/*
 * Tlf - contest logging program for amateur radio operators
 * Copyright (C) 2015 Thomas Beierlein <address@hidden>
 *
 * 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
 */

/* User Interface helpers for ncurses based user interface */


#include <stdlib.h>
#include <termios.h>
#include <unistd.h>

#include <ncurses.h>

static int getkey(int wait);
static int onechar(void);


void stoptx(void)
{
    printw("TX stopped.\n");
    refresh();
}

/** key_get  wait for next key from terminal
 *
 */
int key_get()
{
    return getkey(1);
}

/** key_poll return next key from terminal if there is one
 *
 */
int key_poll()
{
    return getkey(0);
}


/* helper function to set 'nodelay' mode according to 'wait'
 * parameter and then ask for the next character
 * leaves 'nodelay' afterwards always as FALSE (meaning: wait for
 * character
 */
static int getkey(int wait)
{
    int x = 0;

    nodelay(stdscr, wait ? FALSE : TRUE);

    x = onechar();

    nodelay(stdscr, FALSE);

    return x;
}


/* New onechar() that takes advantage of Ncurses keypad mode and processes
 * certain escaped keys and assigns them to Ncurses values known by
 * keyname().  Also catches Escape and processes it immediately as well
 * as calling stoptx() for minimal delay.
 */
static int onechar(void)
{
    int x = 0;
    int trash = 0;

    x = getch();

    /* Replace Ctl-H and Backspace with KEY_BACKSPACE */
    if (x == 8 || x == 127)
	x = KEY_BACKSPACE;

    if (x == 27) {
	nodelay(stdscr, TRUE);

	x = getch();

	/* Escape pressed, not an escaped key. */
	if (x == ERR) {
	    stoptx();

	    return x = 27;

	} else if (x != 91) {

	    switch (x) {

		case 32 ... 57:   // Alt-Space to Alt-9,   160 - 185
		case 97 ... 122:  // Alt-a to alt-z,       225 - 250
		    x += 128;
		    break;

		/* Not all terminals support Ctl-Shift-ch so
		 * treat them as Alt-ch
		 */
		case 65 ... 78:   //   alt-A to alt-N,     225 - 238
		case 80 ... 90:   //   alt-P to alt-Z,     240 - 250
		    x += 160;
		    break;

		case 79: {
		    x = getch();

		    /* Catch Alt-O */
		    if (x == ERR) {
			x = 239;
			break;
		    }

		    /* Key codes for Shift-F1 to Shift-F4 in Xfce terminal. */
		    if (x == 49) {
			x = getch();

			if (x == 59) {
			    x = getch();
			    if (x == 50) {
				x = getch();

				switch (x) {

				    case 80: {
					x = KEY_F(13);
					break;
				    }

				    case 81: {
					x = KEY_F(14);
					break;
				    }

				    case 82: {
					x = KEY_F(15);
					break;
				    }

				    case 83: {
					x = KEY_F(16);
					break;
				    }
				}
			    }
			}
		    }
		}
	    }

	    nodelay(stdscr, FALSE);

	} else {
	    nodelay(stdscr, FALSE);

	    x = getch();        /* Get next code after 91 */

	    switch (x) {

		/* Key codes for this section:
		 * 27 91 49 126 Home
		 * 27 91 52 126 End
		 *
		 * Needed for the keypad Pg-Up and Pg-Dn keys in Xfce terminal.
		 */
		case 49: {
		    x = getch();

		    if (x == 126) {
			x = KEY_HOME;
			break;
		    }
		}

		case 52: {
		    x = KEY_END;
		    trash = getch();
		    break;
		}
	    }
	}
    }

    /* It seems Xterm treats Alt-Space through Alt-9 with a prefix
     * character of 194 followed by 160 through 185.
     */
    if (x == 194) {
	nodelay(stdscr, TRUE);

	trash = getch();

	if (trash == ERR)
	    return x;

	x = trash;

	// Alt-Space to Alt-9
	if (x >= 160 && x <= 185) {
	    nodelay(stdscr, FALSE);

	    return x;
	}
    }

    /* It seems Xterm treats Alt-a to Alt-z with a prefix
     * character of 195 followed by 161-186 (a-z) or
     * 129-154 (A-Z).
     */
    if (x == 195) {
	nodelay(stdscr, TRUE);

	trash = getch();

	if (trash == ERR)
	    return x;

	x = trash;

	switch (x) {

	    case 161 ... 186:  // Alt-a to Alt-z  225 - 250
		x += 64;
		break;

	    case 129 ... 154:  // Alt-A to Alt-Z  225 - 250
		x += 96;
		break;
	}

	nodelay(stdscr, FALSE);
    }

    return x;
}


static struct termios oldt, newt;

int main(void)
{
    int x;

    SCREEN *mainscreen;

    /* modify stdin terminals attributes to allow Ctrl-Q/S key recognition */
    tcgetattr(STDIN_FILENO, &oldt);
    newt = oldt;
    newt.c_iflag &= ~(IXON);
    tcsetattr(STDIN_FILENO, TCSANOW, &newt);

    /* activate ncurses terminal control */
    if ((mainscreen = newterm(NULL, stdout, stdin)) == NULL) {
	perror("initscr");
	printf("\nSorry, wrong terminal type !!!!! \n"
	       "Try a  linux text terminal or set TERM=linux !!!\n");
	sleep(2);

	exit(EXIT_FAILURE);
    }

    noecho();
    crmode();
    keypad(stdscr, TRUE);      // Have Ncurses process most special keys
    scrollok(stdscr, TRUE);

    set_term(mainscreen);

    /* Speed up Escape processing, setting the Ncurses Escape
     * dealy to 25 mS.  Should be enough time to catch escaped
     * key codes.
     */
    set_escdelay(25);

    printw("Tests escaped keys used in Tlf.  Press Ctl-D to exit.\n\n");
    printw("Escape delay time is: %d mS\n", get_escdelay());

    /* Break out with Ctl-D. */
    while (x != 4) {
	x = key_get();
	printw("Ordinal: %d\t\tName: %s\n", x, keyname(x));

	refresh();
    }

    endwin();
    tcsetattr(STDIN_FILENO, TCSANOW, &oldt);

    exit(EXIT_SUCCESS);
}