/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1994 by Sun Microsystems, Inc.
 */


#include <stdlib.h>
#include <errno.h>
#include "ktable.h"
#include "utf_nbyte.h"


/****  _ I C V _ O P E N  ****/

void* _icv_open()
{
	_conv_desc* cd = (_conv_desc*)malloc(sizeof(_conv_desc));

	if (cd == (_conv_desc*)NULL)
	{
		errno = ENOMEM;
		return((void*)-1);
	}

	RESET_CONV_DESC();
	cd->state = ASCII;

	return((void*)cd);
}  /* end of int _icv_open(). */


/****  _ I C V _ C L O S E  ****/

void _icv_close(_conv_desc* cd)
{
	if (!cd)
		errno = EBADF;
	else
		free((void*)cd);
}  /* end of void _icv_close(_conv_desc*). */


/****  _ I C V _ I C O N V  ****/

size_t _icv_iconv(_conv_desc* cd, char** inbuf, size_t* inbufleft,
			char** outbuf, size_t* outbufleft)
{
	void		echo_vowel(char*, int*), echo_consonant(char*, int*);
	size_t		ret_val = 0;
	unsigned char*	ib;
	unsigned char*	ob;
	unsigned char*	ibtail;
	unsigned char*	obtail;

	if (!cd)
	{
		errno = EBADF;
		return((size_t)-1);
	}

	if (!inbuf || !(*inbuf))
	{
		RESET_CONV_DESC();
		cd->state = ASCII;
		return((size_t)0);
	}

	ib = (unsigned char*)*inbuf;
	ob = (unsigned char*)*outbuf;
	ibtail = ib + *inbufleft;
	obtail = ob + *outbufleft;

	while (ib < ibtail)
	{
		if (!(*ib & 0x80))		/* 7 bits */
		{
			PROCESS_PRIOR_CVC();

			if ((obtail - ob) < (cd->state == WANSUNG ? 2 : 1))
			{
				errno = E2BIG;
				ret_val = (size_t)-1;
				break;
			}
			if (cd->state == WANSUNG)
			{
				*ob++ = SI;
				cd->state = ASCII;
			}
			*ob++ = *ib++;
		}
		else if ((*ib & 0xF0) == 0xE0)	/* 16 bits */
		{
			unsigned long	utf;

			if ((ibtail - ib) < 3)
			{
				errno = EINVAL;
				ret_val = (size_t)-1;
				break;
			}

			utf = ((unsigned long)(*ib) << 16) |
			      ((unsigned long)(*(ib + 1)) << 8) |
			      (unsigned long)(*(ib + 2));
			if (utf == 0xE1859F ||
			    (utf >= 0xE18480 && utf <= 0xE18492))  /* Ci */
			{
				PROCESS_PRIOR_CVC();

				cd->ci = (utf == 0xE1859F) ? CVC_FILL
							   : utf - 0xE18480;
				cd->prev_state = CI;
			}
			else if (utf == 0xE185A0 ||
				 (utf >= 0xE185A1 && utf <= 0xE185B5))  /* V */
			{
				if (cd->prev_state != E && cd->prev_state != CI)
					PROCESS_PRIOR_CVC();

				cd->v = (utf == 0xE185A0) ? CVC_FILL
							  : utf - 0xE185A1;
				cd->prev_state = V;
			}
			else if ((utf >= 0xE186A8 && utf <= 0xE186BF) ||
				 (utf >= 0xE18780 && utf <= 0xE18782))  /* Cf */
			{
				if (cd->prev_state != E && cd->prev_state != V)
					PROCESS_PRIOR_CVC();

				cd->cf = utf - ((utf >= 0xE18780) ? 0xE18766
								 : 0xE186A6);
				cd->prev_state = CF;

				PROCESS_PRIOR_CVC();
			}
			else
			{
				PROCESS_PRIOR_CVC();

				/* Let's assume the code is non-identical. */
				if ((obtail - ob) < 2)
				{
					errno = E2BIG;
					ret_val = (size_t)-1;
					break;
				}
				*ob++ = NON_IDENTICAL;
				*ob++ = NON_IDENTICAL;
				ret_val += 2;
			}
			ib += 3;
		}
		else  /* 11, 21, 26 & 31 bits codes won't be able to convert. */
		{
			short int offset;

			PROCESS_PRIOR_CVC();

			if ((*ib & 0xE0) == 0xC0)  /* 11 */
				offset = 2;
			else if ((*ib & 0xF0) == 0xE0)  /* 16 */
				offset = 3;
			else if ((*ib & 0xF8) == 0xF0)  /* 21 */
				offset = 4;
			else if ((*ib & 0xFC) == 0xF8)  /* 26 */
				offset = 5;
			else if ((*ib & 0xFE) == 0xFC)  /* 31 */
				offset = 6;
			else  /* Illegal sequence. */
				offset = 1;

			if ((ibtail - ib) < offset)
			{
				errno = EINVAL;
				ret_val = (size_t)-1;
				break;
			}
			ib += offset;

			/* Let's assume the code is non-identical. */
			offset = (offset > 2) ? 2 : 1;
			if ((obtail - ob) < offset)
			{
				errno = E2BIG;
				ret_val = (size_t)-1;
				break;
			}
			*ob++ = NON_IDENTICAL;
			if (offset > 1)
				*ob++ = NON_IDENTICAL;
			ret_val += offset;
		}
	}

	*inbuf = (char*)ib;
	*inbufleft = ibtail - ib;
	*outbuf = (char*)ob;
	*outbufleft = obtail - ob;

	return(ret_val);
}  /* end of size_t _icv_iconv(_conv_desc*, char**, size_t*, char**, size_t*).*/


/****  E C H O _ V O W E L  ****/

void echo_vowel(char* c,  int* i)
{
	if (c[*i] == 'm')  /* _|_|- */
	{
		c[(*i)++] = 'l';	/* _|_ */
		c[(*i)++] = 'b';	/* |- */
	}
	else if (c[*i] == 'n')  /* _|_H */
	{
		c[(*i)++] = 'l';	/* _|_ */
		c[(*i)++] = 'c';	/* H */
	}
	else if (c[*i] == 'o')  /* _|_| */
	{
		c[(*i)++] = 'l';	/* _|_ */
		c[(*i)++] = '|';	/* | */
	}
	else if (c[*i] == 't')  /* T-| */
	{
		c[(*i)++] = 's';	/* T */
		c[(*i)++] = 'f';	/* -| */
	}
	else if (c[*i] == 'u')  /* T-|| */
	{
		c[(*i)++] = 's';	/* T */
		c[(*i)++] = 'g';	/* -|| */
	}
	else if (c[*i] == 'v')  /* T| */
	{
		c[(*i)++] = 's';	/* T */
		c[(*i)++] = '|';	/* | */
	}
	else if (c[*i] == '{')  /* _| */
	{
		c[(*i)++] = 'z';	/* __ */
		c[(*i)++] = '|';	/* | */
	}
	else
		(*i)++;
}  /* end of void echo_vowel(char*, int*). */


/****  E C H O _ C O N S O N A N T  ****/

void echo_consonant(char* c,  int* i)
{
	if (c[*i] == 'C')  /* gs */
	{
		c[(*i)++] = 'A';	/* g */
		c[(*i)++] = 'U';	/* s */
	}
	else if (c[*i] == 'E')  /* nj */
	{
		c[(*i)++] = 'D';	/* n */
		c[(*i)++] = 'X';	/* j */
	}
	else if (c[*i] == 'F')  /* nh */
	{
		c[(*i)++] = 'D';	/* n */
		c[(*i)++] = '^';	/* h */
	}
	else if (c[*i] == 'J')  /* rg */
	{
		c[(*i)++] = 'I';	/* r */
		c[(*i)++] = 'A';	/* g */
	}
	else if (c[*i] == 'K')  /* rm */
	{
		c[(*i)++] = 'I';	/* r */
		c[(*i)++] = 'Q';	/* m */
	}
	else if (c[*i] == 'L')  /* rb */
	{
		c[(*i)++] = 'I';	/* r */
		c[(*i)++] = 'R';	/* b */
	}
	else if (c[*i] == 'M')  /* rs */
	{
		c[(*i)++] = 'I';	/* r */
		c[(*i)++] = 'U';	/* s */
	}
	else if (c[*i] == 'N')  /* rt */
	{
		c[(*i)++] = 'I';	/* r */
		c[(*i)++] = '\\';	/* t */
	}
	else if (c[*i] == 'O')  /* rp */
	{
		c[(*i)++] = 'I';	/* r */
		c[(*i)++] = ']';	/* p */
	}
	else if (c[*i] == 'P')  /* rh */
	{
		c[(*i)++] = 'I';	/* r */
		c[(*i)++] = '^';	/* h */
	}
	else if (c[*i] == 'T')  /* bs */
	{
		c[(*i)++] = 'R';	/* b */
		c[(*i)++] = 'U';	/* s */
	}
	else
		(*i)++;
}  /* end of void echo_consonant(char*, int*). */