path: root/my-evolution/e-summary-rdf.c

/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
/* e-summary-rdf.c
 *
 * Copyright (C) 2001 Ximian, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * 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 Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Author: Iain Holmes
 */

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

#include <stdlib.h>
#include <glib.h>
#include <gtk/gtkmain.h>

#include <libxml/parser.h>
#include <libxml/xmlmemory.h>

#include <libgnome/gnome-i18n.h>

#include <gal/widgets/e-unicode.h>

#include <libsoup/soup.h>

#include <string.h>

#include "e-summary.h"

struct _ESummaryRDF {
    ESummaryConnection *connection;
    GList *rdfs;

    char *html;
    guint32 timeout;
    gboolean online;
};

typedef struct _RDF {
    char *uri;
    char *html;

    xmlDocPtr cache;
    ESummary *summary;

    gboolean shown;

    /* Soup stuff */
    SoupMessage *message;
} RDF;

extern int xmlSubstituteEntitiesDefaultValue;

char *
e_summary_rdf_get_html (ESummary *summary)
{
    GList *rdfs;
    char *html;
    GString *string;

    if (summary->rdf == NULL) {
        return NULL;
    }

    string = g_string_new ("");
    for (rdfs = summary->rdf->rdfs; rdfs; rdfs = rdfs->next) {
        if (((RDF *)rdfs->data)->html == NULL) {
            continue;
        }

        g_string_append (string, ((RDF *)rdfs->data)->html);
    }

    html = string->str;
    g_string_free (string, FALSE);
    return html;
}

/************ RDF Parser *******************/

static char *
layer_find (xmlNodePtr node, 
        char *match, 
        char *fail)
{
    while (node!=NULL) {
#ifdef RDF_DEBUG
        xmlDebugDumpNode (stdout, node, 32);
        printf("%s.\n", node->name);
#endif
        if (strcasecmp (node->name, match)==0) {
            if (node->children != NULL && node->children->content != NULL) {
                return node->children->content;
            } else {
                return fail;
            }
        }
        node = node->next;
    }
    return fail;
}

static char *
layer_find_url (xmlNodePtr node, 
        char *match, 
        char *fail)
{
    char *p = layer_find (node, match, fail);
    char *r = p;
    static char *wb = NULL;
    char *w;
    
    if (wb) {
        g_free (wb);
    }
    
    wb = w = g_malloc (3 * strlen (p));

    if (w == NULL) {
        return fail;
    }
    
    if (*r == ' ') r++; /* Fix UF bug */

    while (*r) {
        if (strncmp (r, "&amp;", 5) == 0) {
            *w++ = '&';
            r += 5;
            continue;
        }
        if (strncmp (r, "&lt;", 4) == 0) {
            *w++ = '<';
            r += 4;
            continue;
        }
        if (strncmp (r, "&gt;", 4) == 0) {
            *w++ = '>';
            r += 4;
            continue;
        }
        if (*r == '"' || *r == ' '){
            *w++ = '%';
            *w++ = "0123456789ABCDEF"[*r/16];
            *w++ = "0123456789ABCDEF"[*r&15];
            r++;
            continue;
        }
        *w++ = *r++;
    }
    *w = 0;
    return wb;
}

static void 
tree_walk (xmlNodePtr root,
       RDF *r,
       GString *html)
{
    xmlNodePtr walk;
    xmlNodePtr rewalk = root;
    xmlNodePtr channel = NULL;
    xmlNodePtr image = NULL;
    xmlNodePtr item[16];
    int items = 0;
    int limit;
    int i;
    char *t, *u;
    char *tmp;
    char *charset;

    if (r->summary->preferences == NULL) {
        limit = 10;
    } else {
        limit = r->summary->preferences->limit;
    }

    /* check in-memory encoding first, fallback to transport encoding, which may or may not be correct */
    if (r->cache->charset == XML_CHAR_ENCODING_UTF8
        || r->cache->charset == XML_CHAR_ENCODING_ASCII) {
        charset = NULL;
    } else {
        /* bad/missing encoding, fallback to latin1 (locale?) */
        charset = r->cache->encoding ? (char *)r->cache->encoding : "iso-8859-1";
    }

    /* FIXME: Need arrows */
    if (r->shown == FALSE) {
        char *p;

        /* FIXME: Hash table & UID */
        p = g_strdup_printf ("<a href=\"rdf://%d\" style=\"text-decoration: none; color: black\">&#x25b6;</a>", GPOINTER_TO_INT (r));
        g_string_append (html, p);
        g_free (p);
    } else {
        char *p;

        /* FIXME: Hash table & UID */
        p = g_strdup_printf ("<a href=\"rdf://%d\" style=\"text-decoration: none; color: black\">&#x25BC;</a>", GPOINTER_TO_INT (r));
        g_string_append (html, p);
        g_free (p);
    }
    
    do {
        walk = rewalk;
        rewalk = NULL;
        
        while (walk!=NULL){
#ifdef RDF_DEBUG
            printf ("%p, %s\n", walk, walk->name);
#endif
            if (strcasecmp (walk->name, "rdf") == 0) {
                rewalk = walk->children;
                walk = walk->next;
                continue;
            }
            if (strcasecmp (walk->name, "rss") == 0){
                rewalk = walk->children;
                walk = walk->next;
                continue;
            }
            /* This is the channel top level */
#ifdef RDF_DEBUG
            printf ("Top level '%s'.\n", walk->name);
#endif
            if (strcasecmp (walk->name, "channel") == 0) {
                channel = walk;
                rewalk = channel->children;
            }
            if (strcasecmp (walk->name, "image") == 0) {
                image = walk;
            }
            if (strcasecmp (walk->name, "item") == 0 && items < 16) {
                item[items++] = walk;
            }
            walk = walk->next;
        }
    }
    while (rewalk);
    
    if (channel == NULL) {
        fprintf(stderr, "No channel definition.\n");
        return;
    }

    t = layer_find(channel->children, "title", "");
    u = layer_find(channel->children, "link", "");

    if (*u != '\0')
        g_string_sprintfa (html, "<a href=\"%s\" style=\"text-decoration: none; color: black;\"><b>", u);

    if (charset) {
        char *tmp = e_utf8_from_charset_string (charset, t);
        g_string_append (html, tmp);
        g_free (tmp);
    } else {
        g_string_append (html, t);
    }

    if (*u != '\0')
        g_string_append (html, "</a>");
    g_string_append (html, "</b></dt>");

    if (r->shown == FALSE) {
        g_string_append (html, "</dl>");
        return;
    }

    g_string_append (html, "<ul>");

    items = MIN (limit, items);
    for (i = 0; i < items; i++) {
        char *p = layer_find (item[i]->children, "title", "No information");
        
        tmp = g_strdup_printf ("<LI><font size=\"-1\"><A href=\"%s\" style=\"text-decoration: none; color: black;\">\n", layer_find_url(item[i]->children, "link", ""));
        g_string_append (html, tmp);
        g_free (tmp);

        if (charset) {
            char *tmp = e_utf8_from_charset_string (charset, p);
            g_string_append (html, tmp);
            g_free (tmp);
        } else {
            g_string_append (html, p);
        }

        g_string_append (html, "\n</A></font></li>");
    }
    g_string_append (html, "</UL>");
}

static void
display_doc (RDF *r)
{
    GString *html;

    html = g_string_new ("<dl><dt><img src=\"ico-rdf.png\" align=\"middle\" "
                 "width=\"48\" height=\"48\">");

    if (r->cache == NULL) {
        g_string_append_printf (html, "<b>%s:</b><br>%s</dt>",
                    _("Error downloading RDF"),
                    r->uri);
    } else {
        tree_walk (xmlDocGetRootElement (r->cache), r, html);
    }

    g_free (r->html);
    g_string_append (html, "</dl>");
    r->html = html->str;
    g_string_free (html, FALSE);

    e_summary_draw (r->summary);
}

static void
message_finished (SoupMessage *msg,
          gpointer userdata)
{
    xmlDocPtr doc;
    RDF *r = (RDF *) userdata;

    if (SOUP_MESSAGE_IS_ERROR (msg)) {
        g_warning ("Message failed: %d\n%s", msg->errorcode,
               msg->errorphrase);
        r->cache = NULL;
        r->message = NULL;

        display_doc (r);
        return;
    }

    if (r->cache != NULL) {
        xmlFreeDoc (r->cache);
        r->cache = NULL;
    }

    xmlSubstituteEntitiesDefaultValue = 1;
    doc = xmlParseMemory (msg->response.body, msg->response.length);
    r->cache = doc;
    r->message = NULL;

    /* Display it */
    display_doc (r);
}

gboolean
e_summary_rdf_update (ESummary *summary)
{
    GList *r;

    if (summary->rdf->online == FALSE) {
        g_warning ("%s: Repolling but offline", G_GNUC_FUNCTION);
        return TRUE;
    }

    for (r = summary->rdf->rdfs; r; r = r->next) {
        SoupContext *context;
        RDF *rdf = r->data;

        if (rdf->message) {
            continue;
        }

        context = soup_context_get (rdf->uri);
        if (context == NULL) {
            g_warning ("Invalid URL: %s", rdf->uri);
            soup_context_unref (context);
            continue;
        }

        rdf->message = soup_message_new (context, SOUP_METHOD_GET);
        soup_context_unref (context);
        soup_message_queue (rdf->message, message_finished, rdf);
    }

    return TRUE;
}
        
static void
e_summary_rdf_add_uri (ESummary *summary,
               const char *uri)
{
    RDF *r;

    r = g_new0 (RDF, 1);
    r->summary = summary;
    r->uri = g_strdup (uri);
    r->shown = TRUE;
    summary->rdf->rdfs = g_list_append (summary->rdf->rdfs, r);
}

static void
e_summary_rdf_protocol (ESummary *summary,
            const char *uri,
            void *closure)
{
    RDF *r;
    int a;

    a = atoi (uri + 6);
    if (a == 0) {
        g_warning ("A == 0");
        return;
    }

    r = (RDF *) GINT_TO_POINTER (a);
    r->shown = !r->shown;

    display_doc (r);
}

static int
e_summary_rdf_count (ESummary *summary,
             void *data)
{
    ESummaryRDF *rdf;
    GList *p;
    int count = 0;

    rdf = summary->rdf;
    for (p = rdf->rdfs; p; p = p->next) {
        RDF *r = p->data;

        if (r->message != NULL) {
            count++;
        }
    }

    return count;
}

static ESummaryConnectionData *
make_connection (RDF *r)
{
    ESummaryConnectionData *d;

    d = g_new (ESummaryConnectionData, 1);
    d->hostname = g_strdup (r->uri);
    d->type = g_strdup (_("News Feed"));

    return d;
}

static GList *
e_summary_rdf_add (ESummary *summary,
           void *data)
{
    ESummaryRDF *rdf;
    GList *p, *connections = NULL;

    rdf = summary->rdf;
    for (p = rdf->rdfs; p; p = p->next) {
        RDF *r = p->data;

        if (r->message != NULL) {
            ESummaryConnectionData *d;

            d = make_connection (r);
            connections = g_list_prepend (connections, d);
        }
    }

    return connections;
}

static void
rdf_free (RDF *r)
{
    /* Stop the download */
    if (r->message) {
        soup_message_cancel (r->message);
    }

    g_free (r->uri);
    g_free (r->html);

    if (r->cache) {
        xmlFreeDoc (r->cache);
    }

    g_free (r);
}

static void
e_summary_rdf_set_online (ESummary *summary,
              GNOME_Evolution_OfflineProgressListener progress,
              gboolean online,
              void *data)
{
    ESummaryRDF *rdf;
    GList *p;

    rdf = summary->rdf;
    if (rdf->online == online) {
        return;
    }

    if (online == TRUE) {
        e_summary_rdf_update (summary);

        if (summary->preferences->rdf_refresh_time != 0)
            rdf->timeout = gtk_timeout_add (summary->preferences->rdf_refresh_time * 1000,
                            (GtkFunction) e_summary_rdf_update,
                            summary);
    } else {
        for (p = rdf->rdfs; p; p = p->next) {
            RDF *r;

            r = p->data;
            if (r->message) {
                soup_message_cancel (r->message);
                r->message = NULL;
            }
        }

        gtk_timeout_remove (rdf->timeout);
        rdf->timeout = 0;
    }

    rdf->online = online;
}

void
e_summary_rdf_init (ESummary *summary)
{
    ESummaryPrefs *prefs;
    ESummaryRDF *rdf;
    ESummaryConnection *connection;
    GSList *p;
    int timeout;

    g_return_if_fail (summary != NULL);
    g_return_if_fail (IS_E_SUMMARY (summary));

    prefs = summary->preferences;
    g_assert (prefs != NULL);

    rdf = g_new0 (ESummaryRDF, 1);
    summary->rdf = rdf;

    connection = g_new (ESummaryConnection, 1);
    connection->count = e_summary_rdf_count;
    connection->add = e_summary_rdf_add;
    connection->set_online = e_summary_rdf_set_online;
    connection->closure = NULL;
    connection->callback = NULL;
    connection->callback_closure = NULL;

    rdf->connection = connection;
    rdf->online = TRUE;
    e_summary_add_online_connection (summary, connection);

    e_summary_add_protocol_listener (summary, "rdf", e_summary_rdf_protocol, rdf);

    for (p = prefs->rdf_urls; p; p = p->next) {
        e_summary_rdf_add_uri (summary, p->data);
    }
    timeout = prefs->rdf_refresh_time;

    e_summary_rdf_update (summary);

    if (rdf->timeout == 0)
        rdf->timeout = 0;
    else
        rdf->timeout = gtk_timeout_add (timeout * 1000,
                        (GtkFunction) e_summary_rdf_update, summary);

    return;
}

void
e_summary_rdf_reconfigure (ESummary *summary)
{
    ESummaryRDF *rdf;
    GList *old, *p;
    GSList *sp;

    g_return_if_fail (summary != NULL);
    g_return_if_fail (IS_E_SUMMARY (summary));

    rdf = summary->rdf;

    /* Stop timeout */
    if (rdf->timeout != 0) {
        gtk_timeout_remove (rdf->timeout);
        rdf->timeout = 0;
    }

    old = rdf->rdfs;
    rdf->rdfs = NULL;
    for (p = old; p; p = p->next) {
        RDF *r;

        r = p->data;
        rdf_free (r);
    }
    g_list_free (old);

    for (sp = summary->preferences->rdf_urls; sp; sp = sp->next) {
        e_summary_rdf_add_uri (summary, sp->data);
    }

    if (summary->preferences->rdf_refresh_time != 0)
        rdf->timeout = gtk_timeout_add (summary->preferences->rdf_refresh_time * 1000,
                        (GtkFunction) e_summary_rdf_update, summary);

    e_summary_rdf_update (summary);
}

void
e_summary_rdf_free (ESummary *summary)
{
    ESummaryRDF *rdf;
    GList *p;

    g_return_if_fail (summary != NULL);
    g_return_if_fail (IS_E_SUMMARY (summary));

    rdf = summary->rdf;

    if (rdf->timeout != 0)
        gtk_timeout_remove (rdf->timeout);

    for (p = rdf->rdfs; p; p = p->next) {
        RDF *r = p->data;

        rdf_free (r);
    }
    g_list_free (rdf->rdfs);
    g_free (rdf->html);

    e_summary_remove_online_connection (summary, rdf->connection);
    g_free (rdf->connection);

    g_free (rdf);
    summary->rdf = NULL;
}