/*
#     vlshow.c
#     Copyright (C) 2006 Joachim Breitner
#
#     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 St, Fifth Floor, Boston, MA  02110-1301 USA
*/

#include <gtk/gtk.h>
#include <gdk/gdk.h>
#include <pango/pango.h>
#include <string.h>
#include <stdio.h>
#include <math.h>

#include "config.h"

#ifndef _GNU_SOURCE
#define _GNU_SOURCE                             /* for getopt_long */
#endif
#include <getopt.h>

#define min(x,y) ((x) < (y) ? (x) : (y))

#define AUTOHIDE_TIMEOUT 3

static gboolean quality = TRUE;
static gboolean need_resize = TRUE;

static int timeout_id=0;

static GtkWidget* window;
static GtkWidget* draw;
static GdkCursor *cursor;
static GtkWidget* quit;
static GtkWidget* tv;
static GtkWidget* entry_widget;
static GtkSettings* settings;
static GtkTextBuffer* tb;
static PangoFontDescription *font;
static PangoLayout* layout;
static char *foreground = NULL;
static char *background = NULL;
static char *fontdesc = NULL;
static rotation = 0; // 0 = normal, 1 = left, 2 = inverted, 3 = right

gboolean hide_entry(gpointer *user_data) {
	gtk_widget_hide(entry_widget);
	gtk_widget_grab_focus(draw);
	gtk_widget_queue_draw(draw);
	gdk_window_set_cursor(GTK_WIDGET(draw)->window, cursor);
	return FALSE;
}

static void show_entry() {
	if (timeout_id) {
		g_source_remove(timeout_id);
		timeout_id = 0;
	}
	gtk_widget_show(entry_widget);
	gtk_widget_grab_focus(tv);
	gdk_window_set_cursor(GTK_WIDGET(draw)->window, NULL);

	timeout_id = g_timeout_add_seconds (AUTOHIDE_TIMEOUT, (GSourceFunc)hide_entry, NULL);
}

static void clear_text(GtkAccelGroup *accel, GObject *window, guint keyval,  GdkModifierType modifier) {
	if( gtk_text_buffer_get_char_count(tb) ) {
		gtk_text_buffer_set_text(tb,"",-1);
		show_entry();
	} else {
		gtk_main_quit();
	}
}

static char *get_text() {
	GtkTextIter start, end;
	gtk_text_buffer_get_start_iter(tb,&start);
	gtk_text_buffer_get_end_iter(tb,&end);
	return gtk_text_buffer_get_text(tb, &start, &end, FALSE);
}

static void hq(gboolean q, gboolean force){
	if (q != quality) 
		if (q)
			gtk_settings_set_long_property(settings,"gtk-xft-antialias",1,"Hier halt");
		else
			gtk_settings_set_long_property(settings,"gtk-xft-antialias",0,"Hier halt");
	else
		if (force)
			gtk_widget_queue_draw(draw);

	quality = q;
}

static void redraw() {
	const char *text = pango_layout_get_text(layout);
	if (strlen(text) > 0) {
		GdkGC *gc = gtk_widget_get_style(draw)->fg_gc[GTK_STATE_NORMAL];
		int w1, h1;
		pango_layout_get_pixel_size(layout, &w1, &h1);
		if (w1>0 && h1>0) {
			int w2 = window->allocation.width;
			int h2 = window->allocation.height;

			int rw1, rh1;
			if (rotation == 0 || rotation == 2) {
				rw1 = w1;
				rh1 = h1;
			} else {
				rw1 = h1;
				rh1 = w1;
			}

			double s = min ((double)w2/rw1, (double)h2/rh1);
			

			PangoMatrix matrix = PANGO_MATRIX_INIT;
			// Move matrix to the screen center
			pango_matrix_translate(&matrix, w2/2, h2/2);
			// Scale as required
			pango_matrix_scale(&matrix, s, s);
			// Rotate if needed
			pango_matrix_rotate (&matrix, rotation * 90);
			// Move matrix so that text will be centered
			//pango_matrix_translate(&matrix, -w1/2, -h1/2);
			
			// Apply matrix
			PangoContext *context =  pango_layout_get_context(layout);
			pango_context_set_matrix (context, &matrix);
			pango_layout_context_changed (layout);

			gdk_draw_layout(draw->window, gc,
				(w2-(s*rw1))/2, (h2-(s*rh1))/2,layout);
			
			// Reset matrix
			PangoMatrix matrix2 = PANGO_MATRIX_INIT;
			pango_context_set_matrix (context, &matrix2);
			pango_layout_context_changed (layout);

			hq(TRUE, FALSE);
		}
	}
}

static gboolean text_keypress(GtkWidget *widget, GdkEventButton *event, gpointer *user_data) {
	// forward signal to the text view
	gboolean ret;
	g_signal_emit_by_name(tv, "key-press-event", event, &ret);
	gtk_widget_grab_focus(tv);
	return ret;
}

static gboolean text_clicked(GtkWidget *widget, GdkEventButton *event, gpointer *user_data) {
	show_entry();
	if (event->type == GDK_BUTTON_PRESS && event->button == 2) {
		GtkClipboard *cb = gtk_clipboard_get(GDK_SELECTION_PRIMARY);

		gchar *txt = gtk_clipboard_wait_for_text(cb);
		if (txt != NULL) {
			gtk_text_buffer_set_text(tb,txt,-1);
			g_free(txt);
		}

	}
	return FALSE;
}

static void newtext() {
	show_entry();
	pango_layout_set_text(layout, get_text(), -1);
	hq(FALSE, TRUE);
}

static void move_cursor(GtkTextView* tv, GtkMovementStep step, gint count, gboolean extend_selection, gpointer user_data) {
	show_entry();
}

static struct option const long_options[] =
{
	{"help",       no_argument,       NULL, 'h'},
	{"version",    no_argument,       NULL, 'V'},
	{"foreground", required_argument, NULL, 'f'},
	{"background", required_argument, NULL, 'b'},
	{"font",       required_argument, NULL, 'n'},
	{"rotate",     required_argument, NULL, 'r'},
	{0,0,0,0}
};

static void usage(char *cmd) {
	printf("Usage: %s [-h|--help] [-V|--version] [-f|--foreground=colordesc] [-b|--background=colordesc] [-n|--font=fontdesc] [-r|--rotate=0,1,2,3]\n", cmd);
}

static void version() {
	printf("%s\n", PACKAGE_STRING);
}

int main(int argc, char **argv) {
	GString *input;
	int c;
	int input_provided = 0;

	while ((c = getopt_long (argc, argv, "hVf:b:n:r:", long_options, (int *) 0)) != EOF) {
		switch (c) {
			case 'h':
				usage(argv[0]);
				return 0;
				break;

			case 'V':
				version();
				return 0;
				break;

			case 'f':
				foreground = optarg;
				break;

			case 'b':
				background = optarg;
				break;

			case 'n':
				fontdesc = optarg;
				break;
			case 'r':
				rotation = atoi(optarg);
				break;
			default:
				/* unknown switch received - at least
				 * give usage but continue and use the
				 * data */
				usage(argv[0]);
				break;
		}
	}

	gtk_init(&argc, &argv);

	window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	gtk_window_set_decorated(GTK_WINDOW(window), FALSE);
	gtk_window_set_resizable(GTK_WINDOW(window), FALSE);
	gtk_window_set_icon_name (GTK_WINDOW (window), "sm");

	GdkScreen *screen = gtk_window_get_screen(GTK_WINDOW(window));
	gtk_widget_set_size_request(window, gdk_screen_get_width(screen),
					    gdk_screen_get_height(screen));
	gtk_window_fullscreen(GTK_WINDOW(window));
	g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);

	settings = gtk_settings_get_default();
	GdkColormap *colormap = gtk_widget_get_colormap(GTK_WIDGET(window));
	GdkColor white, black;
	gdk_colormap_alloc_color(colormap, &white, TRUE, TRUE);
	gdk_colormap_alloc_color(colormap, &black, TRUE, TRUE);
	if (foreground != NULL) {
		gdk_color_parse(foreground, &black);
	} else {
		gdk_color_parse("black", &black);
	}
	if (background != NULL) {
		gdk_color_parse(background, &white);
	} else {
		gdk_color_parse("white", &white);
	}

	draw = gtk_drawing_area_new();
	gtk_widget_set_events(draw, GDK_BUTTON_PRESS_MASK|GDK_KEY_PRESS_MASK);
	gtk_widget_set_size_request(draw,400,400);
	gtk_widget_modify_bg(draw, GTK_STATE_NORMAL, &white);
	gtk_widget_modify_fg(draw, GTK_STATE_NORMAL, &black);
	g_signal_connect(G_OBJECT(draw), "button-press-event", G_CALLBACK(text_clicked), NULL);
	g_signal_connect(G_OBJECT(draw), "key-press-event", G_CALLBACK(text_keypress), NULL);
	gtk_widget_set_can_focus(draw, TRUE);

	GdkPixmap *pixmap = gdk_pixmap_new(NULL, 1, 1, 1);
	GdkColor color;
	cursor = gdk_cursor_new_from_pixmap(pixmap, pixmap, &color, &color, 0, 0);

	tv = gtk_text_view_new();
	tb = gtk_text_view_get_buffer(GTK_TEXT_VIEW(tv));

	if (argc > optind)
		if (!strcmp(argv[optind], "-") ) {
			// read from stdin
			gchar buf[1024];
			int num;

			input = g_string_new("");

			while ((num = fread (buf, 1, sizeof(buf), stdin)) > 0) {
				g_string_append_len(input, buf, num);
			}

			// remove trailing newline, if any
			if ((input->len > 0) && (input->str[input->len - 1] == '\n')) {
				g_string_truncate(input, input->len - 1);
			}
			input_provided++;
		} else {
			int i;

			input = g_string_new("");

			for (i = optind; i < argc; i++) {
				g_string_append(input, argv[i]);

				if (i < argc - 1) {
					g_string_append(input, " ");
				}
			}
			input_provided++;
		}
	else
		input = g_string_new(":-)");

	gtk_text_buffer_set_text(tb, input->str, input->len);
	g_string_free(input, TRUE);
	GtkTextIter start, end;
	gtk_text_buffer_get_bounds(tb, &start, &end);
	gtk_text_buffer_select_range(tb, &start, &end);

	quit = gtk_button_new_from_stock(GTK_STOCK_QUIT);
	g_signal_connect(G_OBJECT(quit), "clicked", G_CALLBACK(gtk_main_quit), NULL);

	GtkWidget *vbox_button = gtk_vbox_new(FALSE, 0);
	gtk_box_pack_end(GTK_BOX(vbox_button), quit, FALSE, FALSE, 0);

	GtkWidget *hbox = gtk_hbox_new(FALSE,0);
	entry_widget = hbox;
	gtk_box_pack_start(GTK_BOX(hbox), tv,   TRUE,  TRUE,  0);
	gtk_box_pack_start(GTK_BOX(hbox), vbox_button, FALSE, FALSE, 0);

	GtkWidget *vbox = gtk_vbox_new(FALSE,0);
	gtk_box_pack_start(GTK_BOX(vbox), draw, TRUE, TRUE, 0);
	gtk_box_pack_end(GTK_BOX(vbox), hbox, FALSE, FALSE, 0);

	gtk_container_add(GTK_CONTAINER(window), vbox);

	font = pango_font_description_new();
	if (fontdesc != NULL) {
		pango_font_description_set_family(font, fontdesc);
	} else {
		pango_font_description_set_family(font, "sans-serif");
	}
	pango_font_description_set_size(font, 200*PANGO_SCALE);

	layout = gtk_widget_create_pango_layout(window,get_text());
	pango_layout_set_font_description(layout, font);
	pango_layout_set_alignment(layout,PANGO_ALIGN_CENTER);

	GtkAccelGroup *accel = gtk_accel_group_new();
	guint key;
	GdkModifierType mod;
	gtk_accelerator_parse("<Ctrl>Q", &key, &mod);
	gtk_accel_group_connect(accel, key, mod, 0, g_cclosure_new(G_CALLBACK(gtk_main_quit), NULL, NULL));
	gtk_accelerator_parse("Escape", &key, &mod);
	gtk_accel_group_connect(accel, key, mod, 0, g_cclosure_new(G_CALLBACK(clear_text), NULL, NULL));
	gtk_window_add_accel_group(GTK_WINDOW(window), accel);
	gtk_widget_show_all(window);

	g_signal_connect_after(G_OBJECT(draw), "expose-event", G_CALLBACK(redraw), NULL);
	g_signal_connect(G_OBJECT(tb), "changed", G_CALLBACK(newtext), NULL);
	g_signal_connect(G_OBJECT(tv), "move-cursor", G_CALLBACK(move_cursor), NULL);

	if (!input_provided)
		show_entry();
	else
		hide_entry(NULL);

	gtk_main();

	return 0;
}