/*
 *	termcap.c	1.1	20/7/87		agc	Joypace Ltd
 *
 *	Copyright Joypace Ltd, London, UK, 1987. All rights reserved.
 *	This file may be freely distributed provided that this notice
 *	remains attached.
 *
 *	A public domain implementation of the termcap(3) routines.
 *
 *	Made fully functional by Ceriel J.H. Jacobs.
 *
 * BUGS:
 *	- does not check termcap entry sizes
 *	- not fully tested
 */
/* $Id$ */

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

#define CAPABLEN 2

#define ISSPACE(c) ((c) == ' ' || (c) == '\t' || (c) == '\r' || (c) == '\n')
#define ISDIGIT(x) ((x) >= '0' && (x) <= '9')

short ospeed; /* output speed */
char PC; /* padding character */
char* BC; /* back cursor movement */
char* UP; /* up cursor movement */

static const char* capab; /* the capability itself */
static int check_for_tc(void);
static int match_name(const char* buf, const char* name);

/*
 *	tgetent - get the termcap entry for terminal name, and put it
 *	in bp (which must be an array of 1024 chars). Returns 1 if
 *	termcap entry found, 0 if not found, and -1 if file not found.
 */
int tgetent(char* bp, const char* name)
{
	FILE* fp;
	char* file;
	char* cp;
	char buf[1024];

	capab = bp;
	if ((file = getenv("TERMCAP")) != (char*)NULL)
	{
		if (*file != '/' && (cp = getenv("TERM")) != NULL && strcmp(name, cp) == 0)
		{
			(void)strcpy(bp, file);
			return (1);
		}
		else
			file = "/etc/termcap";
	}
	else
		file = "/etc/termcap";

	if ((fp = fopen(file, "r")) == (FILE*)NULL)
		return (-1);
	while (fgets(buf, 1024, fp) != NULL)
	{
		if (buf[0] == '#')
			continue;
		while (*(cp = &buf[strlen(buf) - 2]) == '\\')
			if (fgets(cp, 1024, fp) == NULL)
				goto exit;
		if (match_name(buf, name))
		{
			strcpy(bp, buf);
			fclose(fp);
			return (check_for_tc());
		}
	}
exit:
	fclose(fp);
	return (0);
}

/*
 *	Compare the terminal name with each termcap entry name; Return 1 if a
 *	match is found.
 */
static int
match_name(const char* buf, const char* name)
{
	register const char* tp = buf;
	register const char* np;

	for (;;)
	{
		for (np = name; *np && *tp == *np; np++, tp++)
		{
		}
		if (*np == 0 && (*tp == '|' || *tp == ':' || *tp == 0))
			return (1);
		while (*tp != 0 && *tp != '|' && *tp != ':')
			tp++;
		if (*tp++ != '|')
			return (0);
	}
}

/*
 *	Handle tc= definitions recursively.
 */
static int
check_for_tc(void)
{
	static int count = 0;
	const char* savcapab = capab;
	char buf[1024];
	char terminalname[128];
	register char *p = (char*)capab + strlen(capab) - 2, *q;

	while (*p != ':')
		if (--p < (char*)capab)
			return (0); /* no : in termcap entry */
	if (p[1] != 't' || p[2] != 'c')
		return (1);
	if (count > 16)
		return (0); /* recursion in tc= definitions */
	count++;
	strcpy(terminalname, &p[4]);
	q = terminalname;
	while (*q && *q != ':')
		q++;
	*q = 0;
	if (tgetent(buf, terminalname) != 1)
	{
		--count;
		return (0);
	}
	--count;
	for (q = buf; *q && *q != ':'; q++)
	{
	}
	strcpy(p, q);
	capab = savcapab;
	return (1);
}

/*
 *	tgetnum - get the numeric terminal capability corresponding
 *	to id. Returns the value, -1 if invalid.
 */
int tgetnum(const char* id)
{
	const char* cp;
	int ret;

	if ((cp = capab) == NULL || id == NULL)
		return (-1);
	while (*++cp != ':')
		;
	while (*cp)
	{
		cp++;
		while (ISSPACE(*cp))
			cp++;
		if (strncmp(cp, id, CAPABLEN) == 0)
		{
			while (*cp && *cp != ':' && *cp != '#')
				cp++;
			if (*cp != '#')
				return (-1);
			for (ret = 0, cp++; *cp && ISDIGIT(*cp); cp++)
				ret = ret * 10 + *cp - '0';
			return (ret);
		}
		while (*cp && *cp != ':')
			cp++;
	}
	return (-1);
}

/*
 *	tgetflag - get the boolean flag corresponding to id. Returns -1
 *	if invalid, 0 if the flag is not in termcap entry, or 1 if it is
 *	present.
 */
int tgetflag(const char* id)
{
	const char* cp;

	if ((cp = capab) == NULL || id == NULL)
		return (-1);
	while (*++cp != ':')
		;
	while (*cp)
	{
		cp++;
		while (ISSPACE(*cp))
			cp++;
		if (strncmp(cp, id, CAPABLEN) == 0)
			return (1);
		while (*cp && *cp != ':')
			cp++;
	}
	return (0);
}

/*
 *	tgetstr - get the string capability corresponding to id and place
 *	it in area (advancing area at same time). Expand escape sequences
 *	etc. Returns the string, or NULL if it can't do it.
 */
char* tgetstr(const char* id, char** const area)
{
	const char* cp;
	char* ret;
	int i;

	if ((cp = capab) == NULL || id == NULL)
		return (NULL);
	while (*++cp != ':')
		;
	while (*cp)
	{
		cp++;
		while (ISSPACE(*cp))
			cp++;
		if (strncmp(cp, id, CAPABLEN) == 0)
		{
			while (*cp && *cp != ':' && *cp != '=')
				cp++;
			if (*cp != '=')
				return (NULL);
			for (ret = *area, cp++; *cp && *cp != ':'; (*area)++, cp++)
				switch (*cp)
				{
					case '^':
						**area = *++cp - 'A' + 1;
						break;
					case '\\':
						switch (*++cp)
						{
							case 'E':
								**area = '\033';
								break;
							case 'n':
								**area = '\n';
								break;
							case 'r':
								**area = '\r';
								break;
							case 't':
								**area = '\t';
								break;
							case 'b':
								**area = '\b';
								break;
							case 'f':
								**area = '\f';
								break;
							case '0':
							case '1':
							case '2':
							case '3':
								for (i = 0; *cp && ISDIGIT(*cp); cp++)
									i = i * 8 + *cp - '0';
								**area = i;
								cp--;
								break;
							case '^':
							case '\\':
								**area = *cp;
								break;
						}
						break;
					default:
						**area = *cp;
				}
			*(*area)++ = '\0';
			return (ret);
		}
		while (*cp && *cp != ':')
			cp++;
	}
	return (NULL);
}

/*
 *	tgoto - given the cursor motion string cm, make up the string
 *	for the cursor to go to (destcol, destline), and return the string.
 *	Returns "OOPS" if something's gone wrong, or the string otherwise.
 */
char* tgoto(const char* cm, int destcol, int destline)
{
	register char* rp;
	static char ret[24];
	char added[16];
	int* dp = &destline;
	int numval;
	int swapped = 0;

	added[0] = 0;
	for (rp = ret; *cm; cm++)
	{
		if (*cm == '%')
		{
			switch (*++cm)
			{
				case '>':
					if (dp == NULL)
						return ("OOPS");
					cm++;
					if (*dp > *cm++)
					{
						*dp += *cm;
					}
					break;
				case '+':
				case '.':
					if (dp == NULL)
						return ("OOPS");
					if (*cm == '+')
						*dp = *dp + *++cm;
					for (;;)
					{
						switch (*dp)
						{
							case 0:
							case 04:
							case '\t':
							case '\n':
								/* filter these out */
								if (dp == &destcol || swapped || UP)
								{
									strcat(added, dp == &destcol || swapped ? (BC ? BC : "\b") : UP);
									(*dp)++;
									continue;
								}
						}
						break;
					}
					*rp++ = *dp;
					dp = (dp == &destline) ? &destcol : NULL;
					break;

				case 'r':
				{
					int tmp = destline;

					destline = destcol;
					destcol = tmp;
					swapped = 1 - swapped;
					break;
				}
				case 'n':
					destcol ^= 0140;
					destline ^= 0140;
					break;

				case '%':
					*rp++ = '%';
					break;

				case 'i':
					destcol++;
					destline++;
					break;

				case 'B':
					if (dp == NULL)
						return ("OOPS");
					*dp = 16 * (*dp / 10) + *dp % 10;
					break;

				case 'D':
					if (dp == NULL)
						return ("OOPS");
					*dp = *dp - 2 * (*dp % 16);
					break;

				case 'd':
				case '2':
				case '3':
					if (dp == NULL)
						return ("OOPS");
					numval = *dp;
					dp = (dp == &destline) ? &destcol : NULL;
					if (numval >= 100)
					{
						*rp++ = '0' + numval / 100;
					}
					else if (*cm == '3')
					{
						*rp++ = ' ';
					}
					if (numval >= 10)
					{
						*rp++ = '0' + ((numval % 100) / 10);
					}
					else if (*cm == '3' || *cm == '2')
					{
						*rp++ = ' ';
					}
					*rp++ = '0' + (numval % 10);
					break;
				default:
					return ("OOPS");
			}
		}
		else
			*rp++ = *cm;
	}
	*rp = '\0';
	strcpy(rp, added);
	return (ret);
}

static int tens_of_ms_p_char[] = { /* index as returned by gtty */
	/* assume 10 bits per char */
	0, 2000, 1333, 909, 743, 666, 500, 333, 166, 83, 55, 41, 20, 10, 5, 2
};
/*
 *	tputs - put the string cp out onto the terminal, using the function
 *	outc. Also handle padding.
 */
int tputs(register const char* cp, int affcnt, int (*outc)(int))
{
	int delay = 0;
	if (cp == NULL)
		return (1);
	while (ISDIGIT(*cp))
	{
		delay = delay * 10 + (*cp++ - '0');
	}
	delay *= 10;
	if (*cp == '.')
	{
		cp++;
		if (ISDIGIT(*cp))
		{
			delay += *cp++ - '0';
		}
		while (ISDIGIT(*cp))
			cp++;
	}
	if (*cp == '*')
	{
		delay *= affcnt;
		cp++;
	}
	while (*cp)
		(*outc)(*cp++);
	if (delay != 0 && ospeed > 0 && ospeed < (sizeof tens_of_ms_p_char / sizeof tens_of_ms_p_char[0]))
	{
		delay = (delay + tens_of_ms_p_char[ospeed] - 1) / tens_of_ms_p_char[ospeed];
		while (delay--)
			(*outc)(PC);
	}
	return (1);
}

/*
 *	That's all, folks...
 */