/*
 * This file is part of the Flowee project
 * Copyright (C) 2009-2010 Satoshi Nakamoto
 * Copyright (C) 2009-2015 The Bitcoin Core developers
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "script/standard.h"

#include <SettingsDefaults.h>
#include <hash.h>
#include <primitives/PublicKey.h>
#include "primitives/script.h"
#include "util.h"
#include "utilstrencodings.h"

#include <boost/foreach.hpp>

typedef std::vector<unsigned char> valtype;

bool fAcceptDatacarrier = Settings::DefaultAcceptDataCarrier;
int nMaxDatacarrierBytes = Settings::MaxOpReturnRelay;

bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
{
    std::vector<valtype> vSolutions;
    Script::TxnOutType whichType;
    if (!Script::solver(scriptPubKey, whichType, vSolutions))
        return false;

    if (whichType == Script::TX_PUBKEY) {
        PublicKey pubKey(vSolutions[0]);
        if (!pubKey.isValid())
            return false;

        addressRet = pubKey.getKeyId();
        return true;
    }
    else if (whichType == Script::TX_PUBKEYHASH) {
        addressRet = KeyId(uint160(vSolutions[0]));
        return true;
    }
    else if (whichType == Script::TX_SCRIPTHASH) {
        addressRet = CScriptID(uint160(vSolutions[0]));
        return true;
    }
    // Multisig txns have more than one address...
    return false;
}

bool ExtractDestinations(const CScript& scriptPubKey, Script::TxnOutType& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet)
{
    addressRet.clear();
    typeRet = Script::TX_NONSTANDARD;
    std::vector<valtype> vSolutions;
    if (!Script::solver(scriptPubKey, typeRet, vSolutions))
        return false;
    if (typeRet == Script::TX_NULL_DATA) {
        // This is data, not addresses
        return false;
    }

    if (typeRet == Script::TX_MULTISIG)
    {
        nRequiredRet = vSolutions.front()[0];
        for (unsigned int i = 1; i < vSolutions.size()-1; i++)
        {
            PublicKey pubKey(vSolutions[i]);
            if (!pubKey.isValid())
                continue;

            CTxDestination address = pubKey.getKeyId();
            addressRet.push_back(address);
        }

        if (addressRet.empty())
            return false;
    }
    else
    {
        nRequiredRet = 1;
        CTxDestination address;
        if (!ExtractDestination(scriptPubKey, address))
           return false;
        addressRet.push_back(address);
    }

    return true;
}

namespace
{
class CScriptVisitor : public boost::static_visitor<bool>
{
private:
    CScript *script;
public:
    CScriptVisitor(CScript *scriptin) { script = scriptin; }

    bool operator()(const CNoDestination &dest) const {
        script->clear();
        return false;
    }

    bool operator()(const KeyId &keyID) const {
        script->clear();
        *script << OP_DUP << OP_HASH160 << ToByteVector(keyID) << OP_EQUALVERIFY << OP_CHECKSIG;
        return true;
    }

    bool operator()(const CScriptID &scriptID) const {
        script->clear();
        *script << OP_HASH160 << ToByteVector(scriptID) << OP_EQUAL;
        return true;
    }
};
}

CScript GetScriptForDestination(const CTxDestination& dest)
{
    CScript script;

    boost::apply_visitor(CScriptVisitor(&script), dest);
    return script;
}

CScript GetScriptForRawPubKey(const PublicKey& pubKey)
{
    return CScript() << std::vector<unsigned char>(pubKey.begin(), pubKey.end()) << OP_CHECKSIG;
}

CScript GetScriptForMultisig(int nRequired, const std::vector<PublicKey>& keys)
{
    CScript script;

    script << CScript::EncodeOP_N(nRequired);
    BOOST_FOREACH(const PublicKey& key, keys)
        script << ToByteVector(key);
    script << CScript::EncodeOP_N(keys.size()) << OP_CHECKMULTISIG;
    return script;
}