/*
 * This file is part of the Flowee project
 * Copyright (C) 2018-2020 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 "test_utxo.h"

#include <WorkerThreads.h>
#include <util.h>
#include <utiltime.h>

#include <utxo/UnspentOutputDatabase_p.h>
#include <utxo/UTXOInteralError.h>
#include <fstream>

void TestUtxo::init()
{
    m_testPath = boost::filesystem::temp_directory_path() / strprintf("test_flowee_%lu", (unsigned long)GetTime());
    boost::filesystem::remove_all(m_testPath);
}

void TestUtxo::cleanup()
{
    boost::filesystem::remove_all(m_testPath);
}

void TestUtxo::insertTransactions(UnspentOutputDatabase &db, int number)
{
    for (int i = 0; i < number; ++i) {
        char buf[67];
        sprintf(buf, templateTxId, i);
        uint256 txid = uint256S(buf);
        db.insert(txid, 0, 100+i, 6000+i);
        db.insert(txid, 1, 100+i, 6000+i);

        UnspentOutput uo = db.find(txid, 0);
        QCOMPARE(uo.offsetInBlock(), 6000 + i);
        QCOMPARE(uo.blockHeight(), 100 + i);
    }
}

uint256 TestUtxo::insertedTxId(int index)
{
    char buf[67];
    sprintf(buf, templateTxId, index);
    return uint256S(buf);
}


void TestUtxo::basic()
{
    boost::asio::io_context ioContext;
    UnspentOutputDatabase db(ioContext, m_testPath);
    uint256 txid = uint256S("0xb4749f017444b051c44dfd2720e88f314ff94f3dd6d56d40ef65854fcd7fff6b");
    db.insert(txid, 0, 100, 6000);
    UnspentOutput uo = db.find(txid, 0);
    QCOMPARE(uo.offsetInBlock(), 6000);
    QCOMPARE(uo.blockHeight(), 100);
    QVERIFY(((uo.rmHint() >> 32) & 0xFFFFF) > 0);

    SpentOutput rmData = db.remove(txid, 0, uo.rmHint());
    QVERIFY(rmData.isValid());
    QCOMPARE(rmData.blockHeight, 100);
    QCOMPARE(rmData.offsetInBlock, 6000);

    UnspentOutput uo2 = db.find(txid, 0);
    QCOMPARE(uo2.blockHeight(), 0);

    rmData = db.remove(txid, 0);
    QCOMPARE(rmData.isValid(), false);
    QVERIFY(rmData.blockHeight <= 0);
}

// test if we can keep multiple entries separate
void TestUtxo::multiple()
{
    boost::asio::io_context ioContext;
    UnspentOutputDatabase db(ioContext, m_testPath);

    insertTransactions(db, 100);
    const uint256 remove1 = insertedTxId(20);
    const uint256 remove2 = insertedTxId(89);
    SpentOutput rmData = db.remove(remove1, 0);
    QVERIFY(rmData.isValid());
    QCOMPARE(rmData.blockHeight, 120);
    QCOMPARE(rmData.offsetInBlock, 6020);

    UnspentOutput find1 = db.find(remove1, 0);
    QCOMPARE(find1.blockHeight(), 0); // we just removed it
    UnspentOutput find2 = db.find(remove1, 1);
    QCOMPARE(find2.blockHeight(), 120); // this should not be removed

    UnspentOutput find3 = db.find(remove2, 0);
    QCOMPARE(find3.blockHeight(), 189);
    UnspentOutput find4 = db.find(remove2, 1);
    QCOMPARE(find4.blockHeight(), 189); // its here now

    rmData = db.remove(remove2, 1);
    QVERIFY(rmData.isValid());
    QCOMPARE(rmData.blockHeight, 189);
    QCOMPARE(rmData.offsetInBlock, 6089);

    UnspentOutput find5 = db.find(remove2, 0);
    QCOMPARE(find5.blockHeight(), 189);
    UnspentOutput find6 = db.find(remove2, 1);
    QCOMPARE(find6.blockHeight(), 0); // poof.
}

// test if we can keep entries between restarts
void TestUtxo::restart()
{
    WorkerThreads workers;
    { // scope for DB
        UnspentOutputDatabase db(workers.ioContext(), m_testPath);
        insertTransactions(db, 50);
        db.blockFinished(1, uint256()); // commmit
    }

    logDebug() << "Step 2";
    { // scope for DB
        UnspentOutputDatabase db(workers.ioContext(), m_testPath);

        for (int i = 0; i < 50; ++i) {
            // logDebug() << "select" << i;
            uint256 txid = insertedTxId(i);
            UnspentOutput uo = db.find(txid, 0);
            QCOMPARE(uo.blockHeight(), 100 + i);
            QCOMPARE(uo.offsetInBlock(), 6000 + i);

            UnspentOutput uo2 = db.find(txid, 1);
            QCOMPARE(uo2.blockHeight(), 100 + i);
            QCOMPARE(uo2.offsetInBlock(), 6000 + i);
        }
    }
}

void TestUtxo::commit()
{
    /*
     * delete is by far the most complex usecase.
     * I should test;
     *   1) delete a leaf from an on-disk bucket that only contains the one item
     *   2) delete a leaf from an on-disk bucket where there are more leafs
     *   3) delete a leaf from an in-memory bucket where there are more leafs
     *   4) delete a leaf from an in-memory bucket where its the last leaf
     *
     * Also I should create a new leaf
     *   5) in an existing bucket
     *   6) in a new bucket
     */
    boost::asio::io_context ioContext;
    uint256 txid;
    {   // usecase 3
        UnspentOutputDatabase db(ioContext, m_testPath);
        insertTransactions(db, 100);
        db.blockFinished(1, uint256()); // this is a 'commit'

        txid = insertedTxId(99);
        SpentOutput rmData = db.remove(txid, 0);
        QVERIFY(rmData.isValid());
    }

    {   // usecase 2
        UnspentOutputDatabase db(ioContext, m_testPath);
        // after a restart, the not committed tx is again there.
        SpentOutput rmData = db.remove(txid, 0);
        QVERIFY(rmData.isValid());
    }

    {   // usecase 2 && 2
        UnspentOutputDatabase db(ioContext, m_testPath);
        // after a restart, the not committed tx is again there.
        SpentOutput rmData = db.remove(txid, 0);
        QVERIFY(rmData.isValid());

        db.rollback();
        rmData = db.remove(txid, 0); // it reappeared
        QVERIFY(rmData.isValid());

        db.blockFinished(2, uint256()); // commit

        rmData = db.remove(txid, 0);
        QVERIFY(!rmData.isValid());
    }

    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        // the commit made the removed tx actually go away.
        SpentOutput rmData = db.remove(txid, 0);
        QVERIFY(!rmData.isValid());
    }

    // because the helper method insertTransactions generates transactions
    // that all land in the same bucket I need to create a new one to test buckets with only one tx.
    const char *txid2 = "0x1a3454117444b051c44dfd2720e88f314ff94f3dd6d56d40ef65854fcd7fff6b";

    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        db.insert(uint256S(txid2), 0, 200, 2000);
        SpentOutput rmData = db.remove(uint256S(txid2), 0);
        QVERIFY(rmData.isValid()); // delete should be Ok
    }

    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        // test usecase 5
        SpentOutput rmData = db.remove(uint256S(txid2), 0);
        QVERIFY(!rmData.isValid()); // it was never committed

        // test usecase 1
        db.insert(uint256S(txid2), 0, 200, 2000);
        db.blockFinished(3, uint256());
    }
    {
        // continue to test usecase 1
        UnspentOutputDatabase db(ioContext, m_testPath);
        SpentOutput rmData = db.remove(uint256S(txid2), 0);
        QVERIFY(rmData.isValid());
    }
    {
        // continue to test usecase 1
        UnspentOutputDatabase db(ioContext, m_testPath);
        SpentOutput rmData = db.remove(uint256S(txid2), 0);
        QVERIFY(rmData.isValid()); // it came back!
    }

    const char *txid3 = "0x4a3454117444b051c44dfd2720e88f314ff94f3dd6d56d40ef65854fcd7fff6b";
    // usecase 6
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        db.insert(txid3, 2, 300, 1000);
    }
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        UnspentOutput uo = db.find(uint256S(txid3), 2);
        QVERIFY(!uo.isValid()); // it was never committed
    }

    // test usecase 5
    char buf[67];
    sprintf(buf, templateTxId, 200);
    uint256 txid4 = uint256S(buf);
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        db.insert(txid4, 5, 40, 81);
    }
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        QVERIFY(!db.find(txid4, 5).isValid());
    }
    // now separate the saving of the bucket and the leafs.
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        db.insert(txid4, 6, 40, 81);
        db.blockFinished(4, uint256());
        db.insert(txid4, 7, 40, 81);
    }
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        QVERIFY(!db.find(txid4, 5).isValid());
        QVERIFY(db.find(txid4, 6).isValid());
        QVERIFY(!db.find(txid4, 7).isValid());
    }

    // new usecase; deleting from an in-memory bucket.
    // A bucket was saved to disk, retrieved and stored in memory because I inserted
    // a new item and then I remove an old item.
    // We need to make sure that the on-disk bucket is the one we get after rollback()
    sprintf(buf, templateTxId, 127);
    uint256 txid5 = uint256S(buf);
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        db.insert(txid5, 10, 40, 90);
        db.insert(txid5, 11, 40, 90);
        db.insert(txid5, 13, 40, 90);
        db.blockFinished(5, uint256());
    }
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        db.insert(txid5, 20, 40, 81); // loads from disk, adds item
        // rollback now should revert to the on-disk version.
    }
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        QVERIFY(db.find(txid4, 6).isValid());
        QVERIFY(!db.find(txid5, 20).isValid());
        QVERIFY(db.find(txid5, 10).isValid());
        QVERIFY(db.find(txid5, 11).isValid());
        QVERIFY(db.find(txid5, 13).isValid());
    }
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        db.insert(txid5, 20, 40, 81); // loads from disk, adds item
        SpentOutput rmData = db.remove(txid5, 11); // removes from mem-bucket
        QVERIFY(rmData.isValid());
        // rollback now should revert to the on-disk version.
    }
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        QVERIFY(db.find(txid4, 6).isValid());
        QVERIFY(!db.find(txid5, 20).isValid());
        QVERIFY(db.find(txid5, 10).isValid());
        QVERIFY(db.find(txid5, 11).isValid());
        QVERIFY(db.find(txid5, 13).isValid());
    }
}

void TestUtxo::saveInfo()
{
    boost::asio::io_context ioContext;
    {
        UnspentOutputDatabase db(ioContext, m_testPath);
        db.blockFinished(10, uint256());
    }
    QFileInfo info(QString::fromStdString((m_testPath / "data-1.2.info").string()));
    QVERIFY(info.exists());
    UnspentOutputDatabase db(ioContext, m_testPath);
    QCOMPARE(db.blockheight(), 10);
}

void TestUtxo::cowList()
{
    DataFileList list;
    auto x = DataFile::createDatafile((m_testPath / "testdb").string(), 1, uint256());
    list.append(x);
    QVERIFY(x == list[0]);
    QVERIFY(x == list.at(0));

    auto copy(list);
    QVERIFY(x == copy[0]);
    QVERIFY(x == copy.at(0));

    copy[0] = nullptr;
    QVERIFY(x == list[0]);
    QVERIFY(x == list.at(0));
    QVERIFY(nullptr == copy[0]);
    QVERIFY(nullptr == copy.at(0));

    delete x;
}

void TestUtxo::restore_data()
{
    QTest::addColumn<int>("cycles");
    QTest::addColumn<int>("dbFiles");
    QTest::addColumn<QStringList>("filesToDelete");
    QTest::addColumn<int>("result");

    // delete some files in the beginning of the sequence, which should have zero effect.
    QStringList files;
    files << "data-4.2.info" << "data-3.2.info";
    QTest::newRow("lostFirst")
            << 3 << 4 << files << 3;

    // delete an info file at the end, causing us to go back one block.
    files = QStringList() << "data-2.4.info";
    QTest::newRow("lostFirst")
            << 3 << 4 << files  << 2;


    // numbering in the .info files, as defined in the cpp file of the UTXO
    constexpr int MAX_INFO_NUM = 20;
    files = QStringList() << "data-1.1.info";
    QTest::newRow("goingRound")
            << MAX_INFO_NUM << 1 << files  << 20;
}

void TestUtxo::restore()
{
    QFETCH(int, cycles);
    QFETCH(int, dbFiles);
    QFETCH(QStringList, filesToDelete);
    QFETCH(int, result);

    boost::asio::io_context ioContext;
    for (int cycle = 0; cycle < cycles; ++cycle) {
        UnspentOutputDatabase db(ioContext, m_testPath);
        logDebug() << cycle << db.blockheight();
        UODBPrivate *d = db.priv();
        QVERIFY(d->dataFiles.last());
        while (d->dataFiles.size() < dbFiles) {
            d->dataFiles.last()->m_fileFull = 1;
            insertTransactions(db, 1);
        }
        db.blockFinished(db.blockheight() + 1, uint256());
    }

    QString testPath = QString::fromStdString(m_testPath.string()) + "/";
    logDebug() << testPath;
    QVERIFY(testPath.endsWith("/"));
    for (auto filename : filesToDelete) {
        bool ok = QFile::remove(testPath + filename);
        if (!ok)
            logCritical() << "Failed to delete" << filename;
        QVERIFY(ok);
    }

    UnspentOutputDatabase db(ioContext, m_testPath);
    logDebug() << db.blockheight();
    QCOMPARE(db.blockheight(), result);
}

static void createDBInfo(boost::filesystem::path db, int from, int to) {
    DataFileCache cache(db);
    DataFile df(from, to);
    df.m_writeBuffer = std::make_shared<Streaming::BufferPool>();
    cache.writeInfoFile(&df);

    db.concat(".db");
    std::ofstream file(db.string());
    file.close();
    boost::filesystem::resize_file(db, 100);
}

void TestUtxo::rollback()
{
    // create a bunch of info files and try to follback to different states.
    boost::filesystem::create_directories(m_testPath);

    // create checkpoints!
    createDBInfo(m_testPath / "data-1", 0, 500);
    createDBInfo(m_testPath / "data-1", 0, 702);
    createDBInfo(m_testPath / "data-1", 0, 900);
    createDBInfo(m_testPath / "data-2", 200, 250);
    createDBInfo(m_testPath / "data-2", 200, 400);
    createDBInfo(m_testPath / "data-2", 200, 702);
    createDBInfo(m_testPath / "data-3", 300, 400);
    createDBInfo(m_testPath / "data-3", 300, 702);
    createDBInfo(m_testPath / "data-3", 300, 900);
    // There is only 1 valid checkpoint in this miserable setup: 702

    boost::asio::io_context dummy;
    UODBPrivate p1(dummy, m_testPath);
    p1.memOnly = true;
    QCOMPARE(p1.dataFiles.size(), 3);
    DataFile *db = p1.dataFiles.at(0);
    QCOMPARE(db->m_initialBlockHeight, 0);
    QCOMPARE(db->m_lastBlockHeight, 702);
    db = p1.dataFiles.at(1);
    QCOMPARE(db->m_initialBlockHeight, 200);
    QCOMPARE(db->m_lastBlockHeight, 702);
    db = p1.dataFiles.at(2);
    QCOMPARE(db->m_initialBlockHeight, 300);
    QCOMPARE(db->m_lastBlockHeight, 702);

    try {
        UODBPrivate p2(dummy, m_testPath, 702);
        QFAIL("Should have thrown");
    } catch (const UTXOInternalError &e) {
        logDebug() << "Successfully failed" << e;
    }
}

void TestUtxo::readLeafWithTrailingBytes()
{
    auto pool = std::make_shared<Streaming::BufferPool>();
    const uint256 txid = uint256S("0xb4749f017444b051c44dfd2720e88f314ff94f3dd6d56d40ef65854fcd7fff6b");
    const int outIndex = 3;
    const int blockHeight = 1234;
    const int offsetInBlock = 5678;

    UnspentOutput leaf(pool, txid, outIndex, blockHeight, offsetInBlock);
    std::string storage = leaf.data().toString();
    storage.push_back('\x07'); // Invalid message type after the leaf record.

    const auto mappedFileSlice = Streaming::ConstBuffer::create(storage.data(), storage.size());
    UnspentOutput parsed(txid.GetCheapHash(), mappedFileSlice);

    QCOMPARE(parsed.prevTxId(), txid);
    QCOMPARE(parsed.outIndex(), outIndex);
    QCOMPARE(parsed.blockHeight(), blockHeight);
    QCOMPARE(parsed.offsetInBlock(), offsetInBlock);
}

QTEST_MAIN(TestUtxo)