/*
 * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 */
/*
	chtabgen - character table generator

	Author: Erik Baalbergen (..tjalk!erikb)
	Many mods by Ceriel Jacobs
*/

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

#ifndef NORCSID
static char* RcsId = "$Id$";
#endif

#define MAXBUF 256
#define MAXTAB 10000
#define COMCOM '-'
#define FILECOM '%'

int InputForm = 'c'; /* default input format (and, currently, only one) */
char OutputForm[MAXBUF] = "%s,\n";
/* format for spitting out a string */
char* Table[MAXTAB];
char* ProgCall; /* callname of this program */
int TabSize = 128; /* default size of generated table */
char* InitialValue; /* initial value of all table entries */

void option(char*);
void option_F(char*);
void InitTable(char*);
void PrintTable(void);
int process(char*, int);
int c_proc(char*, char*);
int setval(int, char*);
int quoted(char**);
void DoFile(char*);

int main(int argc, char* argv[])
{

	ProgCall = *argv++;
	argc--;
	while (argc-- > 0)
	{
		if (**argv == COMCOM)
		{
			option(*argv++);
		}
		else
		{
			if (!process(*argv++, InputForm))
			{
				exit(1);
			}
		}
	}
	exit(0);
	/*NOTREACHED*/
}

char* Salloc(char* s)
{
	char* ns = strdup(s);

	if (!ns)
	{
		fprintf(stderr, "%s: out of memory\n", ProgCall);
		exit(1);
	}
	return ns;
}

void option(char* str)
{
	/*	note that *str indicates the source of the option:
		either COMCOM (from command line) or FILECOM (from a file).
	*/
	switch (*++str)
	{

		case ' ': /* command */
		case '\t':
		case '\0':
			break;
		case 'I': /* for future extension */
			InputForm = *++str;
			break;
		case 'f': /* input from file ... */
			if (*++str == '\0')
			{
				fprintf(stderr, "%s: -f: name expected\n", ProgCall);
				exit(1);
			}
			DoFile(str);
			break;
		case 'F': /* new output format string */
			option_F(++str);
			break;
		case 'T': /* insert text literally */
			printf("%s\n", ++str);
			break;
		case 'p': /* print table */
			PrintTable();
			break;
		case 'C': /* clear table */
			InitTable((char*)0);
			break;
		case 'i': /* initialize table with given value */
			if (*++str == '\0')
			{
				InitTable((char*)0);
			}
			else
				InitTable(str);
			break;
		case 'S':
		{
			int i = atoi(++str);

			if (i <= 0 || i > MAXTAB)
			{
				fprintf(stderr, "%s: size would exceed maximum\n",
				    ProgCall);
			}
			else
			{
				TabSize = i;
			}
			break;
		}
		default:
			fprintf(stderr, "%s: bad option -%s\n", ProgCall, str);
	}
}

void option_F(char* form)
{
	int len;
	char* cp;

	/*
	 * The format string must have one '%s' and no other '%'.
	 * Don't allow '%99$s', '%ls', '%n'.
	 */
	cp = strchr(form, '%');
	if (!cp || cp[1] != 's' || strchr(cp + 1, '%'))
		goto bad;
	len = snprintf(OutputForm, sizeof(OutputForm), "%s\n", form);
	if (len < 0 && len >= sizeof(OutputForm))
		goto bad;
	return;

bad:
	fprintf(stderr, "%s: -F: bad format %s\n", ProgCall, form);
	exit(1);
}

void InitTable(char* ival)
{
	int i;

	for (i = 0; i < TabSize; i++)
	{
		Table[i] = 0;
	}
	InitialValue = 0;
	if (ival)
	{
		InitialValue = Salloc(ival);
	}
}

void PrintTable(void)
{
	int i;

	for (i = 0; i < TabSize; i++)
	{
		if (Table[i])
		{
			printf(OutputForm, Table[i]);
		}
		else if (InitialValue)
		{
			printf(OutputForm, InitialValue);
		}
		else
		{
			printf(OutputForm, "0");
		}
	}
}

int process(char* str, int format)
{
	char* cstr = str;
	char* Name = cstr; /* overwrite original string!	*/

	/* strip of the entry name
	*/
	while (*str && *str != ':')
	{
		if (*str == '\\')
		{
			++str;
		}
		*cstr++ = *str++;
	}

	if (*str != ':')
	{
		fprintf(stderr, "%s: bad specification: \"%s\", ignored\n",
		    ProgCall, Name);
		return 0;
	}
	*cstr = '\0';
	str++;

	switch (format)
	{

		case 'c':
			return c_proc(str, Name);
		default:
			fprintf(stderr, "%s: bad input format\n", ProgCall);
	}
	return 0;
}

int c_proc(char* str, char* Name)
{
	int ch, ch2;
	char* name = Salloc(Name);

	while (*str)
	{
		if (*str == '\\')
		{
			ch = quoted(&str);
		}
		else
		{
			ch = *str++ & 0377;
		}
		if (*str == '-')
		{
			if (*++str == '\\')
			{
				ch2 = quoted(&str);
			}
			else
			{
				ch2 = (*str++ & 0377);
				if (!ch2)
					str--;
			}
			if (ch > ch2)
			{
				fprintf(stderr, "%s: bad range\n", ProgCall);
				return 0;
			}
			while (ch <= ch2)
			{
				if (!setval(ch, name))
					return 0;
				ch++;
			}
		}
		else
		{
			if (!setval(ch, name))
				return 0;
		}
	}
	return 1;
}

int setval(int ch, char* nm)
{
	char** p = &Table[ch];

	if (ch < 0 || ch >= TabSize)
	{
		fprintf(stderr, "Illegal index: %d\n", ch);
		return 0;
	}
	if (*(p = &Table[ch]))
	{
		fprintf(stderr, "Warning: redefinition of index %d\n", ch);
	}
	*p = nm;
	return 1;
}

int quoted(char** pstr)
{
	int ch;
	int i;
	char* str = *pstr;

	if ((*++str >= '0') && (*str <= '9'))
	{
		ch = 0;
		for (i = 0; i < 3; i++)
		{
			ch = 8 * ch + (*str - '0');
			if (*++str < '0' || *str > '9')
				break;
		}
	}
	else
	{
		switch (*str++)
		{
			case 'n':
				ch = '\n';
				break;
			case 't':
				ch = '\t';
				break;
			case 'b':
				ch = '\b';
				break;
			case 'r':
				ch = '\r';
				break;
			case 'f':
				ch = '\f';
				break;
			case 'v':
				ch = 013;
				break;
			default:
				ch = *(str - 1);
				break;
		}
	}
	*pstr = str;
	return ch & 0377;
}

char* getln(char* s, int n, FILE* fp)
{
	int c = getc(fp);
	char* str = s;

	while (n--)
	{
		if (c == EOF)
		{
			return NULL;
		}
		else if (c == '\n')
		{
			*str++ = '\0';
			return s;
		}
		*str++ = c;
		c = getc(fp);
	}
	s[n - 1] = '\0';
	return s;
}

#define BUFSIZE 1024

void DoFile(char* name)
{
	char text[BUFSIZE];
	FILE* fp;

	if ((fp = fopen(name, "r")) == NULL)
	{
		fprintf(stderr, "%s: cannot read file %s\n", ProgCall, name);
		exit(1);
	}
	while (getln(text, BUFSIZE, fp) != NULL)
	{
		if (text[0] == FILECOM)
		{
			option(text);
		}
		else
		{
			if (!process(text, InputForm))
			{
				exit(1);
			}
		}
	}
}
