mesg-foundation/core

package keeper

import (
    "fmt"

    "github.com/cosmos/cosmos-sdk/codec"
    sdk "github.com/cosmos/cosmos-sdk/types"
    sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
    "github.com/mesg-foundation/engine/x/credit/internal/types"
    "github.com/tendermint/tendermint/libs/log"
)

// Keeper of the credit store
type Keeper struct {
    storeKey   sdk.StoreKey
    cdc        *codec.Codec
    ak         types.AccountKeeper
    paramstore types.ParamSubspace
}

// NewKeeper creates a credit keeper
func NewKeeper(cdc *codec.Codec, ak types.AccountKeeper, key sdk.StoreKey, paramstore types.ParamSubspace) Keeper {
    keeper := Keeper{
        storeKey:   key,
        cdc:        cdc,
        ak:         ak,
        paramstore: paramstore.WithKeyTable(types.ParamKeyTable()),
    }
    return keeper
}

// Logger returns a module-specific logger.
func (k Keeper) Logger(ctx sdk.Context) log.Logger {
    return ctx.Logger().With("module", fmt.Sprintf("x/%s", types.ModuleName))
}

// Add a number of credits to an address
func (k Keeper) Add(ctx sdk.Context, address sdk.AccAddress, amount sdk.Int) (sdk.Int, error) {
    value, err := k.Get(ctx, address)
    if err != nil {
        return sdk.Int{}, sdkerrors.Wrapf(sdkerrors.ErrInvalidRequest, err.Error())
    }
    res := value.Add(amount)
    // emit event
    ctx.EventManager().EmitEvent(
        sdk.NewEvent(
            types.EventType,
            sdk.NewAttribute(sdk.AttributeKeyAction, types.AttributeActionAdded),
            sdk.NewAttribute(types.AttributeKeyAddress, address.String()),
            sdk.NewAttribute(types.AttributeKeyAmount, amount.String()),
        ),
    )
    return k.set(ctx, address, res)
}

// Sub a number of credits to an address
func (k Keeper) Sub(ctx sdk.Context, address sdk.AccAddress, amount sdk.Int) (sdk.Int, error) {
    value, err := k.Get(ctx, address)
    if err != nil {
        return sdk.Int{}, sdkerrors.Wrapf(sdkerrors.ErrInvalidRequest, err.Error())
    }
    res := value.Sub(amount)
    // emit event
    ctx.EventManager().EmitEvent(
        sdk.NewEvent(
            types.EventType,
            sdk.NewAttribute(sdk.AttributeKeyAction, types.AttributeActionSubtracted),
            sdk.NewAttribute(types.AttributeKeyAddress, address.String()),
            sdk.NewAttribute(types.AttributeKeyAmount, amount.String()),
        ),
    )
    return k.set(ctx, address, res)
}

// Set a number of credit to a specific address
func (k Keeper) set(ctx sdk.Context, address sdk.AccAddress, balance sdk.Int) (sdk.Int, error) {
    if k.ak.GetAccount(ctx, address) == nil {
        k.ak.SetAccount(ctx, k.ak.NewAccountWithAddress(ctx, address))
    }
    store := ctx.KVStore(k.storeKey)
    encoded, err := k.cdc.MarshalBinaryLengthPrefixed(balance)
    if err != nil {
        return sdk.Int{}, sdkerrors.Wrapf(sdkerrors.ErrJSONMarshal, err.Error())
    }
    store.Set(address.Bytes(), encoded)
    return balance, nil
}

// Get the balance of a specific address
func (k Keeper) Get(ctx sdk.Context, address sdk.AccAddress) (sdk.Int, error) {
    store := ctx.KVStore(k.storeKey)
    if !store.Has(address.Bytes()) {
        return sdk.ZeroInt(), nil
    }
    value := store.Get(address.Bytes())
    var balance sdk.Int
    if err := k.cdc.UnmarshalBinaryLengthPrefixed(value, &balance); err != nil {
        return sdk.Int{}, sdkerrors.Wrapf(sdkerrors.ErrJSONUnmarshal, err.Error())
    }
    return balance, nil
}

// Export all credits from the keeper.
func (k *Keeper) Export(ctx sdk.Context) (map[string]sdk.Int, error) {
    var (
        credits = make(map[string]sdk.Int)
        iter    = ctx.KVStore(k.storeKey).Iterator(nil, nil)
    )
    for iter.Valid() {
        var cred sdk.Int
        value := iter.Value()
        if err := k.cdc.UnmarshalBinaryLengthPrefixed(value, &cred); err != nil {
            return nil, sdkerrors.Wrapf(sdkerrors.ErrJSONUnmarshal, err.Error())
        }
        address := sdk.AccAddress(iter.Key())
        credits[address.String()] = cred
        iter.Next()
    }
    iter.Close()
    return credits, nil
}

// Import all credits into the keeper.
func (k *Keeper) Import(ctx sdk.Context, credits map[string]sdk.Int) error {
    for address, balance := range credits {
        addr, err := sdk.AccAddressFromBech32(address)
        if err != nil {
            return err
        }
        k.set(ctx, addr, balance)
    }
    return nil
}