/*
 * ModeStandby.c
 *
 *  Created on: Aug 7, 2024
 *      Author: fw
 */

#include <string.h>     // For memcpy and memset

#include "sys_core.h"   // To disable RAM and Flash ECC
#include "sys_mpu.h"    // To disable MPU

#include "Download.h"
#include "FPGA.h"
#include "ModeStandby.h"
#include "NVDataMgmt.h"
#include "OperationModes.h"
#include "Timers.h"
#include "Utilities.h"


#define WAIT_FOR_UPDATE_FROM_UI_MS                  1000

static MODE_STANDBY_STATE_T standbyCurrentState;
static U32 waitForUpdateMsgStartTimeMS;

static MODE_STANDBY_STATE_T handleStandbyModeCheckForUpdateState( void );
static MODE_STANDBY_STATE_T handleStandbyModeCheckFWAndFPGAImages( void );
static MODE_STANDBY_STATE_T handleStandbyModeIdleState( void );

static void jumpToApplication( void );


void initStandbyMode( void )
{
    standbyCurrentState         = STANDBY_CHECK_FOR_UPDATE_STATE;
    waitForUpdateMsgStartTimeMS = getMSTimerCount();
}

U32 transitionToStandbyMode( void )
{
    initStandbyMode();

    return 0;
}

U32 execStandbyMode( void )
{
    // If the bootloader is the standby mode and and update request is received at any time, request a transition to update mode
    // TODO what if we are in the check image process, should we transition to update upon the request?
    if ( ( UPDATE_CMD_START == getSWUpdateCommandState() ) || ( TRUE == hasUpdateBeenRequested() ) )
    {
        // TODO if we are here because of the FPGA register, clear it so it won't be called again.
        requestNewOperationMode( MODE_UPDATE );
    }

    switch( standbyCurrentState )
    {
        case STANDBY_CHECK_FOR_UPDATE_STATE:
            standbyCurrentState = handleStandbyModeCheckForUpdateState();
            break;

        case STANDBY_CHECK_FW_AND_FPGA_IMAGES_STATE:
            standbyCurrentState = handleStandbyModeCheckFWAndFPGAImages();
            break;

        case STANDBY_IDLE_STATE:
            standbyCurrentState = handleStandbyModeIdleState();
            break;

        default:
            // Do nothing
            break;
    }

    return standbyCurrentState;
}


static MODE_STANDBY_STATE_T handleStandbyModeCheckForUpdateState( void )
{
    MODE_STANDBY_STATE_T state = STANDBY_CHECK_FOR_UPDATE_STATE;

    switch ( getSWUpdateCommandState() )
    {
        case UPDATE_CMD_ABORT:
            state = STANDBY_IDLE_STATE;
            break;

        case UPDATE_CMD_VERIFY:
            state = STANDBY_CHECK_FW_AND_FPGA_IMAGES_STATE;
            break;

        default:
            // Do nothing
            break;
    }

    if ( TRUE == didTimeout( waitForUpdateMsgStartTimeMS, 3000000 /*WAIT_FOR_UPDATE_FROM_UI_MS*/ ) ) // TODO a high number if timeout for development
    {
        state = STANDBY_CHECK_FW_AND_FPGA_IMAGES_STATE;
    }

    return state;
}

static MODE_STANDBY_STATE_T handleStandbyModeCheckFWAndFPGAImages( void )
{
    MODE_STANDBY_STATE_T state = STANDBY_CHECK_FW_AND_FPGA_IMAGES_STATE;
    BOOL isFirmwareImageValid  = FALSE;
    BOOL isFPGAImageValid      = FALSE;
    // TODo timeout and wait for a while prior to transitioning
    // TODO why a bad code passes the CRC?
    _disable_IRQ();
    if ( TRUE == isFWCRCTableValid() )
    {
        isFirmwareImageValid = runFWIntegrityTest();
    }
    _enable_IRQ();

    if ( TRUE == isFPGAIDValid() )
    {
        isFPGAImageValid = TRUE;
    }

    if ( ( TRUE == isFirmwareImageValid ) && ( TRUE == isFPGAImageValid ) )
    {
        // All good, jump to application
        jumpToApplication();
    }
    else
    {
        // TODO do we need to try a few times prior to tansitioning to Idle?

        // If either of the images (firmware or FPGA) failed, go to the idle state until another update request is received
        state = STANDBY_IDLE_STATE;
    }

    return state;
}

static MODE_STANDBY_STATE_T handleStandbyModeIdleState( void )
{
    MODE_STANDBY_STATE_T state = STANDBY_IDLE_STATE;

    // This state does nothing and waits until another update request is received. This could be because the update was aborted or
    // the firmware or FPGA have bad images. So we cannot jump to the application.

    return state;
}

static void jumpToApplication( void )
{
    U32 jumpAddress = (U32)FIRMWARE_START_ADDRESS;

    // Disable various memory protections
    _coreDisableRamEcc_();
    _coreDisableFlashEcc_();
    _mpuDisable_();

    // Disable all interrupts
    _disable_interrupt_();
    _disable_IRQ_interrupt_();
    _disable_FIQ_interrupt_();

    ((void (*)(void))jumpAddress)();
    while(1);
}