package vesting

import (
	"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/auth/keeper"
	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
	"github.com/cosmos/cosmos-sdk/x/auth/vesting/types"
)

// NewHandler returns a handler for x/auth message types.
func NewHandler(ak keeper.AccountKeeper, bk types.BankKeeper) sdk.Handler {
	return func(ctx sdk.Context, msg sdk.Msg) (*sdk.Result, error) {
		ctx = ctx.WithEventManager(sdk.NewEventManager())

		switch msg := msg.(type) {
		case *types.MsgCreateVestingAccount:
			return handleMsgCreateVestingAccount(ctx, ak, bk, msg)

		default:
			return nil, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "unrecognized %s message type: %T", types.ModuleName, msg)
		}
	}
}

func handleMsgCreateVestingAccount(ctx sdk.Context, ak keeper.AccountKeeper, bk types.BankKeeper, msg *types.MsgCreateVestingAccount) (*sdk.Result, error) {
	if err := bk.SendEnabledCoins(ctx, msg.Amount...); err != nil {
		return nil, err
	}

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

	if acc := ak.GetAccount(ctx, msg.ToAddress); acc != nil {
		return nil, sdkerrors.Wrapf(sdkerrors.ErrInvalidRequest, "account %s already exists", msg.ToAddress)
	}

	baseAccount := ak.NewAccountWithAddress(ctx, msg.ToAddress)
	if _, ok := baseAccount.(*authtypes.BaseAccount); !ok {
		return nil, sdkerrors.Wrapf(sdkerrors.ErrInvalidRequest, "invalid account type; expected: BaseAccount, got: %T", baseAccount)
	}

	baseVestingAccount := types.NewBaseVestingAccount(baseAccount.(*authtypes.BaseAccount), msg.Amount.Sort(), msg.EndTime)

	var acc authtypes.AccountI

	if msg.Delayed {
		acc = types.NewDelayedVestingAccountRaw(baseVestingAccount)
	} else {
		acc = types.NewContinuousVestingAccountRaw(baseVestingAccount, ctx.BlockTime().Unix())
	}

	ak.SetAccount(ctx, acc)

	defer func() {
		telemetry.IncrCounter(1, "new", "account")

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

	err := bk.SendCoins(ctx, msg.FromAddress, msg.ToAddress, msg.Amount)
	if err != nil {
		return nil, err
	}

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

	return &sdk.Result{Events: ctx.EventManager().ABCIEvents()}, nil
}