// Copyright (c) 2009-2017 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <core_io.h>

#include <primitives/block.h>
#include <primitives/transaction.h>
#include <script/script.h>
#include <serialize.h>
#include <streams.h>
#include <univalue.h>
#include <util.h>
#include <utilstrencodings.h>
#include <version.h>

#include <boost/algorithm/string/classification.hpp>
#include <boost/algorithm/string/predicate.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <boost/algorithm/string/split.hpp>

CScript ParseScript(const std::string& s)
{
    CScript result;

    static std::map<std::string, opcodetype> mapOpNames;

    if (mapOpNames.empty())
    {
        for (unsigned int op = 0; op <= MAX_OPCODE; op++)
        {
            // Allow OP_RESERVED to get into mapOpNames
            if (op < OP_NOP && op != OP_RESERVED)
                continue;

            const char* name = GetOpName((opcodetype)op);
            if (strcmp(name, "OP_UNKNOWN") == 0)
                continue;
            std::string strName(name);
            mapOpNames[strName] = (opcodetype)op;
            // Convenience: OP_ADD and just ADD are both recognized:
            boost::algorithm::replace_first(strName, "OP_", "");
            mapOpNames[strName] = (opcodetype)op;
        }
    }

    std::vector<std::string> words;
    boost::algorithm::split(words, s, boost::algorithm::is_any_of(" \t\n"), boost::algorithm::token_compress_on);

    for (std::vector<std::string>::const_iterator w = words.begin(); w != words.end(); ++w)
    {
        if (w->empty())
        {
            // Empty string, ignore. (boost::split given '' will return one word)
        }
        else if (all(*w, boost::algorithm::is_digit()) ||
            (boost::algorithm::starts_with(*w, "-") && all(std::string(w->begin()+1, w->end()), boost::algorithm::is_digit())))
        {
            // Number
            int64_t n = atoi64(*w);
            result << n;
        }
        else if (boost::algorithm::starts_with(*w, "0x") && (w->begin()+2 != w->end()) && IsHex(std::string(w->begin()+2, w->end())))
        {
            // Raw hex data, inserted NOT pushed onto stack:
            std::vector<unsigned char> raw = ParseHex(std::string(w->begin()+2, w->end()));
            result.insert(result.end(), raw.begin(), raw.end());
        }
        else if (w->size() >= 2 && boost::algorithm::starts_with(*w, "'") && boost::algorithm::ends_with(*w, "'"))
        {
            // Single-quoted string, pushed as data. NOTE: this is poor-man's
            // parsing, spaces/tabs/newlines in single-quoted strings won't work.
            std::vector<unsigned char> value(w->begin()+1, w->end()-1);
            result << value;
        }
        else if (mapOpNames.count(*w))
        {
            // opcode, e.g. OP_ADD or ADD:
            result << mapOpNames[*w];
        }
        else
        {
            throw std::runtime_error("script parse error");
        }
    }

    return result;
}

// Check that all of the input and output scripts of a transaction contains valid opcodes
bool CheckTxScriptsSanity(const CMutableTransaction& tx)
{
    // Check input scripts for non-coinbase txs
    if (!CTransaction(tx).IsCoinBase()) {
        for (unsigned int i = 0; i < tx.vin.size(); i++) {
            if (!tx.vin[i].scriptSig.HasValidOps() || tx.vin[i].scriptSig.size() > MAX_SCRIPT_SIZE) {
                return false;
            }
        }
    }
    // Check output scripts
    for (unsigned int i = 0; i < tx.vout.size(); i++) {
        if (!tx.vout[i].scriptPubKey.HasValidOps() || tx.vout[i].scriptPubKey.size() > MAX_SCRIPT_SIZE) {
            return false;
        }
    }
    
    return true;
}

bool DecodeHexTx(CMutableTransaction& tx, const std::string& hex_tx, bool try_no_witness, bool try_witness)
{
    if (!IsHex(hex_tx)) {
        return false;
    }

    std::vector<unsigned char> txData(ParseHex(hex_tx));

    if (try_no_witness) {
        CDataStream ssData(txData, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS);
        try {
            ssData >> tx;
            if (ssData.eof() && (!try_witness || CheckTxScriptsSanity(tx))) {
                return true;
            }
        } catch (const std::exception&) {
            // Fall through.
        }
    }

    if (try_witness) {
        CDataStream ssData(txData, SER_NETWORK, PROTOCOL_VERSION);
        try {
            ssData >> tx;
            if (ssData.empty()) {
                return true;
            }
        } catch (const std::exception&) {
            // Fall through.
        }
    }
    
    return false;
}

bool DecodeHexBlk(CBlock& block, const std::string& strHexBlk)
{
    if (!IsHex(strHexBlk))
        return false;

    std::vector<unsigned char> blockData(ParseHex(strHexBlk));
    CDataStream ssBlock(blockData, SER_NETWORK, PROTOCOL_VERSION);
    try {
        ssBlock >> block;
    }
    catch (const std::exception&) {
        return false;
    }

    return true;
}

uint256 ParseHashUV(const UniValue& v, const std::string& strName)
{
    std::string strHex;
    if (v.isStr())
        strHex = v.getValStr();
    return ParseHashStr(strHex, strName);  // Note: ParseHashStr("") throws a runtime_error
}

uint256 ParseHashStr(const std::string& strHex, const std::string& strName)
{
    if (!IsHex(strHex)) // Note: IsHex("") is false
        throw std::runtime_error(strName + " must be hexadecimal string (not '" + strHex + "')");

    uint256 result;
    result.SetHex(strHex);
    return result;
}

std::vector<unsigned char> ParseHexUV(const UniValue& v, const std::string& strName)
{
    std::string strHex;
    if (v.isStr())
        strHex = v.getValStr();
    if (!IsHex(strHex))
        throw std::runtime_error(strName + " must be hexadecimal string (not '" + strHex + "')");
    return ParseHex(strHex);
}
