/*
** Copyright 1998 - 1999 Double Precision, Inc.  See COPYING for
** distribution information.
*/

#if	HAVE_CONFIG_H
#include	"config.h"
#endif
#include	"rfc2045.h"
#include	"rfc2045charset.h"
#if	HAVE_UNISTD_H
#include	<unistd.h>
#endif
#include	<stdio.h>
#include	<stdlib.h>
#include	<ctype.h>
#include       <string.h>
#if    HAVE_STRINGS_H
#include       <strings.h>
#endif
#ifdef WIN32
#define strcasecmp stricmp
#define strncasecmp strnicmp
#define write _write
#include <io.h>
#endif

/* $Id: rfc2045rewrite.c,v 1.2 2006/02/01 10:20:51 jan Exp $ */

static char *rw_boundary_root;
static int rw_boundary_cnt;
static const char *rw_appname;

static FILE *fdin;
static int fdout;
static int (*fdout_func)(const char *, int, void *);
static void *fdout_arg;

static char fdout_buf[512];
static char *fdout_ptr;
static size_t fdout_left;

/* Quoted printable encoding */
static void qpe_start();
static int qpe_do(const char *, size_t, void *);
static void qpe_end();
static int conv_err;

static int fdout_flush()
{
int	n=fdout_ptr-fdout_buf;
int	i=0;
char	*p=fdout_buf;

	while (n)
	{
		i=fdout_func ? (*fdout_func)(p, n, fdout_arg):
				write(fdout, p, n);
		if (i <= 0)	return (-1);
		p += i;
		n -= i;
	}
	fdout_ptr=fdout_buf;
	fdout_left=sizeof(fdout_buf);
	return (0);
}

static int fdout_add(const char *p, size_t cnt)
{
	while (cnt)
	{
		if (cnt < fdout_left)
		{
			memcpy(fdout_ptr, p, cnt);
			fdout_ptr += cnt;
			fdout_left -= cnt;
			return (0);
		}
		if (fdout_left == 0)
		{
			if (fdout_flush())	return (-1);
			continue;
		}
		memcpy(fdout_ptr, p, fdout_left);
		p += fdout_left;
		cnt -= fdout_left;
		fdout_ptr += fdout_left;
		fdout_left=0;
	}
	return (0);
}

static int do_8bit(const char *p, size_t cnt, void *ptr)
{
	if (fdout_add(p, cnt))
		conv_err=1;
	return (0);
}

static int fdout_autoconverted(const char *oldte, const char *newte)
{
	if (fdout_add("X-Mime-Autoconverted: from ", 27) ||
		fdout_add(oldte, strlen(oldte)) ||
		fdout_add(" to ", 4) ||
		fdout_add(newte, strlen(newte)) ||
		(rw_appname && (fdout_add(" by ", 4) ||
			fdout_add(rw_appname, strlen(rw_appname)))) ||
		fdout_add("\n", 1))	return (-1);
	return (0);
}

static int fdout_value(const char *);

static int fdout_attr(const struct rfc2045attr *a)
{
	if (fdout_add(a->name, strlen(a->name)))	return (-1);
	if (a->value && (fdout_add("=", 1) || fdout_value(a->value)))
		return (-1);
	return (0);
}

static int fdout_value(const char *v)
{
size_t i,j;

	for (i=0; v[i]; i++)
	{
		if ( !isalnum((int)(unsigned char)v[i]) && v[i] != '-')
		{
			if (fdout_add("\"", 1))	return (-1);
			for (j=i=0; v[i]; i++)
				if (v[i] == '\\' || v[i] == '"')
				{
					if (fdout_add(v+j, i-j) ||
						fdout_add("\\", 1))
						return (-1);
					j=i;
				}
			if (fdout_add(v+j, i-j) || fdout_add("\"", 1))
				return (-1);
			return (0);
		}
	}
	return (fdout_add(v, i));
}

#define	TE(p)	((p)->rw_transfer_encoding ? \
		(p)->rw_transfer_encoding: (p)->content_transfer_encoding)

static int rwmime(struct rfc2045 *p)
{
static char mimever[]="Mime-Version: 1.0\n";
const char *te;
struct	rfc2045attr *a;

	if (!p->parent)
		if (fdout_add(mimever, sizeof(mimever)-1))	return (-1);

	if (p->content_type)
	{
		if (fdout_add("Content-Type: ", 14) ||
			fdout_add(p->content_type, strlen(p->content_type)))
			return (-1);

		for (a=p->content_type_attr; a; a=a->next)
		{
			if (!a->name || strcmp(a->name, "boundary") == 0)
				continue;
			if ( fdout_add("; ", 2) ||
				fdout_attr(a))	return (-1);
		}
	}

	if (p->firstpart
		&& p->firstpart->next /* ADDED 8/30/99, see below */)
	{
	char	buf[80];

		++rw_boundary_cnt;
		sprintf(buf, "-%d", rw_boundary_cnt);
		if ( fdout_add("; boundary=\"", 12) ||
			fdout_add(rw_boundary_root, strlen(rw_boundary_root)) ||
			fdout_add(buf, strlen(buf)) ||
			fdout_add("\"", 1))	return (-1);
	}
	if (fdout_add("\n", 1))	return (-1);

	/* Show content transfer encoding for top section, or if it's
	** different than the parent.
	*/
	te=TE(p);
	if (te && (!p->parent || strcmp(te, TE(p->parent))))
	{
		if (fdout_add("Content-Transfer-Encoding: ", 27) ||
			fdout_add(te, strlen(te)) ||
			fdout_add("\n", 1))	return (-1);
	}
	return (0);
}

static int dorw(struct rfc2045 *p)
{
/* WTF STATIC??? */ int seen_mime=0;
char	buf[256];
int	c;
int	bcnt;

	if (fseek(fdin, p->startpos, SEEK_SET) == -1)	return (-1);
	if (p->parent)
	{
		seen_mime=1;
		if (rwmime(p))	return (-1);
	}
	while (fgets(buf, sizeof(buf), fdin))
	{
		if (buf[0] == '\n')	break;

		if (RFC2045_ISMIME1DEF(p->mime_version) &&
			strncasecmp(buf, "mime-version:", 13) == 0 &&
			!seen_mime)
		{
			seen_mime=1;
			rwmime(p);
			if (strchr(buf, '\n') == NULL)
				while ((c=getc(fdin)) >= 0 && c != '\n')
					;
			while ((c=getc(fdin)) >= 0 && c != '\n' && isspace(c))
				while ((c=getc(fdin)) >= 0 && c != '\n')
					;
			if (c >= 0)	ungetc(c, fdin);
			continue;
		}

		if (!RFC2045_ISMIME1DEF(p->mime_version) || (
			strncasecmp(buf, "mime-version:", 13) &&
			strncasecmp(buf, "content-type:", 13) &&
			strncasecmp(buf, "content-transfer-encoding:", 26))
			)
		{
			do
			{
				do
				{
					if (fdout_add(buf, strlen(buf)))
						return (-1);
				} while (strchr(buf, '\n') == NULL &&
					fgets(buf, sizeof(buf), fdin));

				c=getc(fdin);
				if (c >= 0)	ungetc(c, fdin);
			} while (c >= 0 && c != '\n' && isspace(c) &&
				    fgets(buf, sizeof(buf), fdin));
		}
		else
			while ( (c=getc(fdin)) >= 0 &&
				(ungetc(c, fdin), c) != '\n' && isspace(c))
			{
				while (fgets(buf, sizeof(buf), fdin) &&
					strchr(buf, '\n') == NULL)
					;
			}
	}
	if (RFC2045_ISMIME1DEF(p->mime_version))
	{
		if (!seen_mime)
			if (rwmime(p))	return (-1);

		if (!p->firstpart && p->rw_transfer_encoding)
			if (fdout_autoconverted(p->content_transfer_encoding,
				p->rw_transfer_encoding))	return (-1);
	}

	if (fdout_add("\n", 1))	return (-1);
	if (fseek(fdin, p->startbody, SEEK_SET) == -1)	return (-1);

	/* For non-multipart section, just print the body */

	if (!p->firstpart)
	{
	off_t	ps=p->startbody;
	int	convmode=0;

		if (p->rw_transfer_encoding)
		{
			if ( strcasecmp(p->rw_transfer_encoding,
				"quoted-printable") == 0)
				convmode=RFC2045_RW_7BIT;
			else
				convmode=RFC2045_RW_8BIT;
		}

		conv_err=0;
		if (convmode == RFC2045_RW_7BIT)
		{
			qpe_start();
			rfc2045_cdecode_start(p, &qpe_do, 0);
		}

		if (convmode == RFC2045_RW_8BIT)
		{
			rfc2045_cdecode_start(p, &do_8bit, 0);
		}

		while (ps < p->endbody)
		{
		int	n;

			if (p->endbody - ps > sizeof(buf))
				n=sizeof(buf);
			else	n=p->endbody-ps;
			n=fread(buf, 1, n, fdin);
			if (n <= 0)	return (-1);
			if (convmode)
				rfc2045_cdecode(p, buf, n);
			else	if (fdout_add(buf, n))	conv_err=1;
			ps += n;
			if (conv_err)	break;
		}
		if (convmode == RFC2045_RW_7BIT)
		{
			rfc2045_cdecode_end(p);
			qpe_end();
		}
		if (convmode == RFC2045_RW_8BIT)
		{
			rfc2045_cdecode_end(p);
		}
		if (conv_err)	return (-1);
		return (0);
	}

	bcnt=rw_boundary_cnt;

	/* Sam 8/30/99 fix - handle message/rfc822:

            --boundary
            Content-Type: message/rfc822

         --><-- we're here, DON'T add RFC2045MIMEMSG and rest of crap here
	*/
	if (p->firstpart->next == 0)
	{
	int	rc;

		p->firstpart->parent=0;
		rc=dorw(p->firstpart);
		p->firstpart->parent=p;
		return (rc);
	}

	if (fdout_add(RFC2045MIMEMSG, sizeof(RFC2045MIMEMSG)-1))
		return (-1);
	for (p=p->firstpart; p; p=p->next)
	{
		if (p->isdummy)	continue;
		sprintf(buf, "\n--%s-%d\n", rw_boundary_root, bcnt);
		if (fdout_add(buf, strlen(buf)))	return (-1);
		if (dorw(p) != 0)	return(-1);
	}
	sprintf(buf, "\n--%s-%d--\n", rw_boundary_root, bcnt);
	if (fdout_add(buf, strlen(buf)))	return (-1);
	return (0);
}

static int rfc2045_rewrite_common(struct rfc2045 *, int, const char *);

int rfc2045_rewrite(struct rfc2045 *p, int fdin_arg, int fdout_arg,
	const char *appname)
{
	fdout=fdout_arg;
	fdout_func=0;
	return (rfc2045_rewrite_common(p, fdin_arg, appname));
}

int rfc2045_rewrite_func(struct rfc2045 *p, int fdin_arg,
	int (*funcarg)(const char *, int, void *), void *funcargarg,
	const char *appname)
{
	fdout= -1;
	fdout_func=funcarg;
	fdout_arg=funcargarg;
	return (rfc2045_rewrite_common(p, fdin_arg, appname));
}

static int rfc2045_rewrite_common(struct rfc2045 *p,
	int fdin_arg, const char *appname)
{
int	rc;
int	fd=dup(fdin_arg);

	if (fd < 0)	return (-1);
	rw_appname=appname;
	fdin=fdopen(fd, "r");
	if (!fdin)
	{
		close(fd);
		return (-1);
	}

	fdout_ptr=fdout_buf;
	fdout_left=sizeof(fdout_buf);

	rw_boundary_root=rfc2045_mk_boundary(p, fd);
	if (rw_boundary_root == 0)
		rc= -1;
	else
	{
		rw_boundary_cnt=1;
		rc=dorw(p);
		free(rw_boundary_root);
	}
	if (rc == 0 && fdout_ptr > fdout_buf)
		rc=fdout_flush();
	fclose(fdin);
	return (rc);
}

static int qpe_pos;

static void qpe_start()
{
	qpe_pos=0;
}

static int qpe_do(const char *p, size_t i, void *ptr)
{
size_t	j,k;

	if (conv_err)	return (0);
	for (j=k=0; j<i; j++)
	{
		if (p[j] == '\n')
		{
			if (fdout_add(p+k, j+1-k))	conv_err=1;
			k=j+1;
			qpe_pos=0;
			continue;
		}
		if (qpe_pos >= 72)
		{
			if (fdout_add(p+k, j-k) ||
				fdout_add("=\n", 2))	conv_err=1;
			k=j;
			qpe_pos=0;
		}

		if (p[j] < 32 || p[j] >= 127 || p[j] == '=')
		{
		char buf[3];
		static char xdigit[16]="0123456789ABCDEF";
		unsigned n= (unsigned char)p[j];

			buf[0]='=';
			buf[1]=xdigit[ n / 16];
			buf[2]=xdigit[ n % 16];
			if (fdout_add(p+k, j-k) ||
				fdout_add(buf, 3))	conv_err=1;
			qpe_pos += 2;
			k=j+1;
		}
		++qpe_pos;
	}
	if (fdout_add(p+k, j-k))	conv_err=1;
	return (0);
}

static void qpe_end()
{
}
