/src/script.h

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2012 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file license.txt or http://www.opensource.org/licenses/mit-license.php.
#ifndef H_BITCOIN_SCRIPT
#define H_BITCOIN_SCRIPT

#include "base58.h"

#include <string>
#include <vector>

#include <boost/foreach.hpp>

class CTransaction;
class CKeyStore;

enum
{
    SIGHASH_ALL = 1,
    SIGHASH_NONE = 2,
    SIGHASH_SINGLE = 3,
    SIGHASH_ANYONECANPAY = 0x80,
};


enum txnouttype
{
    TX_NONSTANDARD,
    // 'standard' transaction types:
    TX_PUBKEY,
    TX_PUBKEYHASH,
    TX_SCRIPTHASH,
    TX_MULTISIG,
};

const char* GetTxnOutputType(txnouttype t);

enum opcodetype
{
    // push value
    OP_0=0,
    OP_FALSE=OP_0,
    OP_PUSHDATA1=76,
    OP_PUSHDATA2,
    OP_PUSHDATA4,
    OP_1NEGATE,
    OP_RESERVED,
    OP_1,
    OP_TRUE=OP_1,
    OP_2,
    OP_3,
    OP_4,
    OP_5,
    OP_6,
    OP_7,
    OP_8,
    OP_9,
    OP_10,
    OP_11,
    OP_12,
    OP_13,
    OP_14,
    OP_15,
    OP_16,

    // control
    OP_NOP,
    OP_VER,
    OP_IF,
    OP_NOTIF,
    OP_VERIF,
    OP_VERNOTIF,
    OP_ELSE,
    OP_ENDIF,
    OP_VERIFY,
    OP_RETURN,

    // stack ops
    OP_TOALTSTACK,
    OP_FROMALTSTACK,
    OP_2DROP,
    OP_2DUP,
    OP_3DUP,
    OP_2OVER,
    OP_2ROT,
    OP_2SWAP,
    OP_IFDUP,
    OP_DEPTH,
    OP_DROP,
    OP_DUP,
    OP_NIP,
    OP_OVER,
    OP_PICK,
    OP_ROLL,
    OP_ROT,
    OP_SWAP,
    OP_TUCK,

    // splice ops
    OP_CAT,
    OP_SUBSTR,
    OP_LEFT,
    OP_RIGHT,
    OP_SIZE,

    // bit logic
    OP_INVERT,
    OP_AND,
    OP_OR,
    OP_XOR,
    OP_EQUAL,
    OP_EQUALVERIFY,
    OP_RESERVED1,
    OP_RESERVED2,

    // numeric
    OP_1ADD,
    OP_1SUB,
    OP_2MUL,
    OP_2DIV,
    OP_NEGATE,
    OP_ABS,
    OP_NOT,
    OP_0NOTEQUAL,

    OP_ADD,
    OP_SUB,
    OP_MUL,
    OP_DIV,
    OP_MOD,
    OP_LSHIFT,
    OP_RSHIFT,

    OP_BOOLAND,
    OP_BOOLOR,
    OP_NUMEQUAL,
    OP_NUMEQUALVERIFY,
    OP_NUMNOTEQUAL,
    OP_LESSTHAN,
    OP_GREATERTHAN,
    OP_LESSTHANOREQUAL,
    OP_GREATERTHANOREQUAL,
    OP_MIN,
    OP_MAX,

    OP_WITHIN,

    // crypto
    OP_RIPEMD160,
    OP_SHA1,
    OP_SHA256,
    OP_HASH160,
    OP_HASH256,
    OP_CODESEPARATOR,
    OP_CHECKSIG,
    OP_CHECKSIGVERIFY,
    OP_CHECKMULTISIG,
    OP_CHECKMULTISIGVERIFY,

    // expansion
    OP_NOP1,
    OP_NOP2,
    OP_NOP3,
    OP_NOP4,
    OP_NOP5,
    OP_NOP6,
    OP_NOP7,
    OP_NOP8,
    OP_NOP9,
    OP_NOP10,



    // template matching params
    OP_SMALLINTEGER = 0xfa,
    OP_PUBKEYS = 0xfb,
    OP_PUBKEYHASH = 0xfd,
    OP_PUBKEY = 0xfe,

    OP_INVALIDOPCODE = 0xff,
};

const char* GetOpName(opcodetype opcode);



inline std::string ValueString(const std::vector<unsigned char>& vch)
{
    if (vch.size() <= 4)
        return strprintf("%d", CBigNum(vch).getint());
    else
        return HexStr(vch);
}

inline std::string StackString(const std::vector<std::vector<unsigned char> >& vStack)
{
    std::string str;
    BOOST_FOREACH(const std::vector<unsigned char>& vch, vStack)
    {
        if (!str.empty())
            str += " ";
        str += ValueString(vch);
    }
    return str;
}









class CScript : public std::vector<unsigned char>
{
protected:
    CScript& push_int64(int64 n)
    {
        if (n == -1 || (n >= 1 && n <= 16))
        {
            push_back(n + (OP_1 - 1));
        }
        else
        {
            CBigNum bn(n);
            *this << bn.getvch();
        }
        return *this;
    }

    CScript& push_uint64(uint64 n)
    {
        if (n >= 1 && n <= 16)
        {
            push_back(n + (OP_1 - 1));
        }
        else
        {
            CBigNum bn(n);
            *this << bn.getvch();
        }
        return *this;
    }

public:
    CScript() { }
    CScript(const CScript& b) : std::vector<unsigned char>(b.begin(), b.end()) { }
    CScript(const_iterator pbegin, const_iterator pend) : std::vector<unsigned char>(pbegin, pend) { }
#ifndef _MSC_VER
    CScript(const unsigned char* pbegin, const unsigned char* pend) : std::vector<unsigned char>(pbegin, pend) { }
#endif

    CScript& operator+=(const CScript& b)
    {
        insert(end(), b.begin(), b.end());
        return *this;
    }

    friend CScript operator+(const CScript& a, const CScript& b)
    {
        CScript ret = a;
        ret += b;
        return ret;
    }


    explicit CScript(char b)           { operator<<(b); }
    explicit CScript(short b)          { operator<<(b); }
    explicit CScript(int b)            { operator<<(b); }
    explicit CScript(long b)           { operator<<(b); }
    explicit CScript(int64 b)          { operator<<(b); }
    explicit CScript(unsigned char b)  { operator<<(b); }
    explicit CScript(unsigned int b)   { operator<<(b); }
    explicit CScript(unsigned short b) { operator<<(b); }
    explicit CScript(unsigned long b)  { operator<<(b); }
    explicit CScript(uint64 b)         { operator<<(b); }

    explicit CScript(opcodetype b)     { operator<<(b); }
    explicit CScript(const uint256& b) { operator<<(b); }
    explicit CScript(const CBigNum& b) { operator<<(b); }
    explicit CScript(const std::vector<unsigned char>& b) { operator<<(b); }


    CScript& operator<<(char b)           { return push_int64(b); }
    CScript& operator<<(short b)          { return push_int64(b); }
    CScript& operator<<(int b)            { return push_int64(b); }
    CScript& operator<<(long b)           { return push_int64(b); }
    CScript& operator<<(int64 b)          { return push_int64(b); }
    CScript& operator<<(unsigned char b)  { return push_uint64(b); }
    CScript& operator<<(unsigned int b)   { return push_uint64(b); }
    CScript& operator<<(unsigned short b) { return push_uint64(b); }
    CScript& operator<<(unsigned long b)  { return push_uint64(b); }
    CScript& operator<<(uint64 b)         { return push_uint64(b); }

    CScript& operator<<(opcodetype opcode)
    {
        if (opcode < 0 || opcode > 0xff)
            throw std::runtime_error("CScript::operator<<() : invalid opcode");
        insert(end(), (unsigned char)opcode);
        return *this;
    }

    CScript& operator<<(const uint160& b)
    {
        insert(end(), sizeof(b));
        insert(end(), (unsigned char*)&b, (unsigned char*)&b + sizeof(b));
        return *this;
    }

    CScript& operator<<(const uint256& b)
    {
        insert(end(), sizeof(b));
        insert(end(), (unsigned char*)&b, (unsigned char*)&b + sizeof(b));
        return *this;
    }

    CScript& operator<<(const CBigNum& b)
    {
        *this << b.getvch();
        return *this;
    }

    CScript& operator<<(const std::vector<unsigned char>& b)
    {
        if (b.size() < OP_PUSHDATA1)
        {
            insert(end(), (unsigned char)b.size());
        }
        else if (b.size() <= 0xff)
        {
            insert(end(), OP_PUSHDATA1);
            insert(end(), (unsigned char)b.size());
        }
        else if (b.size() <= 0xffff)
        {
            insert(end(), OP_PUSHDATA2);
            unsigned short nSize = b.size();
            insert(end(), (unsigned char*)&nSize, (unsigned char*)&nSize + sizeof(nSize));
        }
        else
        {
            insert(end(), OP_PUSHDATA4);
            unsigned int nSize = b.size();
            insert(end(), (unsigned char*)&nSize, (unsigned char*)&nSize + sizeof(nSize));
        }
        insert(end(), b.begin(), b.end());
        return *this;
    }

    CScript& operator<<(const CScript& b)
    {
        // I'm not sure if this should push the script or concatenate scripts.
        // If there's ever a use for pushing a script onto a script, delete this member fn
        assert(!"warning: pushing a CScript onto a CScript with << is probably not intended, use + to concatenate");
        return *this;
    }


    bool GetOp(iterator& pc, opcodetype& opcodeRet, std::vector<unsigned char>& vchRet)
    {
         // Wrapper so it can be called with either iterator or const_iterator
         const_iterator pc2 = pc;
         bool fRet = GetOp2(pc2, opcodeRet, &vchRet);
         pc = begin() + (pc2 - begin());
         return fRet;
    }

    bool GetOp(iterator& pc, opcodetype& opcodeRet)
    {
         const_iterator pc2 = pc;
         bool fRet = GetOp2(pc2, opcodeRet, NULL);
         pc = begin() + (pc2 - begin());
         return fRet;
    }

    bool GetOp(const_iterator& pc, opcodetype& opcodeRet, std::vector<unsigned char>& vchRet) const
    {
        return GetOp2(pc, opcodeRet, &vchRet);
    }

    bool GetOp(const_iterator& pc, opcodetype& opcodeRet) const
    {
        return GetOp2(pc, opcodeRet, NULL);
    }

    bool GetOp2(const_iterator& pc, opcodetype& opcodeRet, std::vector<unsigned char>* pvchRet) const
    {
        opcodeRet = OP_INVALIDOPCODE;
        if (pvchRet)
            pvchRet->clear();
        if (pc >= end())
            return false;

        // Read instruction
        if (end() - pc < 1)
            return false;
        unsigned int opcode = *pc++;

        // Immediate operand
        if (opcode <= OP_PUSHDATA4)
        {
            unsigned int nSize;
            if (opcode < OP_PUSHDATA1)
            {
                nSize = opcode;
            }
            else if (opcode == OP_PUSHDATA1)
            {
                if (end() - pc < 1)
                    return false;
                nSize = *pc++;
            }
            else if (opcode == OP_PUSHDATA2)
            {
                if (end() - pc < 2)
                    return false;
                nSize = 0;
                memcpy(&nSize, &pc[0], 2);
                pc += 2;
            }
            else if (opcode == OP_PUSHDATA4)
            {
                if (end() - pc < 4)
                    return false;
                memcpy(&nSize, &pc[0], 4);
                pc += 4;
            }
            if (end() - pc < nSize)
                return false;
            if (pvchRet)
                pvchRet->assign(pc, pc + nSize);
            pc += nSize;
        }

        opcodeRet = (opcodetype)opcode;
        return true;
    }

    // Encode/decode small integers:
    static int DecodeOP_N(opcodetype opcode)
    {
        if (opcode == OP_0)
            return 0;
        assert(opcode >= OP_1 && opcode <= OP_16);
        return (int)opcode - (int)(OP_1 - 1);
    }
    static opcodetype EncodeOP_N(int n)
    {
        assert(n >= 0 && n <= 16);
        if (n == 0)
            return OP_0;
        return (opcodetype)(OP_1+n-1);
    }

    int FindAndDelete(const CScript& b)
    {
        int nFound = 0;
        if (b.empty())
            return nFound;
        iterator pc = begin();
        opcodetype opcode;
        do
        {
            while (end() - pc >= b.size() && memcmp(&pc[0], &b[0], b.size()) == 0)
            {
                erase(pc, pc + b.size());
                ++nFound;
            }
        }
        while (GetOp(pc, opcode));
        return nFound;
    }
    int Find(opcodetype op) const
    {
        int nFound = 0;
        opcodetype opcode;
        for (const_iterator pc = begin(); pc != end() && GetOp(pc, opcode);)
            if (opcode == op)
                ++nFound;
        return nFound;
    }

    // Pre-version-0.6, Bitcoin always counted CHECKMULTISIGs
    // as 20 sigops. With pay-to-script-hash, that changed:
    // CHECKMULTISIGs serialized in scriptSigs are
    // counted more accurately, assuming they are of the form
    //  ... OP_N CHECKMULTISIG ...
    int GetSigOpCount(bool fAccurate) const;

    // Accurately count sigOps, including sigOps in
    // pay-to-script-hash transactions:
    int GetSigOpCount(const CScript& scriptSig) const;

    bool IsPayToScriptHash() const;

    // Called by CTransaction::IsStandard
    bool IsPushOnly() const
    {
        const_iterator pc = begin();
        while (pc < end())
        {
            opcodetype opcode;
            if (!GetOp(pc, opcode))
                return false;
            if (opcode > OP_16)
                return false;
        }
        return true;
    }


    void SetBitcoinAddress(const CBitcoinAddress& address);
    void SetBitcoinAddress(const std::vector<unsigned char>& vchPubKey)
    {
        SetBitcoinAddress(CBitcoinAddress(vchPubKey));
    }
    void SetMultisig(int nRequired, const std::vector<CKey>& keys);
    void SetPayToScriptHash(const CScript& subscript);


    void PrintHex() const
    {
        printf("CScript(%s)\n", HexStr(begin(), end(), true).c_str());
    }

    std::string ToString() const
    {
        std::string str;
        opcodetype opcode;
        std::vector<unsigned char> vch;
        const_iterator pc = begin();
        while (pc < end())
        {
            if (!str.empty())
                str += " ";
            if (!GetOp(pc, opcode, vch))
            {
                str += "[error]";
                return str;
            }
            if (0 <= opcode && opcode <= OP_PUSHDATA4)
                str += ValueString(vch);
            else
                str += GetOpName(opcode);
        }
        return str;
    }

    void print() const
    {
        printf("%s\n", ToString().c_str());
    }
};





bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, int nHashType);
bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<std::vector<unsigned char> >& vSolutionsRet);
int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions);
bool IsStandard(const CScript& scriptPubKey);
bool IsMine(const CKeyStore& keystore, const CScript& scriptPubKey);
bool ExtractAddress(const CScript& scriptPubKey, CBitcoinAddress& addressRet);
bool ExtractAddresses(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CBitcoinAddress>& addressRet, int& nRequiredRet);
bool SignSignature(const CKeyStore& keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL);
bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, bool fValidatePayToScriptHash, int nHashType);

#endif