// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin Core developers
// Distributed under the GPLv3 software license, see the accompanying
// file COPYING or https://www.gnu.org/licenses/gpl-3.0.en.html

/******************************************************************************
 * Copyright © 2014-2019 The SuperNET Developers.                             *
 *                                                                            *
 * See the AUTHORS, DEVELOPER-AGREEMENT and LICENSE files at                  *
 * the top-level directory of this distribution for the individual copyright  *
 * holder information and the developer policies on copyright and licensing.  *
 *                                                                            *
 * Unless otherwise agreed in a custom licensing agreement, no part of the    *
 * SuperNET software, including this file may be copied, modified, propagated *
 * or distributed except according to the terms contained in the LICENSE file *
 *                                                                            *
 * Removal or modification of this copyright notice is prohibited.            *
 *                                                                            *
 ******************************************************************************/

#ifndef BITCOIN_SCRIPT_SIGN_H
#define BITCOIN_SCRIPT_SIGN_H

#include "script/interpreter.h"

class CKey;
class CKeyID;
class CKeyStore;
class CScript;
class CTransaction;

struct CMutableTransaction;

/** Virtual base class for signature creators. */
class BaseSignatureCreator {
protected:
    const CKeyStore* keystore;

public:
    BaseSignatureCreator(const CKeyStore* keystoreIn) : keystore(keystoreIn) {}
    const bool IsKeystoreValid() const { return keystore != NULL; }
    const CKeyStore& KeyStore() const { return *keystore; }
    virtual ~BaseSignatureCreator() {}
    virtual const BaseSignatureChecker& Checker() const =0;

    /** Create a singular (non-script) signature. */
    virtual bool CreateSig(std::vector<unsigned char>& vchSig, 
                           const CKeyID& keyid, 
                           const CScript& scriptCode, 
                           uint32_t consensusBranchId, 
                           CKey *key = NULL, 
                           void *extraData = NULL) const = 0;
};

/** A signature creator for transactions. */
class TransactionSignatureCreator : public BaseSignatureCreator {
    const CTransaction* txTo;
    unsigned int nIn;
    int nHashType;
    CAmount amount;
    const TransactionSignatureChecker checker;

public:
    TransactionSignatureCreator(const CKeyStore* keystoreIn, const CTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, int nHashTypeIn=SIGHASH_ALL);
    const BaseSignatureChecker& Checker() const { return checker; }
    bool CreateSig(std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode, uint32_t consensusBranchId, CKey *key = NULL, void *extraData = NULL) const;
};

class MutableTransactionSignatureCreator : public TransactionSignatureCreator {
    CTransaction tx;

public:
    MutableTransactionSignatureCreator(const CKeyStore* keystoreIn, const CMutableTransaction* txToIn, unsigned int nInIn, const CAmount& amount, int nHashTypeIn) : TransactionSignatureCreator(keystoreIn, &tx, nInIn, amount, nHashTypeIn), tx(*txToIn) {}
};

/** A signature creator that just produces 72-byte empty signatures. */
class DummySignatureCreator : public BaseSignatureCreator {
public:
    DummySignatureCreator(const CKeyStore* keystoreIn) : BaseSignatureCreator(keystoreIn) {}
    const BaseSignatureChecker& Checker() const;
    bool CreateSig(std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode, uint32_t consensusBranchId, CKey *key = NULL, void *extraData = NULL) const;
};

struct SignatureData {
    CScript scriptSig;

    SignatureData() {}
    explicit SignatureData(const CScript& script) : scriptSig(script) {}
};

/** Produce a script signature using a generic signature creator. */
bool ProduceSignature(const BaseSignatureCreator& creator, const CScript& scriptPubKey, SignatureData& sigdata, uint32_t consensusBranchId);

/** Produce a script signature for a transaction. */
bool SignSignature(
    const CKeyStore &keystore,
    const CScript& fromPubKey,
    CMutableTransaction& txTo,
    unsigned int nIn,
    const CAmount& amount,
    int nHashType,
    uint32_t consensusBranchId);
bool SignSignature(
    const CKeyStore& keystore,
    const CTransaction& txFrom,
    CMutableTransaction& txTo,
    unsigned int nIn,
    int nHashType,
    uint32_t consensusBranchId);

/** Combine two script signatures using a generic signature checker, intelligently, possibly with OP_0 placeholders. */
SignatureData CombineSignatures(
    const CScript& scriptPubKey,
    const BaseSignatureChecker& checker,
    const SignatureData& scriptSig1,
    const SignatureData& scriptSig2,
    uint32_t consensusBranchId);

/** Extract signature data from a transaction, and insert it. */
SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nIn);
void UpdateTransaction(CMutableTransaction& tx, unsigned int nIn, const SignatureData& data);

#endif // BITCOIN_SCRIPT_SIGN_H