/* See LICENSE file for copyright and license details. */
#include "cg-base.h"

#include <libclut.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>



/**
 * The default filter priority for the program
 */
const int64_t default_priority = NO_DEFAULT_PRIORITY;

/**
 * The default class base for the program
 */
char default_class[] = PKGNAME "::cg-linear::standard";

/**
 * Class suffixes
 */
const char *const *class_suffixes = (const char *const[]){":start", ":stop", NULL};



/**
 * -d: keep process alive and remove filter on death
 */
static int dflag = 0;

/**
 * -x: remove filter rather than adding it
 */
static int xflag = 0;

/**
 * +r: do not touch the red channel
 */
static int rplus = 0;

/**
 * +g: do not touch the green channel
 */
static int gplus = 0;

/**
 * +b: do not touch the blue channel
 */
static int bplus = 0;

/**
 * The priority of the linearisation filter
 */
static int64_t start_priority;

/**
 * The priority of the delinearisation filter
 */
static int64_t stop_priority;



/**
 * Print usage information and exit
 */
void
usage(void)
{
	fprintf(stderr,
	        "usage: %s [-M method] [-S site] [-c crtc]... [-R rule-base] "
	        "(-x | -p start-priority:stop-priority [-d] [+rgb])\n",
	        argv0);
	exit(1);
}


/**
 * Handle a command line option
 * 
 * @param   opt  The option, it is a NUL-terminate two-character
 *               string starting with either '-' or '+', if the
 *               argument is not recognised, call `usage`. This
 *               string will not be "-M", "-S", "-c", "-p", or "-R".
 * @param   arg  The argument associated with `opt`,
 *               `NULL` there is no next argument, if this
 *               parameter is `NULL` but needed, call `usage`
 * @return       0 if `arg` was not used,
 *               1 if `arg` was used,
 *               -1 on error
 */
int
handle_opt(char *opt, char *arg)
{
	if (opt[0] == '-') {
		switch (opt[1]) {
		case 'd':
			if (dflag || xflag)
				usage();
			dflag = 1;
			break;
		case 'x':
			if (xflag || dflag)
				usage();
			xflag = 1;
			break;
		default:
			usage();
		}
	} else {
		switch (opt[1]) {
		case 'r':
			if (rplus)
				usage();
			rplus = 1;
			break;
		case 'g':
			if (gplus)
				usage();
			gplus = 1;
			break;
		case 'b':
			if (bplus)
				usage();
			bplus = 1;
			break;
		default:
			usage();
		}
	}
	return 0;
	(void) arg;
}


/**
 * This function is called after the last
 * call to `handle_opt`
 * 
 * @param   argc  The number of unparsed arguments
 * @param   argv  `NULL` terminated list of unparsed arguments
 * @param   prio  The argument associated with the "-p" option
 * @return        Zero on success, -1 on error
 */
int
handle_args(int argc, char *argv[], char *prio)
{
	int q = xflag + (dflag | rplus | gplus | bplus);
	char *p, *end;
	if (argc || q > 1 || (xflag && prio))
		usage();
	if (!xflag && !prio)
		usage();
	if (prio) {
		p = strchr(prio, ':');
		if (!p)
			usage();
		*p++ = '\0';
		errno = 0;
		start_priority = (int64_t)strtoll(prio, &end, 10);
		if (errno || *end || !*prio)
			usage();
		stop_priority = (int64_t)strtoll(p, &end, 10);
		if (errno || *end || !*prio)
			usage();
		p[-1] = ':';
	}
	return 0;
	(void) argv;
}


/**
 * Fill a filter
 * 
 * @param  filter    The filter to fill
 * @param  is_start  If the fitler is a linearisation filter
 */
static void
fill_filter(libcoopgamma_filter_t *restrict filter, int is_start)
{
	switch (filter->depth) {
#define X(CONST, MEMBER, MAX, TYPE)\
		case CONST:\
			if (is_start)\
				libclut_linearise(&filter->ramps.MEMBER, MAX, TYPE, !rplus, !gplus, !bplus);\
			else\
				libclut_standardise(&filter->ramps.MEMBER, MAX, TYPE, !rplus, !gplus, !bplus);\
			break;
		LIST_DEPTHS
#undef X
	default:
		abort();
	}
}


/**
 * The main function for the program-specific code
 * 
 * @return  0: Success
 *          -1: Error, `errno` set
 *          -2: Error, `cg.error` set
 *          -3: Error, message already printed
 */
int
start(void)
{
	int r, is_start;
	size_t i, j;

	if (xflag)
		for (i = 0; i < filters_n; i++)
			crtc_updates[i].filter.lifespan = LIBCOOPGAMMA_REMOVE;
	else if (dflag)
		for (i = 0; i < filters_n; i++)
			crtc_updates[i].filter.lifespan = LIBCOOPGAMMA_UNTIL_DEATH;
	else
		for (i = 0; i < filters_n; i++)
			crtc_updates[i].filter.lifespan = LIBCOOPGAMMA_UNTIL_REMOVAL;

	for (i = 0, r = 1; i < filters_n; i++) {
		if (!crtc_info[crtc_updates[i].crtc].supported)
			continue;
		if (!xflag) {
			is_start = strchr(crtc_updates[i].filter.class, '\0')[-1] == 't';
			fill_filter(&crtc_updates[i].filter, is_start);
			crtc_updates[i].filter.priority = is_start ? start_priority : stop_priority;
		}
		r = update_filter(i, 0);
		if (r == -2 || (r == -1 && errno != EAGAIN))
			return r;
	}

	while (r != 1)
		if ((r = synchronise(-1)) < 0)
			return r;

	if (!dflag)
		return 0;

	if (libcoopgamma_set_nonblocking(&cg, 0) < 0)
		return -1;
	for (;;) {
		if (libcoopgamma_synchronise(&cg, NULL, 0, &j) < 0) {
			switch (errno) {
			case 0:
				break;
			case ENOTRECOVERABLE:
				goto enotrecoverable;
			default:
				return -1;
			}
		}
	}

enotrecoverable:
	pause();
	return -1;
}