#include <string.h>
#include <strings.h>
#include <stdio.h>
#include <stdlib.h>
#include <pcsclite.h>
#include <winscard.h>

SCARDCONTEXT hContext;
SCARDHANDLE hCard;
char *reader_list, *selected_reader;
unsigned select_reader_num;

setup_pcsc_context()
{
	LONG rv;

	rv = SCardEstablishContext(SCARD_SCOPE_SYSTEM, NULL, NULL, &hContext);
	if (rv != SCARD_S_SUCCESS) {
		fprintf(stderr, "SCardEstablishContext: %s\n",
			pcsc_stringify_error(rv));
		exit(1);
	}
	return(0);
}

get_reader_list()
{
	LONG rv;
	DWORD dwReaders;

	rv = SCardListReaders(hContext, NULL, NULL, &dwReaders);
	if (rv != SCARD_S_SUCCESS) {
		fprintf(stderr, "SCardListReaders 1st call: %s\n",
			pcsc_stringify_error(rv));
		SCardReleaseContext(hContext);
		exit(1);
	}
	if (dwReaders < 1) {
		fprintf(stderr,
	"error: dwReaders returned by SCardListReaders() is less than 1\n");
		SCardReleaseContext(hContext);
		exit(1);
	}
	reader_list = malloc(dwReaders);
	if (!reader_list) {
		perror("malloc for readers list");
		SCardReleaseContext(hContext);
		exit(1);
	}
	reader_list[0] = '\0';
	rv = SCardListReaders(hContext, NULL, reader_list, &dwReaders);
	if (rv != SCARD_S_SUCCESS) {
		fprintf(stderr, "SCardListReaders 2nd call: %s\n",
			pcsc_stringify_error(rv));
		SCardReleaseContext(hContext);
		exit(1);
	}
	return(0);
}

select_reader_by_num()
{
	char *cp;
	unsigned num;

	for (cp = reader_list, num = 0; *cp; num++) {
		if (num == select_reader_num) {
			selected_reader = cp;
			return(0);
		}
		cp += strlen(cp) + 1;
	}
	fprintf(stderr,
		"error: requested reader #%u, but only %u reader(s) found\n",
		select_reader_num, num);
	SCardReleaseContext(hContext);
	exit(1);
}

connect_to_card()
{
	LONG rv;
	DWORD dwActiveProtocol;

	rv = SCardConnect(hContext, selected_reader, SCARD_SHARE_EXCLUSIVE,
			  SCARD_PROTOCOL_T0, &hCard, &dwActiveProtocol);
	if (rv != SCARD_S_SUCCESS) {
		fprintf(stderr, "SCardConnect: %s\n", pcsc_stringify_error(rv));
		SCardReleaseContext(hContext);
		exit(1);
	}
	return(0);
}