#if defined STM32F1
# include <stm32f10x.h>
#elif defined STM32F4
# include <stm32f4xx.h>
#endif

#include "stm32f4xx_conf.h"

#include <stdio.h>
#include <time.h>

#if defined STM32F4
extern uint64_t virtualClock;
void SysTick_Handler(void)
{
	virtualClock++;
}
#endif


void initGPIO()
{
    GPIO_InitTypeDef GPIO_Config;
#if defined STM32F1
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

    /* USART1 Tx */
    GPIO_Config.GPIO_Pin = GPIO_Pin_9;
    GPIO_Config.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Config.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_Config);

    /* USART1 Rx */
    GPIO_Config.GPIO_Pin = GPIO_Pin_10;
    GPIO_Config.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Config.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_Config);
#elif defined STM32F4
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);

    /* USART3 Tx */
    GPIO_Config.GPIO_Mode = GPIO_Mode_AF;
    GPIO_Config.GPIO_OType = GPIO_OType_PP;
    GPIO_Config.GPIO_Pin = GPIO_Pin_10;
    GPIO_Config.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Config.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOC, &GPIO_Config);

    /* USART3 Rx */
    GPIO_Config.GPIO_Pin = GPIO_Pin_11;
    GPIO_Init(GPIOC, &GPIO_Config);

    GPIO_PinAFConfig(GPIOC, GPIO_PinSource10, GPIO_AF_USART3);
    GPIO_PinAFConfig(GPIOC, GPIO_PinSource11, GPIO_AF_USART3);
#endif
}

void initRTC()
{
#if defined STM32F1
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);

    if (BKP_ReadBackupRegister(BKP_DR1) != 0xA5A5)
    {
        PWR_BackupAccessCmd(ENABLE);

        BKP_DeInit();
        RCC_LSEConfig(RCC_LSE_ON);

        while (RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET);

        RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);

        RCC_RTCCLKCmd(ENABLE);
        RTC_WaitForSynchro();
        RTC_WaitForLastTask();

        RTC_SetPrescaler(32767);
        RTC_WaitForLastTask();

        BKP_WriteBackupRegister(BKP_DR1, 0xA5A5);
        PWR_BackupAccessCmd(DISABLE);
    }
    RTC_WaitForSynchro();
    RTC_WaitForLastTask();
#elif defined STM32F4
    SysTick_Config(SystemCoreClock / 8 / 1000);
    SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK_Div8);
#endif
}

void initUSART()
{
    USART_InitTypeDef USART_InitStructure;

    USART_InitStructure.USART_BaudRate = 115200;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

#if defined STM32F1
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
    USART_Init(USART1, &USART_InitStructure);
    USART_Cmd(USART1, ENABLE);
#elif defined STM32F4
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
    USART_Init(USART3, &USART_InitStructure);
    USART_Cmd(USART3, ENABLE);
#endif

}

void setTime(uint32_t time)
{
#if defined STM32F1
    PWR_BackupAccessCmd(ENABLE);
    RTC_WaitForLastTask();
    RTC_SetCounter(time);
    RTC_WaitForLastTask();
    PWR_BackupAccessCmd(DISABLE);
#elif defined STM32F4
    virtualClock = (uint64_t)time * 1000;
#endif
}

void initAll(void)
{
    initRTC();
    initGPIO();
    initUSART();
    RCC_ClearFlag();
}

int main(void)
{
    initAll();
    for (;;)
    {
        char c;
        time_t t;
        scanf("%c", &c);
        switch (c)
        {
        case 's':
            scanf("%d", &t);
            setTime(t);
            printf("Current time changed: %d - %s\r", t, ctime(&t));
            break;
        default:
            t = time(0);
            printf("Current time: %d - %s\r", t, ctime(&t));
            break;
        }
    }
    return 0;
}