// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.settings;

using fuchsia.ui.types;

/// Settings related to display.
///
/// Supported SettingsEpitaph enums:
/// REQUEST_NOT_SUPPORTED, INTERNAL_SERVICE_ERROR, PERSISTENT_STORAGE_ERROR
[Discoverable]
protocol Display {
    /// Gets the current [DisplaySettings]. Returns immediately on first call;
    /// subsequent calls return when the value changes.
    ///
    /// If this call fails, it is considered a fatal error and the channel
    /// will be closed.
    Watch() -> (DisplaySettings settings);

    /// Obtains the current data from the light sensor. Returns immediately on
    /// first call; subsequent calls return when the light sensor value changes
    ///  by a certain amount measured in lux.
    ///
    /// If this call fails, it is considered a fatal error and the channel
    /// will be closed.
    [Transitional = "Deprecated in favor of WatchLightSensor"]
    WatchLightSensor2(float32 delta) -> (LightSensorData light_sensor_data);

    /// Obtains the current data from the light sensor. Returns immediately on
    /// first call; subsequent calls return when the light sensor value changes
    ///  by a certain amount measured in lux.
    ///
    /// If this call fails, it is considered a fatal error and the channel
    /// will be closed.
    [Transitional = "Future replacement for WatchLightSensor2"]
    WatchLightSensor(float32 delta) -> (LightSensorData light_sensor_data);

    /// Sets display settings. Any field not explicitly set in the table performs a
    /// no-op, and will not make any changes.
    Set(DisplaySettings settings) -> () error Error;
};

/// DisplaySettings are used to determine the output state of the display.
/// The display can be toggled between two modes, auto-brightness on and
/// auto-brightness off.
///
/// Adjusted_auto_brightness is used to set a specific brightness level for the
/// current lighting conditions. Auto-brightness will continue to make the
/// screen darker and brighter as the surrounding light changes.
///
/// Brightness_value is used in manual mode to set a specific brightness level
/// for the screen. This level will be maintained while in manual mode.
table DisplaySettings {
    /// Auto brightness enabled.
    1: bool auto_brightness;
    /// Manually set brightness value [0.0 - 1.0]. Not a number, infinity or
    /// negative infinity will cause SetDisplayInfo to fail with INVALID_VALUE.
    2: float32 brightness_value;
    3: reserved;
    /// The low light mode state of the device.
    4: LowLightMode low_light_mode;
    /// Whether the screen is enabled.
    5: bool screen_enabled;
    /// Theme to be used for the device's user interface.
    6: Theme theme;
    /// Brightness value to adjust auto-brightness to [0.0 - 1.0].
    7: float32 adjusted_auto_brightness;
};

table LightSensorData {
    /// Brightness from the light sensor measured in lux.
    1: float32 illuminance_lux;

    /// Color measured by light sensor in rgb.
    2: fuchsia.ui.types.ColorRgb color;
};

table Theme {
    // theme_type will be absent if no theme has been set.
    1: ThemeType theme_type;
    // Lack of a theme mode can be represented by an absent theme_mode or a
    // theme_mode of 0x0.
    2: ThemeMode theme_mode;
};

enum LowLightMode {
    /// Device should not be in low-light mode.
    DISABLE = 0;
    /// Device should not be in low-light mode and should transition
    /// out of it immediately.
    DISABLE_IMMEDIATELY = 1;
    /// Device should be in low-light mode.
    ENABLE = 2;
};

// Specifies a specific theme that should be used by the UI.
// Any other theme information, such as guidance as to how to pick a theme,
// should be communicated using `ThemeMode`.
enum ThemeType {
    DEFAULT = 0;
    LIGHT = 1;
    DARK = 2;

    /// Product can choose a theme based on ambient cues.
    // DEPRECATED: AUTO should be indicated using the AUTO value in
    // ThemeMode.
    //
    // TODO(https://bugs.fuchsia.dev/p/fuchsia/issues/detail?id=64775):
    // Remove AUTO.
    AUTO = 3;
};

// Specifies options that pertain to selection or display of a theme in the
// UI. If a specific theme needs to be specified, that should be done using
// `ThemeType`.
bits ThemeMode {
    /// Product can choose a theme based on ambient cues.
    AUTO = 0x01;
};