Method BuyByAddress

11_app_dev/chaincode_example05.go:73–133

(ctx contractapi.TransactionContextInterface, sellerAddress string, buyerSignature string, buyerAddress string, energy string)

}

func (s *SmartContract) BuyByAddress(ctx contractapi.TransactionContextInterface, sellerAddress string, buyerSignature string, buyerAddress string, energy string) (*EnergyTransaction, error) {
	energyValue, err := parsePositiveAmount(energy)
	if err != nil {
		return nil, err
	}
	if !validSignature(buyerAddress, buyerSignature) {
		return nil, fmt.Errorf("invalid buyer signature")
	}

	seller, err := readHome(ctx, sellerAddress)
	if err != nil {
		return nil, err
	}
	if seller.Status != homeAvailableForTrade {
		return nil, fmt.Errorf("seller %s is not available for trading", sellerAddress)
	}
	buyer, err := readHome(ctx, buyerAddress)
	if err != nil {
		return nil, err
	}
	if seller.Energy < energyValue {
		return nil, fmt.Errorf("seller has insufficient energy")
	}
	if buyer.Money < energyValue {
		return nil, fmt.Errorf("buyer has insufficient money")
	}

	seller.Energy -= energyValue
	seller.Money += energyValue
	buyer.Energy += energyValue
	buyer.Money -= energyValue

	if err := putHome(ctx, seller); err != nil {
		return nil, err
	}
	if err := putHome(ctx, buyer); err != nil {
		return nil, err
	}

	id, err := nextID(ctx, energyTxCounterKey)
	if err != nil {
		return nil, err
	}
	timestamp, err := txUnixTime(ctx)
	if err != nil {
		return nil, err
	}
	transaction := &EnergyTransaction{
		BuyerAddress:     buyerAddress,
		BuyerAddressSign: buyerSignature,
		SellerAddress:    sellerAddress,
		Energy:           energyValue,
		Money:            energyValue,
		ID:               id,
		Time:             timestamp,
	}
	if err := putJSON(ctx, energyTransactionKey(id), transaction); err != nil {
		return nil, err