/*
 * TFTP.c
 *
 * Created: 26.05.2021 17:39:50
 *  Author: Admin
 */ 

#include "lwip/api.h"
#include "tftp_server.h"
#include "ff.h"
#include "string.h"
#include "log_and_debug.h"

uint32_t TFTPbyteWrite = 0;
uint32_t TFTPbyteRead = 0;

static void* tftp_open(const char* fname, const char* mode, u8_t write);
static void tftp_close(void* handle);
static int tftp_write(void* handle, struct pbuf* p);
static int tftp_read(void* handle, void* buf, int bytes);

void tftpServer_init(void)
{
	static const struct  tftp_context tftp = {
		tftp_open,
		tftp_close,
		tftp_read,
		tftp_write,
	};
	
	if(tftp_init(&tftp) == ERR_OK) __debug(DEBUG_SERVSE, "TFTP server started: port 69\r\n");
}

static void* tftp_open(const char* fname, const char* mode, u8_t write)
{
	void *file = NULL;
	static FIL FSFileTFTP;
	
	__debug(DEBUG_SERVSE, "TFTP: path to file %s %s\r\n", fname, write ? "write" : "read");
	
	switch(write){
		case 0:
		if(f_open(&FSFileTFTP, fname, FA_READ) == FR_OK)file = (void*)&FSFileTFTP;
		break;
		case 1:
		if(f_open(&FSFileTFTP, fname, FA_CREATE_ALWAYS | FA_WRITE) == FR_OK)file = (void*)&FSFileTFTP;
		break;
	}
	return file;
}

static void tftp_close(void* handle)
{
	f_close((FIL*)handle);
	TFTPbyteWrite = 0;
	TFTPbyteRead = 0;
}

static int tftp_write(void* handle, struct pbuf* p)
{
	uint32_t TFTPbyteWritten = 0;
	if((FIL*)handle == NULL) return -1;
	f_lseek((FIL*)handle, TFTPbyteWrite);
	if(f_write((FIL*)handle, p->payload, (UINT)p->len, (UINT*)&TFTPbyteWritten) != FR_OK)return -1;
	TFTPbyteWrite += p->len;
	return 0;
}

static int tftp_read(void* handle, void* buf, int bytes)
{
	uint32_t TFTPbyteReading = 0;
	if((FIL*)handle == NULL) return -1;
	f_lseek((FIL*)handle, TFTPbyteRead);
	if(f_read((FIL*)handle, buf, (UINT)bytes, (UINT*)&TFTPbyteReading) != FR_OK)return -1;
	TFTPbyteRead += bytes;
	return TFTPbyteReading;
}