/*
 * This file is part of the Flowee project
 * Copyright (C) 2018-2026 Tom Zander <tom@flowee.org>
 *
 * 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 "BlocksDB.h"
#include "UnspentOutputData.h"
#include "chain.h"

#include <primitives/Block.h>
#include <primitives/Tx.h>

UnspentOutputData UnspentOutputData::fromUtxoDB(const UnspentOutput &uo)
{
    if (!uo.isValid())
        throw std::runtime_error("invalid UnspentOutput");
    assert(uo.offsetInBlock() > 80);

    Blocks::DB *blockDb = Blocks::DB::instance();
    auto blockIndex = blockDb->headerChain()[uo.blockHeight()];
    if (blockIndex == nullptr)
        throw std::runtime_error("Invalid blockheight");

    auto block = blockDb->loadBlock(blockIndex->GetBlockPos());
    if (!block.isFullBlock())
        throw std::runtime_error("Missing block");
    assert(block.size() > uo.offsetInBlock());

    Tx::Iterator iter(block, uo.offsetInBlock());
    iter.next();
    assert(iter.tag() == Tx::TxVersion);
    auto prevTxVersion = iter.intData();
    auto answer = UnspentOutputData(iter.nextOutput(uo.outIndex()));
    answer.blockHeight = uo.blockHeight();
    answer.isCoinbase = uo.offsetInBlock() < 100;
    answer.prevTxVersion = prevTxVersion;
    return answer;
}