// Copyright (c) 2009-2010 Satoshi Nakamoto

// Copyright (c) 2009-present 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 <chainparams.h>

#include <common/args.h>

#include <logging.h>

#include <util/fs.h>

#include <wallet/db.h>

#include <algorithm>

#include <exception>

#include <fstream>

#include <string>

#include <system_error>

#include <vector>

namespace wallet {

bool operator<(BytePrefix a, std::span<const std::byte> b) { return std::ranges::lexicographical_compare(a.prefix, b.subspan(0, std::min(a.prefix.size(), b.size()))); }

bool operator<(std::span<const std::byte> a, BytePrefix b) { return std::ranges::lexicographical_compare(a.subspan(0, std::min(a.size(), b.prefix.size())), b.prefix); }

std::vector<std::pair<fs::path, std::string>> ListDatabases(const fs::path& wallet_dir)

{

    std::vector<std::pair<fs::path, std::string>> paths;

    std::error_code ec;

    for (auto it = fs::recursive_directory_iterator(wallet_dir, ec); it != fs::recursive_directory_iterator(); it.increment(ec)) {

  Branch (28:70): [True: 0, False: 0]

        if (ec) {

  Branch (29:13): [True: 0, False: 0]

            if (fs::is_directory(*it)) {

  Branch (30:17): [True: 0, False: 0]

                it.disable_recursion_pending();

                LogPrintf("%s: %s %s -- skipping.\n", __func__, ec.message(), fs::PathToString(it->path()));

            } else {

                LogPrintf("%s: %s %s\n", __func__, ec.message(), fs::PathToString(it->path()));

            }

            continue;

        }

        try {

            const fs::path path{it->path().lexically_relative(wallet_dir)};

            if (it->status().type() == fs::file_type::directory) {

  Branch (42:17): [True: 0, False: 0]

                if (IsBDBFile(BDBDataFile(it->path()))) {

  Branch (43:21): [True: 0, False: 0]

                    // Found a directory which contains wallet.dat btree file, add it as a wallet with BERKELEY format.

                    paths.emplace_back(path, "bdb");

                } else if (IsSQLiteFile(SQLiteDataFile(it->path()))) {

  Branch (46:28): [True: 0, False: 0]

                    // Found a directory which contains wallet.dat sqlite file, add it as a wallet with SQLITE format.

                    paths.emplace_back(path, "sqlite");

                }

            } else if (it.depth() == 0 && it->symlink_status().type() == fs::file_type::regular && it->path().extension() != ".bak") {

  Branch (50:24): [True: 0, False: 0]
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                if (it->path().filename() == "wallet.dat") {

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                    // Found top-level wallet.dat file, add top level directory ""

                    // as a wallet.

                    if (IsBDBFile(it->path())) {

  Branch (54:25): [True: 0, False: 0]

                        paths.emplace_back(fs::path(), "bdb");

                    } else if (IsSQLiteFile(it->path())) {

  Branch (56:32): [True: 0, False: 0]

                        paths.emplace_back(fs::path(), "sqlite");

                    }

                } else if (IsBDBFile(it->path())) {

  Branch (59:28): [True: 0, False: 0]

                    // Found top-level btree file not called wallet.dat. Current bitcoin

                    // software will never create these files but will allow them to be

                    // opened in a shared database environment for backwards compatibility.

                    // Add it to the list of available wallets.

                    paths.emplace_back(path, "bdb");

                }

            }

        } catch (const std::exception& e) {

            LogPrintf("%s: Error scanning %s: %s\n", __func__, fs::PathToString(it->path()), e.what());

            it.disable_recursion_pending();

        }

    }

    return paths;

}

fs::path BDBDataFile(const fs::path& wallet_path)

{

    if (fs::is_regular_file(wallet_path)) {

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        // Special case for backwards compatibility: if wallet path points to an

        // existing file, treat it as the path to a BDB data file in a parent

        // directory that also contains BDB log files.

        return wallet_path;

    } else {

        // Normal case: Interpret wallet path as a directory path containing

        // data and log files.

        return wallet_path / "wallet.dat";

    }

}

fs::path SQLiteDataFile(const fs::path& path)

{

    return path / "wallet.dat";

}

bool IsBDBFile(const fs::path& path)

{

    if (!fs::exists(path)) return false;

  Branch (97:9): [True: 11.0k, False: 0]

    // A Berkeley DB Btree file has at least 4K.

    // This check also prevents opening lock files.

    std::error_code ec;

    auto size = fs::file_size(path, ec);

    if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), fs::PathToString(path));

  Branch (103:9): [True: 0, False: 0]

    if (size < 4096) return false;

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    std::ifstream file{path, std::ios::binary};

    if (!file.is_open()) return false;

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    file.seekg(12, std::ios::beg); // Magic bytes start at offset 12

    uint32_t data = 0;

    file.read((char*) &data, sizeof(data)); // Read 4 bytes of file to compare against magic

    // Berkeley DB Btree magic bytes, from:

    //  https://github.com/file/file/blob/5824af38469ec1ca9ac3ffd251e7afe9dc11e227/magic/Magdir/database#L74-L75

    //  - big endian systems - 00 05 31 62

    //  - little endian systems - 62 31 05 00

    return data == 0x00053162 || data == 0x62310500;

  Branch (117:12): [True: 0, False: 0]
  Branch (117:34): [True: 0, False: 0]

}

bool IsSQLiteFile(const fs::path& path)

{

    if (!fs::exists(path)) return false;

  Branch (122:9): [True: 11.0k, False: 0]

    // A SQLite Database file is at least 512 bytes.

    std::error_code ec;

    auto size = fs::file_size(path, ec);

    if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), fs::PathToString(path));

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    if (size < 512) return false;

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    std::ifstream file{path, std::ios::binary};

    if (!file.is_open()) return false;

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    // Magic is at beginning and is 16 bytes long

    char magic[16];

    file.read(magic, 16);

    // Application id is at offset 68 and 4 bytes long

    file.seekg(68, std::ios::beg);

    char app_id[4];

    file.read(app_id, 4);

    file.close();

    // Check the magic, see https://sqlite.org/fileformat.html

    std::string magic_str(magic, 16);

    if (magic_str != std::string{"SQLite format 3\000", 16}) {

  Branch (146:9): [True: 0, False: 0]

        return false;

    }

    // Check the application id matches our network magic

    return memcmp(Params().MessageStart().data(), app_id, 4) == 0;

}

void ReadDatabaseArgs(const ArgsManager& args, DatabaseOptions& options)

{

    // Override current options with args values, if any were specified

    options.use_unsafe_sync = args.GetBoolArg("-unsafesqlitesync", options.use_unsafe_sync);

}

} // namespace wallet