// Copyright (c) 2019, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//    used to endorse or promote products derived from this software without specific
//    prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include <lmdb.h>

#include <array>

#include "blockchain_db/blockchain_db.h"
#include "blockchain_db/lmdb/db_lmdb.h"
#include "blockchain_objects.h"
#include "common/command_line.h"
#include "common/fs.h"
#include "common/pruning.h"
#include "common/string_util.h"
#include "cryptonote_core/blockchain.h"
#include "cryptonote_core/cryptonote_core.h"
#include "version.h"

#define MDB_val_set(var, val) MDB_val var = {sizeof(val), (void*)&val}

namespace po = boost::program_options;
using namespace cryptonote;

static auto logcat = log::Cat("bcutil");

static fs::path db_path;

// default to fast:1
static uint64_t records_per_sync = 128;
static const size_t slack = 512 * 1024 * 1024;

static std::error_code replace_file(
        const fs::path& replacement_name, const fs::path& replaced_name) {
    std::error_code ec = fs::rename(replacement_name, replaced_name);
    if (ec)
        log::error(
                logcat,
                "Error renaming {} to {}: {}",
                replacement_name,
                replaced_name,
                ec.message());
    return ec;
}

static void open(MDB_env*& env, const fs::path& path, uint64_t db_flags, bool readonly) {
    int dbr;
    int flags = 0;

    if (db_flags & DBF_FAST)
        flags |= MDB_NOSYNC;
    if (db_flags & DBF_FASTEST)
        flags |= MDB_NOSYNC | MDB_WRITEMAP | MDB_MAPASYNC;
    if (readonly)
        flags |= MDB_RDONLY;

    dbr = mdb_env_create(&env);
    if (dbr)
        throw std::runtime_error(
                "Failed to create LDMB environment: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_env_set_maxdbs(env, 32);
    if (dbr)
        throw std::runtime_error("Failed to set max env dbs: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_env_open(env, path.string().c_str(), flags, 0664);
    if (dbr)
        throw std::runtime_error(
                "Failed to open database file '" + path.string() +
                "': " + std::string(mdb_strerror(dbr)));
}

static void close(MDB_env* env) {
    mdb_env_close(env);
}

static void add_size(MDB_env* env, uint64_t bytes) {
    try {
        auto si = fs::space(db_path);
        if (si.available < bytes) {
            log::error(
                    logcat,
                    "!! WARNING: Insufficient free space to extend database !!: ",
                    (si.available >> 20L) << " MB available, " << (bytes >> 20L) << " MB needed");
            return;
        }
    } catch (...) {
        // print something but proceed.
        log::warning(logcat, "Unable to query free disk space.");
    }

    MDB_envinfo mei;
    mdb_env_info(env, &mei);
    MDB_stat mst;
    mdb_env_stat(env, &mst);

    uint64_t new_mapsize = (uint64_t)mei.me_mapsize + bytes;
    new_mapsize += (new_mapsize % mst.ms_psize);

    int result = mdb_env_set_mapsize(env, new_mapsize);
    if (result)
        throw std::runtime_error(
                "Failed to set new mapsize to " + std::to_string(new_mapsize) + ": " +
                std::string(mdb_strerror(result)));

    log::info(
            logcat,
            "LMDB Mapsize increased.  Old: {}MiB, New: {}MiB",
            mei.me_mapsize / (1024 * 1024),
            new_mapsize / (1024 * 1024));
}

static void check_resize(MDB_env* env, size_t bytes) {
    MDB_envinfo mei;
    MDB_stat mst;

    mdb_env_info(env, &mei);
    mdb_env_stat(env, &mst);

    uint64_t size_used = mst.ms_psize * mei.me_last_pgno;
    if (size_used + bytes + slack >= mei.me_mapsize)
        add_size(env, size_used + bytes + 2 * slack - mei.me_mapsize);
}

static bool resize_point(size_t nrecords, MDB_env* env, MDB_txn** txn, size_t& bytes) {
    if (nrecords % records_per_sync && bytes <= slack / 2)
        return false;
    int dbr = mdb_txn_commit(*txn);
    if (dbr)
        throw std::runtime_error("Failed to commit txn: " + std::string(mdb_strerror(dbr)));
    check_resize(env, bytes);
    dbr = mdb_txn_begin(env, NULL, 0, txn);
    if (dbr)
        throw std::runtime_error(
                "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    bytes = 0;
    return true;
}

static void copy_table(
        MDB_env* env0,
        MDB_env* env1,
        const char* table,
        unsigned int flags,
        unsigned int putflags,
        int (*cmp)(const MDB_val*, const MDB_val*) = 0) {
    MDB_dbi dbi0, dbi1;
    MDB_txn *txn0, *txn1;
    MDB_cursor *cur0, *cur1;
    bool tx_active0 = false, tx_active1 = false;
    int dbr;

    log::info(logcat, "Copying {}", table);

    OXEN_DEFER {
        if (tx_active1)
            mdb_txn_abort(txn1);
        if (tx_active0)
            mdb_txn_abort(txn0);
    };

    dbr = mdb_txn_begin(env0, NULL, MDB_RDONLY, &txn0);
    if (dbr)
        throw std::runtime_error(
                "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    tx_active0 = true;
    dbr = mdb_txn_begin(env1, NULL, 0, &txn1);
    if (dbr)
        throw std::runtime_error(
                "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    tx_active1 = true;

    dbr = mdb_dbi_open(txn0, table, flags, &dbi0);
    if (dbr)
        throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
    if (cmp)
        ((flags & MDB_DUPSORT) ? mdb_set_dupsort : mdb_set_compare)(txn0, dbi0, cmp);

    dbr = mdb_dbi_open(txn1, table, flags, &dbi1);
    if (dbr)
        throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
    if (cmp)
        ((flags & MDB_DUPSORT) ? mdb_set_dupsort : mdb_set_compare)(txn1, dbi1, cmp);

    dbr = mdb_txn_commit(txn1);
    if (dbr)
        throw std::runtime_error("Failed to commit txn: " + std::string(mdb_strerror(dbr)));
    tx_active1 = false;
    MDB_stat stats;
    dbr = mdb_env_stat(env0, &stats);
    if (dbr)
        throw std::runtime_error(
                "Failed to stat " + std::string(table) +
                " LMDB table: " + std::string(mdb_strerror(dbr)));
    check_resize(
            env1,
            (stats.ms_branch_pages + stats.ms_overflow_pages + stats.ms_leaf_pages) *
                    stats.ms_psize);
    dbr = mdb_txn_begin(env1, NULL, 0, &txn1);
    if (dbr)
        throw std::runtime_error(
                "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    tx_active1 = true;

    dbr = mdb_drop(txn1, dbi1, 0);
    if (dbr)
        throw std::runtime_error(
                "Failed to empty " + std::string(table) +
                " LMDB table: " + std::string(mdb_strerror(dbr)));

    dbr = mdb_cursor_open(txn0, dbi0, &cur0);
    if (dbr)
        throw std::runtime_error("Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_cursor_open(txn1, dbi1, &cur1);
    if (dbr)
        throw std::runtime_error("Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));

    MDB_val k;
    MDB_val v;
    MDB_cursor_op op = MDB_FIRST;
    size_t nrecords = 0, bytes = 0;
    while (1) {
        int ret = mdb_cursor_get(cur0, &k, &v, op);
        op = MDB_NEXT;
        if (ret == MDB_NOTFOUND)
            break;
        if (ret)
            throw std::runtime_error(
                    "Failed to enumerate " + std::string(table) +
                    " records: " + std::string(mdb_strerror(ret)));

        bytes += k.mv_size + v.mv_size;
        if (resize_point(++nrecords, env1, &txn1, bytes)) {
            dbr = mdb_cursor_open(txn1, dbi1, &cur1);
            if (dbr)
                throw std::runtime_error(
                        "Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));
        }

        ret = mdb_cursor_put(cur1, &k, &v, putflags);
        if (ret)
            throw std::runtime_error(
                    "Failed to write " + std::string(table) +
                    " record: " + std::string(mdb_strerror(ret)));
    }

    mdb_cursor_close(cur1);
    mdb_cursor_close(cur0);
    mdb_txn_commit(txn1);
    tx_active1 = false;
    mdb_txn_commit(txn0);
    tx_active0 = false;
    mdb_dbi_close(env1, dbi1);
    mdb_dbi_close(env0, dbi0);
}

static bool is_v1_tx(MDB_cursor* c_txs_pruned, MDB_val* tx_id) {
    MDB_val v;
    int ret = mdb_cursor_get(c_txs_pruned, tx_id, &v, MDB_SET);
    if (ret)
        throw std::runtime_error(
                "Failed to find transaction pruned data: " + std::string(mdb_strerror(ret)));
    if (v.mv_size == 0)
        throw std::runtime_error("Invalid transaction pruned data");
    return cryptonote::is_v1_tx(std::string_view{(const char*)v.mv_data, v.mv_size});
}

static void prune(MDB_env* env0, MDB_env* env1) {
    MDB_dbi dbi0_blocks, dbi0_txs_pruned, dbi0_txs_prunable, dbi0_tx_indices, dbi1_txs_prunable,
            dbi1_txs_prunable_tip, dbi1_properties;
    MDB_txn *txn0, *txn1;
    MDB_cursor *cur0_txs_pruned, *cur0_txs_prunable, *cur0_tx_indices, *cur1_txs_prunable,
            *cur1_txs_prunable_tip;
    bool tx_active0 = false, tx_active1 = false;
    int dbr;

    log::info(logcat, "Creating pruned txs_prunable");

    OXEN_DEFER {
        if (tx_active1)
            mdb_txn_abort(txn1);
        if (tx_active0)
            mdb_txn_abort(txn0);
    };

    dbr = mdb_txn_begin(env0, NULL, MDB_RDONLY, &txn0);
    if (dbr)
        throw std::runtime_error(
                "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    tx_active0 = true;
    dbr = mdb_txn_begin(env1, NULL, 0, &txn1);
    if (dbr)
        throw std::runtime_error(
                "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    tx_active1 = true;

    dbr = mdb_dbi_open(txn0, "txs_pruned", MDB_INTEGERKEY, &dbi0_txs_pruned);
    if (dbr)
        throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
    mdb_set_compare(txn0, dbi0_txs_pruned, BlockchainLMDB::compare_uint64);
    dbr = mdb_cursor_open(txn0, dbi0_txs_pruned, &cur0_txs_pruned);
    if (dbr)
        throw std::runtime_error("Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));

    dbr = mdb_dbi_open(txn0, "txs_prunable", MDB_INTEGERKEY, &dbi0_txs_prunable);
    if (dbr)
        throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
    mdb_set_compare(txn0, dbi0_txs_prunable, BlockchainLMDB::compare_uint64);
    dbr = mdb_cursor_open(txn0, dbi0_txs_prunable, &cur0_txs_prunable);
    if (dbr)
        throw std::runtime_error("Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));

    dbr = mdb_dbi_open(
            txn0, "tx_indices", MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED, &dbi0_tx_indices);
    if (dbr)
        throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
    mdb_set_dupsort(txn0, dbi0_tx_indices, BlockchainLMDB::compare_hash32);
    dbr = mdb_cursor_open(txn0, dbi0_tx_indices, &cur0_tx_indices);
    if (dbr)
        throw std::runtime_error("Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));

    dbr = mdb_dbi_open(txn1, "txs_prunable", MDB_INTEGERKEY, &dbi1_txs_prunable);
    if (dbr)
        throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
    mdb_set_compare(txn1, dbi1_txs_prunable, BlockchainLMDB::compare_uint64);
    dbr = mdb_cursor_open(txn1, dbi1_txs_prunable, &cur1_txs_prunable);
    if (dbr)
        throw std::runtime_error("Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));

    dbr = mdb_dbi_open(
            txn1,
            "txs_prunable_tip",
            MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED,
            &dbi1_txs_prunable_tip);
    if (dbr)
        throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
    mdb_set_dupsort(txn1, dbi1_txs_prunable_tip, BlockchainLMDB::compare_uint64);
    dbr = mdb_cursor_open(txn1, dbi1_txs_prunable_tip, &cur1_txs_prunable_tip);
    if (dbr)
        throw std::runtime_error("Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));

    dbr = mdb_drop(txn1, dbi1_txs_prunable, 0);
    if (dbr)
        throw std::runtime_error("Failed to empty LMDB table: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_drop(txn1, dbi1_txs_prunable_tip, 0);
    if (dbr)
        throw std::runtime_error("Failed to empty LMDB table: " + std::string(mdb_strerror(dbr)));

    dbr = mdb_dbi_open(txn1, "properties", 0, &dbi1_properties);
    if (dbr)
        throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));

    MDB_val k, v;
    uint32_t pruning_seed =
            tools::make_pruning_seed(tools::get_random_stripe(), PRUNING_LOG_STRIPES);
    static char pruning_seed_key[] = "pruning_seed";
    k.mv_data = pruning_seed_key;
    k.mv_size = strlen("pruning_seed") + 1;
    v.mv_data = (void*)&pruning_seed;
    v.mv_size = sizeof(pruning_seed);
    dbr = mdb_put(txn1, dbi1_properties, &k, &v, 0);
    if (dbr)
        throw std::runtime_error("Failed to save pruning seed: " + std::string(mdb_strerror(dbr)));

    MDB_stat stats;
    dbr = mdb_dbi_open(txn0, "blocks", 0, &dbi0_blocks);
    if (dbr)
        throw std::runtime_error("Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
    dbr = mdb_stat(txn0, dbi0_blocks, &stats);
    if (dbr)
        throw std::runtime_error(
                "Failed to query size of blocks: " + std::string(mdb_strerror(dbr)));
    mdb_dbi_close(env0, dbi0_blocks);
    const uint64_t blockchain_height = stats.ms_entries;
    size_t nrecords = 0, bytes = 0;

    MDB_cursor_op op = MDB_FIRST;
    while (1) {
        int ret = mdb_cursor_get(cur0_tx_indices, &k, &v, op);
        op = MDB_NEXT;
        if (ret == MDB_NOTFOUND)
            break;
        if (ret)
            throw std::runtime_error(
                    "Failed to enumerate records: " + std::string(mdb_strerror(ret)));

        const txindex* ti = (const txindex*)v.mv_data;
        const uint64_t block_height = ti->data.block_id;
        MDB_val_set(kk, ti->data.tx_id);
        if (block_height + PRUNING_TIP_BLOCKS >= blockchain_height) {
            log::debug(logcat, "{}/{} is in tip", block_height, blockchain_height);
            MDB_val_set(vv, block_height);
            dbr = mdb_cursor_put(cur1_txs_prunable_tip, &kk, &vv, 0);
            if (dbr)
                throw std::runtime_error(
                        "Failed to write prunable tx tip data: " + std::string(mdb_strerror(dbr)));
            bytes += kk.mv_size + vv.mv_size;
        }
        if (tools::has_unpruned_block(block_height, blockchain_height, pruning_seed) ||
            is_v1_tx(cur0_txs_pruned, &kk)) {
            MDB_val vv;
            dbr = mdb_cursor_get(cur0_txs_prunable, &kk, &vv, MDB_SET);
            if (dbr)
                throw std::runtime_error(
                        "Failed to read prunable tx data: " + std::string(mdb_strerror(dbr)));
            bytes += kk.mv_size + vv.mv_size;
            if (resize_point(++nrecords, env1, &txn1, bytes)) {
                dbr = mdb_cursor_open(txn1, dbi1_txs_prunable, &cur1_txs_prunable);
                if (dbr)
                    throw std::runtime_error(
                            "Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));
                dbr = mdb_cursor_open(txn1, dbi1_txs_prunable_tip, &cur1_txs_prunable_tip);
                if (dbr)
                    throw std::runtime_error(
                            "Failed to create LMDB cursor: " + std::string(mdb_strerror(dbr)));
            }
            dbr = mdb_cursor_put(cur1_txs_prunable, &kk, &vv, 0);
            if (dbr)
                throw std::runtime_error(
                        "Failed to write prunable tx data: " + std::string(mdb_strerror(dbr)));
        } else {
            log::debug(logcat, "{}/{} should be pruned, dropping", block_height, blockchain_height);
        }
    }

    mdb_cursor_close(cur1_txs_prunable_tip);
    mdb_cursor_close(cur1_txs_prunable);
    mdb_cursor_close(cur0_txs_prunable);
    mdb_cursor_close(cur0_txs_pruned);
    mdb_cursor_close(cur0_tx_indices);
    mdb_txn_commit(txn1);
    tx_active1 = false;
    mdb_txn_commit(txn0);
    tx_active0 = false;
    mdb_dbi_close(env1, dbi1_properties);
    mdb_dbi_close(env1, dbi1_txs_prunable_tip);
    mdb_dbi_close(env1, dbi1_txs_prunable);
    mdb_dbi_close(env0, dbi0_txs_prunable);
    mdb_dbi_close(env0, dbi0_txs_pruned);
    mdb_dbi_close(env0, dbi0_tx_indices);
}

static bool parse_db_sync_mode(std::string db_sync_mode, uint64_t& db_flags) {
    auto options = tools::split_any(db_sync_mode, " :", true);

    for (const auto& option : options)
        log::debug(logcat, "option: {}", option);

    // default to fast:async:1
    uint64_t DEFAULT_FLAGS = DBF_FAST;

    db_flags = 0;

    if (options.size() == 0) {
        // default to fast:async:1
        db_flags = DEFAULT_FLAGS;
    }

    bool safemode = false;
    if (options.size() >= 1) {
        if (options[0] == "safe") {
            safemode = true;
            db_flags = DBF_SAFE;
        } else if (options[0] == "fast") {
            db_flags = DBF_FAST;
        } else if (options[0] == "fastest") {
            db_flags = DBF_FASTEST;
            records_per_sync = 1000;  // default to fastest:async:1000
        } else
            return false;
    }

    if (options.size() >= 2 && !safemode) {
        char* endptr;
        std::string bpsstr{options[1]};
        uint64_t bps = strtoull(bpsstr.c_str(), &endptr, 0);
        if (*endptr != '\0')
            return false;
        records_per_sync = bps;
    }

    return true;
}

int main(int argc, char* argv[]) {
    TRY_ENTRY();

    epee::string_tools::set_module_name_and_folder(argv[0]);

    uint32_t log_level = 0;

    tools::on_startup();

    auto opt_size = command_line::boost_option_sizes();

    po::options_description desc_cmd_only("Command line options", opt_size.first, opt_size.second);
    po::options_description desc_cmd_sett(
            "Command line options and settings options", opt_size.first, opt_size.second);
    const command_line::arg_descriptor<std::string> arg_log_level = {
            "log-level", "0-4 or categories", ""};
    const command_line::arg_descriptor<std::string> arg_db_sync_mode = {
            "db-sync-mode",
            "Specify sync option, using format [safe|fast|fastest]:[nrecords_per_sync].",
            "fast:1000"};
    const command_line::arg_descriptor<bool> arg_copy_pruned_database = {
            "copy-pruned-database", "Copy database anyway if already pruned"};

    command_line::add_arg(desc_cmd_sett, cryptonote::arg_data_dir);
    command_line::add_arg(desc_cmd_sett, cryptonote::arg_testnet_on);
    command_line::add_arg(desc_cmd_sett, cryptonote::arg_devnet_on);
    command_line::add_arg(desc_cmd_sett, arg_log_level);
    command_line::add_arg(desc_cmd_sett, arg_db_sync_mode);
    command_line::add_arg(desc_cmd_sett, arg_copy_pruned_database);
    command_line::add_arg(desc_cmd_only, command_line::arg_help);

    po::options_description desc_options("Allowed options");
    desc_options.add(desc_cmd_only).add(desc_cmd_sett);

    po::variables_map vm;
    bool r = command_line::handle_error_helper(desc_options, [&]() {
        auto parser = po::command_line_parser(argc, argv).options(desc_options);
        po::store(parser.run(), vm);
        po::notify(vm);
        return true;
    });
    if (!r)
        return 1;

    if (command_line::get_arg(vm, command_line::arg_help)) {
        std::cout << "Oxen '" << OXEN_RELEASE_NAME << "' (v" << OXEN_VERSION_FULL << ")\n\n";
        std::cout << desc_options << std::endl;
        return 1;
    }

    mlog_configure(mlog_get_default_log_path("oxen-blockchain-prune.log"), true);
    if (!command_line::is_arg_defaulted(vm, arg_log_level))
        mlog_set_log(command_line::get_arg(vm, arg_log_level).c_str());
    else
        mlog_set_log(std::string(std::to_string(log_level) + ",bcutil:INFO").c_str());

    log::info(logcat, "Starting...");

    bool opt_testnet = command_line::get_arg(vm, cryptonote::arg_testnet_on);
    bool opt_devnet = command_line::get_arg(vm, cryptonote::arg_devnet_on);
    network_type net_type = opt_testnet ? network_type::TESTNET
                          : opt_devnet  ? network_type::DEVNET
                                        : network_type::MAINNET;
    bool opt_copy_pruned_database = command_line::get_arg(vm, arg_copy_pruned_database);
    std::string data_dir = command_line::get_arg(vm, cryptonote::arg_data_dir);
    while (tools::ends_with(data_dir, "/") || tools::ends_with(data_dir, "\\"))
        data_dir.pop_back();

    std::string db_sync_mode = command_line::get_arg(vm, arg_db_sync_mode);
    uint64_t db_flags = 0;
    if (!parse_db_sync_mode(db_sync_mode, db_flags)) {
        log::error(logcat, "Invalid db sync mode: {}", db_sync_mode);
        return 1;
    }

    // If we wanted to use the memory pool, we would set up a fake_core.

    // Use Blockchain instead of lower-level BlockchainDB for two reasons:
    // 1. Blockchain has the init() method for easy setup
    // 2. exporter needs to use get_current_blockchain_height(), get_block_id_by_height(),
    // get_block_by_hash()
    //
    // cannot match blockchain_storage setup above with just one line,
    // e.g.
    //   Blockchain* core_storage = new Blockchain(NULL);
    // because unlike blockchain_storage constructor, which takes a pointer to
    // tx_memory_pool, Blockchain's constructor takes tx_memory_pool object.
    log::info(logcat, "Initializing source blockchain (BlockchainDB)");
    std::array<Blockchain*, 2> core_storage;
    fs::path paths[2];
    bool already_pruned = false;
    for (size_t n = 0; n < core_storage.size(); ++n) {
        blockchain_objects_t* blockchain_objects = new blockchain_objects_t();
        core_storage[n] = &(blockchain_objects->m_blockchain);

        BlockchainDB* db = new_db();
        if (db == NULL) {
            log::error(logcat, "Failed to initialize a database");
            throw std::runtime_error("Failed to initialize a database");
        }

        if (n == 1) {
            paths[1] = fs::u8path(data_dir) / (db->get_db_name() + "-pruned");
            if (fs::exists(paths[1])) {
                if (!fs::is_directory(paths[1])) {
                    log::error(
                            logcat,
                            "LMDB needs a directory path, but a file was passed: {}",
                            paths[1].string());
                    return 1;
                }
            } else {
                if (!fs::create_directories(paths[1])) {
                    log::error(logcat, "Failed to create directory: {}", paths[1].string());
                    return 1;
                }
            }
            db_path = paths[1];
        } else {
            paths[0] = fs::u8path(data_dir) / db->get_db_name();
        }

        log::info(logcat, "Loading blockchain from folder {} ...", paths[n]);

        try {
            db->open(paths[n].string(), core_storage[n]->nettype(), n == 0 ? DBF_RDONLY : 0);
        } catch (const std::exception& e) {
            log::error(logcat, "Error opening database: {}", e.what());
            return 1;
        }
        r = core_storage[n]->init(db, nullptr /*ons_db*/, net_type);

        std::string source_dest = n == 0 ? "source" : "pruned";
        CHECK_AND_ASSERT_MES(r, 1, "Failed to initialize " << source_dest << " blockchain storage");
        log::info(logcat, "{} blockchain storage initialized OK", source_dest);
        if (n == 0 && core_storage[0]->get_blockchain_pruning_seed()) {
            if (!opt_copy_pruned_database) {
                log::error(
                        logcat,
                        "Blockchain is already pruned, use --{} to copy it anyway",
                        arg_copy_pruned_database.name);
                return 1;
            }
            already_pruned = true;
        }
    }
    core_storage[0]->deinit();
    delete core_storage[0];
    core_storage[1]->deinit();
    delete core_storage[1];

    log::info(logcat, "Pruning...");
    MDB_env *env0 = NULL, *env1 = NULL;
    open(env0, paths[0], db_flags, true);
    open(env1, paths[1], db_flags, false);
    copy_table(env0, env1, "blocks", MDB_INTEGERKEY, MDB_APPEND);
    copy_table(
            env0,
            env1,
            "block_info",
            MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED,
            MDB_APPENDDUP,
            BlockchainLMDB::compare_uint64);
    copy_table(
            env0,
            env1,
            "block_heights",
            MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED,
            0,
            BlockchainLMDB::compare_hash32);
    // copy_table(env0, env1, "txs", MDB_INTEGERKEY);
    copy_table(env0, env1, "txs_pruned", MDB_INTEGERKEY, MDB_APPEND);
    copy_table(
            env0,
            env1,
            "txs_prunable_hash",
            MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED,
            MDB_APPEND);
    // not copied: prunable, prunable_tip
    copy_table(
            env0,
            env1,
            "tx_indices",
            MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED,
            0,
            BlockchainLMDB::compare_hash32);
    copy_table(env0, env1, "tx_outputs", MDB_INTEGERKEY, MDB_APPEND);
    copy_table(
            env0,
            env1,
            "output_txs",
            MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED,
            MDB_APPENDDUP,
            BlockchainLMDB::compare_uint64);
    copy_table(
            env0,
            env1,
            "output_amounts",
            MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED,
            MDB_APPENDDUP,
            BlockchainLMDB::compare_uint64);
    copy_table(
            env0,
            env1,
            "spent_keys",
            MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED,
            MDB_NODUPDATA,
            BlockchainLMDB::compare_hash32);
    copy_table(env0, env1, "txpool_meta", 0, MDB_NODUPDATA, BlockchainLMDB::compare_hash32);
    copy_table(env0, env1, "txpool_blob", 0, MDB_NODUPDATA, BlockchainLMDB::compare_hash32);
    copy_table(env0, env1, "hf_versions", MDB_INTEGERKEY, MDB_APPEND);
    copy_table(env0, env1, "properties", 0, 0, BlockchainLMDB::compare_string);
    if (already_pruned) {
        copy_table(
                env0,
                env1,
                "txs_prunable",
                MDB_INTEGERKEY,
                MDB_APPEND,
                BlockchainLMDB::compare_uint64);
        copy_table(
                env0,
                env1,
                "txs_prunable_tip",
                MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED,
                MDB_NODUPDATA,
                BlockchainLMDB::compare_uint64);
    } else {
        prune(env0, env1);
    }
    close(env1);
    close(env0);

    log::info(
            logcat,
            "Swapping databases, pre-pruning blockchain will be left in {}",
            paths[0].string() + "-old and can be removed if desired");
    fs::path old = paths[0];
    old += "-old";
    if (replace_file(paths[0], old) || replace_file(paths[1], paths[0])) {
        log::error(logcat, "Blockchain pruned OK, but renaming failed");
        return 1;
    }

    log::info(logcat, "Blockchain pruned OK");
    return 0;

    CATCH_ENTRY("Pruning error", 1);
}