/*
 *  Copyright (c) 2017, The OpenThread Authors.
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the copyright holder nor the
 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdint.h>
#include <string.h>
#include <assert.h>

#include <openthread/types.h>
#include <openthread/platform/alarm.h>

#include <utils/code_utils.h>
#include <utils/flash.h>

#include "platform-nrf5.h"
#include "softdevice.h"

#define MIN(a, b)        (((a) < (b)) ? (a) : (b))
#define FLASH_PAGE_SIZE  4096
#define FLASH_TIMEOUT    1000

typedef enum {
    FLASH_STATUS_IDLE,
    FLASH_STATUS_PENDING,
    FLASH_STATUS_SUCCESS,
    FLASH_STATUS_FAILED
} SdFlashStatus;

static volatile SdFlashStatus sFlashStatus;

void nrf5SdSocFlashProcess(uint32_t aEvtId)
{
    switch (aEvtId)
    {
    case NRF_EVT_FLASH_OPERATION_SUCCESS:
        if (sFlashStatus == FLASH_STATUS_PENDING)
        {
            sFlashStatus = FLASH_STATUS_SUCCESS;
        }

        break;

    case NRF_EVT_FLASH_OPERATION_ERROR:
        if (sFlashStatus == FLASH_STATUS_PENDING)
        {
            sFlashStatus = FLASH_STATUS_FAILED;
        }

        break;

    default:
        break;
    }
}

static otError sdFlashSingleWrite(uint32_t aAddress, uint8_t *aData, uint32_t aSize)
{
    uint32_t retval;
    uint32_t startTime = otPlatAlarmGetNow();

    // Expect SotfDevice Flash Complete event.
    sFlashStatus = FLASH_STATUS_PENDING;

    retval = sd_flash_write((uint32_t *)aAddress, (uint32_t *)aData, aSize);

    if (retval == NRF_SUCCESS)
    {
        // Wait for SoftDevice Flash Complete event.
        do
        {
            if (sFlashStatus != FLASH_STATUS_PENDING)
            {
                break;
            }
        }
        while (otPlatAlarmGetNow() - startTime < FLASH_TIMEOUT);

        if (sFlashStatus != FLASH_STATUS_SUCCESS)
        {
            retval = NRF_ERROR_INTERNAL;
        }
    }

    sFlashStatus = FLASH_STATUS_IDLE;

    return nrf5SdErrorToOtError(retval);
}

otError nrf5FlashPageErase(uint32_t aAddress)
{
    uint32_t retval;
    uint32_t startTime = otPlatAlarmGetNow();

    // Expect SotfDevice Flash Complete event.
    sFlashStatus = FLASH_STATUS_PENDING;

    retval = sd_flash_page_erase(aAddress / FLASH_PAGE_SIZE);

    if (retval == NRF_SUCCESS)
    {
        // Wait for SoftDevice Flash Complete event.
        do
        {
            if (sFlashStatus != FLASH_STATUS_PENDING)
            {
                break;
            }
        }
        while (otPlatAlarmGetNow() - startTime < FLASH_TIMEOUT);

        if (sFlashStatus != FLASH_STATUS_SUCCESS)
        {
            retval = NRF_ERROR_INTERNAL;
        }
    }

    sFlashStatus = FLASH_STATUS_IDLE;

    return nrf5SdErrorToOtError(retval);
}

bool nrf5FlashIsBusy(void)
{
    return sFlashStatus != FLASH_STATUS_IDLE;
}

uint32_t nrf5FlashWrite(uint32_t aAddress, uint8_t *aData, uint32_t aSize)
{
    otError  error = OT_ERROR_NONE;
    uint32_t result = 0;
    uint32_t remainder = (aAddress % sizeof(uint32_t));
    uint32_t blockSize;
    uint32_t blockValue;

    otEXPECT(sFlashStatus == FLASH_STATUS_IDLE);

    // Check if @p aAddress is aligned to full word size. If not, make additional
    // flash write at the beginning.
    if (remainder)
    {
        blockSize  = MIN((sizeof(uint32_t) - remainder), aSize);
        blockValue = 0xffffffff;

        memcpy((uint8_t *)&blockValue + remainder, aData, blockSize);

        error = sdFlashSingleWrite(aAddress - remainder,
                                   (uint8_t *)&blockValue,
                                   sizeof(blockValue) / sizeof(uint32_t));

        otEXPECT(error == OT_ERROR_NONE);

        aAddress += blockSize;
        aData    += blockSize;
        aSize    -= blockSize;
        result   += blockSize;
    }

    otEXPECT(aSize);

    // Store the middle block of data.
    remainder = aSize % sizeof(uint32_t);
    blockSize = aSize - remainder;

    error = sdFlashSingleWrite(aAddress,
                               aData,
                               blockSize / sizeof(uint32_t));

    otEXPECT(error == OT_ERROR_NONE);

    aAddress += blockSize;
    aData    += blockSize;
    aSize    -= blockSize;
    result   += blockSize;

    // Store any additional bytes that didn't fit into middle block.
    if (remainder)
    {
        blockValue = 0xffffffff;

        memcpy((uint8_t *)&blockValue, aData, remainder);

        error = sdFlashSingleWrite(aAddress,
                                   (uint8_t *)&blockValue,
                                   sizeof(blockValue) / sizeof(uint32_t));

        otEXPECT(error == OT_ERROR_NONE);

        result += remainder;
    }

exit:
    return result;
}