/* See LICENSE file for copyright and license details. */
#include "libgamma_AdjustmentMethod.h"
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include <libgamma.h>


#if LIBGAMMA_METHOD_COUNT > 6
# error LIBGAMMA_METHOD_COUNT has been updated
#endif


/**
 * List available adjustment methods by their order of preference based on the environment
 * 
 * @param   operation  Allowed values:
 *                       0: Methods that the environment suggests will work, excluding fake
 *                       1: Methods that the environment suggests will work, including fake
 *                       2: All real non-fake methods
 *                       3: All real methods
 *                       4: All methods
 *                     Other values invoke undefined behaviour
 * @return             List available adjustment methods by their order of preference
 */
jintArray
Java_libgamma_AdjustmentMethod_libgamma_1list_1methods(JNIEnv *env, jclass class, jint operation)
{
	int methods[LIBGAMMA_METHOD_COUNT];
	size_t i, n;
	jintArray rc;

	n = libgamma_list_methods(methods, LIBGAMMA_METHOD_COUNT, operation);
	if (n > LIBGAMMA_METHOD_COUNT)
		abort(); /* Prevented by the #if above and package maintenance */

	rc = (*env)->NewIntArray(env, (jsize)n);

	/* Remember, jint is 32 bits, int is 16+ bits. */
	for (i = 0; i < n; i++)
		(*env)->SetIntArrayRegion(env, rc, (jsize)i, 1, methods + i);

	return rc;
	(void) class;
}

/**
 * Check whether an adjustment method is available, non-existing (invalid) methods will be
 * identified as not available under the rationale that the library may be out of date
 * 
 * @param   method  The adjustment method
 * @return          Whether the adjustment method is available
 */
jint
Java_libgamma_AdjustmentMethod_libgamma_1is_1method_1available(JNIEnv *env, jclass class, jint method)
{
	return libgamma_is_method_available(method);
	(void) env;
	(void) class;
}

/**
 * Return the capabilities of an adjustment method
 * 
 * @param   method  The adjustment method (display server and protocol)
 * @return          Element 0: Input parameter to the constructor of {@link AdjustmentMethodCapabilities}
 *                  Element 1: Error code, zero on success
 */
jlongArray
Java_libgamma_AdjustmentMethod_libgamma_1method_1capabilities(JNIEnv *env, jclass class, jint method)
{
	jlongArray rv = (*env)->NewLongArray(env, 2);
	struct libgamma_method_capabilities caps;
	jlong rc = 0, e = 0;
	int r = libgamma_method_capabilities(&caps, sizeof(caps), method);
	if (r) {
		e = (jlong)(r == LIBGAMMA_ERRNO_SET ? errno : r);
		goto out;
	}
	rc = (jlong)(caps.crtc_information);
	rc &= 0xFFFFFFFFLL;
	rc |= caps.default_site_known            ? (1LL << 33) : 0;
	rc |= caps.multiple_sites                ? (1LL << 34) : 0;
	rc |= caps.multiple_partitions           ? (1LL << 35) : 0;
	rc |= caps.multiple_crtcs                ? (1LL << 36) : 0;
	rc |= caps.partitions_are_graphics_cards ? (1LL << 37) : 0;
	rc |= caps.site_restore                  ? (1LL << 38) : 0;
	rc |= caps.partition_restore             ? (1LL << 39) : 0;
	rc |= caps.crtc_restore                  ? (1LL << 40) : 0;
	rc |= caps.identical_gamma_sizes         ? (1LL << 41) : 0;
	rc |= caps.fixed_gamma_size              ? (1LL << 42) : 0;
	rc |= caps.fixed_gamma_depth             ? (1LL << 43) : 0;
	rc |= caps.real                          ? (1LL << 44) : 0;
	rc |= caps.fake                          ? (1LL << 45) : 0;
out:
	(*env)->SetLongArrayRegion(env, rv, 0, 1, &rc);
	(*env)->SetLongArrayRegion(env, rv, 1, 1, &e);
	return rv;
	(void) env;
	(void) class;
}

/**
 * Return the default site for an adjustment method
 * 
 * @param   method  The adjustment method (display server and protocol)
 * @return          The default site, {@code null} if it cannot be determined or
 *                  if multiple sites are not supported by the adjustment method
 */
jstring
Java_libgamma_AdjustmentMethod_libgamma_1method_1default_1site(JNIEnv *env, jclass class, jint method)
{
	/* It is really unlikely that `malloc` returns `NULL` here
	 * and error handing makes this unnecessarily comples,
	 * therefore we will simply skip it */

	const char *do_not_free_this = libgamma_method_default_site(method);
	char *this_will_be_freed;
	size_t n;
	if (!do_not_free_this)
		return NULL;

	n = strlen(do_not_free_this) + 1;
	this_will_be_freed = malloc(n * sizeof(char));
	memcpy(this_will_be_freed, do_not_free_this, n * sizeof(char));

	return (*env)->NewStringUTF(env, this_will_be_freed);
	(void) class;
}

/**
 * Return the default variable that determines
 * the default site for an adjustment method
 * 
 * @param   method  The adjustment method (display server and protocol)
 * @return          The environ variables that is used to determine the
 *                  default site; {@code null} if there is none, that is,
 *                  if the method does not support multiple sites
 */
jstring
Java_libgamma_AdjustmentMethod_libgamma_1method_1default_1site_1variable(JNIEnv *env, jclass class, jint method)
{
	/* It is really unlikely that `malloc` returns `NULL` here
	 * and error handing makes this unnecessarily comples,
	 * therefore we will simply skip it */

	const char *do_not_free_this = libgamma_method_default_site_variable(method);
	char *this_will_be_freed;
	size_t n;
	if (!do_not_free_this)
		return NULL;

	n = strlen(do_not_free_this) + 1;
	this_will_be_freed = malloc(n * sizeof(char));
	memcpy(this_will_be_freed, do_not_free_this, n * sizeof(char));

	return (*env)->NewStringUTF(env, this_will_be_freed);
	(void) class;
}