/**********************************************************************//**
 *
 *  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 ModeRecirculate.c
 *
 *  @date 03-Apr-2020
 *  @author S. Nash
 *
 *  @brief Top-level state machine for the re-circulate mode.
 *
 **************************************************************************/

#include "FPGA.h"
#include "OperationModes.h"
#include "ROPump.h"
#include "TaskGeneral.h"
#include "Timers.h"
#include "ModeRecirculate.h"

/**
 *  @addtogroup RecirculateMode
 *  @{
 */

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

#define TARGET_RO_PRESSURE_PSI          120                    ///< Target pressure for RO pump.
#define FLUSH_LINES_VOLUME_L            0.1                    ///< Water volume (in Liters) to flush when starting re-circulate mode.

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

static RECIRCULATE_MODE_STATE_T recircState;                   ///< Currently active re-circulation state.
static F32 flushLinesVolume = 0.0;                             ///< Volume of water pumped by RO pump during flush lines state.

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

static RECIRCULATE_MODE_STATE_T handleFlushLinesState( void );
static RECIRCULATE_MODE_STATE_T handleRecircWaterState( void );
static RECIRCULATE_MODE_STATE_T handleRecircPauseState( void );

/*********************************************************************//**
 * @brief
 * The initRecirculateMode function initializes the Fill Mode module.
 * @details
 * Inputs : none
 * Outputs : Fill Mode module initialized.
 * @return none
 *************************************************************************/
void initRecirculateMode( void )
{
    recircState = RECIRCULATE_MODE_STATE_START;
    flushLinesVolume = 0.0;
}

/*********************************************************************//**
 * @brief
 * The transitionToRecirculateMode function prepares for transition to \n
 * fill mode.
 * @details
 * Inputs : none
 * Outputs : recircState
 * @return none
 *************************************************************************/
void transitionToRecirculateMode( void )
{
    // re-initialize each time we transition to re-circulate mode
    initRecirculateMode();

    // TODO - set initial actuator states
    setFPGAValveStates(0x014F);
    // VPi open, VRc re-circ, VDr and VPo to drain
    // UV on
    // Primary heater on
}

/*********************************************************************//**
 * @brief
 * The execRecirculateMode function executes the Re-circulate Mode state machine.
 * @details
 * Inputs : recircState
 * Outputs : recircState
 * @return none
 *************************************************************************/
void execRecirculateMode( void )
{
    // execute current re-circulate state
    switch ( recircState )
    {
        case RECIRCULATE_MODE_STATE_START:
            setROPumpTargetPressure( TARGET_RO_PRESSURE_PSI, PUMP_CONTROL_MODE_CLOSED_LOOP );
            recircState = RECIRCULATE_MODE_STATE_FLUSH_LINES;
            break;

        case RECIRCULATE_MODE_STATE_FLUSH_LINES:
            recircState = handleFlushLinesState();
            break;

        case RECIRCULATE_MODE_STATE_RECIRC_WATER:
            recircState = handleRecircWaterState();
            break;

        case RECIRCULATE_MODE_STATE_PAUSE:
            recircState = handleRecircPauseState();
            break;

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

/*********************************************************************//**
 * @brief
 * The handleCheckInletWaterState function executes the flush lines \n
 * state of the Re-circulate Mode state machine.
 * @details
 * Inputs : none
 * Outputs :
 * @return the next state
 *************************************************************************/
static RECIRCULATE_MODE_STATE_T handleFlushLinesState( void )
{
    RECIRCULATE_MODE_STATE_T result = RECIRCULATE_MODE_STATE_FLUSH_LINES;
    F32 waterFlowRate = getMeasuredROFlowRate();
    F32 waterVolume = ( ( waterFlowRate / SEC_PER_MIN ) / ( MS_PER_SECOND / TASK_GENERAL_INTERVAL ) );

    flushLinesVolume += waterVolume;

    // when enough water volume has flowed to flush the lines, transition to re-circ state
    if ( flushLinesVolume >= FLUSH_LINES_VOLUME_L )
    {
        // TODO - change VDr from drain to re-circulate
        result = RECIRCULATE_MODE_STATE_RECIRC_WATER;
    }

    return result;
}

/*********************************************************************//**
 * @brief
 * The handleRecircProductWaterState function executes the re-circulate \n
 * water state of the Re-circulate Mode state machine.
 * @details
 * Inputs : none
 * Outputs :
 * @return the next state
 *************************************************************************/
static RECIRCULATE_MODE_STATE_T handleRecircWaterState( void )
{
    RECIRCULATE_MODE_STATE_T result = RECIRCULATE_MODE_STATE_RECIRC_WATER;

    return result;
}

/*********************************************************************//**
 * @brief
 * The handleRecircPauseState function executes the pause state of the \n
 * Re-circulate Mode state machine.
 * @details
 * Inputs : none
 * Outputs :
 * @return the next state
 *************************************************************************/
static RECIRCULATE_MODE_STATE_T handleRecircPauseState( void )
{
    RECIRCULATE_MODE_STATE_T result = RECIRCULATE_MODE_STATE_PAUSE;

    return result;
}

/*********************************************************************//**
 * @brief
 * The requestDGStop function handles an HD request to stop (return to Standby mode).
 * @details
 * Inputs : none
 * Outputs : DG standby mode requested
 * @return TRUE if request accepted, FALSE if not.
 *************************************************************************/
BOOL requestDGStop( void )
{
    BOOL result = TRUE;

    requestNewOperationMode( MODE_STAN );

    return result;
}

/*********************************************************************//**
 * @brief
 * The getRecirculateModeState function returns the current state of the \n
 * re-circulate mode.
 * @details
 * Inputs : recircState
 * Outputs : none
 * @return the current state of re-circulate mode.
 *************************************************************************/
RECIRCULATE_MODE_STATE_T getRecirculateModeState( void )
{
    return recircState;
}

/**@}*/