttributeKeyModule, types.AttributeValueCategory),
		),
	)

	return &types.MsgSendResponse{}, nil
}

func (k msgServer) MultiSend(goCtx context.Context, msg *types.MsgMultiSend) (*types.MsgMultiSendResponse, error) {
	ctx := sdk.UnwrapSDKContext(goCtx)

	// NOTE: totalIn == totalOut should already have been checked
	for _, in := range msg.Inputs {
		if err := k.SendEnabledCoins(ctx, in.Coins...); err != nil {
			return nil, err
		}
	}

	for _, out := range msg.Outputs {
		accAddr, err := sdk.AccAddressFromBech32(out.Address)
		if err != nil {
			panic(err)
		}
		if k.BlockedAddr(accAddr) {
			return nil, sdkerrors.Wrapf(sdkerrors.ErrUnauthorized, "%s is not allowed to receive transactions", out.Address)
		}
	}

	err := k.InputOutputCoins(ctx, msg.Inputs, msg.Outputs)
	if err != nil {
		return nil, err
	}

	ctx.EventManager().EmitEvent(
		sdk.NewEvent(
			sdk.EventTypeMessage,
			sdk.NewAttribute(sdk.AttributeKeyModule, types.AttributeValueCategory),
		),
	)

	return &types.MsgMultiSendResponse{}, nil
}