#include "parameters.h"
#include <stm32l1xx.h>
#include <string.h>
#include <chprintf.h>

static int32_t * const data_eeprom = (int32_t * const)0x08080000;

typedef struct {
    int32_t *variable;
    char name[32];
} parameter_t;

#define X(variable) {&variable, #variable},
static const parameter_t param_defs[] =
{
    PARAMETERS
};
#undef X
#define NUM_PARAMETERS (sizeof(param_defs) / sizeof(param_defs[0]))
static const int signature = 0x53504800 ^ PARAMETERS_VERSION;

// Collect variable values to an array
static void collect_data(int32_t *array)
{
    *array++ = signature;
    *array++ = NUM_PARAMETERS;
    chSysLock();
    for (int i = 0; i < NUM_PARAMETERS; i++)
    {
        *array++ = *param_defs[i].variable;
    }
    chSysUnlock();
}

// Restore variable values from array to variables
static bool restore_data(int32_t *array)
{
    if (*array++ != signature)
        return false;
    
    int num_in_mem = *array++;
    if (num_in_mem > NUM_PARAMETERS)
        num_in_mem = NUM_PARAMETERS;
    
    chSysLock();
    for (int i = 0; i < num_in_mem; i++)
    {
        *param_defs[i].variable = *array++;
    }
    chSysUnlock();
    
    return true;
}

void parameters_save()
{
    int32_t params[NUM_PARAMETERS + 2] = {};
    collect_data(params);
    
    FLASH->PEKEYR = 0x89ABCDEF;
    FLASH->PEKEYR = 0x02030405;
    int32_t *dest = data_eeprom;
    int32_t *src = params;
    for (int i = 0; i < NUM_PARAMETERS + 2; i++)
    {
        while (FLASH->SR & FLASH_SR_BSY) chThdSleepMilliseconds(1);
        
        *dest++ = *src++;
    }
    FLASH->PECR |= FLASH_PECR_PELOCK;
}

bool parameters_load()
{
    return restore_data(data_eeprom);
}

void parameters_print(BaseSequentialStream *chp, bool machine_readable)
{
    int32_t *array = data_eeprom;
    if (*array++ != signature)
    {
        chprintf(chp, "EEPROM signature invalid\r\n");
    }

    array++;
    
    for (int i = 0; i < NUM_PARAMETERS; i++)
    {
        if (machine_readable)
            chprintf(chp, "set %s %d\r\n",param_defs[i].name, *param_defs[i].variable);
        else
            chprintf(chp, "%32s current: %6d  stored: %6d\r\n",
                 param_defs[i].name, *param_defs[i].variable, *array++);
    }
}

bool parameter_set(const char *name, int32_t value)
{
    for (int i = 0; i < NUM_PARAMETERS; i++)
    {
        if (strcasecmp(name, param_defs[i].name) == 0)
        {
            *param_defs[i].variable = value;
            return true;
        }
    }
    return false;
}

bool parameter_get(const char *name, int32_t *value)
{
    for (int i = 0; i < NUM_PARAMETERS; i++)
    {
        if (strcasecmp(name, param_defs[i].name) == 0)
        {
            *value = *param_defs[i].variable;
            return true;
        }
    }
    return false;
}