//This program is dedicated to creating a communication between a PC and a Terasic DE1-SoC (Altera).
//The link between the two entities is a mini-USB
//The library that we use is libusb whose version is 1.0

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include "./include/libusb-1.0/libusb.h"

typedef struct libusb_device libusb_device;
typedef struct libusb_device_descriptor libusb_device_descriptor;
typedef struct libusb_device_handle libusb_device_handle;
typedef struct libusb_config_descriptor libusb_config_descriptor;



libusb_device ** list = NULL;
libusb_device * myDevice = NULL;
libusb_device_descriptor desc;
libusb_device_handle * handle = NULL;
libusb_config_descriptor * confDesc = NULL;

int main(void)
{
	//Initialization
	if (libusb_init(NULL) == 0) printf("Initialization : success\n");
	else printf("Initialization : failed\n");

	//Retrieves plugged USB devices in a data structure
	int cnt = libusb_get_device_list(NULL, &list);
	printf("%d found devices\n",cnt);

	//Looks for the one we're interested in
	int i = 0;
	bool done = false;

	while (i < cnt && done == false)
	{
		if (libusb_get_device_descriptor (list[i], &desc) != 0) printf("Descriptor : Failed");
		printf("Product ID : %d Vendor ID : %d\n",desc.idProduct,desc.idVendor);
		if((desc.idProduct == 0x6001 && desc.idVendor == 0x0403) == true) done = true;
		i++;	
	} 

	if (done == true)
	{
		i--;
		printf("Device found\n");
		printf("Port : %d\n",libusb_get_port_number (list[i]));
		myDevice = list[i];
	}
	else printf("Device not found\n");

	//Places a handle on a given device
	int handleReturn = -1;
	if (done == true) handleReturn = libusb_open(myDevice,&handle);
	if (handleReturn == 0) printf("Handle : success\n");
	else printf("Handle : failed Error code : %d\n",handleReturn); 
	
	//Frees the list of devices and unereferences the devices
	for(i=0; i<cnt; i++)
	{
		libusb_unref_device (list[i]);
	}
	libusb_free_device_list (list,0);
	printf("Devices list freed and devices unereferenced\n");
	
	//If we got a handle on the device we want to control, we can proceed, otherwise we release/free everything and end the program
	if(handleReturn == 0)
	{
		//Retrieves and applies configuration
		int config;
		if (libusb_get_configuration(handle,&config) == 0) printf("Configuration retrieved. Number : %d\n",config); 	
		else
		{
			config = -1;
			printf("Configuration failed\n");
		}
		
		int confApply = libusb_set_configuration(handle,config);
		if (confApply == 0) printf("Configuration : applied\n");
		else printf("Configuration : failed to apply Error : %d\n",confApply);
		
		//Claims the interface
		int confDescReturn, claimReturn;
		confDescReturn = libusb_get_config_descriptor_by_value(myDevice,config,&confDesc);
		if (confDescReturn == 0) printf("Configuration Descriptor : Retrieved\n");
		else printf("Configuration Descriptor : Failed to retrieve %d\n",confDescReturn);
		
		claimReturn = libusb_claim_interface(handle,(*confDesc).interface[0].altsetting[0].bInterfaceNumber);
		if (claimReturn == 0) printf("Interface : Claimed\n");	//since bNumInterfaces and num_altsetting = 1
		else printf("Interface : Failed to Claimed Error : %d\n",claimReturn);
					
		//Retrieves the speed of the connection
		printf("Speed of the device : %d\n",libusb_get_device_speed(myDevice));
	
		//Transfer the data
		unsigned char c = 0xAA;
		int transferred;
		int result;
		int repeat = 1;
		int addEndpoint = (*confDesc).interface[0].altsetting[0].endpoint[1].bEndpointAddress;
		
		do
		{
			result = libusb_bulk_transfer(handle,addEndpoint,&c,1,&transferred,1000); 
			if (result == 0) printf("Transfer : Success Nb of bytes transferred : %d\n",transferred);
			else printf("Transfer : Failed Error : %d\n",result);
			printf("Tapez 1 pour renvoyer un caractère et 0 pour arrêter\n");
			scanf("%d",&repeat);
		}
		while (repeat == 1);
		//Releases interface
		libusb_release_interface(handle,(*confDesc).interface[0].altsetting[0].bInterfaceNumber);
		printf("Interface released\n");
		
		//Closes handle
		libusb_close(handle);
		printf("Handle closed\n");
		
	}
	
	//Closes the lib
	libusb_exit(NULL); 	
	printf("Exit\n");
	
	system ("pause");
	return 0;
}


//Linux code portion for freeing the device from the yoke of the kernel
/*
	if (libusb_get_active_config_descriptor (list[i],&confDesc) == 0) printf("Configuration Descriptor : Retrieved\n");
	else printf("Configuration Descriptor : Failed to retrieve\n");
	
	int j;
	int kernelReturn;
	int kernelDetachReturn;
	int interNumber = (*confDesc).bNumInterfaces;

	for(j=0; j < interNumber; j++)
	{
		kernelReturn = libusb_kernel_driver_active(handle,(*confDesc).interface[config].altsetting[j].bInterfaceNumber);
		printf("ok");
		if (kernelReturn == 0) printf("No kernel driver is active\n");
		else if (kernelReturn == 1) 
		{
			printf("A kernel driver is active\n");
			kernelDetachReturn = libusb_detach_kernel_driver(handle,(*confDesc).interface[config].altsetting[j].bInterfaceNumber); 
			if (kernelDetachReturn == 0) printf("Kernel Detachment : Success\n");
			else printf("Kernel Detachment : Failed Error : %d\n",kernelDetachReturn);
		}		
		else printf("Error\n");
	}
*/