/*
 * $LynxId: HTPlain.c,v 1.51 2013/05/02 11:09:30 tom Exp $
 *
 *		Plain text object		HTWrite.c
 *		=================
 *
 *	This version of the stream object just writes to a socket.
 *	The socket is assumed open and left open.
 *
 *	Bugs:
 *		strings written must be less than buffer size.
 */

#define HTSTREAM_INTERNAL 1

#include <HTUtils.h>
#include <LYCharVals.h>		/* S/390 -- gil -- 0288 */

#include <HTPlain.h>

#include <HTChunk.h>
#include <HText.h>
#include <HTStyle.h>
#define Lynx_HTML_Handler
#include <HTML.h>		/* styles[] */

#define BUFFER_SIZE 4096;	/* Tradeoff */

#include <HTMLDTD.h>
#include <HTCJK.h>
#include <UCMap.h>
#include <UCDefs.h>
#include <UCAux.h>

#include <LYCharSets.h>
#include <LYStrings.h>
#include <LYLeaks.h>

static int HTPlain_lastraw = -1;
static int HTPlain_bs_pending = 0;	/* 1:bs 2:underline 3:underline+bs - kw */

/*		HTML Object
 *		-----------
 */
struct _HTStream {
    const HTStreamClass *isa;
    HText *text;
    /*
     * The node_anchor UCInfo and handle for the input (PARSER) stage.  - FM
     */
    LYUCcharset *inUCI;
    int inUCLYhndl;
    /*
     * The node_anchor UCInfo and handle for the output (HTEXT) stage.  - FM
     */
    LYUCcharset *outUCI;
    int outUCLYhndl;
    /*
     * Counter, value, buffer and pointer for UTF-8 handling.  - FM
     */
    char utf_count;
    UCode_t utf_char;
    char utf_buf[8];
    char *utf_buf_p;
    /*
     * The charset transformation structure.  - FM
     */
    UCTransParams T;
};

static char replace_buf[64];	/* buffer for replacement strings */

static void HTPlain_getChartransInfo(HTStream *me, HTParentAnchor *anchor)
{
    if (me->inUCLYhndl < 0) {
	HTAnchor_copyUCInfoStage(anchor, UCT_STAGE_PARSER, UCT_STAGE_MIME,
				 UCT_SETBY_PARSER);
	me->inUCLYhndl = HTAnchor_getUCLYhndl(anchor, UCT_STAGE_PARSER);
    }
    if (me->outUCLYhndl < 0) {
	int chndl = HTAnchor_getUCLYhndl(anchor, UCT_STAGE_HTEXT);

	if (chndl < 0) {
	    chndl = current_char_set;
	    HTAnchor_setUCInfoStage(anchor, chndl,
				    UCT_STAGE_HTEXT, UCT_SETBY_DEFAULT);
	}
	HTAnchor_setUCInfoStage(anchor, chndl,
				UCT_STAGE_HTEXT, UCT_SETBY_DEFAULT);
	me->outUCLYhndl = HTAnchor_getUCLYhndl(anchor, UCT_STAGE_HTEXT);
    }
    me->inUCI = HTAnchor_getUCInfoStage(anchor, UCT_STAGE_PARSER);
    me->outUCI = HTAnchor_getUCInfoStage(anchor, UCT_STAGE_HTEXT);
}

/*	Write the buffer out to the socket
 *	----------------------------------
 */

/*_________________________________________________________________________
 *
 *			A C T I O N	R O U T I N E S
 */

static void HTPlain_write(HTStream *me, const char *s,
			  int l);

/*	Character handling
 *	------------------
 */
static void HTPlain_put_character(HTStream *me, int c)
{
#ifdef REMOVE_CR_ONLY
    /*
     * Throw away \r's.
     */
    if (c != '\r') {
	HText_appendCharacter(me->text, c);
    }
#else
    /*
     * See HTPlain_write() for explanations of the following code (we've been
     * called via HTPlain_put_string() to do for each character of a terminated
     * string what HTPlain_write() does via a while loop for each character in
     * a stream of given length).  - FM
     */
    if ((HTPlain_lastraw == '\r') && c == '\n') {
	HTPlain_lastraw = -1;
	return;
    }
    if (c == '\b' || c == '_' || HTPlain_bs_pending) {
	char temp[1];

	temp[0] = (char) c;
	HTPlain_write(me, temp, 1);
	return;
    }
    HTPlain_lastraw = UCH(c);
    if (c == '\r') {
	HText_appendCharacter(me->text, '\n');
    } else if (TOASCII(UCH(c)) >= 127) {	/* S/390 -- gil -- 0305 */
	char temp[1];

	temp[0] = (char) c;
	/*
	 * For now, don't repeat everything here that has been done below - KW
	 */
	HTPlain_write(me, temp, 1);
    } else if (IS_CJK_TTY) {
	HText_appendCharacter(me->text, c);
    } else if (TOASCII(UCH(c)) >= 127 && TOASCII(UCH(c)) < 161 &&
	       HTPassHighCtrlRaw) {
	HText_appendCharacter(me->text, c);
#if CH_NBSP < 127
    } else if (UCH(c) == CH_NBSP) {	/* S/390 -- gil -- 0341 */
	HText_appendCharacter(me->text, ' ');
#endif
#if CH_SHY < 127
    } else if (UCH(c) == CH_SHY) {
	return;
#endif
    } else if ((UCH(c) >= ' ' && TOASCII(UCH(c)) < 127) ||
	       c == '\n' || c == '\t') {
	HText_appendCharacter(me->text, c);
    }
#endif /* REMOVE_CR_ONLY */
}

/*	String handling
 *	---------------
 *
 */
static void HTPlain_put_string(HTStream *me, const char *s)
{
#ifdef REMOVE_CR_ONLY
    HText_appendText(me->text, s);
#else
    const char *p;

    if (s == NULL)
	return;
    for (p = s; *p; p++) {
	HTPlain_put_character(me, *p);
    }
#endif /* REMOVE_CR_ONLY */
}

/*
 *	Entry function for displayed text/plain and WWW_SOURCE strings. - FM
 *	---------------------------------------------------------------
 */
static void HTPlain_write(HTStream *me, const char *s, int l)
{
    const char *p;
    const char *e = s + l;
    char c;
    unsigned c_unsign;
    BOOL chk;
    UCode_t code, uck = -1;
    char saved_char_in = '\0';

    for (p = s; p < e; p++) {
#ifdef REMOVE_CR_ONLY
	/*
	 * Append the whole string, but remove any \r's.  - FM
	 */
	if (*p != '\r') {
	    HText_appendCharacter(me->text, *p);
	}
#else
	if (*p == '\b') {
	    if (HTPlain_lastraw >= UCH(' ') &&
		HTPlain_lastraw != '\r' && HTPlain_lastraw != '\n') {
		if (!HTPlain_bs_pending) {
		    HTPlain_bs_pending = 1;
		    continue;
		} else if (HTPlain_bs_pending == 2) {
		    HTPlain_bs_pending = 3;
		    continue;
		}
	    }
	    if (HTPlain_bs_pending >= 2)
		HText_appendCharacter(me->text, '_');
	    HTPlain_bs_pending = 0;
	} else if (*p == '_') {
	    if (!HTPlain_bs_pending) {
		HTPlain_bs_pending = 2;
		HTPlain_lastraw = UCH(*p);
		continue;
#if 0
	    } else if (HTPlain_bs_pending != 2) {
		HTPlain_bs_pending--;	/* 1 -> 0, 3 -> 2 */
		HTPlain_lastraw = UCH(*p);
		continue;
#endif
	    }
	}

	/*
	 * Try to handle lone LFs, CRLFs and lone CRs as newline, and to deal
	 * with control, ASCII, and 8-bit characters based on best guesses of
	 * what's appropriate.  - FM
	 */
	if ((HTPlain_lastraw == '\r') && *p == '\n') {
	    HTPlain_lastraw = -1;
	    continue;
	}

	if (HTPlain_bs_pending &&
	    !(UCH(*p) >= ' ' && *p != '\r' && *p != '\n' &&
	      (HTPlain_lastraw == UCH(*p) ||
	       HTPlain_lastraw == UCH('_') ||
	       *p == '_'))) {
	    if (HTPlain_bs_pending >= 2)
		HText_appendCharacter(me->text, '_');
	    HTPlain_bs_pending = 0;
	} else if (HTPlain_bs_pending == 1) {
	    HTPlain_bs_pending = 0;
	    continue;		/* ignore last two of "X\bX" or "X\b_" - kw */
	} else if (HTPlain_bs_pending == 3) {
	    if (*p == '_') {
		HTPlain_bs_pending = 2;
		continue;	/* ignore last two of "_\b_" - kw */
	    } else {
		HTPlain_bs_pending = 0;
		/* ignore first two of "_\bX" - kw */
	    }
	} else if (HTPlain_bs_pending == 2) {
	    HText_appendCharacter(me->text, '_');
	    if (*p == '_')
		continue;	/* keep second of "__" pending - kw */
	    HTPlain_bs_pending = 0;
	} else {
	    HTPlain_bs_pending = 0;
	}
	HTPlain_lastraw = UCH(*p);
	if (*p == '\r') {
	    HText_appendCharacter(me->text, '\n');
	    continue;
	}
	/*
	 * Make sure the character is handled as Unicode whenever that's
	 * appropriate.  - FM
	 */
	c = *p;
	c_unsign = UCH(c);
	code = (UCode_t) c_unsign;
	saved_char_in = '\0';
	/*
	 * Combine any UTF-8 multibytes into Unicode to check for special
	 * characters.  - FM
	 */
	if (me->T.decode_utf8) {
	    /*
	     * Combine UTF-8 into Unicode.  Incomplete characters silently
	     * ignored.  from Linux kernel's console.c - KW
	     */
	    if (TOASCII(c_unsign) > 127) {	/* S/390 -- gil -- 0371 */
		/*
		 * We have an octet from a multibyte character.  - FM
		 */
		if (me->utf_count > 0 && (c & 0xc0) == 0x80) {
		    /*
		     * Adjust the UCode_t value, add the octet to the buffer,
		     * and decrement the byte count.  - FM
		     */
		    me->utf_char = (me->utf_char << 6) | (c & 0x3f);
		    me->utf_count--;
		    *(me->utf_buf_p) = c;
		    (me->utf_buf_p)++;
		    if (me->utf_count == 0) {
			/*
			 * Got a complete multibyte character.
			 */
			*(me->utf_buf_p) = '\0';
			code = me->utf_char;
			if (code > 0 && code < 256) {
			    c = FROMASCII((char) code);
			    c_unsign = UCH(c);
			}
		    } else {
			/*
			 * Get the next byte.  - FM
			 */
			continue;
		    }
		} else {
		    /*
		     * Start handling a new multibyte character.  - FM
		     */
		    me->utf_buf_p[0] = c;
		    me->utf_buf_p = &me->utf_buf[1];
		    if ((*p & 0xe0) == 0xc0) {
			me->utf_count = 1;
			me->utf_char = (c & 0x1f);
		    } else if ((*p & 0xf0) == 0xe0) {
			me->utf_count = 2;
			me->utf_char = (c & 0x0f);
		    } else if ((*p & 0xf8) == 0xf0) {
			me->utf_count = 3;
			me->utf_char = (c & 0x07);
		    } else if ((*p & 0xfc) == 0xf8) {
			me->utf_count = 4;
			me->utf_char = (c & 0x03);
		    } else if ((*p & 0xfe) == 0xfc) {
			me->utf_count = 5;
			me->utf_char = (c & 0x01);
		    } else {
			/*
			 * We got garbage, so ignore it.  - FM
			 */
			me->utf_count = 0;
			me->utf_buf_p[0] = '\0';
			me->utf_buf_p = me->utf_buf;
		    }
		    /*
		     * Get the next byte.  - FM
		     */
		    continue;
		}
	    } else if (me->utf_count > 0) {
		/*
		 * Got an ASCII character when expecting UTF-8 multibytes, so
		 * ignore the buffered multibye characters and fall through
		 * with the current ASCII character.  - FM
		 */
		me->utf_count = 0;
		me->utf_buf[0] = '\0';
		me->utf_buf_p = me->utf_buf;
		code = (UCode_t) c_unsign;
	    } else {
		/*
		 * Got a valid ASCII character, so fall through with it.  - FM
		 */
		code = (UCode_t) c_unsign;
	    }
	}
	/*
	 * Convert characters from non-UTF-8 charsets to Unicode (if
	 * appropriate).  - FM
	 */
	if (!(me->T.decode_utf8 &&
	      UCH(*p) > 127)) {
#ifdef NOTDEFINED
	    if (me->T.strip_raw_char_in)
		saved_char_in = c;
#endif /* NOTDEFINED */
	    if (me->T.trans_to_uni &&
		(TOASCII(code) >= LYlowest_eightbit[me->inUCLYhndl] ||	/* S/390 -- gil -- 0389 */
		 (code < ' ' && code != 0 &&
		  me->T.trans_C0_to_uni))) {
		/*
		 * Convert the octet to Unicode.  - FM
		 */
		code = (UCode_t) UCTransToUni(c, me->inUCLYhndl);
		if (code > 0) {
		    saved_char_in = c;
		    if (code < 256) {
			c = FROMASCII((char) code);
			c_unsign = UCH(c);
		    }
		}
	    } else if (code < 32 && code != 0 &&
		       me->T.trans_C0_to_uni) {
		/*
		 * Quote from SGML.c:
		 * "This else if may be too ugly to keep.  - KW"
		 */
		if (me->T.trans_from_uni &&
		    (((code = UCTransToUni(c, me->inUCLYhndl)) >= 32) ||
		     (me->T.transp &&
		      (code = UCTransToUni(c, me->inUCLYhndl)) > 0))) {
		    saved_char_in = c;
		    if (code < 256) {
			c = FROMASCII((char) code);
			c_unsign = UCH(c);
		    }
		} else {
		    uck = -1;
		    if (me->T.transp) {
			uck = UCTransCharStr(replace_buf, 60, c,
					     me->inUCLYhndl,
					     me->inUCLYhndl, NO);
		    }
		    if (!me->T.transp || uck < 0) {
			uck = UCTransCharStr(replace_buf, 60, c,
					     me->inUCLYhndl,
					     me->outUCLYhndl, YES);
		    }
		    if (uck == 0) {
			continue;
		    } else if (uck < 0) {
			me->utf_buf[0] = '\0';
		    } else {
			c = replace_buf[0];
			if (c && replace_buf[1]) {
			    HText_appendText(me->text, replace_buf);
			    continue;
			}
		    }
		    me->utf_buf[0] = '\0';
		    code = UCH(c);
		}		/*  Next line end of ugly stuff for C0. - KW */
	    } else {
		me->utf_buf[0] = '\0';
		code = UCH(c);
	    }
	}
	/*
	 * At this point we have either code in Unicode (and c in latin1 if
	 * code is in the latin1 range), or code and c will have to be passed
	 * raw.
	 */

	/*
	 * If CJK mode is on, we'll assume the document matches the user's
	 * display character set, and if not, the user should toggle off
	 * raw/CJK mode to reload.  - FM
	 */
	if (IS_CJK_TTY) {
	    HText_appendCharacter(me->text, c);

#define PASSHICTRL (me->T.transp || \
		    code >= LYlowest_eightbit[me->inUCLYhndl])
#define PASS8859SPECL me->T.pass_160_173_raw
#define PASSHI8BIT (HTPassEightBitRaw || \
		    (me->T.do_8bitraw && !me->T.trans_from_uni))
	    /*
	     * If HTPassHighCtrlRaw is set (e.g., for KOI8-R) assume the
	     * document matches and pass 127-160 8-bit characters.  If it
	     * doesn't match, the user should toggle raw/CJK mode off.  - FM
	     */
	} else if (TOASCII(code) >= 127 && TOASCII(code) < 161 &&	/* S/390 -- gil -- 0427 */
		   PASSHICTRL && PASS8859SPECL) {
	    HText_appendCharacter(me->text, c);
	} else if (code == CH_SHY && PASS8859SPECL) {
	    HText_appendCharacter(me->text, c);
	    /*
	     * If neither HTPassHighCtrlRaw nor CJK is set, play it safe and
	     * treat 160 (nbsp) as an ASCII space (32).  - FM
	     */
	} else if (code == CH_NBSP) {
	    HText_appendCharacter(me->text, ' ');
	    /*
	     * If neither HTPassHighCtrlRaw nor CJK is set, play it safe and
	     * ignore 173 (shy).  - FM
	     * Now only ignore it for color style, which doesn't handle it
	     * anyway.  Otherwise pass it on as LY_SOFT_HYPHEN and let HText
	     * deal with it.  It should be either ignored, or displayed as a
	     * hyphen if it was indeed at the end of a line.  Well it should. 
	     * - kw
	     */
	} else if (code == CH_SHY) {
#ifndef USE_COLOR_STYLE
	    HText_appendCharacter(me->text, LY_SOFT_HYPHEN);
#endif
	    continue;
	    /*
	     * If we get to here, pass the displayable ASCII characters.  - FM
	     */
	} else if ((code >= ' ' && TOASCII(code) < 127) ||
		   (PASSHI8BIT &&
		    c >= LYlowest_eightbit[me->outUCLYhndl]) ||
		   *p == '\n' || *p == '\t') {
	    HText_appendCharacter(me->text, c);
	    /*
	     * Use an ASCII space (32) for ensp, emsp or thinsp.  - FM
	     */
	} else if (code == 8194 || code == 8195 || code == 8201) {
	    HText_appendCharacter(me->text, ' ');
	    /*
	     * If we want the raw character, pass it now.  - FM
	     */
	} else if (me->T.use_raw_char_in && saved_char_in) {
	    HText_appendCharacter(me->text, saved_char_in);
/******************************************************************
 * I.  LATIN-1 OR UCS2 TO DISPLAY CHARSET
 ******************************************************************/
	} else if ((chk = (BOOL) (me->T.trans_from_uni && code >= 160)) &&
		   (uck = UCTransUniChar(code,
					 me->outUCLYhndl)) >= ' ' &&	/* S/390 -- gil -- 0464 */
		   uck < 256) {
	    CTRACE((tfp, "UCTransUniChar returned 0x%.2" PRI_UCode_t
		    ":'%c'.\n",
		    uck, FROMASCII(UCH(uck))));
	    HText_appendCharacter(me->text, ((char) (uck & 0xff)));
	} else if (chk &&
		   (uck == -4 ||
		    (me->T.repl_translated_C0 && uck > 0 && uck < ' ')) &&	/* S/390 -- gil -- 0481 */
	    /*
	     * Not found; look for replacement string.
	     */
		   (uck = UCTransUniCharStr(replace_buf, 60, code,
					    me->outUCLYhndl, 0) >= 0)) {
	    /*
	     * No further tests for valididy - assume that whoever defined
	     * replacement strings knew what she was doing.
	     */
	    HText_appendText(me->text, replace_buf);
	    /*
	     * If we get to here, and should have translated, translation has
	     * failed so far.
	     */
	} else if (chk && TOASCII(code) > 127 && me->T.output_utf8) {	/* S/390 -- gil -- 0498 */
	    /*
	     * We want UTF-8 output, so do it now.  - FM
	     */
	    if (*me->utf_buf) {
		HText_appendText(me->text, me->utf_buf);
		me->utf_buf[0] = '\0';
		me->utf_buf_p = me->utf_buf;
	    } else if (UCConvertUniToUtf8(code, replace_buf)) {
		HText_appendText(me->text, replace_buf);
	    } else {
		/*
		 * Out of luck, so use the UHHH notation (ugh).  - gil
		 */
		/* S/390 -- gil -- 0517 */
		sprintf(replace_buf, "U%.2lX", (unsigned long) TOASCII(code));
		HText_appendText(me->text, replace_buf);
	    }
#ifdef NOTDEFINED
	} else if (me->T.strip_raw_char_in &&
		   UCH(*p) >= 192 &&
		   UCH(*p) < 255) {
	    /*
	     * KOI special:  strip high bit, gives (somewhat) readable ASCII.
	     */
	    HText_appendCharacter(me->text, (char) (*p & 0x7f));
#endif /* NOTDEFINED */
	    /*
	     * If we don't actually want the character, make it safe and output
	     * that now.  - FM
	     */
	} else if ((c_unsign > 0 &&
		    (int) c_unsign < LYlowest_eightbit[me->outUCLYhndl]) ||
		   (me->T.trans_from_uni && !HTPassEightBitRaw)) {
	    /*
	     * If we do not have the "7-bit approximations" as our output
	     * character set (in which case we did it already) seek a
	     * translation for that.  Otherwise, or if the translation fails,
	     * use UHHH notation.  - FM
	     */
	    if ((chk = (BOOL) (me->outUCLYhndl !=
			       UCGetLYhndl_byMIME("us-ascii"))) &&
		(uck = UCTransUniChar(code,
				      UCGetLYhndl_byMIME("us-ascii")))
		>= ' ' && TOASCII(uck) < 127) {		/* S/390 -- gil -- 0535 */
		/*
		 * Got an ASCII character (yippey).  - FM
		 */
		c = FROMASCII((char) uck);
		HText_appendCharacter(me->text, c);
	    } else if ((chk && uck == -4) &&
		       (uck = UCTransUniCharStr(replace_buf,
						60, code,
						UCGetLYhndl_byMIME("us-ascii"),
						0) >= 0)) {
		/*
		 * Got a repacement string (yippey).  - FM
		 */
		HText_appendText(me->text, replace_buf);
	    } else if (code == 8204 || code == 8205) {
		/*
		 * Ignore 8204 (zwnj) or 8205 (zwj), if we get to here.  - FM
		 */
		CTRACE((tfp, "HTPlain_write: Ignoring '%" PRI_UCode_t "'.\n", code));
	    } else if (code == 8206 || code == 8207) {
		/*
		 * Ignore 8206 (lrm) or 8207 (rlm), if we get to here.  - FM
		 */
		CTRACE((tfp, "HTPlain_write: Ignoring '%" PRI_UCode_t "'.\n", code));
	    } else {
		/*
		 * Out of luck, so use the UHHH notation (ugh).  - FM
		 */
		/* do not print UHHH for now
		   sprintf(replace_buf, "U%.2lX", code);
		   HText_appendText(me->text, replace_buf);
		 */
	    }
	    /*
	     * If we get to here and have a monobyte character, pass it.  - FM
	     */
	} else if (c_unsign != 0 && c_unsign < 256) {
	    HText_appendCharacter(me->text, c);
	}
#endif /* REMOVE_CR_ONLY */
    }
}

/*	Free an HTML object
 *	-------------------
 *
 *	Note that the SGML parsing context is freed, but the created object is
 *	not, as it takes on an existence of its own unless explicitly freed.
 */
static void HTPlain_free(HTStream *me)
{
    if (HTPlain_bs_pending >= 2)
	HText_appendCharacter(me->text, '_');
    FREE(me);
}

/*	End writing
*/
static void HTPlain_abort(HTStream *me, HTError e GCC_UNUSED)
{
    HTPlain_free(me);
}

/*		Structured Object Class
 *		-----------------------
 */
static const HTStreamClass HTPlain =
{
    "PlainPresenter",
    HTPlain_free,
    HTPlain_abort,
    HTPlain_put_character, HTPlain_put_string, HTPlain_write,
};

/*		New object
 *		----------
 */
HTStream *HTPlainPresent(HTPresentation *pres GCC_UNUSED, HTParentAnchor *anchor,
			 HTStream *sink GCC_UNUSED)
{

    HTStream *me = (HTStream *) malloc(sizeof(*me));

    if (me == NULL)
	outofmem(__FILE__, "HTPlain_new");

    assert(me != NULL);

    me->isa = &HTPlain;

    HTPlain_lastraw = -1;

    me->utf_count = 0;
    me->utf_char = 0;
    me->utf_buf[0] = me->utf_buf[6] = me->utf_buf[7] = '\0';
    me->utf_buf_p = me->utf_buf;
    me->outUCLYhndl = HTAnchor_getUCLYhndl(anchor, UCT_STAGE_HTEXT);
    me->inUCLYhndl = HTAnchor_getUCLYhndl(anchor, UCT_STAGE_PARSER);
    HTPlain_getChartransInfo(me, anchor);
    UCSetTransParams(&me->T,
		     me->inUCLYhndl, me->inUCI,
		     me->outUCLYhndl,
		     HTAnchor_getUCInfoStage(anchor, UCT_STAGE_HTEXT));

    me->text = HText_new(anchor);
    HText_setStyle(me->text, LYstyles(HTML_XMP));
    HText_beginAppend(me->text);

    return (HTStream *) me;
}
