contracts.go

package ethereum

import (
	"encoding/json"
	"fmt"

	"github.com/ethereum/go-ethereum/core/types"
)

// Contract is an interface defines how a vault interact with the smart contract
type Contract interface {
	// Deploy deploys the smart contract to ethereum blockchain
	Deploy(
		wallet *Wallet,
		arguments json.RawMessage) (address string, txID string, err error)

	// Call calls a smart contract method
	Call(
		wallet *Wallet,
		method,
		fund string,
		arguments json.RawMessage,
		noSend bool,
		gasLimit uint64,
		gasPrice *int64,
		nonce *uint64) (tx *types.Transaction, err error)

	// Pack packs the method and arguments into a byte array representing
	// the smart contract call data
	Pack(
		method string,
		arguments json.RawMessage) ([]byte, error)

	// Parse parses the arguments as JSON format into an array of smart
	// contract function call arguments
	Parse(
		method string,
		arguments json.RawMessage) ([]interface{}, error)
}

// ContractFactory is a function that takes an address and return a Contract instance
type ContractFactory func(string) Contract

// contracts is a singleton of all registered contract factory function
var contracts = map[string]ContractFactory{}

// GetContract returns
func GetContract(name string) ContractFactory {
	return contracts[name]
}

// RegisterContract registers a contract
func RegisterContract(name string, contract ContractFactory) error {
	if _, ok := contracts[name]; ok {
		return fmt.Errorf("duplicated contract name has registered")
	}

	contracts[name] = contract
	return nil
}