#include "usart.h"
#include "crc.h"
#include "stm32f1xx.h"
#include "main.h"



// USART1 Send Byte (blocking)
void USART1_SendByte(uint8_t byte) {
    while (!(USART1->SR & USART_SR_TXE));  // Wait until transmit buffer empty
    USART1->DR = byte;                     // Send byte
    while (!(USART1->SR & USART_SR_TC));   // Wait until transmission complete
}

// USART1 Receive Byte (blocking)
uint8_t USART1_ReceiveByte(void) {
    while (!(USART1->SR & USART_SR_RXNE)); // Wait until data received
    return USART1->DR;                     // Return received byte
}
// Receive byte with timeout (returns 0xFF if timeout)
uint8_t USART1_ReceiveByteTimeout(uint32_t timeout) {
    uint32_t start = HAL_GetTick();
    while (!(USART1->SR & USART_SR_RXNE)) {
        if (HAL_GetTick() - start > timeout) {
            return 0xFF;  // Timeout
        }
    }
    return USART1->DR;
}
// Flush receive buffer
void USART1_Flush(void) {
    while (USART1->SR & USART_SR_RXNE) {
        USART1->DR;  // Read and discard
    }
}

void USART1_SendPacket(const uint8_t *data, uint8_t length) {

    uint16_t crc = crc16(data, length);
    uint8_t crc_h = (crc >> 8) & 0xFF;    // CRC high byte (big-endian)
    uint8_t crc_l = crc & 0xFF;           // CRC low byte

    USART1_SendByte(0x02); // Start byte
    USART1_SendByte(0x02); // length type < 256
    USART1_SendByte(length);
    for (uint16_t i = 0; i < length; i++) {
        USART1_SendByte(data[i]);
    }
    USART1_SendByte(crc_h);
    USART1_SendByte(crc_l);
    USART1_SendByte(0x03);
}
void USART1_ReceivePacket(void) {

}

// Receive data types (big-endian)
uint16_t USART1_ReceiveUInt16(void) {
    uint16_t value = (uint16_t)USART1_ReceiveByte() << 8;  // MSB first
    value |= USART1_ReceiveByte();                          // LSB second
    return value;
}

int16_t USART1_ReceiveInt16(void) {
    return (int16_t) USART1_ReceiveUInt16();  // Same byte order, just cast
}

uint32_t USART1_ReceiveUInt32(void) {
    uint32_t value = (uint32_t)USART1_ReceiveByte() << 24;  // MSB first
    value |= (uint32_t)USART1_ReceiveByte() << 16;
    value |= (uint32_t)USART1_ReceiveByte() << 8;
    value |= USART1_ReceiveByte();                          // LSB last
    return value;
}

int32_t USART1_ReceiveInt32(void) {
    return (int32_t)USART1_ReceiveUInt32();  // Same byte order, just cast
}