SharedAppState shared_app_state = ZI;

////////////////////////////////
//~ Write directory

String InitializeAppWriteDirectory(Arena *arena, String write_dir)
{
    TempArena scratch = BeginScratch(arena);

    /* Create write path */
    String base_write_dir = P_GetWritePath(scratch.arena);
    String write_path_fmt = base_write_dir.len > 0 ? Lit("%F/%F/") : Lit("%F%F/");
    String write_path = StringFormat(
        arena,
        write_path_fmt,
        FmtString(base_write_dir),
        FmtString(write_dir)
    );

    /* Create write dir if not present */
    if (!P_IsDir(write_path)) {
        P_MkDir(write_path);
        /* TODO: handle failure */
    }

    EndScratch(scratch);

    return write_path;
}

String CatAppWritePath(Arena *arena, String filename)
{
    SharedAppState *g = &shared_app_state;
    return CatString(arena, g->write_path, filename);
}

////////////////////////////////
//~ Default settings

P_WindowSettings GetDefaultAppWindowSettings(P_Window *window)
{
    __prof;

    Vec2 monitor_size = P_GetWindowMonitorSize(window);

    i32 width = 1280;
    i32 height = RoundF32ToI32(width / (f32)(DEFAULT_CAMERA_WIDTH / DEFAULT_CAMERA_HEIGHT));
    i32 x = RoundF32ToI32(monitor_size.x / 2.f - width / 2);
    i32 y = RoundF32ToI32(monitor_size.y / 2.f - height / 2);

    return (P_WindowSettings) {
        .title = WINDOW_TITLE,
        .floating_x = x,
        .floating_y = y,
        .floating_width = width,
        .floating_height = height
    };
}

////////////////////////////////
//~ Args

/* TODO: Remove this and do real argument parsing */
AppArgList ParseAppArgs(Arena *arena, String args_str)
{
    AppArgList result = ZI;
    i64 mode = 0;
    i64 i = 0;
    i64 key_start = -1;
    i64 key_end = -1;
    i64 value_start = -1;
    i64 value_end = -1;
    while (i < (i64)args_str.len) {
        u8 c = args_str.text[i];
        switch (mode) {
            case 0:
            {
                if (c == '-') {
                    mode = 1;
                    key_start = i + 1;
                }
                ++i;
            } break;

            case 1:
            {
                if (c == '=') {
                    key_end = i;
                    value_start = i + 1;
                    mode = 2;
                }
                ++i;
            } break;

            case 2:
            {
                if (c == '-' || i == (i64)args_str.len - 1) {
                    if (c == '-') {
                        value_end = i;
                    } else {
                        value_end = i + 1;
                    }
                    if (key_start >= 0 && key_end > key_start && key_end <= (i64)args_str.len && value_start >= 0 && value_end > value_start && value_end <= (i64)args_str.len) {
                        String key = PushString(arena, STRING(key_end - key_start, args_str.text + key_start));
                        String value = PushString(arena, STRING(value_end - value_start, args_str.text + value_start));
                        AppArg *arg = PushStruct(arena, AppArg);
                        arg->key = key;
                        arg->value = value;
                        if (result.last) {
                            result.last->next = arg;
                        } else {
                            result.first = arg;
                        }
                        result.last = arg;
                        ++result.count;
                    }
                    key_start = i + 1;
                    mode = 1;
                }
                ++i;
            } break;
            default: break;
        }
    }
    return result;
}

////////////////////////////////
//~ Entry point

void P_AppStartup(String args_str)
{
    __prof;
    TempArena scratch = BeginScratchNoConflict();
    SharedAppState *g = &shared_app_state;

    AppArgList args = ParseAppArgs(scratch.arena, args_str);
    String logfile_name = Lit("log.log");
    String settings_file_name = Lit("settings.txt");
    String connect_address = ZI;
    for (AppArg *arg = args.first; arg; arg = arg->next) {
        String key = arg->key;
        String value = arg->value;
        if (EqString(key, Lit("log"))) {
            logfile_name = value;
        } else if (EqString(key, Lit("settings"))) {
            settings_file_name = value;
        } else if (EqString(key, Lit("connect"))) {
            connect_address = value;
        }
    }

    LAX args;
    LAX logfile_name;
    LAX settings_file_name;
    LAX connect_address;
    LAX GetDefaultAppWindowSettings;

#if !RtcIsEnabled
    /* Verify test modes aren't left on by accident in release mode */
    StaticAssert(BITBUFF_DEBUG == 0);
    StaticAssert(BITBUFF_TEST == 0);
#endif

#if BITBUFF_TEST
    BB_Test();
#endif

    g->arena = AllocArena(Gibi(64));

    g->write_path = InitializeAppWriteDirectory(g->arena, Lit(WRITE_DIR));

    /* Startup logging */
    {
        TempArena temp = BeginTempArena(scratch.arena);

        String logfile_dir = CatString(temp.arena, g->write_path, Lit("logs/"));
        String logfile_path = CatString(temp.arena, logfile_dir, logfile_name);
        P_MkDir(logfile_dir);

        P_LogStartup(logfile_path);
        P_LogInfoF("Start of logs");
        EndTempArena(temp);
    }
    P_LogInfoF("App started with args \"%F\" (%F parsed)", FmtString(args_str), FmtUint(args.count));
    for (AppArg *arg = args.first; arg; arg = arg->next) {
        P_LogInfoF("Parsed arg: key = \"%F\", value = \"%F\"", FmtString(arg->key), FmtString(arg->value));
    }

#if 0
    /* Read window settings from file */
    {
        TempArena temp = BeginTempArena(scratch.arena);

        P_WindowSettings window_settings = ZI;
        String settings_path = CatAppWritePath(temp.arena, settings_file_name);
        P_LogInfoF("Looking for settings file \"%F\"", FmtString(settings_path));
        if (P_IsFile(settings_path)) {
            P_LogInfoF("Settings file found");
            P_File settings_file = P_OpenFileRead(settings_path);
            String file_data = P_ReadFile(temp.arena, settings_file);
            P_CloseFIle(settings_file);
            P_LogInfoF("Deserializing settings file data: %F", FmtString(file_data));
            String error = ZI;
            P_WindowSettings *deser = SETTINGS_WindowSettingsFromString(temp.arena, file_data, &error);
            if (error.len > 0) {
                P_LogInfoF("Failed to load settings file with error - %F", FmtString(error));
                String msg = StringFormat(temp.arena,
                                                  Lit(
                                                      "Failed to loading settings file \"%F\":\n"
                                                      "------------\n"
                                                      "%F\n"
                                                      "------------\n"
                                                      "To stop this error from appearing, either fix the issue above or delete the file from the system."
                                                  ),
                                                  FmtString(settings_path),
                                                  FmtString(error));
                P_Panic(msg);
            }
            P_LogInfoF("Settings file loaded successfully");
            window_settings = *deser;
        } else {
            P_LogInfoF("Settings file not found, loading default");
            window_settings = GetDefaultAppWindowSettings(window);
        }
        PushStringToBuffer(StringFromArray(window_settings.title), Lit(WINDOW_TITLE));
        P_UpdateWindowSettings(window, &window_settings);

        EndTempArena(temp);
    }
#endif

    /* Global systems */
    RES_Startup();
    W_Startup();
    GPU_Startup();

    /* Subsystems */
    AC_StartupReceipt asset_cache_sr    = AC_Startup();
    TTF_Startup();
    S_StartupReceipt sprite_sr          = S_Startup();
    MIX_StartupReceipt mixer_sr         = MIX_Startup();
    D_StartupReceipt draw_sr            = D_Startup();

    /* Interface systems */
    SimStartupReceipt sim_sr            = SimStartup();
    PB_StartupReceipt playback_sr       = PB_Startup(&mixer_sr);
    UserStartupReceipt user_sr          = StartupUser(&sprite_sr, &draw_sr, &asset_cache_sr, &mixer_sr, &sim_sr, connect_address);

    LAX user_sr;
    LAX playback_sr;

#if 0
    /* Write window settings to file */
    {
        __profn("Write settings file");
        TempArena temp = BeginTempArena(scratch.arena);

        String window_settings_path = CatAppWritePath(temp.arena, settings_file_name);

        P_WindowSettings settings = P_GetWindowSettings(window);
        String str = SETTINGS_StringFromWindowSettings(temp.arena, &settings);
        P_LogInfoF("Serialized window settings: %F", FmtString(str));

        P_LogInfoF("Writing settings file to path \"%F\"", FmtString(window_settings_path));
        P_File settings_file = P_OpenFileWrite(window_settings_path);
        P_WriteFile(settings_file, str);
        P_CloseFIle(settings_file);
        P_LogInfoF("Finished writing settings file");

        EndTempArena(temp);
    }
#endif

#if 0
    P_ReleaseWindow(window);
#endif

    //P_LogInfoF("Program exited normally");
    EndScratch(scratch);
}