// Copyright (c) 2020 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 <wallet/sqlite.h>

#include <logging.h>
#include <sync.h>
#include <util/memory.h>
#include <util/strencodings.h>
#include <util/translation.h>
#include <wallet/db.h>

#include <sqlite3.h>
#include <stdint.h>

static const char* const DATABASE_FILENAME = "wallet.dat";

static Mutex g_sqlite_mutex;
static int g_sqlite_count GUARDED_BY(g_sqlite_mutex) = 0;

static void ErrorLogCallback(void* arg, int code, const char* msg)
{
    // From sqlite3_config() documentation for the SQLITE_CONFIG_LOG option:
    // "The void pointer that is the second argument to SQLITE_CONFIG_LOG is passed through as
    // the first parameter to the application-defined logger function whenever that function is
    // invoked."
    // Assert that this is the case:
    assert(arg == nullptr);
    LogPrintf("SQLite Error. Code: %d. Message: %s\n", code, msg);
}

SQLiteDatabase::SQLiteDatabase(const fs::path& dir_path, const fs::path& file_path, bool mock)
    : WalletDatabase(), m_mock(mock), m_dir_path(dir_path.string()), m_file_path(file_path.string())
{
    {
        LOCK(g_sqlite_mutex);
        LogPrintf("Using SQLite Version %s\n", SQLiteDatabaseVersion());
        LogPrintf("Using wallet %s\n", m_dir_path);

        if (++g_sqlite_count == 1) {
            // Setup logging
            int ret = sqlite3_config(SQLITE_CONFIG_LOG, ErrorLogCallback, nullptr);
            if (ret != SQLITE_OK) {
                throw std::runtime_error(strprintf("SQLiteDatabase: Failed to setup error log: %s\n", sqlite3_errstr(ret)));
            }
        }
        int ret = sqlite3_initialize(); // This is a no-op if sqlite3 is already initialized
        if (ret != SQLITE_OK) {
            throw std::runtime_error(strprintf("SQLiteDatabase: Failed to initialize SQLite: %s\n", sqlite3_errstr(ret)));
        }
    }

    try {
        Open();
    } catch (const std::runtime_error&) {
        // If open fails, cleanup this object and rethrow the exception
        Cleanup();
        throw;
    }
}

SQLiteDatabase::~SQLiteDatabase()
{
    Cleanup();
}

void SQLiteDatabase::Cleanup() noexcept
{
    Close();

    LOCK(g_sqlite_mutex);
    if (--g_sqlite_count == 0) {
        int ret = sqlite3_shutdown();
        if (ret != SQLITE_OK) {
            LogPrintf("SQLiteDatabase: Failed to shutdown SQLite: %s\n", sqlite3_errstr(ret));
        }
    }
}

void SQLiteDatabase::Open()
{
}

bool SQLiteDatabase::Rewrite(const char* skip)
{
    return false;
}

bool SQLiteDatabase::Backup(const std::string& dest) const
{
    return false;
}

void SQLiteDatabase::Close()
{
}

std::unique_ptr<DatabaseBatch> SQLiteDatabase::MakeBatch(bool flush_on_close)
{
    return nullptr;
}

SQLiteBatch::SQLiteBatch(SQLiteDatabase& database)
    : m_database(database)
{
}

void SQLiteBatch::Close()
{
}

bool SQLiteBatch::ReadKey(CDataStream&& key, CDataStream& value)
{
    return false;
}

bool SQLiteBatch::WriteKey(CDataStream&& key, CDataStream&& value, bool overwrite)
{
    return false;
}

bool SQLiteBatch::EraseKey(CDataStream&& key)
{
    return false;
}

bool SQLiteBatch::HasKey(CDataStream&& key)
{
    return false;
}

bool SQLiteBatch::StartCursor()
{
    return false;
}

bool SQLiteBatch::ReadAtCursor(CDataStream& key, CDataStream& value, bool& complete)
{
    return false;
}

void SQLiteBatch::CloseCursor()
{
}

bool SQLiteBatch::TxnBegin()
{
    return false;
}

bool SQLiteBatch::TxnCommit()
{
    return false;
}

bool SQLiteBatch::TxnAbort()
{
    return false;
}

bool ExistsSQLiteDatabase(const fs::path& path)
{
    return false;
}

std::unique_ptr<SQLiteDatabase> MakeSQLiteDatabase(const fs::path& path, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error)
{
    return MakeUnique<SQLiteDatabase>(path, path / DATABASE_FILENAME);
}

std::string SQLiteDatabaseVersion()
{
    return std::string(sqlite3_libversion());
}