#include "flash_config.h"
#include <string.h>

// 计算校验和
static uint32_t Calculate_Checksum(const uint8_t *data, uint32_t len)
{
    uint32_t sum = 0;
    for(uint32_t i = 0; i < len; i++) {
        sum += data[i];
    }
    return sum;
}

// 擦除配置页
static HAL_StatusTypeDef Flash_Config_Erase(void)
{
    FLASH_EraseInitTypeDef EraseInitStruct;
    uint32_t PAGEError;

    HAL_FLASH_Unlock();

    EraseInitStruct.TypeErase   = FLASH_TYPEERASE_PAGES;
    EraseInitStruct.PageAddress = FLASH_CONFIG_PAGE_ADDR;
    EraseInitStruct.NbPages     = 1;

    if(HAL_FLASHEx_Erase(&EraseInitStruct, &PAGEError) != HAL_OK)
    {
        HAL_FLASH_Lock();
        return HAL_ERROR;
    }

    HAL_FLASH_Lock();
    return HAL_OK;
}

// 保存配置到Flash
HAL_StatusTypeDef Flash_Config_Save(FlashConfig_t *config)
{
    HAL_StatusTypeDef status;
    uint32_t *source = (uint32_t*)config;
    uint32_t address = FLASH_CONFIG_PAGE_ADDR;
    uint32_t words = (sizeof(FlashConfig_t) + 3) / 4;

    // 设置魔数和计算校验和
    config->magic = FLASH_CONFIG_MAGIC;
    config->checksum = Calculate_Checksum((uint8_t*)config, 
                                        sizeof(FlashConfig_t) - sizeof(uint32_t));

    // 擦除页
    if((status = Flash_Config_Erase()) != HAL_OK)
        return status;

    // 写入数据
    HAL_FLASH_Unlock();
    
    for(uint32_t i = 0; i < words; i++)
    {
        if(HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, 
                            address + (i * 4), 
                            source[i]) != HAL_OK)
        {
            HAL_FLASH_Lock();
            return HAL_ERROR;
        }
    }

    HAL_FLASH_Lock();
    return HAL_OK;
}

// 从Flash加载配置
HAL_StatusTypeDef Flash_Config_Load(FlashConfig_t *config)
{
    FlashConfig_t *flash_config = (FlashConfig_t*)FLASH_CONFIG_PAGE_ADDR;
    
    // 检查魔数
    if(flash_config->magic != FLASH_CONFIG_MAGIC)
    {
        Flash_Config_SetDefault(config);
        return HAL_ERROR;
    }

    // 复制数据
    memcpy(config, flash_config, sizeof(FlashConfig_t));

    // 验证校验和
    uint32_t checksum = Calculate_Checksum((uint8_t*)config, 
                                         sizeof(FlashConfig_t) - sizeof(uint32_t));
    if(checksum != config->checksum)
    {
        Flash_Config_SetDefault(config);
        return HAL_ERROR;
    }

    return HAL_OK;
}

// 设置默认配置
void Flash_Config_SetDefault(FlashConfig_t *config)
{
    // 设置默认网络配置
    config->net_config.mac[0] = 0x00;
    config->net_config.mac[1] = 0x08;
    config->net_config.mac[2] = 0xDC;
    config->net_config.mac[3] = 0x12;
    config->net_config.mac[4] = 0x34;
    config->net_config.mac[5] = 0x56;

    config->net_config.ip[0] = 169;
    config->net_config.ip[1] = 254;
    config->net_config.ip[2] = 1;
    config->net_config.ip[3] = 11;

    config->net_config.sn[0] = 255;
    config->net_config.sn[1] = 255;
    config->net_config.sn[2] = 255;
    config->net_config.sn[3] = 0;

    config->net_config.gw[0] = 169;
    config->net_config.gw[1] = 254;
    config->net_config.gw[2] = 1;
    config->net_config.gw[3] = 1;

    config->net_config.dns[0] = 8;
    config->net_config.dns[1] = 8;
    config->net_config.dns[2] = 8;
    config->net_config.dns[3] = 8;

    config->net_config.dhcp = NETINFO_STATIC;
}