Microblog (#18)

* Microblog Plugin

Display information about new blog entry

development/microblog.c

@@ -0,0 +1,191 @@
+/*
+ * Copyright (C) 2020 Stefan Kropp <stefan@debxwoody.de>
+ *
+ * This file is part of profanity.
+ *
+ * profanity 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, version 3 of the License.
+ *
+ * profanity 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 profanity.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ * !!!    Status: Development / Testing         !!!!
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ *
+ * File: microblog.c
+ *
+ * The microblog plugin can be used for Movim Users. If profanity gets a message
+ * "urn:xmpp:microblog:0", it will display the from, title and ID information of
+ * the blog post.
+ *
+ * Profanity will display a message like this, in the main Window:
+ *
+ * Blog from user@domain.tld - Title of the post (ID of the post)
+ *
+ * Compile:
+ *
+ * gcc -shared -fpic -g3 -O0 -Wextra -pedantic \
+ * -L/usr/lib/profanity -lprofanity `pkg-config --libs --cflags libxml-2.0` \
+ * -o microblog.so microblog.c
+ *
+ * Install:
+ *
+ * cp microblog.so \
+ * ~/.local/share/profanity/plugins/
+ *
+ * Documentation:
+ *
+ * https://profanity-im.github.io/plugins.html
+ *
+ */
+
+#define _GNU_SOURCE
+
+#include <profapi.h>
+
+#include <assert.h>
+#include <libxml/parser.h>
+#include <libxml/xpath.h>
+#include <libxml/xpathInternals.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define PLUGIN_NAME "microblog"
+#define PLUGIN_VERSION "0.0.1-DEV"
+
+#define XMPP_URN_MICROBLOG "urn:xmpp:microblog:0"
+
+/**
+ * PubSubEvent is the struct with all data of the stanza, which should be
+ * displayed or processed by the plugin..
+ */
+typedef struct {
+  char *id;    // id of the item
+  char *from;  // jid from
+  char *title; // title of the item
+} PubSubEvent;
+
+// Enable or disable Plugin
+
+static bool enabled = true;
+
+/**
+ * Parse the char* stanza and return the information in event.
+ * The function will return true on success, otherwise false.
+ */
+bool parse(const char *stanza, PubSubEvent *event) {
+  bool result = false;
+  // stanza and event are mandatory
+  if (stanza == NULL || event == NULL || strlen(stanza) == 0) {
+    return result;
+  }
+
+  xmlDocPtr doc;
+  xmlNode *root_element = NULL;
+
+  doc = xmlReadMemory(stanza, strlen(stanza), NULL, NULL, 0);
+  if (doc == NULL) {
+    return result;
+  }
+
+  xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
+  xmlXPathRegisterNs(xpathCtx, BAD_CAST "ev",
+                     BAD_CAST "http://jabber.org/protocol/pubsub#event");
+  xmlXPathRegisterNs(xpathCtx, BAD_CAST "a",
+                     BAD_CAST "http://www.w3.org/2005/Atom");
+
+  xmlXPathObjectPtr xpathObj = xmlXPathEvalExpression(
+      "//message/ev:event/ev:items/attribute::node", xpathCtx);
+
+  if (xpathObj != NULL && xpathObj->nodesetval != NULL &&
+      xpathObj->nodesetval->nodeTab[0] != NULL) {
+    if (xpathObj->nodesetval->nodeTab[0]->children != NULL &&
+        xpathObj->nodesetval->nodeTab[0]->children->content != NULL) {
+      if (strcmp(xpathObj->nodesetval->nodeTab[0]->children->content,
+                 XMPP_URN_MICROBLOG) == 0) {
+        xpathObj =
+            xmlXPathEvalExpression("//message/attribute::from", xpathCtx);
+        assert(xpathObj != NULL);
+
+        event->from =
+            strdup(xpathObj->nodesetval->nodeTab[0]->children->content);
+        xmlXPathFreeObject(xpathObj);
+
+        xpathObj = xmlXPathEvalExpression(
+            "//message/ev:event/ev:items/ev:item/a:entry/a:title", xpathCtx);
+        assert(xpathObj != NULL);
+
+        event->title =
+            strdup(xpathObj->nodesetval->nodeTab[0]->children->content);
+        xmlXPathFreeObject(xpathObj);
+
+        xpathObj = xmlXPathEvalExpression(
+            "//message/ev:event/ev:items/ev:item/attribute::id", xpathCtx);
+        assert(xpathObj != NULL);
+
+        event->id = strdup(xpathObj->nodesetval->nodeTab[0]->children->content);
+        xmlXPathFreeObject(xpathObj);
+        result = true;
+      }
+    }
+  }
+
+  if (xpathCtx) {
+    xmlXPathFreeContext(xpathCtx);
+  }
+  if (doc) {
+    xmlFreeDoc(doc);
+  }
+  return result;
+}
+
+void prof_init(const char *const version, const char *const status,
+               const char *const account_name, const char *const fulljid) {
+  char *s = NULL;
+  asprintf(&s, "Loaded Plugin %s %s", PLUGIN_NAME, PLUGIN_VERSION);
+  prof_cons_show(s);
+  free(s);
+}
+
+void prof_on_start(void) {}
+
+void prof_on_shutdown(void) {}
+
+void prof_on_unload(void) {
+  char *s = NULL;
+  asprintf(&s, "Unloading Plugin %s %s", PLUGIN_NAME, PLUGIN_VERSION);
+  prof_cons_show(s);
+  free(s);
+}
+
+int prof_on_message_stanza_receive(const char *const stanza) {
+  if (enabled) {
+    PubSubEvent event;
+    event.id = NULL;
+    event.from = NULL;
+    event.title = NULL;
+    if (parse(stanza, &event)) {
+      int size =
+          strlen(event.id) + strlen(event.from) + strlen(event.title) + 30;
+      char *message = calloc(size, sizeof(char));
+      snprintf(message, size, "Blog from %s - %s (%s)", event.from, event.title,
+               event.id);
+      prof_cons_show(message);
+      prof_cons_alert();
+      free(message);
+      free(event.id);
+      free(event.from);
+      free(event.title);
+    }
+  }
+  return 1;
+}