/* 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., 51 Franklin Street, 5th Floor, Boston, MA 02110-1301, USA.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <X11/Xutil.h>
#include <X11/keysym.h>

#include "commands.h"
#include "image.h"
#include "options.h"
#include "thumbs.h"
#include "types.h"
#include "util.h"
#include "window.h"

#define _MAPPINGS_CONFIG
#include "config.h"

enum {
	TITLE_LEN = 256,
	FNAME_CNT = 1024
};

appmode_t mode;
img_t img;
tns_t tns;
win_t win;

fileinfo_t *files;
int filecnt, fileidx;
size_t filesize;

char win_title[TITLE_LEN];

int timo_cursor;
int timo_redraw;

void cleanup() {
	static int in = 0;

	if (!in++) {
		img_close(&img, 0);
		tns_free(&tns);
		win_close(&win);
	}
}

void check_add_file(char *filename) {
	if (!filename || !*filename)
		return;

	if (access(filename, R_OK)) {
		warn("could not open file: %s", filename);
		return;
	}

	if (fileidx == filecnt) {
		filecnt *= 2;
		files = (fileinfo_t*) s_realloc(files, filecnt * sizeof(fileinfo_t));
	}
	if (*filename != '/') {
		files[fileidx].path = absolute_path(filename);
		if (!files[fileidx].path) {
			warn("could not get absolute path of file: %s\n", filename);
			return;
		}
	}
	files[fileidx].name = s_strdup(filename);
	if (*filename == '/')
		files[fileidx].path = files[fileidx].name;
	fileidx++;
}

void remove_file(int n, unsigned char silent) {
	if (n < 0 || n >= filecnt)
		return;

	if (filecnt == 1) {
		if (!silent)
			fprintf(stderr, "sxiv: no more files to display, aborting\n");
		cleanup();
		exit(!silent);
	}

	if (n + 1 < filecnt) {
		if (files[n].path != files[n].name)
			free((void*) files[n].path);
		free((void*) files[n].name);
		memmove(files + n, files + n + 1, (filecnt - n - 1) * sizeof(fileinfo_t));
	}
	if (n + 1 < tns.cnt) {
		memmove(tns.thumbs + n, tns.thumbs + n + 1, (tns.cnt - n - 1) *
		        sizeof(thumb_t));
		memset(tns.thumbs + tns.cnt - 1, 0, sizeof(thumb_t));
	}

	filecnt--;
	if (n < tns.cnt)
		tns.cnt--;
}

void load_image(int new) {
	struct stat fstats;

	if (new < 0 || new >= filecnt)
		return;

	/* cursor gets reset in redraw() */
	win_set_cursor(&win, CURSOR_WATCH);
	img_close(&img, 0);
		
	while (!img_load(&img, &files[new])) {
		remove_file(new, 0);
		if (new >= filecnt)
			new = filecnt - 1;
	}

	fileidx = new;
	if (!stat(files[new].path, &fstats))
		filesize = fstats.st_size;
	else
		filesize = 0;
}

void update_title() {
	int n;
	float size;
	const char *unit;

	if (mode == MODE_THUMB) {
		n = snprintf(win_title, TITLE_LEN, "sxiv: [%d/%d] %s",
		             tns.cnt ? tns.sel + 1 : 0, tns.cnt,
		             tns.cnt ? files[tns.sel].name : "");
	} else {
		size = filesize;
		size_readable(&size, &unit);
		if (img.multi.cnt)
			n = snprintf(win_title, TITLE_LEN,
			             "sxiv: [%d/%d] <%d%%> <%dx%d> (%.2f%s) {%d/%d} %s",
			             fileidx + 1, filecnt, (int) (img.zoom * 100.0), img.w,
			             img.h, size, unit, img.multi.sel + 1, img.multi.cnt,
			             files[fileidx].name);
		else
			n = snprintf(win_title, TITLE_LEN,
			             "sxiv: [%d/%d] <%d%%> <%dx%d> (%.2f%s) %s",
			             fileidx + 1, filecnt, (int) (img.zoom * 100.0), img.w,
			             img.h, size, unit, files[fileidx].name);
	}

	if (n >= TITLE_LEN) {
		for (n = 0; n < 3; n++)
			win_title[TITLE_LEN - n - 2] = '.';
	}

	win_set_title(&win, win_title);
}

void redraw() {
	if (mode == MODE_IMAGE) {
		img_render(&img, &win);
		if (timo_cursor)
			win_set_cursor(&win, CURSOR_ARROW);
		else
			win_set_cursor(&win, CURSOR_NONE);
	} else {
		tns_render(&tns, &win);
	}
	update_title();
	timo_redraw = 0;
}

Bool keymask(const keymap_t *k, unsigned int state) {
	return (k->ctrl ? ControlMask : 0) == (state & ControlMask);
}

Bool buttonmask(const button_t *b, unsigned int state) {
	return ((b->ctrl ? ControlMask : 0) | (b->shift ? ShiftMask : 0)) ==
	       (state & (ControlMask | ShiftMask));
}

void on_keypress(XKeyEvent *kev) {
	int i;
	KeySym ksym;
	char key;

	if (!kev)
		return;

	XLookupString(kev, &key, 1, &ksym, NULL);

	for (i = 0; i < LEN(keys); i++) {
		if (keys[i].ksym == ksym && keymask(&keys[i], kev->state)) {
			if (keys[i].cmd && keys[i].cmd(keys[i].arg))
				redraw();
			return;
		}
	}
}

void on_buttonpress(XButtonEvent *bev) {
	int i, sel;

	if (!bev)
		return;

	if (mode == MODE_IMAGE) {
		win_set_cursor(&win, CURSOR_ARROW);
		timo_cursor = TO_CURSOR_HIDE;

		for (i = 0; i < LEN(buttons); i++) {
			if (buttons[i].button == bev->button &&
			    buttonmask(&buttons[i], bev->state))
			{
				if (buttons[i].cmd && buttons[i].cmd(buttons[i].arg))
					redraw();
				return;
			}
		}
	} else {
		/* thumbnail mode (hard-coded) */
		switch (bev->button) {
			case Button1:
				if ((sel = tns_translate(&tns, bev->x, bev->y)) >= 0) {
					if (sel == tns.sel) {
						load_image(tns.sel);
						mode = MODE_IMAGE;
						timo_cursor = TO_CURSOR_HIDE;
					} else {
						tns_highlight(&tns, &win, tns.sel, False);
						tns_highlight(&tns, &win, sel, True);
						tns.sel = sel;
					}
					redraw();
					break;
				}
				break;
			case Button4:
			case Button5:
				if (tns_scroll(&tns, bev->button == Button4 ? DIR_UP : DIR_DOWN))
					redraw();
				break;
		}
	}
}

void run() {
	int xfd, timeout;
	fd_set fds;
	struct timeval tt, t0, t1;
	XEvent ev;

	timo_cursor = mode == MODE_IMAGE ? TO_CURSOR_HIDE : 0;

	redraw();

	while (1) {
		if (mode == MODE_THUMB && tns.cnt < filecnt) {
			/* load thumbnails */
			win_set_cursor(&win, CURSOR_WATCH);
			gettimeofday(&t0, 0);

			while (tns.cnt < filecnt && !XPending(win.env.dpy)) {
				if (tns_load(&tns, tns.cnt, &files[tns.cnt], False, False))
					tns.cnt++;
				else
					remove_file(tns.cnt, 0);
				gettimeofday(&t1, 0);
				if (TIMEDIFF(&t1, &t0) >= TO_THUMBS_LOAD)
					break;
			}
			if (tns.cnt == filecnt)
				win_set_cursor(&win, CURSOR_ARROW);
			if (!XPending(win.env.dpy)) {
				redraw();
				continue;
			} else {
				timo_redraw = TO_THUMBS_LOAD;
			}
		} else if (timo_cursor || timo_redraw) {
			/* check active timeouts */
			gettimeofday(&t0, 0);
			timeout = MIN(timo_cursor + 1, timo_redraw + 1);
			MSEC_TO_TIMEVAL(timeout, &tt);
			xfd = ConnectionNumber(win.env.dpy);
			FD_ZERO(&fds);
			FD_SET(xfd, &fds);

			if (!XPending(win.env.dpy))
				select(xfd + 1, &fds, 0, 0, &tt);
			gettimeofday(&t1, 0);
			timeout = MIN(TIMEDIFF(&t1, &t0), timeout);

			/* timeouts fired? */
			if (timo_cursor) {
				timo_cursor = MAX(0, timo_cursor - timeout);
				if (!timo_cursor)
					win_set_cursor(&win, CURSOR_NONE);
			}
			if (timo_redraw) {
				timo_redraw = MAX(0, timo_redraw - timeout);
				if (!timo_redraw)
					redraw();
			}
			if ((timo_cursor || timo_redraw) && !XPending(win.env.dpy))
				continue;
		}

		if (!XNextEvent(win.env.dpy, &ev)) {
			/* handle events */
			switch (ev.type) {
				case ButtonPress:
					on_buttonpress(&ev.xbutton);
					break;
				case ClientMessage:
					if ((Atom) ev.xclient.data.l[0] == wm_delete_win)
						return;
					break;
				case ConfigureNotify:
					if (win_configure(&win, &ev.xconfigure)) {
						timo_redraw = TO_WIN_RESIZE;
						if (mode == MODE_IMAGE)
							img.checkpan = 1;
						else
							tns.dirty = 1;
					}
					break;
				case KeyPress:
					on_keypress(&ev.xkey);
					break;
				case MotionNotify:
					if (!timo_cursor)
						win_set_cursor(&win, CURSOR_ARROW);
					timo_cursor = TO_CURSOR_HIDE;
					break;
			}
		}
	}
}

int fncmp(const void *a, const void *b) {
	return strcoll(((fileinfo_t*) a)->name, ((fileinfo_t*) b)->name);
}

int main(int argc, char **argv) {
	int i, len, start;
	size_t n;
	char *filename;
	struct stat fstats;
	r_dir_t dir;

	parse_options(argc, argv);

	if (options->clean_cache) {
		tns_init(&tns, 0);
		tns_clean_cache(&tns);
		exit(0);
	}

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

	if (options->recursive || options->from_stdin)
		filecnt = FNAME_CNT;
	else
		filecnt = options->filecnt;

	files = (fileinfo_t*) s_malloc(filecnt * sizeof(fileinfo_t));
	fileidx = 0;

	/* build file list: */
	if (options->from_stdin) {
		filename = NULL;
		while ((len = getline(&filename, &n, stdin)) > 0) {
			if (filename[len-1] == '\n')
				filename[len-1] = '\0';
			check_add_file(filename);
		}
	} else {
		for (i = 0; i < options->filecnt; i++) {
			filename = options->filenames[i];

			if (stat(filename, &fstats) || !S_ISDIR(fstats.st_mode)) {
				check_add_file(filename);
			} else {
				if (!options->recursive) {
					warn("ignoring directory: %s", filename);
					continue;
				}
				if (r_opendir(&dir, filename)) {
					warn("could not open directory: %s", filename);
					continue;
				}
				start = fileidx;
				printf("reading dir: %s\n", filename);
				while ((filename = r_readdir(&dir))) {
					check_add_file(filename);
					free((void*) filename);
				}
				r_closedir(&dir);
				if (fileidx - start > 1)
					qsort(files + start, fileidx - start, sizeof(fileinfo_t), fncmp);
			}
		}
	}

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

	filecnt = fileidx;
	fileidx = options->startnum < filecnt ? options->startnum : 0;

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

	if (options->thumbnails) {
		mode = MODE_THUMB;
		tns_init(&tns, filecnt);
		while (!tns_load(&tns, 0, &files[0], False, False))
			remove_file(0, 0);
		tns.cnt = 1;
	} else {
		mode = MODE_IMAGE;
		tns.thumbs = NULL;
		load_image(fileidx);
	}

	win_open(&win);
	
	run();
	cleanup();

	return 0;
}