// Package verify contains RPC wrappers for verify contract.
package verify

import (
	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
	"github.com/nspcc-dev/neo-go/pkg/util"
	"math/big"
)

// Hash contains contract hash.
var Hash = util.Uint160{0x33, 0x22, 0x11, 0x0, 0xff, 0xee, 0xdd, 0xcc, 0xbb, 0xaa, 0x99, 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11, 0x0}

// Actor is used by Contract to call state-changing methods.
type Actor interface {
	MakeCall(contract util.Uint160, method string, params ...interface{}) (*transaction.Transaction, error)
	MakeRun(script []byte) (*transaction.Transaction, error)
	MakeUnsignedCall(contract util.Uint160, method string, attrs []transaction.Attribute, params ...interface{}) (*transaction.Transaction, error)
	MakeUnsignedRun(script []byte, attrs []transaction.Attribute) (*transaction.Transaction, error)
	SendCall(contract util.Uint160, method string, params ...interface{}) (util.Uint256, uint32, error)
	SendRun(script []byte) (util.Uint256, uint32, error)
}

// Contract implements all contract methods.
type Contract struct {
	actor Actor
}

// New creates an instance of Contract using Hash and the given Actor.
func New(actor Actor) *Contract {
	return &Contract{actor}
}


func scriptForVerify() ([]byte, error) {
	return smartcontract.CreateCallWithAssertScript(Hash, "verify")
}

// Verify creates a transaction invoking `verify` method of the contract.
// This transaction is signed and immediately sent to the network.
// The values returned are its hash, ValidUntilBlock value and error if any.
func (c *Contract) Verify() (util.Uint256, uint32, error) {
	script, err := scriptForVerify()
	if err != nil {
		return util.Uint256{}, 0, err
	}
	return c.actor.SendRun(script)
}

// VerifyTransaction creates a transaction invoking `verify` method of the contract.
// This transaction is signed, but not sent to the network, instead it's
// returned to the caller.
func (c *Contract) VerifyTransaction() (*transaction.Transaction, error) {
	script, err := scriptForVerify()
	if err != nil {
		return nil, err
	}
	return c.actor.MakeRun(script)
}

// VerifyUnsigned creates a transaction invoking `verify` method of the contract.
// This transaction is not signed, it's simply returned to the caller.
// Any fields of it that do not affect fees can be changed (ValidUntilBlock,
// Nonce), fee values (NetworkFee, SystemFee) can be increased as well.
func (c *Contract) VerifyUnsigned() (*transaction.Transaction, error) {
	script, err := scriptForVerify()
	if err != nil {
		return nil, err
	}
	return c.actor.MakeUnsignedRun(script, nil)
}

// OnNEP17Payment creates a transaction invoking `onNEP17Payment` method of the contract.
// This transaction is signed and immediately sent to the network.
// The values returned are its hash, ValidUntilBlock value and error if any.
func (c *Contract) OnNEP17Payment(from []byte, amount *big.Int, data interface{}) (util.Uint256, uint32, error) {
	return c.actor.SendCall(Hash, "onNEP17Payment", from, amount, data)
}

// OnNEP17PaymentTransaction creates a transaction invoking `onNEP17Payment` method of the contract.
// This transaction is signed, but not sent to the network, instead it's
// returned to the caller.
func (c *Contract) OnNEP17PaymentTransaction(from []byte, amount *big.Int, data interface{}) (*transaction.Transaction, error) {
	return c.actor.MakeCall(Hash, "onNEP17Payment", from, amount, data)
}

// OnNEP17PaymentUnsigned creates a transaction invoking `onNEP17Payment` method of the contract.
// This transaction is not signed, it's simply returned to the caller.
// Any fields of it that do not affect fees can be changed (ValidUntilBlock,
// Nonce), fee values (NetworkFee, SystemFee) can be increased as well.
func (c *Contract) OnNEP17PaymentUnsigned(from []byte, amount *big.Int, data interface{}) (*transaction.Transaction, error) {
	return c.actor.MakeUnsignedCall(Hash, "onNEP17Payment", nil, from, amount, data)
}