/* sxiv: main.c
 * Copyright (c) 2011 Bert Muennich <muennich at informatik.hu-berlin.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *  
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *  
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <stdlib.h>
#include <stdio.h>
#include <sys/select.h>

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/keysym.h>

#include "sxiv.h"
#include "image.h"
#include "options.h"
#include "window.h"

void on_keypress(XEvent*);
void on_configurenotify(XEvent*);

void update_title();

static void (*handler[LASTEvent])(XEvent*) = {
	[KeyPress] = on_keypress,
	[ConfigureNotify] = on_configurenotify
};

img_t img;
win_t win;

const char **filenames;
int filecnt, fileidx;

unsigned char timeout;

#define TITLE_LEN 256
char win_title[TITLE_LEN];

void run() {
	int xfd;
	fd_set fds;
	struct timeval t;
	XEvent ev;

	timeout = 0;

	while (1) {
		if (timeout) {
			t.tv_sec = 0;
			t.tv_usec = 250;
			xfd = ConnectionNumber(win.env.dpy);
			FD_ZERO(&fds);
			FD_SET(xfd, &fds);
			
			if (!XPending(win.env.dpy) && !select(xfd + 1, &fds, 0, 0, &t)) {
				img_render(&img, &win);
				timeout = 0;
			}
		}

		if (!XNextEvent(win.env.dpy, &ev) && handler[ev.type])
			handler[ev.type](&ev);
	}
}

int main(int argc, char **argv) {
	int i;

	parse_options(argc, argv);

	if (!options->filecnt) {
		print_usage();
		exit(1);
	}

	if (!(filenames = (const char**) malloc(options->filecnt * sizeof(char*))))
		DIE("could not allocate memory");
	
	fileidx = 0;
	filecnt = 0;

	for (i = 0; i < options->filecnt; ++i) {
		if (!(img_load(&img, options->filenames[i]) < 0))
			filenames[filecnt++] = options->filenames[i];
	}

	if (!filecnt) {
		fprintf(stderr, "sxiv: no valid image filename given, aborting\n");
		exit(1);
	}

	win_open(&win);
	img_init(&img, &win);

	img_load(&img, filenames[fileidx]);
	img_render(&img, &win);
	update_title();

	run();

	cleanup();

	return 0;
}

void cleanup() {
	static int in = 0;

	if (!in++) {
		img_free(&img);
		win_close(&win);
	}
}

void on_keypress(XEvent *ev) {
	char key;
	KeySym keysym;
	int changed;

	if (!ev)
		return;
	
	XLookupString(&ev->xkey, &key, 1, &keysym, NULL);
	changed = 0;

	switch (keysym) {
		case XK_Escape:
			cleanup();
			exit(2);
		case XK_space:
			key = 'n';
			break;
		case XK_BackSpace:
			key = 'p';
			break;
	}

	switch (key) {
		case 'q':
			cleanup();
			exit(0);

		/* navigate through image list */
		case 'n':
			if (fileidx + 1 < filecnt) {
				img_load(&img, filenames[++fileidx]);
				changed = 1;
			}
			break;
		case 'p':
			if (fileidx > 0) {
				img_load(&img, filenames[--fileidx]);
				changed = 1;
			}
			break;
		case '[':
			if (fileidx != 0) {
				fileidx = MAX(0, fileidx - 10);
				img_load(&img, filenames[fileidx]);
				changed = 1;
			}
			break;
		case ']':
			if (fileidx != filecnt - 1) {
				fileidx = MIN(fileidx + 10, filecnt - 1);
				img_load(&img, filenames[fileidx]);
				changed = 1;
			}
			break;
		case 'g':
			if (fileidx != 0) {
				fileidx = 0;
				img_load(&img, filenames[fileidx]);
				changed = 1;
			}
			break;
		case 'G':
			if (fileidx != filecnt - 1) {
				fileidx = filecnt - 1;
				img_load(&img, filenames[fileidx]);
				changed = 1;
			}
			break;

		/* zooming */
		case '+':
		case '=':
			changed = img_zoom_in(&img);
			break;
		case '-':
			changed = img_zoom_out(&img);
			break;

		/* panning */
		case 'h':
			changed = img_pan(&img, &win, PAN_LEFT);
			break;
		case 'j':
			changed = img_pan(&img, &win, PAN_DOWN);
			break;
		case 'k':
			changed = img_pan(&img, &win, PAN_UP);
			break;
		case 'l':
			changed = img_pan(&img, &win, PAN_RIGHT);
			break;

		/* change window state */
		case 'f':
			win_toggle_fullscreen(&win);
			break;
	}

	if (changed) {
		img_render(&img, &win);
		update_title();
		timeout = 0;
	}
}

void on_configurenotify(XEvent *ev) {
	if (!ev)
		return;

	if (win_configure(&win, &ev->xconfigure)) {
		img.checkpan = 1;
		timeout = 1;
	}
}

void update_title() {
	int n;

	n = snprintf(win_title, TITLE_LEN, "sxiv: [%d/%d] <%d%%> %s", fileidx + 1,
	             filecnt, (int) (img.zoom * 100.0), filenames[fileidx]);
	
	if (n >= TITLE_LEN) {
		win_title[TITLE_LEN - 2] = '.';
		win_title[TITLE_LEN - 3] = '.';
		win_title[TITLE_LEN - 4] = '.';
	}

	win_set_title(&win, win_title);
}