#ifndef SQLITEPP
#define SQLITEPP

#include <iostream>
#include <unordered_map>
#include <vector>

#ifndef WIN32

#include <sqlite3.h>

#else

#include "sqlite3.h"
#include <codecvt>
#include <shlobj.h>

std::string _w_2_8( const std::wstring &wstring ) {
    std::wstring_convert< std::codecvt_utf8_utf16< wchar_t > > wconv;
    return wconv.to_bytes( wstring );
}

std::wstring _8_2_w( const std::string &utf8 ) {
    std::wstring_convert< std::codecvt_utf8_utf16< wchar_t > > wconv;
    return wconv.from_bytes( utf8 );
}

#endif

namespace SQLite {

constexpr size_t OPEN_READONLY = 0x00000001;
constexpr size_t OPEN_READWRITE = 0x00000002;
constexpr size_t OPEN_CREATE = 0x00000004;
constexpr size_t OPEN_URI = 0x00000040;
constexpr size_t OPEN_MEMORY = 0x00000080;
constexpr size_t OPEN_NOMUTEX = 0x00008000;
constexpr size_t OPEN_FULLMUTEX = 0x00010000;
constexpr size_t OPEN_SHAREDCACHE = 0x00020000;
constexpr size_t OPEN_PRIVATECACHE = 0x00040000;

class Database {
public:
    Database() {}

    Database( const std::string &file, size_t options ) {
        open( file, options );
    }

#ifdef WIN32
    Database( const std::wstring &file, size_t options ) {
        open( file, options );
    }
#endif

    ~Database() {
        close();
    }

    void open( const std::string &file, size_t options ) {
        if ( sqlite3_open_v2( file.c_str(), &db, options, nullptr ) ) {
            throw std::runtime_error( "Could not open database " + file );
        }
    }

#ifdef WIN32
    void open( const std::wstring &file, size_t options ) {
        if ( sqlite3_open_v2( _w_2_8( file ).c_str(), &db, options,
                              nullptr ) ) {
            throw std::runtime_error( "Could not open database " +
                                      _w_2_8( file ) );
        }
    }
#endif

    // execute command without output
    void exec( const std::string &command ) {
        char *errMsg = nullptr;
        int rc = sqlite3_exec( db, command.c_str(), nullptr, nullptr, &errMsg );
        if ( rc )
            throw std::runtime_error( "\"" + command +
                                      "\" resulted in an error:\n" + errMsg );
        sqlite3_free( errMsg );
    }

#ifdef WIN32
    void exec( const std::wstring &command ) {
        char *errMsg = nullptr;
        int rc = sqlite3_exec( db, _w_2_8( command ).c_str(), nullptr, nullptr,
                               &errMsg );
        if ( rc )
            throw std::runtime_error( "\"" + _w_2_8( command ) +
                                      "\" resulted in an error:\n" + errMsg );
        sqlite3_free( errMsg );
    }
#endif

    // execute command that should only output 1 result
    void exec( const std::string &command, std::string &output ) {
        char *errMsg = nullptr;
        int rc = sqlite3_exec( db, command.c_str(), insert_val_s,
                               static_cast< void * >( &output ), &errMsg );
        if ( rc )
            throw std::runtime_error( "\"" + command +
                                      "\" resulted in an error:\n" + errMsg );
        sqlite3_free( errMsg );
    }

#ifdef WIN32
    void exec( const std::wstring &command, std::wstring &output ) {
        char *errMsg = nullptr;
        int rc = sqlite3_exec( db, _w_2_8( command ).c_str(), insert_val_ws,
                               static_cast< void * >( &output ), &errMsg );
        if ( rc )
            throw std::runtime_error( "\"" + _w_2_8( command ) +
                                      "\" resulted in an error:\n" + errMsg );
        sqlite3_free( errMsg );
    }
#endif

    // didn't work with set for some reason, so only vector is allowed
    void exec( const std::string &command,
               std::vector< std::unordered_map< std::string, std::string > >
                   &object ) {
        char *errMsg = nullptr;
        int rc = sqlite3_exec( db, command.c_str(), insert_col_val,
                               static_cast< void * >( &object ), &errMsg );
        if ( rc )
            throw std::runtime_error( "\"" + command +
                                      "\" resulted in an error:\n" + errMsg );
        sqlite3_free( errMsg );
    }

#ifdef WIN32
    // didn't work with set for some reason, so only vector is allowed
    void exec( const std::wstring &command,
               std::vector< std::unordered_map< std::wstring, std::wstring > >
                   &object ) {
        char *errMsg = nullptr;
        int rc = sqlite3_exec( db, _w_2_8( command ).c_str(), insert_col_val_w,
                               static_cast< void * >( &object ), &errMsg );
        if ( rc )
            throw std::runtime_error( "\"" + _w_2_8( command ) +
                                      "\" resulted in an error:\n" + errMsg );
        sqlite3_free( errMsg );
    }
#endif

    // execute command with output and store output in object (store only
    // values) object can by any container as long as it's template is
    // 'std::string'
    template < typename V > void exec( const std::string &command, V &object ) {
        char *errMsg = nullptr;
        int rc = sqlite3_exec( db, command.c_str(), insert_val< V >,
                               static_cast< void * >( &object ), &errMsg );
        if ( rc )
            throw std::runtime_error( "\"" + command +
                                      "\" resulted in an error:\n" + errMsg );
        sqlite3_free( errMsg );
    }

#ifdef WIN32
    template < typename V >
    void exec( const std::wstring &command, V &object ) {
        char *errMsg = nullptr;
        int rc = sqlite3_exec( db, _w_2_8( command ).c_str(), insert_val_w< V >,
                               static_cast< void * >( &object ), &errMsg );
        if ( rc )
            throw std::runtime_error( "\"" + _w_2_8( command ) +
                                      "\" resulted in an error:\n" + errMsg );
        sqlite3_free( errMsg );
    }
#endif

    void close() {
        sqlite3_close( db );
    }

private:
    sqlite3 *db;

    static int insert_col_val( void *d, int argc, char **argv,
                               char **azColName ) {
        auto &data = *static_cast<
            std::vector< std::unordered_map< std::string, std::string > > * >(
            d );
        std::unordered_map< std::string, std::string > buffer;
        for ( int i = 0; i < argc; i++ ) {
            // insert all columns and values into 'data'
            buffer[azColName[i]] = argv[i] ? argv[i] : "";
        }
        data.insert( data.end(), std::move( buffer ) );
        return 0;
    }

#ifdef WIN32
    static int insert_col_val_w( void *d, int argc, char **argv,
                                 char **azColName ) {
        auto &data = *static_cast<
            std::vector< std::unordered_map< std::wstring, std::wstring > > * >(
            d );
        std::unordered_map< std::wstring, std::wstring > buffer;
        for ( int i = 0; i < argc; i++ ) {
            // insert all columns and values into 'data'
            buffer[_8_2_w( azColName[i] )] = argv[i] ? _8_2_w( argv[i] ) : L"";
        }
        data.insert( data.end(), std::move( buffer ) );
        return 0;
    }
#endif

    static int insert_val_s( void *d, int argc, char **argv,
                             char ** /*UNUSED*/ ) {
        auto &data = *static_cast< std::string * >( d );
        if ( argc > 0 ) {
            data = argv[0] ? argv[0] : "";
        }
        return 0;
    }

#ifdef WIN32
    static int insert_val_ws( void *d, int argc, char **argv,
                              char ** /*UNUSED*/ ) {
        auto &data = *static_cast< std::wstring * >( d );
        if ( argc > 0 ) {
            data = argv[0] ? _8_2_w( argv[0] ) : L"";
        }
        return 0;
    }
#endif

    template < typename V >
    static int insert_val( void *d, int argc, char **argv,
                           char ** /*UNUSED*/ ) {
        auto &data = *static_cast< V * >( d );
        for ( int i = 0; i < argc; i++ ) {
            // insert all values into 'data'
            data.insert( data.end(), argv[i] ? argv[i] : "" );
        }
        return 0;
    }

#ifdef WIN32
    template < typename V >
    static int insert_val_w( void *d, int argc, char **argv,
                             char ** /*UNUSED*/ ) {
        auto &data = *static_cast< V * >( d );
        for ( int i = 0; i < argc; i++ ) {
            // insert all values into 'data'
            data.insert( data.end(), argv[i] ? _8_2_w( argv[i] ) : L"" );
        }
        return 0;
    }
#endif
};

} // namespace SQLite

#endif