// SPDX-License-Identifier: Apache-2.0
// Copyright (c) 2012-2024 Scott Penrose <scottp@dd.com.au> and WII5 Buoy contributors
//
// This file is part of WII5 Buoy firmware.
// See LICENSE for full terms.

/**
 * @file WII5ModePosition.h
 * @brief Declares WII5ModeLowBattery (low-battery mode).
 *
 * @note The WII5ModePosition.h / WII5ModeLowBattery.h header pair are
 * swapped relative to their filenames in this codebase: this file
 * (WII5ModePosition.h) declares class WII5ModeLowBattery, and
 * WII5ModeLowBattery.h declares class WII5ModePosition. The corresponding
 * .cpp files match their filenames. TODO: untangle and rename.
 */

#ifndef WII5ModeLowBattery_h
#define WII5ModeLowBattery_h

#include <Arduino.h>
#include <WII5.h>
#include <TimeLib.h>

enum WII5LOWBATTERY_STEPS {
  WII5LOWBATTERY_START,
  WII5LOWBATTERY_STROBE,
  WII5LOWBATTERY_TIME,
  WII5LOWBATTERY_GPS_START,
  WII5LOWBATTERY_GPS_WAIT,
  WII5LOWBATTERY_IRIDIUM_WAIT,
  WII5LOWBATTERY_END
};

/**
 * @brief Low-battery mode: degraded operation when supply is depleted.
 *
 * Suppresses Capture mode's heavy operations (IMU, SD writes), keeps
 * a minimum-viable position+telemetry cadence, and pesters Iridium
 * with a battery-low alert. The buoy returns to its default mode once
 * battery voltage recovers (or via an explicit Iridium override).
 */
class WII5ModeLowBattery : public WII5Mode {
  public:
		WII5ModeLowBattery() {}
    /** @brief Reset to WII5LOWBATTERY_START. */
    void reset();
    /** @brief One-time bring-up. */
    void begin();
    /** @brief State-machine tick. */
    void loop();
    /** @brief Begin a low-battery alert cycle. */
    void start();
    /** @brief Abort the current cycle. */
    void stop();

  protected:
    bool first;
    elapsedMillis displayWait;
    elapsedMillis wait;
    WII5LOWBATTERY_STEPS step;
    WII5LOWBATTERY_STEPS lastStep;
    uint32_t minutes; // since midnight.
};

extern WII5ModeLowBattery wii5ModeLowBattery;

#endif