//
//	aegis - project change supervisor
//	Copyright (C) 1999, 2002-2006, 2008 Peter Miller
//
//	This program is free software; you can redistribute it and/or modify
//	it under the terms of the GNU General Public License as published by
//	the Free Software Foundation; either version 3 of the License, or
//	(at your option) any later version.
//
//	This program is distributed in the hope that it will be useful,
//	but WITHOUT ANY WARRANTY; without even the implied warranty of
//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//	GNU General Public License for more details.
//
//	You should have received a copy of the GNU General Public License
//	along with this program. If not, see
//	<http://www.gnu.org/licenses/>.
//

#include <common/trace.h>
#include <libaegis/input/crlf.h>
#include <libaegis/sub.h>


input_crlf::~input_crlf()
{
    trace(("input_crlf::~input_crlf(this = %08lX)\n{\n", (long)this));
    pullback_transfer(deeper);
    deeper.close();
    trace(("}\n"));
}


input_crlf::input_crlf(input &arg1, bool arg2) :
    deeper(arg1),
    pos(0),
    line_number(0),
    prev_was_newline(true),
    newlines_may_be_escaped(arg2)
{
    trace(("input_crlf::input_crlf(this = %08lX)\n{\n", (long)this));
    trace(("}\n"));
}


long
input_crlf::read_inner(void *data, size_t len)
{
    trace(("input_crlf::read_inner(this = %08lX)\n{\n", (long)this));
    if (prev_was_newline)
    {
	++line_number;
	prev_was_newline = false;

	//
	// The name cache includes the line number, and the line
	// number just changed, so nuke it.
	//
	name_cache.clear();
    }

    unsigned char *cp = (unsigned char *)data;
    unsigned char *end = cp + len;
    while (cp < end)
    {
	int c = deeper->getch();
	switch (c)
	{
	case '\r':
	    c = deeper->getch();
	    if (c == '\n')
		goto newline;
	    if (c >= 0)
		deeper->ungetc(c);
#ifdef __mac_os_x__
	    goto newline;
#else
	    *cp++ = '\r';
	    continue;
#endif

	case '\\':
	    if (newlines_may_be_escaped)
	    {
		c = deeper->getch();
		if (c == '\n')
		{
		    //
		    // Don't put the newline in the
		    // buffer, but DO stop here,
		    // so that the line numbers
		    // are right.
		    //
		    prev_was_newline = 1;
		    break;
		}
		if (c >= 0)
		    deeper->ungetc(c);
	    }
	    *cp++ = '\\';
	    continue;

	case -1:
	    break;

	case 0:
	    //
	    // For plain ASCII text, the conditions reads
	    //
	    //	if (!isprint((unsigned char)c) &&
	    //		!isspace((unsigned char)c))
	    //
	    // However, for international text, just about
	    // anything is acceptable.  But not NUL.
	    //
	    {
		sub_context_ty sc;
		sc.var_set_format("Name", "\\%o", c);
		string_ty *s = sc.subst_intl(i18n("illegal '$name' character"));
		fatal_error(s->str_text);
	    }
	    continue;

	default:
	    //
	    // The default should be enough, but these are
	    // to force the use of a lookup table instead of
	    // an if-then-else chain in the code generated for
	    // the switch.
	    //
	case '!': case '"': case '#': case '$': case '%': case '&':
	case '\'': case '(': case ')': case '*': case '+': case ',':
	case '-': case '.': case '/': case '0': case '1': case '2':
	case '3': case '4': case '5': case '6': case '7': case '8':
	case '9': case ':': case ';': case '<': case '=': case '>':
	case '?': case '@': case 'A': case 'B': case 'C': case 'D':
	case 'E': case 'F': case 'G': case 'H': case 'I': case 'J':
	case 'K': case 'L': case 'M': case 'N': case 'O': case 'P':
	case 'Q': case 'R': case 'S': case 'T': case 'U': case 'V':
	case 'W': case 'X': case 'Y': case 'Z': case '[': case ']':
	case '^': case '_': case '`': case 'a': case 'b': case 'c':
	case 'd': case 'e': case 'f': case 'g': case 'h': case 'i':
	case 'j': case 'k': case 'l': case 'm': case 'n': case 'o':
	case 'p': case 'q': case 'r': case 's': case 't': case 'u':
	case 'v': case 'w': case 'x': case 'y': case 'z': case '{':
	case '|': case '}': case '~':
	    *cp++ = c;
	    continue;

	case '\n':
	    //
	    // We are line buffered.  This is the best way to
	    // allow us to report line numbers accurately.
	    // It results is some inefficiencies, but it also
	    // lets us get rid of a whole layer of function
	    // calls in the lexer.
	    //
	    newline:
	    *cp++ = '\n';
	    prev_was_newline = 1;
	    break;
	}
	break;
    }

    //
    // Figure what happened.
    //
    size_t nbytes = (cp - (unsigned char *)data);
    pos += nbytes;
    trace(("return %ld;\n", (long)nbytes));
    trace(("}\n"));
    return nbytes;
}


long
input_crlf::ftell_inner()
{
    trace(("input_crlf_ftell(this = %08lX) => %ld\n", (long)this, pos));
    return pos;
}


nstring
input_crlf::name()
{
    trace(("input_crlf_name(this = %08lX)\n", (long)this));
    if (!line_number)
	return deeper->name();
    if (!name_cache)
    {
	name_cache =
	    nstring::format("%s: %ld", deeper->name().c_str(), line_number);
    }
    return name_cache;
}


long
input_crlf::length()
{
    trace(("input_crlf_length(this = %08lX) => -1\n", (long)this));
    return -1;
}


void
input_crlf::keepalive()
{
    deeper->keepalive();
}


bool
input_crlf::is_remote()
    const
{
    return deeper->is_remote();
}