/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1985-2007 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * regex collation symbol support
 */

#include "reglib.h"

#include <ccode.h>

#ifndef UCS_BYTE
#define UCS_BYTE	1
#endif

#include "ucs_names.h"

typedef struct Ucs_map_s
{
	Ucs_attr_t		attr[3];
	Ucs_code_t		code;
	const char*		name;
	Dtlink_t		link;
	struct Ucs_map_s*	next;
} Ucs_map_t;

#define setattr(a,i)	((a)[(i)>>5]|=(1<<((i)&((1<<5)-1))))
#define tstattr(a,i)	((a)[(i)>>5]&(1<<((i)&((1<<5)-1))))
#define clrattr(a,i)	((a)[(i)>>5]&=~(1<<((i)&((1<<5)-1))))

static struct Local_s
{
	int		fatal;
	Dt_t*		attrs;
	Dt_t*		names;
	Dtdisc_t	dtdisc;
#if CC_NATIVE != CC_ASCII
	unsigned char*	a2n;
#endif
} local;

/*
 * initialize the writeable tables from the readonly data
 * the tables are big enough to be concerned about text vs. data vs. bss
 *	UCS_BYTE==0 100K
 *	UCS_BYTE==1  20K
 */

static int
initialize(void)
{
	register int		i;
	register Ucs_map_t*	a;
	register Ucs_map_t*	w;

	if (local.fatal)
		return -1;
	local.dtdisc.link = offsetof(Ucs_map_t, link);
	local.dtdisc.key = offsetof(Ucs_map_t, name);
	local.dtdisc.size = -1;
	if (!(w = (Ucs_map_t*)malloc(sizeof(Ucs_map_t) * (elementsof(ucs_attrs) + elementsof(ucs_names)))))
	{
		local.fatal = 1;
		return -1;
	}
	if (!(local.attrs = dtopen(&local.dtdisc, Dttree)))
	{
		free(w);
		local.fatal = 1;
		return -1;
	}
	if (!(local.names = dtopen(&local.dtdisc, Dttree)))
	{
		free(w);
		dtclose(local.attrs);
		local.fatal = 1;
		return -1;
	}
	for (i = 0; i < elementsof(ucs_attrs); i++, w++)
	{
		memcpy(w, &ucs_attrs[i], offsetof(Ucs_dat_t, table));
		w->name = ucs_strings[ucs_attrs[i].table] + ucs_attrs[i].index;
		w->next = 0;
		dtinsert(local.attrs, w);
	}
	for (i = 0; i < elementsof(ucs_names); i++, w++)
	{
		memcpy(w, &ucs_names[i], offsetof(Ucs_dat_t, table));
		w->name = ucs_strings[ucs_names[i].table] + ucs_names[i].index;
		w->next = 0;
		if (a = (Ucs_map_t*)dtsearch(local.names, w))
		{
			while (a->next)
				a = a->next;
			a->next = w;
		}
		else
			dtinsert(local.names, w);
	}
#if CC_NATIVE != CC_ASCII
	local.a2n = ccmap(CC_ASCII, CC_NATIVE);
#endif
	return 0;
}

/*
 * return the collating symbol delimited by [c c], where c is either '=' or '.'
 * s points to the first char after the initial [
 * if e!=0 it is set to point to the next char in s on return
 *
 * the collating symbol is converted to multibyte in <buf,size>
 * the return value is:
 *	-1	syntax error or buf not large enough
 *	>=0	size with 0-terminated mb collation element
 *		or ligature value in buf
 */

int
regcollate(register const char* s, char** e, char* buf, int size)
{
	register int		c;
	register char*		u;
	register char*		b;
	register char*		x;
	register Ucs_map_t*	a;
	Ucs_map_t*		z;
	const char*		t;
	const char*		v;
	int			n;
	int			r;
	int			ul;
	int			term;
	wchar_t			w[2];
	Ucs_attr_t		attr[3];

	if (size < 2)
		r = -1;
	else if ((term = *s++) != '.' && term != '=')
	{
		s--;
		r = -1;
	}
	else if (*s == term && *(s + 1) == ']')
		r = -1;
	else
	{
		t = s;
		mbchar(s);
		if ((n = (s - t)) == 1)
		{
			if (*s == term && *(s + 1) == ']')
			{
				s += 2;
				r = -1;
			}
			else
			{
				if (!local.attrs && initialize())
					return -1;
				attr[0] = attr[1] = attr[2] = 0;
				ul = 0;
				b = buf;
				x = buf + size - 2;
				r = 1;
				s = t;
				do
				{
					v = s;
					u = b;
					for (;;)
					{
						if (!(c = *s++))
							return -1;
						if (c == term)
						{
							if (!(c = *s++))
								return -1;
							if (c != term)
							{
								if (c != ']')
									return -1;
								r = -1;
								break;
							}
						}
						if (c == ' ' || c == '-' && u > b && *s != ' ' && *s != '-')
							break;
						if (isupper(c))
							c = tolower(c);
						if (u > x)
							break;
						*u++ = c;
					}
					*u = 0;
					if (a = (Ucs_map_t*)dtmatch(local.attrs, b))
						setattr(attr, a->code);
					else
					{
						if (u < x)
							*u++ = ' ';
						if (b == buf)
						{
							if (isupper(*v))
								ul = UCS_UC;
							else if (islower(*v))
								ul = UCS_LC;
						}
						b = u;
					}
				} while (r > 0);
				if (b > buf && *(b - 1) == ' ')
					b--;
				*b = 0;
				attr[0] &= ~((Ucs_attr_t)1);
				if (ul)
				{
					if (tstattr(attr, UCS_UC) || tstattr(attr, UCS_LC))
						ul = 0;
					else
						setattr(attr, ul);
				}
				if (z = (Ucs_map_t*)dtmatch(local.names, buf))
					for(;;)
					{
						for (a = z; a; a = a->next)
							if ((attr[0] & a->attr[0]) == attr[0] && (attr[1] & a->attr[1]) == attr[1] && (attr[2] & a->attr[2]) == attr[2])
							{
								if (a->code <= 0xff)
								{
#if CC_NATIVE != CC_ASCII
									buf[0] = local.a2n[a->code];
#else
									buf[0] = a->code;
#endif
									buf[r = 1] = 0;
									ul = 0;
									break;
								}
								w[0] = a->code;
								w[1] = 0;
								if ((r = wcstombs(buf, w, size)) > 0)
								{
									r--;
									ul = 0;
								}
								break;
							}
						if (!ul)
							break;
						clrattr(attr, ul);
						ul = 0;
					}
			}
			if (r < 0)
			{
				if ((r = s - t - 2) > (size - 1))
					return -1;
				memcpy(buf, t, r);
				buf[r] = 0;
			}
		}
		else if (*s++ != term || *s++ != ']')
		{
			s--;
			r = -1;
		}
		else if (n > (size - 1))
			r = -1;
		else
		{
			memcpy(buf, t, n);
			buf[r = n] = 0;
		}
	}
	if (e)
		*e = (char*)s;
	return r;
}