path: root/camel/camel-mime-filter-enriched.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *  Authors: Jeffrey Stedfast <fejj@ximian.com>
 *
 *  Copyright 2002 Ximian, Inc. (www.ximian.com)
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.
 *
 */


#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>

#include <camel/camel-string-utils.h>

#include "camel-mime-filter-enriched.h"

/* text/enriched is rfc1896 */

typedef char * (*EnrichedParamParser) (const char *inptr, int inlen);

static char *param_parse_colour (const char *inptr, int inlen);
static char *param_parse_font (const char *inptr, int inlen);
static char *param_parse_lang (const char *inptr, int inlen);

static struct {
    char *enriched;
    char *html;
    gboolean needs_param;
    EnrichedParamParser parse_param; /* parses *and* validates the input */
} enriched_tags[] = {
    { "bold",        "<b>",                 FALSE, NULL               },
    { "/bold",       "</b>",                FALSE, NULL               },
    { "italic",      "<i>",                 FALSE, NULL               },
    { "/italic",     "</i>",                FALSE, NULL               },
    { "fixed",       "<tt>",                FALSE, NULL               },
    { "/fixed",      "</tt>",               FALSE, NULL               },
    { "smaller",     "<font size=-1>",      FALSE, NULL               },
    { "/smaller",    "</font>",             FALSE, NULL               },
    { "bigger",      "<font size=+1>",      FALSE, NULL               },
    { "/bigger",     "</font>",             FALSE, NULL               },
    { "underline",   "<u>",                 FALSE, NULL               },
    { "/underline",  "</u>",                FALSE, NULL               },
    { "center",      "<p align=center>",    FALSE, NULL               },
    { "/center",     "</p>",                FALSE, NULL               },
    { "flushleft",   "<p align=left>",      FALSE, NULL               },
    { "/flushleft",  "</p>",                FALSE, NULL               },
    { "flushright",  "<p align=right>",     FALSE, NULL               },
    { "/flushright", "</p>",                FALSE, NULL               },
    { "excerpt",     "<blockquote>",        FALSE, NULL               },
    { "/excerpt",    "</blockquote>",       FALSE, NULL               },
    { "paragraph",   "<p>",                 FALSE, NULL               },
    { "signature",   "<address>",           FALSE, NULL               },
    { "/signature",  "</address>",          FALSE, NULL               },
    { "comment",     "<!-- ",               FALSE, NULL               },
    { "/comment",    " -->",                FALSE, NULL               },
    { "np",          "<hr>",                FALSE, NULL               },
    { "fontfamily",  "<font face=\"%s\">",  TRUE,  param_parse_font   },
    { "/fontfamily", "</font>",             FALSE, NULL               },
    { "color",       "<font color=\"%s\">", TRUE,  param_parse_colour },
    { "/color",      "</font>",             FALSE, NULL               },
    { "lang",        "<span lang=\"%s\">",  TRUE,  param_parse_lang   },
    { "/lang",       "</span>",             FALSE, NULL               },
    
    /* don't handle this tag yet... */
    { "paraindent",  "<!-- ",               /* TRUE */ FALSE, NULL    },
    { "/paraindent", " -->",                FALSE, NULL               },
    
    /* as soon as we support all the tags that can have a param
     * tag argument, these should be unnecessary, but we'll keep
     * them anyway just in case? */
    { "param",       "<!-- ",               FALSE, NULL               },
    { "/param",      " -->",                FALSE, NULL               },
};

#define NUM_ENRICHED_TAGS (sizeof (enriched_tags) / sizeof (enriched_tags[0]))

static GHashTable *enriched_hash = NULL;


static void camel_mime_filter_enriched_class_init (CamelMimeFilterEnrichedClass *klass);
static void camel_mime_filter_enriched_init       (CamelMimeFilterEnriched *filter);
static void camel_mime_filter_enriched_finalize   (CamelObject *obj);

static void filter_filter (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
               char **out, size_t *outlen, size_t *outprespace);
static void filter_complete (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
                 char **out, size_t *outlen, size_t *outprespace);
static void filter_reset (CamelMimeFilter *filter);


static CamelMimeFilterClass *parent_class = NULL;


CamelType
camel_mime_filter_enriched_get_type (void)
{
    static CamelType type = CAMEL_INVALID_TYPE;
    
    if (type == CAMEL_INVALID_TYPE) {
        type = camel_type_register (camel_mime_filter_get_type (),
                        "CamelMimeFilterEnriched",
                        sizeof (CamelMimeFilterEnriched),
                        sizeof (CamelMimeFilterEnrichedClass),
                        (CamelObjectClassInitFunc) camel_mime_filter_enriched_class_init,
                        NULL,
                        (CamelObjectInitFunc) camel_mime_filter_enriched_init,
                        (CamelObjectFinalizeFunc) camel_mime_filter_enriched_finalize);
    }
    
    return type;
}

static void
camel_mime_filter_enriched_class_init (CamelMimeFilterEnrichedClass *klass)
{
    CamelMimeFilterClass *filter_class = (CamelMimeFilterClass *) klass;
    int i;
    
    parent_class = CAMEL_MIME_FILTER_CLASS (camel_mime_filter_get_type ());
    
    filter_class->reset = filter_reset;
    filter_class->filter = filter_filter;
    filter_class->complete = filter_complete;
    
    if (!enriched_hash) {
        enriched_hash = g_hash_table_new (camel_strcase_hash, camel_strcase_equal);
        for (i = 0; i < NUM_ENRICHED_TAGS; i++)
            g_hash_table_insert (enriched_hash, enriched_tags[i].enriched,
                         enriched_tags[i].html);
    }
}

static void
camel_mime_filter_enriched_finalize (CamelObject *obj)
{
    ;
}

static void
camel_mime_filter_enriched_init (CamelMimeFilterEnriched *filter)
{
    filter->flags = 0;
    filter->nofill = 0;
}


#if 0
static gboolean
enriched_tag_needs_param (const char *tag)
{
    int i;
    
    for (i = 0; i < NUM_ENRICHED_TAGS; i++)
        if (!strcasecmp (tag, enriched_tags[i].enriched))
            return enriched_tags[i].needs_param;
    
    return FALSE;
}
#endif

static gboolean
html_tag_needs_param (const char *tag)
{
    return strstr (tag, "%s") != NULL;
}

static const char *valid_colours[] = {
    "red", "green", "blue", "yellow", "cyan", "magenta", "black", "white"
};

#define NUM_VALID_COLOURS  (sizeof (valid_colours) / sizeof (valid_colours[0]))

static char *
param_parse_colour (const char *inptr, int inlen)
{
    const char *inend, *end;
    guint32 rgb = 0;
    guint v;
    int i;
    
    for (i = 0; i < NUM_VALID_COLOURS; i++) {
        if (!strncasecmp (inptr, valid_colours[i], inlen))
            return g_strdup (valid_colours[i]);
    }
    
    /* check for numeric r/g/b in the format: ####,####,#### */
    if (inptr[4] != ',' || inptr[9] != ',') {
        /* okay, mailer must have used a string name that
         * rfc1896 did not specify? do some simple scanning
         * action, a colour name MUST be [a-zA-Z] */
        end = inptr;
        inend = inptr + inlen;
        while (end < inend && ((*end >= 'a' && *end <= 'z') || (*end >= 'A' && *end <= 'Z')))
            end++;
        
        return g_strndup (inptr, end - inptr);
    }
    
    for (i = 0; i < 3; i++) {
        v = strtoul (inptr, (char **) &end, 16);
        if (end != inptr + 4)
            goto invalid_format;
        
        v >>= 8;
        rgb = (rgb << 8) | (v & 0xff);
        
        inptr += 5;
    }
    
    return g_strdup_printf ("#%.6X", rgb);
    
 invalid_format:
    
    /* default colour? */
    return g_strdup ("black");
}

static char *
param_parse_font (const char *fontfamily, int inlen)
{
    register const char *inptr = fontfamily;
    const char *inend = inptr + inlen;
    
    /* don't allow any of '"', '<', nor '>' */
    while (inptr < inend && *inptr != '"' && *inptr != '<' && *inptr != '>')
        inptr++;
    
    return g_strndup (fontfamily, inptr - fontfamily);
}

static char *
param_parse_lang (const char *lang, int inlen)
{
    register const char *inptr = lang;
    const char *inend = inptr + inlen;
    
    /* don't allow any of '"', '<', nor '>' */
    while (inptr < inend && *inptr != '"' && *inptr != '<' && *inptr != '>')
        inptr++;
    
    return g_strndup (lang, inptr - lang);
}

static char *
param_parse (const char *enriched, const char *inptr, int inlen)
{
    int i;
    
    for (i = 0; i < NUM_ENRICHED_TAGS; i++) {
        if (!strcasecmp (enriched, enriched_tags[i].enriched))
            return enriched_tags[i].parse_param (inptr, inlen);
    }
    
    g_assert_not_reached ();
    
    return NULL;
}

#define IS_RICHTEXT CAMEL_MIME_FILTER_ENRICHED_IS_RICHTEXT

static void
enriched_to_html (CamelMimeFilter *filter, char *in, size_t inlen, size_t prespace,
          char **out, size_t *outlen, size_t *outprespace, gboolean flush)
{
    CamelMimeFilterEnriched *enriched = (CamelMimeFilterEnriched *) filter;
    const char *tag, *inend, *outend;
    register const char *inptr;
    register char *outptr;
    
    camel_mime_filter_set_size (filter, inlen * 2 + 6, FALSE);
    
    inptr = in;
    inend = in + inlen;
    outptr = filter->outbuf;
    outend = filter->outbuf + filter->outsize;
    
 retry:
    do {
        while (inptr < inend && outptr < outend && !strchr (" <>&\n", *inptr))
            *outptr++ = *inptr++;
        
        if (outptr == outend)
            goto backup;
        
        if ((inptr + 1) >= inend)
            break;
        
        switch (*inptr++) {
        case ' ':
            while (inptr < inend && (outptr + 7) < outend && *inptr == ' ') {
                memcpy (outptr, "&nbsp;", 6);
                outptr += 6;
                inptr++;
            }
            
            if (outptr < outend)
                *outptr++ = ' ';
            
            break;
        case '\n':
            if (!(enriched->flags & IS_RICHTEXT) && enriched->nofill <= 0) {
                /* text/enriched */
                while (inptr < inend && (outptr + 4) < outend && *inptr == '\n') {
                    memcpy (outptr, "<br>", 4);
                    outptr += 4;
                    inptr++;
                }
            } else {
                /* text/richtext */
                *outptr++ = ' ';
            }
            break;
        case '>':
            if ((outptr + 4) < outend) {
                memcpy (outptr, "&gt;", 4);
                outptr += 4;
            } else {
                inptr--;
                goto backup;
            }
            break;
        case '&':
            if ((outptr + 5) < outend) {
                memcpy (outptr, "&amp;", 5);
                outptr += 5;
            } else {
                inptr--;
                goto backup;
            }
            break;
        case '<':
            if (!(enriched->flags & IS_RICHTEXT)) {
                /* text/enriched */
                if (*inptr == '<') {
                    if ((outptr + 4) < outend) {
                        memcpy (outptr, "&lt;", 4);
                        outptr += 4;
                        inptr++;
                        break;
                    } else {
                        inptr--;
                        goto backup;
                    }
                }
            } else {
                /* text/richtext */
                if ((inend - inptr) >= 3 && (outptr + 4) < outend) {
                    if (strncmp (inptr, "lt>", 3) == 0) {
                        memcpy (outptr, "&lt;", 4);
                        outptr += 4;
                        inptr += 3;
                        break;
                    } else if (strncmp (inptr, "nl>", 3) == 0) {
                        memcpy (outptr, "<br>", 4);
                        outptr += 4;
                        inptr += 3;
                        break;
                    }
                } else {
                    inptr--;
                    goto backup;
                }
            }
            
            tag = inptr;
            while (inptr < inend && *inptr != '>')
                inptr++;
            
            if (inptr == inend) {
                inptr = tag - 1;
                goto need_input;
            }
            
            if (!strncasecmp (tag, "nofill>", 7)) {
                if ((outptr + 5) < outend) {
                    memcpy (outptr, "<pre>", 5);
                    enriched->nofill++;
                    outptr += 5;
                } else {
                    inptr = tag - 1;
                    goto backup;
                }
            } else if (!strncasecmp (tag, "/nofill>", 8)) {
                if ((outptr + 6) < outend) {
                    memcpy (outptr, "</pre>", 6);
                    enriched->nofill--;
                    outptr += 6;
                } else {
                    inptr = tag - 1;
                    goto backup;
                }
            } else {
                const char *html_tag;
                char *enriched_tag;
                int len;
                
                len = inptr - tag;
                enriched_tag = g_alloca (len + 1);
                memcpy (enriched_tag, tag, len);
                enriched_tag[len] = '\0';
                
                html_tag = g_hash_table_lookup (enriched_hash, enriched_tag);
                
                if (html_tag) {
                    if (html_tag_needs_param (html_tag)) {
                        const char *start;
                        char *param;
                        
                        while (inptr < inend && *inptr != '<')
                            inptr++;
                        
#define PARAM_TAG_MIN_LEN  (sizeof ("<param>") + sizeof ("</param>") - 1)
                        if (inptr == inend || (inend - inptr) <= PARAM_TAG_MIN_LEN) {
                            inptr = tag - 1;
                            goto need_input;
                        }
                        
                        if (strncasecmp (inptr, "<param>", 7) != 0) {
                            /* ignore the enriched command tag... */
                            inptr -= 1;
                            goto loop;
                        }
                        
                        inptr += 7;
                        start = inptr;
                        
                        while (inptr < inend && *inptr != '<')
                            inptr++;
                        
                        if (inptr == inend || (inend - inptr) <= 8) {
                            inptr = tag - 1;
                            goto need_input;
                        }
                        
                        if (strncasecmp (inptr, "</param>", 8) != 0) {
                            /* ignore the enriched command tag... */
                            inptr += 7;
                            goto loop;
                        }
                        
                        len = inptr - start;
                        param = param_parse (enriched_tag, start, len);
                        len = strlen (param);
                        
                        inptr += 7;
                        
                        len += strlen (html_tag);
                        
                        if ((outptr + len) < outend) {
                            outptr += snprintf (outptr, len, html_tag, param);
                            g_free (param);
                        } else {
                            g_free (param);
                            inptr = tag - 1;
                            goto backup;
                        }
                    } else {
                        len = strlen (html_tag);
                        if ((outptr + len) < outend) {
                            memcpy (outptr, html_tag, len);
                            outptr += len;
                        } else {
                            inptr = tag - 1;
                            goto backup;
                        }
                    }
                }
            }
            
        loop:
            inptr++;
            break;
        default:
            break;
        }
    } while (inptr < inend);
    
 need_input:
    
    /* the reason we ignore @flush here is because if there isn't
           enough input to parse a tag, then there's nothing we can
           do. */
    
    if (inptr < inend)
        camel_mime_filter_backup (filter, inptr, (unsigned) (inend - inptr));
    
    *out = filter->outbuf;
    *outlen = outptr - filter->outbuf;
    *outprespace = filter->outpre;
    
    return;
    
 backup:
    
    if (flush) {
        size_t offset, grow;
        
        grow = (inend - inptr) * 2 + 20;
        offset = outptr - filter->outbuf;
        camel_mime_filter_set_size (filter, filter->outsize + grow, TRUE);
        outend = filter->outbuf + filter->outsize;
        outptr = filter->outbuf + offset;
        
        goto retry;
    } else {
        camel_mime_filter_backup (filter, inptr, (unsigned) (inend - inptr));
    }
    
    *out = filter->outbuf;
    *outlen = outptr - filter->outbuf;
    *outprespace = filter->outpre;
}

static void
filter_filter (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
           char **out, size_t *outlen, size_t *outprespace)
{
    enriched_to_html (filter, in, len, prespace, out, outlen, outprespace, FALSE);
}

static void 
filter_complete (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
         char **out, size_t *outlen, size_t *outprespace)
{
    enriched_to_html (filter, in, len, prespace, out, outlen, outprespace, TRUE);
}

static void
filter_reset (CamelMimeFilter *filter)
{
    CamelMimeFilterEnriched *enriched = (CamelMimeFilterEnriched *) filter;
    
    enriched->nofill = 0;
}


/**
 * camel_mime_filter_enriched_new:
 * @flags:
 *
 * Creates a new CamelMimeFilterEnriched object.
 *
 * Returns a new CamelMimeFilter object.
 **/
CamelMimeFilter *
camel_mime_filter_enriched_new (guint32 flags)
{
    CamelMimeFilterEnriched *new;
    
    new = (CamelMimeFilterEnriched *) camel_object_new (CAMEL_TYPE_MIME_FILTER_ENRICHED);
    new->flags = flags;
    
    return CAMEL_MIME_FILTER (new);
}

char *
camel_enriched_to_html(const char *in, guint32 flags)
{
    CamelMimeFilter *filter;
    size_t outlen, outpre;
    char *outbuf;

    if (in == NULL)
        return NULL;
    
    filter = camel_mime_filter_enriched_new(flags);
    
    camel_mime_filter_complete(filter, (char *)in, strlen(in), 0, &outbuf, &outlen, &outpre);
    outbuf = g_strndup (outbuf, outlen);
    camel_object_unref (filter);
    
    return outbuf;
}