// Copyright (c) 2010 Satoshi Nakamoto
// Copyright (c) 2009-2021 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 <rpc/rawtransaction_util.h>

#include <coins.h>
#include <consensus/amount.h>
#include <core_io.h>
#include <interfaces/chain.h>
#include <key_io.h>
#include <policy/policy.h>
#include <primitives/transaction.h>
#include <rpc/request.h>
#include <rpc/util.h>
#include <script/signingprovider.h>
#include <univalue.h>
#include <util/strencodings.h>
#include <validation.h>
#include <txmempool.h>
#include <util/translation.h>

CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime)
{
    if (outputs_in.isNull()) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, output argument must be non-null");
    }

    UniValue inputs;
    if (inputs_in.isNull()) {
        inputs = UniValue::VARR;
    } else {
        inputs = inputs_in.get_array();
    }

    const bool outputs_is_obj = outputs_in.isObject();
    UniValue outputs = outputs_is_obj ? outputs_in.get_obj() : outputs_in.get_array();

    CMutableTransaction rawTx;
    if (!locktime.isNull()) {
        int64_t nLockTime = locktime.getInt<int64_t>();
        if (nLockTime < 0 || nLockTime > LOCKTIME_MAX)
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, locktime out of range");
        rawTx.nLockTime = nLockTime;
    }

    for (unsigned int idx = 0; idx < inputs.size(); idx++) {
        const UniValue& input = inputs[idx];
        const UniValue& o = input.get_obj();

        uint256 txid = ParseHashO(o, "txid");

        const UniValue& vout_v = o.find_value("vout");
        if (!vout_v.isNum())
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, missing vout key");
        int nOutput = vout_v.getInt<int>();
        if (nOutput < 0)
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout cannot be negative");

        uint32_t nSequence;
        if (rawTx.nLockTime) {
            nSequence = CTxIn::MAX_SEQUENCE_NONFINAL; /* CTxIn::SEQUENCE_FINAL - 1 */
        } else {
            nSequence = CTxIn::SEQUENCE_FINAL;
        }

        // set the sequence number if passed in the parameters object
        const UniValue& sequenceObj = o.find_value("sequence");
        if (sequenceObj.isNum()) {
            int64_t seqNr64 = sequenceObj.getInt<int64_t>();
            if (seqNr64 < 0 || seqNr64 > CTxIn::SEQUENCE_FINAL)
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, sequence number is out of range");
            else
                nSequence = (uint32_t)seqNr64;
        }

        CTxIn in(COutPoint(txid, nOutput), CScript(), nSequence);

        rawTx.vin.push_back(in);
    }

    if (!outputs_is_obj) {
        // Translate array of key-value pairs into dict
        UniValue outputs_dict = UniValue(UniValue::VOBJ);
        for (size_t i = 0; i < outputs.size(); ++i) {
            const UniValue& output = outputs[i];
            if (!output.isObject()) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, key-value pair not an object as expected");
            }
            if (output.size() != 1) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, key-value pair must contain exactly one key");
            }
            outputs_dict.pushKVs(output);
        }
        outputs = std::move(outputs_dict);
    }

    // Duplicate checking
    std::set<CTxDestination> destinations;
    bool has_data{false};

    for (const std::string& name_ : outputs.getKeys()) {
        if (name_ == "data") {
            if (has_data) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, duplicate key: data");
            }
            has_data = true;
            std::vector<unsigned char> data = ParseHexV(outputs[name_].getValStr(), "Data");

            CTxOut out(0, CScript() << OP_RETURN << data);
            rawTx.vout.push_back(out);
        } else {
            CTxDestination destination = DecodeDestination(name_);
            if (!IsValidDestination(destination)) {
                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, std::string("Invalid Cosanta address: ") + name_);
            }

            if (!destinations.insert(destination).second) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated address: ") + name_);
            }

            CScript scriptPubKey = GetScriptForDestination(destination);
            CAmount nAmount = AmountFromValue(outputs[name_]);

            CTxOut out(nAmount, scriptPubKey);
            rawTx.vout.push_back(out);
        }
    }

    return rawTx;
}

/** Pushes a JSON object for script verification or signing errors to vErrorsRet. */
static void TxInErrorToJSON(const CTxIn& txin, UniValue& vErrorsRet, const std::string& strMessage)
{
    UniValue entry(UniValue::VOBJ);
    entry.pushKV("txid", txin.prevout.hash.ToString());
    entry.pushKV("vout", (uint64_t)txin.prevout.n);
    entry.pushKV("scriptSig", HexStr(txin.scriptSig));
    entry.pushKV("sequence", (uint64_t)txin.nSequence);
    entry.pushKV("error", strMessage);
    vErrorsRet.push_back(entry);
}

void ParsePrevouts(const UniValue& prevTxsUnival, FillableSigningProvider* keystore, std::map<COutPoint, Coin>& coins)
{
    if (!prevTxsUnival.isNull()) {
        const UniValue& prevTxs = prevTxsUnival.get_array();
        for (unsigned int idx = 0; idx < prevTxs.size(); ++idx) {
            const UniValue& p = prevTxs[idx];
            if (!p.isObject()) {
                throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "expected object with {\"txid'\",\"vout\",\"scriptPubKey\"}");
            }

            const UniValue& prevOut = p.get_obj();

            RPCTypeCheckObj(prevOut,
                {
                    {"txid", UniValueType(UniValue::VSTR)},
                    {"vout", UniValueType(UniValue::VNUM)},
                    {"scriptPubKey", UniValueType(UniValue::VSTR)},
                });

            uint256 txid = ParseHashO(prevOut, "txid");

            int nOut = prevOut.find_value("vout").getInt<int>();
            if (nOut < 0) {
                throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "vout cannot be negative");
            }

            COutPoint out(txid, nOut);
            std::vector<unsigned char> pkData(ParseHexO(prevOut, "scriptPubKey"));
            CScript scriptPubKey(pkData.begin(), pkData.end());

            {
                auto coin = coins.find(out);
                if (coin != coins.end() && !coin->second.IsSpent() && coin->second.out.scriptPubKey != scriptPubKey) {
                    std::string err("Previous output scriptPubKey mismatch:\n");
                    err = err + ScriptToAsmStr(coin->second.out.scriptPubKey) + "\nvs:\n"+
                        ScriptToAsmStr(scriptPubKey);
                    throw JSONRPCError(RPC_DESERIALIZATION_ERROR, err);
                }
                Coin newcoin;
                newcoin.out.scriptPubKey = scriptPubKey;
                newcoin.out.nValue = 0;
                if (prevOut.exists("amount")) {
                    newcoin.out.nValue = AmountFromValue(prevOut.find_value("amount"));
                }
                newcoin.nHeight = 1;
                coins[out] = std::move(newcoin);
            }

            // if redeemScript and private keys were given, add redeemScript to the keystore so it can be signed
            const bool is_p2sh = scriptPubKey.IsPayToScriptHash();
            if (keystore && is_p2sh) {
                RPCTypeCheckObj(prevOut,
                {
                    {"redeemScript", UniValueType(UniValue::VSTR)},
                });
                const UniValue& rs{prevOut.find_value("redeemScript")};
                if (rs.isNull()) {
                    throw JSONRPCError(RPC_INVALID_PARAMETER, "Missing redeemScript");
                }

                std::vector<unsigned char> scriptData(ParseHexV(rs, "redeemScript"));
                CScript script(scriptData.begin(), scriptData.end());
                keystore->AddCScript(script);

                if (is_p2sh) {
                    const CTxDestination p2sh{ScriptHash(script)};
                    if (scriptPubKey == GetScriptForDestination(p2sh)) {
                        // traditional p2sh; arguably an error if
                        // we got here with rs.IsNull(), because
                        // that means the p2sh script was specified
                        // via witnessScript param, but for now
                        // we'll just quietly accept it
                    } else {
                        // otherwise, can't generate scriptPubKey from
                        // either script, so we got unusable parameters
                        throw JSONRPCError(RPC_INVALID_PARAMETER, "redeemScript does not match scriptPubKey");
                    }
                }
                if (rs.isNull()) {
                    throw JSONRPCError(RPC_INVALID_PARAMETER, "Missing redeemScript");
                }
            }
        }
    }
}

void SignTransaction(CMutableTransaction& mtx, const SigningProvider* keystore, const std::map<COutPoint, Coin>& coins, const UniValue& hashType, UniValue& result)
{
    int nHashType = ParseSighashString(hashType);

    // Script verification errors
    std::map<int, bilingual_str> input_errors;

    bool complete = SignTransaction(mtx, keystore, coins, nHashType, input_errors);
    SignTransactionResultToJSON(mtx, complete, coins, input_errors, result);
}

void SignTransactionResultToJSON(CMutableTransaction& mtx, bool complete, const std::map<COutPoint, Coin>& coins, const std::map<int, bilingual_str>& input_errors, UniValue& result)
{
    // Make errors UniValue
    UniValue vErrors(UniValue::VARR);
    for (const auto& err_pair : input_errors) {
        if (err_pair.second.original == "Missing amount") {
            // This particular error needs to be an exception for some reason
            throw JSONRPCError(RPC_TYPE_ERROR, strprintf("Missing amount for %s", coins.at(mtx.vin.at(err_pair.first).prevout).out.ToString()));
        }
        TxInErrorToJSON(mtx.vin.at(err_pair.first), vErrors, err_pair.second.original);
    }

    result.pushKV("hex", EncodeHexTx(CTransaction(mtx)));
    result.pushKV("complete", complete);
    if (!vErrors.empty()) {
        if (result.exists("errors")) {
            vErrors.push_backV(result["errors"].getValues());
        }
        result.pushKV("errors", vErrors);
    }
}
