//
// Flash: Nonvolatile storage for settings / etc
//

#include "stm32f3xx_hal.h"
#include "flash.h"
#include "config.h"


// Private variables
static __attribute__((__section__(".eeprom"))) uint16_t eeprom_emulation[512]; // Takes up 1 page (1k size)
static therm_settings_t settings;
static therm_status_t status;


// Initialize flash and restore settings
void flash_init(void)
{
    flash_restoresettings();
}


// Save settings to flash memory
void flash_savesettings()
{
    // Unlock flash memory
    HAL_FLASH_Unlock();

    // Initialize eraser to erase one page of flash
    FLASH_EraseInitTypeDef eraser =
    {
            .TypeErase = TYPEERASE_PAGES,
            .PageAddress = eeprom_emulation,
            .NbPages = 1,
    };
    uint32_t errvar = 0;

    // Erase flash page
    HAL_FLASHEx_Erase(&eraser, &errvar);

    // Write new flash data
    uint16_t writectr;
    for(writectr = 0; writectr < 128; writectr++)// 128 bytes data
    {
        HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, (uint32_t)(eeprom_emulation+writectr), settings.data[writectr]);
    }

    // Write magic value to flash
    HAL_FLASH_Program(TYPEPROGRAM_HALFWORD, (uint32_t)(eeprom_emulation+FLASH_MAGIC_LOC),FLASH_MAGIC_VALUE);

    // Lock flash memory
    HAL_FLASH_Lock();
    HAL_Delay(2);
}


// Restore configuration from flash memory, if any was previously saved
void flash_restoresettings(void)
{
    // Check for magic flash value
    if(eeprom_emulation[FLASH_MAGIC_LOC] == FLASH_MAGIC_VALUE)
    {
        // Read page of flash into settings structure
        uint16_t readctr = 0;
        for(readctr = 0; readctr < 128; readctr++)
        {
            settings.data[readctr] = eeprom_emulation[readctr];
        }
    }
    // No data in flash! Set defaults here
    //TODO: Set all defaults
    else
    {
        settings.val.k_p = DEFAULT_K_P;
        settings.val.k_i = DEFAULT_K_I;
        settings.val.k_d = DEFAULT_K_D;
        settings.val.windup_guard = DEFAULT_WINDUP_GUARD;
        settings.val.sensor_type = 1;
        settings.val.setpoint_count = DEFAULT_SETPOINT_COUNT;
        settings.val.control_mode = DEFAULT_CONTROL_MODE;
        settings.val.plant_type = DEFAULT_PLANT_TYPE;
    }
}


// Accessor to retrieve settings structure
inline therm_settings_t* flash_getsettings(void)
{
    return &settings;
}

inline therm_status_t* runtime_status(void)
{
    return &status;
}