/**
 * Project: AVR ATtiny USB Tutorial at http://codeandlife.com/
 * Author: Joonas Pihlajamaa, joonas.pihlajamaa@iki.fi
 * Based on V-USB example code by Christian Starkjohann
 * Copyright: (C) 2012 by Joonas Pihlajamaa
 * License: GNU GPL v3 (see License.txt)
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <usb.h>

// used to get descriptor strings for device identification
static int usbGetDescriptorString(usb_dev_handle *dev, int index, int langid,
                                  char *buf, int buflen)
{
	char buffer[256];
	int rval, i;

	// make standard request GET_DESCRIPTOR, type string and given index
	// (e.g. dev->iProduct)
	rval = usb_control_msg(dev,
	                       USB_TYPE_STANDARD | USB_RECIP_DEVICE | USB_ENDPOINT_IN,
	                       USB_REQ_GET_DESCRIPTOR, (USB_DT_STRING << 8) + index, langid,
	                       buffer, sizeof(buffer), 1000);

	if(rval < 0) // error
		return rval;

	// rval should be bytes read, but buffer[0] contains the actual response size
	if((unsigned char)buffer[0] < rval)
		rval = (unsigned char)buffer[0]; // string is shorter than bytes read

	if(buffer[1] != USB_DT_STRING) // second byte is the data type
		return 0; // invalid return type

	// we're dealing with UTF-16LE here so actual chars is half of rval,
	// and index 0 doesn't count
	rval /= 2;

	// lossy conversion to ISO Latin1
	for(i = 1; i < rval && i < buflen; i++)
	{
		if(buffer[2 * i + 1] == 0)
			buf[i-1] = buffer[2 * i];
		else
			buf[i-1] = '?'; // outside of ISO Latin1 range
	}
	buf[i-1] = 0;

	return i-1;
}

static usb_dev_handle * usbOpenDevice(int vendor, char *vendorName,
                                      int product, char *productName)
{
	struct usb_bus *bus;
	struct usb_device *dev;
	char devVendor[256], devProduct[256];

	usb_dev_handle * handle = NULL;

	usb_set_debug(3);

	usb_init();
	usb_find_busses();
	usb_find_devices();

	for(bus=usb_get_busses(); bus; bus=bus->next)
	{
		for(dev=bus->devices; dev; dev=dev->next)
		{
			if(dev->descriptor.idVendor != vendor ||
			        dev->descriptor.idProduct != product)
				continue;

			// we need to open the device in order to query strings
			if(!(handle = usb_open(dev)))
			{
				fprintf(stderr, "Warning: cannot open USB device: %s\n",
				        usb_strerror());
				continue;
			}

			// get vendor name
			if(usbGetDescriptorString(handle, dev->descriptor.iManufacturer, 0x0409, devVendor, sizeof(devVendor)) < 0)
			{
				fprintf(stderr,
				        "Warning: cannot query manufacturer for device: %s\n",
				        usb_strerror());
				usb_close(handle);
				continue;
			}

			// get product name
			if(usbGetDescriptorString(handle, dev->descriptor.iProduct,
			                          0x0409, devProduct, sizeof(devVendor)) < 0)
			{
				fprintf(stderr,
				        "Warning: cannot query product for device: %s\n",
				        usb_strerror());
				usb_close(handle);
				continue;
			}

			if(strcmp(devVendor, vendorName) == 0 &&
			        strcmp(devProduct, productName) == 0)
				return handle;
			else
				usb_close(handle);
		}
	}

	return NULL;
}


void usage(const char* argv0)
{
	printf("Usage: %s read\n"
	       "       %s write <PAGE> <BYTE1> <BYTE2> ... <BYTE32>\n"
	       "                where <PAGE> is 0,1,2,3\n"
	       "                and <BYTEn> is in hex, without 0x.\n"
	       "                example: write 2 13 37 DE AD be ef ...\n\n", argv0, argv0);
	exit(0);
}

int main(int argc, char **argv)
{
	usb_dev_handle *handle = NULL;
	int nBytes = 0;
	char buffer[256];

	int mode;
	#define MODE_READ 0
	#define MODE_WRITE 1

	int write_page = -1; // which page should be written to? contains 0,1,2,3

	if (argc <= 1)
		usage(argv[0]);
	
	if (strcmp(argv[1], "read")==0 && argc == 2)
		mode=MODE_READ;
	else if (strcmp(argv[1], "write")==0 && argc == 2+1+32)
	{
		mode=MODE_WRITE;
		write_page = atoi(argv[2]) - 1;

		if (write_page > 3 || write_page < 0)
		{
			printf("ERROR: invalid page\n\n");
			exit(1);
		}

		for (int i=0; i<32; i++)
			buffer[i] = strtol(argv[3+i],NULL,16);
	}
	else
		usage(argv[0]);


	handle = usbOpenDevice(0x16C0, "windfisch.org", 0x05DC, "DS1992 Dumper");

	if(handle == NULL)
	{
		fprintf(stderr, "Could not find USB device!\n");
		exit(1);
	}

	printf("got device\n");

	if (mode == MODE_READ)
	{
		// read from device
		nBytes = usb_control_msg(handle, 
			USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN, 
			0x21, 0, 0, (char *)buffer, sizeof(buffer), 1000);
			printf("Got %d bytes: %s = ", nBytes, buffer);
			for (int i=0; i<nBytes; i++)
			{
				if (i%16 == 0) printf("\n");
				printf("%.2X ",buffer[i] & 0xFF);
			}
			printf("\n");
	}
	else if (mode == MODE_WRITE)
	{
		buffer[32] = write_page;

		// write to device
		nBytes = usb_control_msg(handle, 
			USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_OUT, 
			0x42, 0, 0, buffer, 32+1 /*length*/, 1000);
			printf("Wrote %d bytes\n", nBytes);




		// read from device
		nBytes = usb_control_msg(handle, 
			USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN, 
			0x21, 0, 0, (char *)buffer, sizeof(buffer), 1000);
			printf("Got %d bytes: %s = ", nBytes, buffer);
			for (int i=0; i<nBytes; i++)
			{
				if (i%16 == 0) printf("\n");
				printf("%.2X ",buffer[i] & 0xFF);
			}
			printf("\n");
	}

/*

	nBytes = usb_control_msg(handle, 
		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN, 
		0x42, 0,0, 
		(char *)buffer, sizeof(buffer), 5000);
	if(strcmp(argv[1], "on") == 0)
	{
		nBytes = usb_control_msg(handle,
		                         USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN,
		                         USB_LED_ON, 0, 0, (char *)buffer, sizeof(buffer), 5000);
	}
	else if(strcmp(argv[1], "off") == 0)
	{
		nBytes = usb_control_msg(handle,
		                         USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN,
		                         USB_LED_OFF, 0, 0, (char *)buffer, sizeof(buffer), 5000);
	}
	else if(strcmp(argv[1], "out") == 0)
	{
		nBytes = usb_control_msg(handle,
		                         USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN,
		                         USB_DATA_OUT, 0, 0, (char *)buffer, sizeof(buffer), 5000);
		printf("Got %d bytes: %s\n", nBytes, buffer);
	}
	else if(strcmp(argv[1], "write") == 0)
	{
		nBytes = usb_control_msg(handle,
		                         USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN,
		                         USB_DATA_WRITE, 'T' + ('E' << 8), 'S' + ('T' << 8),
		                         (char *)buffer, sizeof(buffer), 5000);
	}
	else if(strcmp(argv[1], "in") == 0 && argc > 2)
	{
		nBytes = usb_control_msg(handle,
		                         USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_OUT,
		                         USB_DATA_IN, 0, 0, argv[2], strlen(argv[2])+1, 5000);
	}
*/
	if(nBytes < 0)
		fprintf(stderr, "USB error: %s\n", usb_strerror());

	usb_close(handle);

	return 0;
}