/**************************************************************************
*
* Copyright (c) 2019-2020 Diality Inc. - All Rights Reserved.
*
* THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
* WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
*
* @file ModeDrain.c
*
* @author (last) Quang Nguyen
* @date (last) 24-Aug-2020
*
* @author (original) Leonardo Baloa
* @date (original) 20-Dec-2019
*
***************************************************************************/

#include "ConductivitySensors.h"
#include "DrainPump.h"
#include "ModeDrain.h"
#include "OperationModes.h"
#include "Pressures.h"
#include "Reservoirs.h"
#include "ROPump.h"
#include "TaskGeneral.h"
#include "TemperatureSensors.h"
#include "Valves.h"

/**
 *  @addtogroup DGDrainMode
 *  @{
 */

// ********** private definitions **********

#define TARGET_DRAIN_PUMP_RPM           1800                                ///< Target drain pump speed (in RPM).
#define DRAIN_WEIGH_UNCHANGE_TIMEOUT    ( 2 * MS_PER_SECOND )               ///< Time period of unchanged weight during draining before timeout.

#define TARGET_RO_PRESSURE_PSI          130                                 ///< Target pressure for RO pump.
#define TARGET_RO_FLOW_RATE_L           0.3                                 ///< Target flow rate for RO pump.

// ********** private data **********

static DG_DRAIN_STATE_T drainState = DG_DRAIN_STATE_START;                  ///< Currently active drain state.

// ********** private function prototypes **********

static DG_DRAIN_STATE_T handleDrainState( void );

/*********************************************************************//**
 * @brief
 * The initDrainMode function initializes the drain mode module.
 * @details Inputs: none
 * @details Outputs: drainState
 * @return none
 *************************************************************************/
void initDrainMode( void )
{
    drainState = DG_DRAIN_STATE_START;
}

/*********************************************************************//**
 * @brief
 * The transitionToDrainMode function prepares for transition to drain mode.
 * @details Inputs: none
 * @details Outputs: Drain mode initialized
 * @return none
 *************************************************************************/
void transitionToDrainMode( void )
{
    // re-initialize each time we transition to drain mode
    initDrainMode();

    // set initial actuator states
    setValveState( VDR, VALVE_STATE_DRAIN_C_TO_NO );
    setDrainPumpTargetRPM( TARGET_DRAIN_PUMP_RPM );
    setROPumpTargetFlowRate( TARGET_RO_FLOW_RATE_L, TARGET_RO_PRESSURE_PSI );
}

/*********************************************************************//**
 * @brief
 * The execDrainMode function executes the drain mode state machine.
 * @details Inputs: drainState
 * @details Outputs: Check water quality, drain mode state machine executed
 * @return current state.
 *************************************************************************/
U32 execDrainMode( void )
{
    // check inlet water conductivity, temperature, pressure, and RO rejection ratio
    checkInletWaterConductivity();
    checkInletWaterTemperature();
    checkInletPressure();
    checkRORejectionRatio();

    // execute current drain state
    switch ( drainState )
    {
        case DG_DRAIN_STATE_START:
            drainState = DG_DRAIN_STATE_DRAIN;
            break;

        case DG_DRAIN_STATE_DRAIN:
            drainState = handleDrainState();
            break;

        default:
            SET_ALARM_WITH_2_U32_DATA( ALARM_ID_DG_SOFTWARE_FAULT, 0, drainState ) // TODO - add s/w fault enum to 1st data param
            drainState = DG_DRAIN_STATE_START;
            break;
    }

    return drainState;
}

/*********************************************************************//**
 * @brief
 * The handleDrainState function handles the drain state  of the drain mode state machine.
 * @details Inputs: none
 * @details Outputs: Drain out from reservoir
 * @return the next state
 *************************************************************************/
static DG_DRAIN_STATE_T handleDrainState( void )
{
    DG_DRAIN_STATE_T result = DG_DRAIN_STATE_DRAIN;
    DG_RESERVOIR_ID_T inactiveReservoir = getInactiveReservoir();

    // if we have reached our target drain to volume (by weight) or cannot drain anymore, we are done draining - go back to re-circ mode
    if ( hasTargetDrainVolumeBeenReached( inactiveReservoir, DRAIN_WEIGH_UNCHANGE_TIMEOUT ) )
    {
        setDrainPumpTargetRPM( 0 );
        requestNewOperationMode( DG_MODE_CIRC );
    }

    return result;
}

/*********************************************************************//**
 * @brief
 * The getCurrentDrainState function returns the current state of the drain mode.
 * @details Inputs: drainState
 * @details Outputs: none
 * @return the current state of drain mode.
 *************************************************************************/
DG_DRAIN_STATE_T getCurrentDrainState( void )
{
    return drainState;
}

/**@}*/