Merge pull request #84 from rootAvish/epub

Epub support in Atril

1 files changed, 1771 insertions, 0 deletions

diff --git a/backend/epub/epub-document.c b/backend/epub/epub-document.c
new file mode 100644
index 00000000..dd5d458c
--- /dev/null
+++ b/backend/epub/epub-document.c
@@ -0,0 +1,1771 @@
+/* this file is part of atril, a mate document viewer
+ *
+ *  Copyright (C) 2014 Avishkar Gupta
+ *
+ *  Author:
+ *   Avishkar Gupta <[email protected]>
+ *
+ * Atril 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.
+ *
+ * Atril 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "epub-document.h"
+#include "ev-file-helpers.h"
+#include "unzip.h"
+#include "ev-document-thumbnails.h"
+#include "ev-document-find.h"
+#include "ev-backends-manager.h"
+#include "ev-document-links.h"
+#include "ev-document-misc.h"
+#include <libxml/parser.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/HTMLparser.h>
+#include <config.h>
+
+#include <glib/gi18n.h>
+#include <glib/gstdio.h>
+
+#include <gtk/gtk.h>
+
+/*For strcasestr(),strstr()*/
+#include <string.h>
+
+typedef enum _xmlParseReturnType 
+{
+    XML_ATTRIBUTE,
+    XML_KEYWORD
+}xmlParseReturnType;
+
+typedef struct _contentListNode {  
+    gchar* key ;
+    gchar* value ;
+	gint index ;
+}contentListNode;
+
+typedef struct _linknode {
+    gchar *pagelink;
+	GList *children;
+    gchar *linktext;
+	guint page;
+}linknode;
+
+typedef struct _EpubDocumentClass EpubDocumentClass;
+
+struct _EpubDocumentClass
+{
+    EvDocumentClass parent_class;
+};
+
+struct _EpubDocument
+{
+    EvDocument parent_instance;
+	/*Stores the path to the source archive*/
+    gchar* archivename ;
+	/*Stores the path of the directory where we unzipped the epub*/
+    gchar* tmp_archive_dir ;
+	/*Stores the contentlist in a sorted manner*/
+    GList* contentList ;
+    /* A variable to hold our epubDocument for unzipping*/
+    unzFile epubDocument ;
+	/*The (sub)directory that actually houses the document*/
+	gchar* documentdir;
+	/*Stores the table of contents*/
+	GList *index;
+	/*Document title, for the sidebar links*/
+	gchar *docTitle;
+};
+
+static void       epub_document_document_thumbnails_iface_init (EvDocumentThumbnailsInterface *iface);
+static void       epub_document_document_find_iface_init       (EvDocumentFindInterface       *iface); 
+static void       epub_document_document_links_iface_init      (EvDocumentLinksInterface      *iface);
+
+EV_BACKEND_REGISTER_WITH_CODE (EpubDocument, epub_document,
+	{
+		EV_BACKEND_IMPLEMENT_INTERFACE (EV_TYPE_DOCUMENT_THUMBNAILS,
+						epub_document_document_thumbnails_iface_init);
+		 EV_BACKEND_IMPLEMENT_INTERFACE (EV_TYPE_DOCUMENT_FIND,
+								 epub_document_document_find_iface_init);
+        EV_BACKEND_IMPLEMENT_INTERFACE (EV_TYPE_DOCUMENT_LINKS,
+                                 epub_document_document_links_iface_init);
+
+	} );
+
+static void
+epub_document_thumbnails_get_dimensions (EvDocumentThumbnails *document,
+                                         EvRenderContext      *rc,
+                                         gint                 *width,
+                                         gint                 *height)
+{
+	gdouble page_width, page_height;
+	
+	page_width = 800;
+	page_height = 1080;
+	
+	*width = MAX ((gint)(page_width * rc->scale + 0.5), 1);
+	*height = MAX ((gint)(page_height * rc->scale + 0.5), 1);
+}
+
+static GdkPixbuf *
+epub_document_thumbnails_get_thumbnail (EvDocumentThumbnails *document,
+                                        EvRenderContext      *rc,
+                                        gboolean              border)
+{
+	cairo_surface_t *webpage;
+	GdkPixbuf *thumbnailpix = NULL ;
+	gint width,height;
+	epub_document_thumbnails_get_dimensions(document,rc,&width,&height);
+	webpage = ev_document_misc_surface_rotate_and_scale(rc->page->backend_page,width,height,0);
+	thumbnailpix = ev_document_misc_pixbuf_from_surface(webpage);
+	return thumbnailpix;
+}
+
+static gboolean
+in_tag(const char* found)
+{
+    const char* bracket = found ;
+
+    /* Since the dump started with the body tag, the '<' will be the first
+     * character in the haystack.
+     */
+    while (*bracket != '<') {
+        bracket--;
+        if (*bracket == '>') {
+            /*We encounted a close brace before an open*/
+            return FALSE ;
+        }
+    }
+
+    return TRUE;
+}
+
+static int 
+get_substr_count(const char * haystack,const char *needle,gboolean case_sensitive)
+{
+    const char* tmp = haystack ;
+    char* (*string_compare_function)(const char*,const char*);
+    int count=0;
+    if (case_sensitive) {
+        string_compare_function = strstr ;
+    }
+    else {
+        string_compare_function = strcasestr;
+    }
+
+    while ((tmp=string_compare_function(tmp,needle))) {
+        if (!in_tag(tmp)) {
+            count++;
+        }
+        tmp = tmp + strlen(needle);
+    }
+
+    return count;
+}
+
+static guint
+epub_document_check_hits(EvDocumentFind *document_find,
+                         EvPage         *page,
+                         const gchar    *text,
+                         gboolean        case_sensitive)
+{
+	gchar *filepath = g_filename_from_uri((gchar*)page->backend_page,NULL,NULL);
+	htmlDocPtr htmldoc =  xmlParseFile(filepath); 
+	htmlNodePtr htmltag = xmlDocGetRootElement(htmldoc);
+	int count=0;
+	htmlNodePtr bodytag = htmltag->xmlChildrenNode;
+
+	while ( xmlStrcmp(bodytag->name,(xmlChar*)"body") ) {
+		bodytag = bodytag->next;
+	}
+	
+	xmlBufferPtr bodybuffer = xmlBufferCreate();
+	xmlNodeDump(bodybuffer,htmldoc,bodytag,0,1);
+
+	count = get_substr_count((char*)bodybuffer->content,text,case_sensitive);
+	
+	xmlBufferFree(bodybuffer);
+	xmlFreeDoc(htmldoc);
+
+	return count;
+}
+
+static gboolean
+epub_document_links_has_document_links(EvDocumentLinks *document_links)
+{
+    EpubDocument *epub_document = EPUB_DOCUMENT(document_links);
+
+    g_return_if_fail(EPUB_IS_DOCUMENT(epub_document));
+
+    if (!epub_document->index)
+        return FALSE;
+
+    return TRUE;
+}
+
+
+typedef struct _LinksCBStruct {
+	GtkTreeModel *model;
+	GtkTreeIter  *parent;
+}LinksCBStruct;
+
+static void
+epub_document_make_tree_entry(linknode* ListData,LinksCBStruct* UserData)
+{
+	GtkTreeIter tree_iter;
+	EvLink *link = NULL;
+	gboolean expand;
+	char *title_markup;
+
+	if (ListData->children) {
+		expand=TRUE;
+	}
+	else {
+		expand=FALSE;
+	}
+	
+	EvLinkDest *ev_dest = NULL;
+	EvLinkAction *ev_action;
+
+	/* We shall use a EV_LINK_DEST_TYPE_PAGE for page links,
+	 * and a EV_LINK_DEST_TYPE_HLINK(custom) for refs on a page of type url#label
+	 * because we need both dest and page label for this.
+	 */
+
+	if (g_strrstr(ListData->pagelink,"#") == NULL) {
+		ev_dest = ev_link_dest_new_page(ListData->page);
+	}
+	else {
+		ev_dest = ev_link_dest_new_hlink((gchar*)ListData->pagelink,ListData->page);
+	}
+	
+	ev_action = ev_link_action_new_dest (ev_dest);
+
+	link = ev_link_new((gchar*)ListData->linktext,ev_action);
+
+	gtk_tree_store_append (GTK_TREE_STORE (UserData->model), &tree_iter,(UserData->parent));
+	title_markup = g_strdup((gchar*)ListData->linktext);
+	
+	gtk_tree_store_set (GTK_TREE_STORE (UserData->model), &tree_iter,
+			    EV_DOCUMENT_LINKS_COLUMN_MARKUP, title_markup,
+			    EV_DOCUMENT_LINKS_COLUMN_LINK, link,
+			    EV_DOCUMENT_LINKS_COLUMN_EXPAND, expand,
+			    -1);
+
+	if (ListData->children) {
+		LinksCBStruct cbstruct;
+		cbstruct.parent = &tree_iter;
+		cbstruct.model = UserData->model;
+		g_list_foreach (ListData->children,(GFunc)epub_document_make_tree_entry,&cbstruct);
+	}
+	
+	g_free (title_markup);
+	g_object_unref (link);		
+}
+
+static GtkTreeModel *
+epub_document_links_get_links_model(EvDocumentLinks *document_links) 
+{
+    GtkTreeModel *model = NULL;
+
+	g_return_val_if_fail (EPUB_IS_DOCUMENT (document_links), NULL);
+	
+    EpubDocument *epub_document = EPUB_DOCUMENT(document_links);
+	
+    model = (GtkTreeModel*) gtk_tree_store_new (EV_DOCUMENT_LINKS_COLUMN_NUM_COLUMNS,
+                                                G_TYPE_STRING,
+                                                G_TYPE_OBJECT,
+                                                G_TYPE_BOOLEAN,
+                                                G_TYPE_STRING);
+
+	LinksCBStruct linkStruct;
+	linkStruct.model = model;
+	EvLink *link = ev_link_new(epub_document->docTitle,
+	                           ev_link_action_new_dest(ev_link_dest_new_page(0)));
+	GtkTreeIter parent;
+
+	linkStruct.parent = &parent;
+	
+	gtk_tree_store_append (GTK_TREE_STORE (model), &parent,NULL);
+		
+	gtk_tree_store_set (GTK_TREE_STORE (model), &parent,
+			    EV_DOCUMENT_LINKS_COLUMN_MARKUP, epub_document->docTitle,
+			    EV_DOCUMENT_LINKS_COLUMN_LINK, link,
+			    EV_DOCUMENT_LINKS_COLUMN_EXPAND, TRUE,
+			    -1);
+
+	g_object_unref(link);
+	
+	if (epub_document->index) {
+		g_list_foreach (epub_document->index,(GFunc)epub_document_make_tree_entry,&linkStruct);
+	}
+	
+    return model;
+}
+
+static void
+epub_document_document_thumbnails_iface_init (EvDocumentThumbnailsInterface *iface)
+{
+	iface->get_thumbnail = epub_document_thumbnails_get_thumbnail;
+	iface->get_dimensions = epub_document_thumbnails_get_dimensions;
+}
+
+static void
+epub_document_document_find_iface_init (EvDocumentFindInterface *iface) 
+{
+	iface->check_for_hits = epub_document_check_hits;
+}
+
+static void
+epub_document_document_links_iface_init(EvDocumentLinksInterface *iface)
+{
+    iface->has_document_links = epub_document_links_has_document_links;
+    iface->get_links_model = epub_document_links_get_links_model;  
+}
+
+static gboolean
+epub_document_save (EvDocument *document,
+                    const char *uri,
+                    GError    **error)
+{
+	EpubDocument *epub_document = EPUB_DOCUMENT (document);
+
+	return ev_xfer_uri_simple (epub_document->archivename, uri, error);
+}
+
+static int
+epub_document_get_n_pages (EvDocument *document)
+{   
+	EpubDocument *epub_document = EPUB_DOCUMENT (document);
+
+        if (epub_document-> contentList == NULL)
+                return 0;
+            
+	return g_list_length(epub_document->contentList);
+}
+
+/**
+ * epub_remove_temporary_dir : Removes a directory recursively. 
+ * This function is same as comics_remove_temporary_dir
+ * Returns:
+ *   	0 if it was successfully deleted,
+ * 	-1 if an error occurred 		
+ */
+static int 
+epub_remove_temporary_dir (gchar *path_name) 
+{
+	GDir  *content_dir;
+	const gchar *filename;
+	gchar *filename_with_path;
+	
+	if (g_file_test (path_name, G_FILE_TEST_IS_DIR)) {
+		content_dir = g_dir_open  (path_name, 0, NULL);
+		filename  = g_dir_read_name (content_dir);
+		while (filename) {
+			filename_with_path = 
+				g_build_filename (path_name, 
+						  filename, NULL);
+			epub_remove_temporary_dir (filename_with_path);
+			g_free (filename_with_path);
+			filename = g_dir_read_name (content_dir);
+		}
+		g_dir_close (content_dir);
+	}
+	/* Note from g_remove() documentation: on Windows, it is in general not 
+	 * possible to remove a file that is open to some process, or mapped 
+	 * into memory.*/
+	return (g_remove (path_name));
+}
+
+
+static gboolean
+check_mime_type             (const gchar* uri,
+                             GError** error);
+
+static gboolean 
+open_xml_document           (const gchar* filename);
+
+static gboolean 
+set_xml_root_node           (xmlChar* rootname);
+
+static xmlNodePtr
+xml_get_pointer_to_node     (xmlChar* parserfor,
+                             xmlChar* attributename,
+                             xmlChar* attributevalue);
+static void 
+xml_parse_children_of_node  (xmlNodePtr parent, 
+                             xmlChar* parserfor,
+                             xmlChar* attributename,
+                             xmlChar* attributevalue);
+
+static gboolean 
+xml_check_attribute_value   (xmlNode* node,
+                             xmlChar * attributename,
+                             xmlChar* attributevalue);
+
+static xmlChar* 
+xml_get_data_from_node      (xmlNodePtr node,
+                             xmlParseReturnType rettype,
+                             xmlChar* attributename);
+
+static void 
+xml_free_doc();
+
+static void
+free_tree_nodes             (gpointer data);
+
+/*Global variables for XML parsing*/
+static xmlDocPtr    xmldocument ;
+static xmlNodePtr   xmlroot ;
+static xmlNodePtr   xmlretval ;
+
+/*
+**Functions to parse the xml files.
+**Open a XML document for reading 
+*/
+static gboolean 
+open_xml_document ( const gchar* filename )
+{
+	xmldocument = xmlParseFile(filename);
+
+	if ( xmldocument == NULL )
+	{
+		return FALSE ;
+	}
+	else
+	{
+		return TRUE ;
+	}
+}
+
+/**
+ *Check if the root value is same as rootname .
+ *if supplied rootvalue = NULL ,just set root to rootnode . 
+**/
+static gboolean 
+set_xml_root_node(xmlChar* rootname)
+{
+	xmlroot = xmlDocGetRootElement(xmldocument);
+	
+	if (xmlroot == NULL) {
+
+		xmlFreeDoc(xmldocument);	
+		return FALSE;
+	}
+
+    if ( rootname == NULL )
+    {
+        return TRUE ;
+    }
+
+    if ( !xmlStrcmp(xmlroot->name,rootname))
+    {
+        return TRUE ;
+    }
+    else
+    {
+	   return FALSE;
+    }
+} 
+
+static xmlNodePtr
+xml_get_pointer_to_node(xmlChar* parserfor,
+                        xmlChar*  attributename,
+                        xmlChar* attributevalue )
+{
+    xmlNodePtr topchild,children ;
+
+    xmlretval = NULL ;
+
+    if ( !xmlStrcmp( xmlroot->name, parserfor) )
+    {
+        return xmlroot ;
+    }
+
+    topchild = xmlroot->xmlChildrenNode ;
+
+    while ( topchild != NULL )
+    {
+        if ( !xmlStrcmp(topchild->name,parserfor) )
+        {
+            if ( xml_check_attribute_value(topchild,attributename,attributevalue) == TRUE )
+            {
+                 xmlretval = topchild;
+                 return xmlretval;     
+            }
+            else 
+            {
+                /*No need to parse children node*/
+                topchild = topchild->next ;
+                continue ;
+            }
+        }
+
+        xml_parse_children_of_node(topchild , parserfor, attributename, attributevalue) ;
+
+        topchild = topchild->next ;
+    }
+
+    return xmlretval ;
+}
+
+static void 
+xml_parse_children_of_node(xmlNodePtr parent, 
+                           xmlChar* parserfor,
+                           xmlChar* attributename,
+                           xmlChar* attributevalue )
+{
+    xmlNodePtr child = parent->xmlChildrenNode ;
+    
+    while ( child != NULL )
+    {
+        if ( !xmlStrcmp(child->name,parserfor))
+        {
+            if ( xml_check_attribute_value(child,attributename,attributevalue) == TRUE )
+            {
+                 xmlretval = child;
+                 return ;
+            }
+            else 
+            {
+                /*No need to parse children node*/
+                child = child->next ;
+                continue ;
+            }
+        }
+
+        /*return already if we have xmlretval set*/
+        if ( xmlretval != NULL )
+        {
+            return ;
+        }
+
+        xml_parse_children_of_node(child,parserfor,attributename,attributevalue) ;
+        child = child->next ;
+    }
+}
+
+static void 
+xml_free_doc()
+{
+    xmlFreeDoc(xmldocument);
+	xmldocument = NULL;
+}
+
+static gboolean 
+xml_check_attribute_value(xmlNode* node,
+                          xmlChar * attributename,
+                          xmlChar* attributevalue)
+{
+    xmlChar* attributefromfile ;
+    if ( attributename == NULL || attributevalue == NULL )
+    {
+         return TRUE ;     
+    }
+    else if ( !xmlStrcmp(( attributefromfile = xmlGetProp(node,attributename)),
+                           attributevalue) )
+    {
+        xmlFree(attributefromfile);
+        return TRUE ;
+    }
+    xmlFree(attributefromfile);
+    return FALSE ;
+}
+
+static xmlChar* 
+xml_get_data_from_node(xmlNodePtr node,
+                       xmlParseReturnType rettype,
+                       xmlChar* attributename)
+{
+    xmlChar* datastring ;
+    if ( rettype == XML_ATTRIBUTE )
+       datastring= xmlGetProp(node,attributename);
+    else
+       datastring= xmlNodeListGetString(xmldocument,node->xmlChildrenNode, 1);
+
+    return datastring;
+}
+
+static gboolean
+check_mime_type(const gchar* uri,GError** error)
+{
+    GError * err = NULL ;
+    const gchar* mimeFromFile = ev_file_get_mime_type(uri,FALSE,&err);
+    
+    gchar* mimetypes[] = {"application/epub+zip","application/x-booki+zip"};
+    int typecount = 2;
+    if ( !mimeFromFile )
+    {
+        if (err)    {
+            g_propagate_error (error, err);
+        } 
+        else    {
+            g_set_error_literal (error,
+                         EV_DOCUMENT_ERROR,
+                         EV_DOCUMENT_ERROR_INVALID,
+                         _("Unknown MIME Type"));
+        }
+        return FALSE;
+    }
+    else
+    {
+        int i=0;
+        for (i=0; i < typecount ;i++) {
+           if ( g_strcmp0(mimeFromFile, mimetypes[i]) == 0  ) {
+                return TRUE;
+           }
+        }
+
+        /*We didn't find a match*/
+        g_set_error_literal (error,
+                     EV_DOCUMENT_ERROR,
+                     EV_DOCUMENT_ERROR_INVALID,
+                     _("Not an ePub document"));
+
+        return FALSE;
+    }
+}
+
+static gboolean
+extract_one_file(EpubDocument* epub_document,GError ** error)
+{
+    GFile * outfile ;
+    gsize writesize = 0;
+    GString * gfilepath ;
+    unz_file_info64 info ;  
+    gchar* directory;
+	GString* dir_create;
+    GFileOutputStream * outstream ;
+    gpointer currentfilename = g_malloc0(512);
+    gpointer buffer = g_malloc0(512);
+    gchar* createdirnametemp = NULL ;
+    gchar* createdirname = NULL;
+    if ( unzOpenCurrentFile(epub_document->epubDocument) != UNZ_OK )
+    {
+            return FALSE ;
+    } 
+        
+    unzGetCurrentFileInfo64(epub_document->epubDocument,&info,currentfilename,512,NULL,0,NULL,0) ;
+    directory = g_strrstr(currentfilename,"/") ;
+
+    if ( directory != NULL )
+        directory++; 
+
+    gfilepath = g_string_new(epub_document->tmp_archive_dir) ;
+    g_string_append_printf(gfilepath,"/%s",(gchar*)currentfilename);
+
+    /*if we encounter a directory, make a directory inside our temporary folder.*/
+    if (directory != NULL && *directory == '\0')
+    {
+        g_mkdir(gfilepath->str,0777);
+        unzCloseCurrentFile (epub_document->epubDocument) ;
+        g_string_free(gfilepath,TRUE);
+        g_free(currentfilename);
+        g_free(buffer);
+        return TRUE;
+    }
+    else if (directory != NULL && *directory != '\0' ) {
+        gchar* createdir = currentfilename;
+        /*Since a substring can't be longer than the parent string, allocating space equal to the parent's size should suffice*/
+        createdirname = g_malloc0(strlen(currentfilename));
+        /* Add the name of the directory and subdiectories,if any to a buffer and then create it */
+        createdirnametemp = createdirname;        
+        while ( createdir != directory ) {
+            (*createdirnametemp) = (*createdir);
+            createdirnametemp++;
+            createdir++;
+        }
+        (*createdirnametemp) = '\0';
+		dir_create = g_string_new(epub_document->tmp_archive_dir);
+		g_string_append_printf(dir_create,"/%s",createdirname);
+        g_mkdir_with_parents(dir_create->str,0777);
+		g_string_free(dir_create,TRUE);
+    }
+
+    outfile = g_file_new_for_path(gfilepath->str);
+    outstream = g_file_create(outfile,G_FILE_CREATE_PRIVATE,NULL,error);
+    while ( (writesize = unzReadCurrentFile(epub_document->epubDocument,buffer,512) ) != 0 )
+    {
+        if ( g_output_stream_write((GOutputStream*)outstream,buffer,writesize,NULL,error) == -1 )
+        {
+            return FALSE ;
+        }
+    }
+    g_output_stream_close((GOutputStream*)outstream,NULL,error);
+    g_object_unref(outfile) ;
+    g_object_unref(outstream) ;
+   
+    unzCloseCurrentFile (epub_document->epubDocument) ;
+    g_string_free(gfilepath,TRUE);
+    g_free(currentfilename);
+    g_free(buffer);
+	if ( createdirname != NULL) {
+		g_free(createdirname);
+	}
+	return TRUE;
+}
+
+static gboolean 
+extract_epub_from_container (const gchar* uri, 
+                             EpubDocument *epub_document,
+                             GError ** error)
+{
+    GError* err = NULL ;
+    GString * temporary_sub_directory ; 
+    epub_document->archivename = g_filename_from_uri(uri,NULL,error);
+    gchar* epubfilename ;
+    if ( !epub_document->archivename )
+    {
+         if (err)    {
+            g_propagate_error (error, err);
+        } 
+        else    {
+            g_set_error_literal (error,
+                         EV_DOCUMENT_ERROR,
+                         EV_DOCUMENT_ERROR_INVALID,
+                         _("could not retrieve filename"));
+        }
+        return FALSE ;
+    }
+
+    epubfilename = g_strrstr(epub_document->archivename,"/");
+    if ( *epubfilename == '/' )
+    epubfilename++ ;
+
+    temporary_sub_directory = g_string_new( epubfilename );
+    g_string_append(temporary_sub_directory,"XXXXXX") ;
+
+    epub_document->tmp_archive_dir = ev_mkdtemp(temporary_sub_directory->str,error) ;
+
+    if (!epub_document->tmp_archive_dir) {
+        return FALSE ;
+    }
+
+    g_string_free(temporary_sub_directory,TRUE);
+
+    epub_document->epubDocument = unzOpen64(epub_document->archivename);
+
+    if ( epub_document->epubDocument == NULL )
+    {
+        if (err)    {
+            g_propagate_error (error, err);
+        } 
+        else    {
+            g_set_error_literal (error,
+                         EV_DOCUMENT_ERROR,
+                         EV_DOCUMENT_ERROR_INVALID,
+                         _("could not open archive"));
+        }
+        return FALSE ;
+    }
+    if ( unzGoToFirstFile(epub_document->epubDocument) != UNZ_OK )
+    {
+        if (err) {
+            g_propagate_error (error, err);
+        } 
+        else    {
+            g_set_error_literal (error,
+                         EV_DOCUMENT_ERROR,
+                         EV_DOCUMENT_ERROR_INVALID,
+                         _("could not extract archive"));
+        }
+        return FALSE ;
+    }
+    while ( TRUE )
+    {
+        if ( extract_one_file(epub_document,&err) == FALSE )
+        {
+            if (err) {
+                g_propagate_error (error, err);
+            } 
+            else    {
+                g_set_error_literal (error,
+                             EV_DOCUMENT_ERROR,
+                             EV_DOCUMENT_ERROR_INVALID,
+                             _("could not extract archive"));
+            }
+			return FALSE;
+        }   
+
+        if ( unzGoToNextFile(epub_document->epubDocument) == UNZ_END_OF_LIST_OF_FILE )
+            break ;
+    }
+
+    unzClose(epub_document->epubDocument);
+    return TRUE ;
+}
+
+static gchar* 
+get_uri_to_content(const gchar* uri,GError ** error,EpubDocument *epub_document)
+{
+	gchar* tmp_archive_dir = epub_document->tmp_archive_dir;
+    GError *   err = NULL ; 
+    gchar*     containerpath = g_filename_from_uri(uri,NULL,&err);
+    GString*   absolutepath ;
+    gchar*     content_uri ;
+    xmlNodePtr rootfileNode ;
+    xmlChar*   relativepath;
+	gchar*     directorybuffer = g_malloc0(sizeof(gchar*)*100);
+	
+    if ( !containerpath )
+    {
+        if (err) {
+            g_propagate_error (error,err);
+        } 
+        else    {
+            g_set_error_literal (error,
+                                 EV_DOCUMENT_ERROR,
+                                 EV_DOCUMENT_ERROR_INVALID,
+                                 _("could not retrieve container file"));
+        }
+        return NULL ;
+    }    
+
+    if ( open_xml_document(containerpath) == FALSE )
+    {
+        g_set_error_literal(error,
+                            EV_DOCUMENT_ERROR,
+                            EV_DOCUMENT_ERROR_INVALID,
+                            _("could not open container file"));
+    
+        return NULL ;
+    }
+
+    if ( set_xml_root_node((xmlChar*)"container") == FALSE)  {
+
+        g_set_error_literal(error,
+                            EV_DOCUMENT_ERROR,
+                            EV_DOCUMENT_ERROR_INVALID,
+                            _("container file is corrupt"));    
+        return NULL ;
+    }
+
+    if ( (rootfileNode = xml_get_pointer_to_node((xmlChar*)"rootfile",(xmlChar*)"media-type",(xmlChar*)"application/oebps-package+xml")) == NULL)
+    {
+        g_set_error_literal(error,
+                            EV_DOCUMENT_ERROR,
+                            EV_DOCUMENT_ERROR_INVALID,
+                            _("epub file is invalid or corrput"));
+        return NULL ;
+    }
+    
+    relativepath = xml_get_data_from_node(rootfileNode,XML_ATTRIBUTE,(xmlChar*)"full-path") ;
+   if ( relativepath == NULL )
+    {
+        g_set_error_literal(error,
+                            EV_DOCUMENT_ERROR,
+                            EV_DOCUMENT_ERROR_INVALID,
+                            _("epub file is corrupt,no container"));
+        return NULL ;
+    }
+	absolutepath = g_string_new(tmp_archive_dir);
+	gchar* documentfolder = g_strrstr((gchar*)relativepath,"/");
+	if (documentfolder != NULL) {
+		gchar* copybuffer = (gchar*)relativepath ;
+		gchar* writer = directorybuffer;
+
+		while(copybuffer != documentfolder) {
+			(*writer) = (*copybuffer);
+			writer++;copybuffer++;
+		}
+		*writer = '\0';
+		GString *documentdir = g_string_new(tmp_archive_dir);
+		g_string_append_printf(documentdir,"/%s",directorybuffer);
+		epub_document->documentdir = g_strdup(documentdir->str);
+
+		g_string_free(documentdir,TRUE);
+	}
+	else
+	{
+		epub_document->documentdir = g_strdup(tmp_archive_dir);
+	}
+
+    g_string_append_printf(absolutepath,"/%s",relativepath);
+    content_uri = g_filename_to_uri(absolutepath->str,NULL,&err);
+    if ( !content_uri )  {
+    if (err) {
+            g_propagate_error (error,err);
+        } 
+        else    {
+            g_set_error_literal (error,
+                                 EV_DOCUMENT_ERROR,
+                                 EV_DOCUMENT_ERROR_INVALID,
+                                 _("could not retrieve container file"));
+        }
+        return NULL ;
+    }
+    g_string_free(absolutepath,TRUE);
+	g_free(directorybuffer);
+	xml_free_doc();
+    return content_uri ; 
+}
+
+static gboolean
+link_present_on_page(const gchar* link,const gchar *page_uri)
+{
+	gchar *res;
+	if ((res=g_strrstr(link, page_uri)) != NULL) {
+		return TRUE;
+	}
+	else {
+		return FALSE;
+	}
+}
+
+static void
+check_add_page_numbers(linknode *listdata, contentListNode *comparenode)
+{
+    if (link_present_on_page(listdata->pagelink, comparenode->value)) {
+		listdata->page = comparenode->index - 1;
+	}
+    if (listdata->children != NULL) {
+        g_list_foreach(listdata->children,(GFunc)check_add_page_numbers,comparenode);
+    }
+}
+
+static GList*
+setup_document_content_list(const gchar* content_uri, GError** error,gchar *documentdir)
+{
+    GList* newlist = NULL ;
+    GError *   err = NULL ; 
+    gint indexcounter= 1;
+    xmlNodePtr manifest,spine,itemrefptr,itemptr ;
+    gboolean errorflag = FALSE;
+
+    gchar* relativepath ;
+    GString* absolutepath = g_string_new(NULL);
+
+    if ( open_xml_document(content_uri) == FALSE )
+    {
+        g_set_error_literal(error,
+                            EV_DOCUMENT_ERROR,
+                            EV_DOCUMENT_ERROR_INVALID,
+                            _("could not parse content manifest"));
+    
+        return FALSE ;
+    }
+    if ( set_xml_root_node((xmlChar*)"package") == FALSE)  {
+
+        g_set_error_literal(error,
+                            EV_DOCUMENT_ERROR,
+                            EV_DOCUMENT_ERROR_INVALID,
+                            _("content file is invalid"));    
+        return FALSE ;
+    }
+
+    if ( ( spine = xml_get_pointer_to_node((xmlChar*)"spine",NULL,NULL) )== NULL )  
+    {
+         g_set_error_literal(error,
+                            EV_DOCUMENT_ERROR,
+                            EV_DOCUMENT_ERROR_INVALID,
+                            _("epub file has no spine"));    
+        return FALSE ;
+    }
+    
+    if ( ( manifest = xml_get_pointer_to_node((xmlChar*)"manifest",NULL,NULL) )== NULL )  
+    {
+         g_set_error_literal(error,
+                            EV_DOCUMENT_ERROR,
+                            EV_DOCUMENT_ERROR_INVALID,
+                            _("epub file has no manifest"));    
+        return FALSE ;
+    }
+
+    xmlretval = NULL ;
+
+    /*Get first instance of itemref from the spine*/
+    xml_parse_children_of_node(spine,(xmlChar*)"itemref",NULL,NULL);
+    
+    if ( xmlretval != NULL )
+        itemrefptr = xmlretval ;
+    else
+    {
+        errorflag=TRUE;
+    }
+    /*Parse the spine for remaining itemrefs*/
+    do
+    {
+        /*for the first time that we enter the loop, if errorflag is set we break*/
+        if ( errorflag )
+        {
+            break;
+        }
+        if ( xmlStrcmp(itemrefptr->name,(xmlChar*)"itemref") == 0)
+        {    
+            contentListNode* newnode = g_malloc0(sizeof(newnode));    
+            newnode->key = (gchar*)xml_get_data_from_node(itemrefptr,XML_ATTRIBUTE,(xmlChar*)"idref");
+                   if ( newnode->key == NULL )
+            {
+                errorflag =TRUE;    
+                break;
+            }
+            xmlretval=NULL ;
+            xml_parse_children_of_node(manifest,(xmlChar*)"item",(xmlChar*)"id",(xmlChar*)newnode->key);
+            
+            if ( xmlretval != NULL )
+            {
+                itemptr = xmlretval ;
+            }
+            else
+            {
+                errorflag=TRUE;
+                break;
+            }
+            relativepath = (gchar*)xml_get_data_from_node(itemptr,XML_ATTRIBUTE,(xmlChar*)"href");
+            g_string_assign(absolutepath,documentdir);
+            g_string_append_printf(absolutepath,"/%s",relativepath);
+            newnode->value = g_filename_to_uri(absolutepath->str,NULL,&err);
+            if ( newnode->value == NULL )
+            {
+                errorflag =TRUE;    
+                break;
+            }
+			
+			newnode->index = indexcounter++ ;
+
+            newlist = g_list_prepend(newlist,newnode);
+        }
+        itemrefptr = itemrefptr->next ;
+    }
+    while ( itemrefptr != NULL );
+
+    if ( errorflag )
+    {
+        if ( err )
+        {
+            g_propagate_error(error,err);
+        }
+        else
+        {            
+            g_set_error_literal(error,
+                                EV_DOCUMENT_ERROR,
+                                EV_DOCUMENT_ERROR_INVALID,
+                                _("Could not set up document tree for loading, some files missing"));
+        }
+        /*free any nodes that were set up and return empty*/
+        g_string_free(absolutepath,TRUE);
+        g_list_free_full(newlist,(GDestroyNotify)free_tree_nodes);
+        return NULL ;
+    }
+	newlist = g_list_reverse(newlist);
+    g_string_free(absolutepath,TRUE);
+	xml_free_doc();
+    return newlist ;
+
+}
+
+/* Callback function to free the contentlist.*/
+static void
+free_tree_nodes(gpointer data)
+{
+    contentListNode* dataptr = data ;
+    g_free(dataptr->value);
+    g_free(dataptr->key);
+    g_free(dataptr);
+}
+
+static void
+free_link_nodes(gpointer data)
+{
+    linknode* dataptr = data ;
+    g_free(dataptr->pagelink);
+    g_free(dataptr->linktext);
+
+	if (dataptr->children) {
+		g_list_free_full(dataptr->children,(GDestroyNotify)free_link_nodes);
+	}
+    g_free(dataptr);
+}
+
+static gchar*
+get_toc_file_name(gchar *containeruri)
+{
+	gchar *containerfilename = g_filename_from_uri(containeruri,NULL,NULL);
+
+	open_xml_document(containerfilename);
+
+	set_xml_root_node(NULL);
+
+	xmlNodePtr manifest = xml_get_pointer_to_node((xmlChar*)"manifest",NULL,NULL);
+	xmlNodePtr spine = xml_get_pointer_to_node((xmlChar*)"spine",NULL,NULL);
+
+	xmlChar *ncx = xml_get_data_from_node(spine,XML_ATTRIBUTE,(xmlChar*)"toc");
+
+    /*In an epub3, there is sometimes no toc, and we need to then use the nav file for this.*/
+    if (ncx == NULL) {
+        return NULL;
+    }
+
+	xmlretval = NULL;
+	xml_parse_children_of_node(manifest,(xmlChar*)"item",(xmlChar*)"id",ncx);
+
+	gchar* tocfilename = (gchar*)xml_get_data_from_node(xmlretval,XML_ATTRIBUTE,(xmlChar*)"href");
+	xml_free_doc();
+
+	return tocfilename;
+}
+
+static gchar*
+epub_document_get_nav_file(gchar* containeruri)
+{
+    open_xml_document(containeruri);
+    set_xml_root_node(NULL);
+    xmlNodePtr manifest = xml_get_pointer_to_node((xmlChar*)"manifest",NULL,NULL);
+    xmlretval = NULL;
+    xml_parse_children_of_node(manifest,(xmlChar*)"item",(xmlChar*)"properties",(xmlChar*)"nav");
+
+    gchar *uri = (gchar*)xml_get_data_from_node(xmlretval,XML_ATTRIBUTE, (xmlChar*)"href");
+
+    xml_free_doc();
+    return uri;
+}
+
+static GList*
+get_child_list(xmlNodePtr ol,gchar* documentdir)
+{
+    GList *childlist = NULL;
+    xmlNodePtr li = ol->xmlChildrenNode;
+
+    while (li != NULL) {
+		if (xmlStrcmp(li->name,(xmlChar*)"li")) {
+			li = li->next;
+			continue;
+		}
+        xmlNodePtr children = li->xmlChildrenNode;
+        linknode *newlinknode = g_new0(linknode, 1);
+        while (children != NULL) {
+            if ( !xmlStrcmp(children->name,(xmlChar*)"a")) {
+                newlinknode->linktext = (gchar*)xml_get_data_from_node(children,XML_KEYWORD,NULL);
+                gchar* filename = (gchar*)xml_get_data_from_node(children,XML_ATTRIBUTE,(xmlChar*)"href");
+				gchar *filepath = g_strdup_printf("%s/%s",documentdir,filename);
+				newlinknode->pagelink = g_filename_to_uri(filepath,NULL,NULL);
+				g_free(filename);
+				g_free(filepath);
+                newlinknode->children = NULL;
+                childlist = g_list_prepend(childlist,newlinknode);
+            }
+            else if ( !xmlStrcmp(children->name,(xmlChar*)"ol")){
+                newlinknode->children = get_child_list(children,documentdir);
+            }
+
+			children = children->next;
+        }
+
+        li = li->next;
+    }
+
+    return g_list_reverse(childlist);
+}
+
+/* For an epub3 style navfile */
+static GList*
+setup_index_from_navfile(gchar *tocpath)
+{
+    GList *index = NULL;
+    open_xml_document(tocpath);
+    set_xml_root_node(NULL);
+    xmlNodePtr nav = xml_get_pointer_to_node((xmlChar*)"nav",(xmlChar*)"id",(xmlChar*)"toc");
+    xmlretval=NULL;
+    xml_parse_children_of_node(nav,(xmlChar*)"ol", NULL,NULL);
+	gchar *navdirend = g_strrstr(tocpath,"/");
+	gchar *navdir = g_malloc0(strlen(tocpath));
+	gchar *reader = tocpath;
+	gchar *writer = navdir;
+
+	while (reader != navdirend) {
+		(*writer) = (*reader) ;
+		writer++;reader++;
+	}
+    index = get_child_list(xmlretval,navdir);
+	g_free(navdir);
+    xml_free_doc();
+    return index;
+}
+
+static GList*
+setup_document_index(EpubDocument *epub_document,gchar *containeruri) 
+{
+    GString *tocpath = g_string_new(epub_document->documentdir);
+    gchar *tocfilename = get_toc_file_name(containeruri);
+    GList *index = NULL;
+
+    if (tocfilename == NULL) {
+        tocfilename = epub_document_get_nav_file(containeruri);
+        g_string_append_printf (tocpath,"/%s",tocfilename);
+        index = setup_index_from_navfile(tocpath->str);
+        g_string_free(tocpath,TRUE);
+        return index;
+    }
+
+    g_string_append_printf (tocpath,"/%s",tocfilename);
+    GString *pagelink;
+    open_xml_document(tocpath->str);
+    g_string_free(tocpath,TRUE);
+    set_xml_root_node((xmlChar*)"ncx");
+
+	xmlNodePtr docTitle = xml_get_pointer_to_node((xmlChar*)"docTitle",NULL,NULL);
+	xmlretval = NULL;
+	xml_parse_children_of_node(docTitle,(xmlChar*)"text",NULL,NULL);
+
+	while (epub_document->docTitle == NULL && xmlretval != NULL) {
+		epub_document->docTitle = (gchar*)xml_get_data_from_node(xmlretval,XML_KEYWORD,NULL);
+		xmlretval = xmlretval->next;
+	}
+    xmlNodePtr navMap = xml_get_pointer_to_node((xmlChar*)"navMap",NULL,NULL);
+	xmlretval = NULL;
+    xml_parse_children_of_node(navMap,(xmlChar*)"navPoint",NULL,NULL);
+
+    xmlNodePtr navPoint = xmlretval;
+
+    do {
+
+        if ( !xmlStrcmp(navPoint->name,(xmlChar*)"navPoint")) {
+    		xmlretval = NULL;
+    		xml_parse_children_of_node(navPoint,(xmlChar*)"navLabel",NULL,NULL);
+    		xmlNodePtr navLabel = xmlretval;
+    		xmlretval = NULL;
+    		gchar *fragment=NULL,*end=NULL;
+    		GString *uri = NULL;
+
+    		xml_parse_children_of_node(navLabel,(xmlChar*)"text",NULL,NULL);
+            linknode *newnode = g_new0(linknode,1);
+    		newnode->linktext = NULL;
+    		while (newnode->linktext == NULL) {
+        		newnode->linktext = (gchar*)xml_get_data_from_node(xmlretval,XML_KEYWORD,NULL);
+    			xmlretval = xmlretval->next;
+    		}
+    		xmlretval = NULL;
+            xml_parse_children_of_node(navPoint,(xmlChar*)"content",NULL,NULL);
+            pagelink = g_string_new(epub_document->documentdir);
+            newnode->pagelink = (gchar*)xml_get_data_from_node(xmlretval,XML_ATTRIBUTE,(xmlChar*)"src");
+            g_string_append_printf(pagelink,"/%s",newnode->pagelink);
+            xmlFree(newnode->pagelink);
+
+            if ((end = g_strrstr(pagelink->str,"#")) != NULL) {
+            	fragment = g_strdup(g_strrstr(pagelink->str,"#"));
+            	*end = '\0';
+            }
+            uri = g_string_new(g_filename_to_uri(pagelink->str,NULL,NULL));
+     		g_string_free(pagelink,TRUE);
+     		       
+            if (fragment) {
+            	g_string_append(uri,fragment);
+            }
+
+            newnode->pagelink = g_strdup(uri->str);
+            g_string_free(uri,TRUE);
+            index = g_list_prepend(index,newnode);
+        }
+        
+        navPoint = navPoint->next;
+
+    } while(navPoint != NULL);
+
+	xml_free_doc();
+    
+    return g_list_reverse(index);
+}
+
+static EvDocumentInfo*
+epub_document_get_info(EvDocument *document)
+{
+	EpubDocument *epub_document = EPUB_DOCUMENT(document);
+	GError *error = NULL ;
+	gchar* infofile ;
+	xmlNodePtr metanode ;
+	GString* buffer ;
+	gchar* archive_dir = epub_document->tmp_archive_dir;
+	GString* containerpath = g_string_new(epub_document->tmp_archive_dir);
+	g_string_append_printf(containerpath,"/META-INF/container.xml");
+	gchar* containeruri = g_filename_to_uri(containerpath->str,NULL,&error);
+	if ( error )
+	{
+		return NULL ;
+	}
+	gchar* uri = get_uri_to_content (containeruri,&error,epub_document);
+	if ( error )
+	{
+		return NULL ;
+	}
+	EvDocumentInfo* epubinfo = g_new0 (EvDocumentInfo, 1);
+
+	epubinfo->fields_mask = EV_DOCUMENT_INFO_TITLE |
+			    EV_DOCUMENT_INFO_FORMAT |
+			    EV_DOCUMENT_INFO_AUTHOR |
+			    EV_DOCUMENT_INFO_SUBJECT |
+			    EV_DOCUMENT_INFO_KEYWORDS |
+			    EV_DOCUMENT_INFO_LAYOUT |
+			    EV_DOCUMENT_INFO_CREATOR |
+			    EV_DOCUMENT_INFO_LINEARIZED |
+				EV_DOCUMENT_INFO_PERMISSIONS |
+			    EV_DOCUMENT_INFO_N_PAGES ;
+
+	infofile = g_filename_from_uri(uri,NULL,&error);
+	if ( error )
+		return epubinfo;
+	
+	open_xml_document(infofile);
+
+	set_xml_root_node((xmlChar*)"package");
+
+	metanode = xml_get_pointer_to_node((xmlChar*)"title",NULL,NULL);
+	if ( metanode == NULL )
+	  epubinfo->title = NULL ;
+	else
+	  epubinfo->title = (char*)xml_get_data_from_node(metanode,XML_KEYWORD,NULL);
+	
+	metanode = xml_get_pointer_to_node((xmlChar*)"creator",NULL,NULL);
+	if ( metanode == NULL )
+	  epubinfo->author = g_strdup("unknown");
+	else
+	  epubinfo->author = (char*)xml_get_data_from_node(metanode,XML_KEYWORD,NULL);
+
+	metanode = xml_get_pointer_to_node((xmlChar*)"subject",NULL,NULL);
+	if ( metanode == NULL )
+	   epubinfo->subject = g_strdup("unknown");
+	else
+	   epubinfo->subject = (char*)xml_get_data_from_node(metanode,XML_KEYWORD,NULL);
+
+	buffer = g_string_new((gchar*)xml_get_data_from_node (xmlroot,XML_ATTRIBUTE,(xmlChar*)"version"));
+	g_string_prepend(buffer,"epub ");
+	epubinfo->format = g_strdup(buffer->str);
+	
+	/*FIXME: Add more of these as you write the corresponding modules*/
+	
+	epubinfo->layout = EV_DOCUMENT_LAYOUT_SINGLE_PAGE;
+
+	metanode = xml_get_pointer_to_node((xmlChar*)"publisher",NULL,NULL);
+	if ( metanode == NULL )
+	   epubinfo->creator = g_strdup("unknown");
+	else
+	   epubinfo->creator = (char*)xml_get_data_from_node(metanode,XML_KEYWORD,NULL);
+
+	/* number of pages */
+	epubinfo->n_pages = epub_document_get_n_pages(document);
+
+	/*Copying*/
+	epubinfo->permissions = EV_DOCUMENT_PERMISSIONS_OK_TO_COPY;
+	/*TODO : Add a function to get date*/
+	g_free(uri);
+	g_string_free(containerpath,TRUE);
+	g_string_free(buffer,TRUE);
+	
+	if (xmldocument)
+		xml_free_doc();
+	return epubinfo ;
+}
+
+static EvPage*
+epub_document_get_page(EvDocument *document,
+                       gint index)
+{
+	EpubDocument *epub_document = EPUB_DOCUMENT(document);
+	EvPage* page = ev_page_new(index);
+	contentListNode *listptr = g_list_nth_data (epub_document->contentList,index);
+	page->backend_page = g_strdup(listptr->value);
+	return page ;
+}
+
+static void
+change_to_night_sheet(contentListNode *nodedata,gpointer user_data)
+{
+    gchar *filename = g_filename_from_uri(nodedata->value,NULL,NULL);
+    open_xml_document(filename);
+    set_xml_root_node(NULL);
+    xmlNodePtr head =xml_get_pointer_to_node((xmlChar*)"head",NULL,NULL);
+	gchar *class = NULL;
+    xmlretval = NULL;
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"rel",(xmlChar*)"stylesheet");
+
+    xmlNodePtr day = xmlretval;
+	if ( (class = (gchar*)xml_get_data_from_node(day,XML_ATTRIBUTE,(xmlChar*)"class")) == NULL) {
+		xmlSetProp(day,(xmlChar*)"class",(xmlChar*)"day");
+	}
+	g_free(class);
+    xmlSetProp(day,(xmlChar*)"rel",(xmlChar*)"alternate stylesheet");
+    xmlretval = NULL;
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"class",(xmlChar*)"night");
+    xmlSetProp(xmlretval,(xmlChar*)"rel",(xmlChar*)"stylesheet");
+    xmlSaveFormatFile (filename, xmldocument, 0);
+    xml_free_doc();
+    g_free(filename);
+}
+
+static void
+change_to_day_sheet(contentListNode *nodedata,gpointer user_data)
+{
+    gchar *filename = g_filename_from_uri(nodedata->value,NULL,NULL);
+    open_xml_document(filename);
+    set_xml_root_node(NULL);
+    xmlNodePtr head =xml_get_pointer_to_node((xmlChar*)"head",NULL,NULL);
+
+    xmlretval = NULL;
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"rel",(xmlChar*)"stylesheet");
+
+    xmlNodePtr day = xmlretval;
+    xmlSetProp(day,(xmlChar*)"rel",(xmlChar*)"alternate stylesheet");
+
+    xmlretval = NULL;
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"class",(xmlChar*)"day");
+    xmlSetProp(xmlretval,(xmlChar*)"rel",(xmlChar*)"stylesheet");
+    xmlSaveFormatFile (filename, xmldocument, 0);
+    xml_free_doc();
+    g_free(filename);
+}
+
+static gchar*
+epub_document_get_alternate_stylesheet(gchar *docuri)
+{
+    gchar *filename = g_filename_from_uri(docuri,NULL,NULL);
+    open_xml_document(filename);
+
+    set_xml_root_node(NULL);
+
+    xmlNodePtr head= xml_get_pointer_to_node((xmlChar*)"head",NULL,NULL);
+
+    xmlretval = NULL;
+
+    xml_parse_children_of_node(head,(xmlChar*)"link",(xmlChar*)"class",(xmlChar*)"night");
+
+    if (xmlretval != NULL) {
+        return (gchar*)xml_get_data_from_node(xmlretval,XML_ATTRIBUTE,(xmlChar*)"href");
+    }
+    g_free(filename);
+    xml_free_doc();
+    return NULL;
+}
+
+static void
+add_night_sheet(contentListNode *listdata,gchar *sheet)
+{
+    gchar *sheeturi = g_filename_to_uri(sheet,NULL,NULL);
+    open_xml_document(listdata->value);
+
+    set_xml_root_node(NULL);
+    xmlNodePtr head = xml_get_pointer_to_node((xmlChar*)"head",NULL,NULL);
+    
+    xmlNodePtr link = xmlNewTextChild(head,NULL,(xmlChar*)"link",NULL);
+    xmlAttrPtr href = xmlNewProp(link,(xmlChar*)"href",(xmlChar*)sheeturi);
+    xmlAttrPtr rel = xmlNewProp(link,(xmlChar*)"rel",(xmlChar*)"alternate stylesheet");
+    xmlAttrPtr class =  xmlNewProp(link,(xmlChar*)"class",(xmlChar*)"night");
+
+    xmlSaveFormatFile (listdata->value, xmldocument, 0);
+    xml_free_doc();
+    g_free(sheeturi);
+}
+
+static void
+epub_document_check_add_night_sheet(EvDocument *document)
+{
+    EpubDocument *epub_document = EPUB_DOCUMENT(document);
+
+    g_return_if_fail(EPUB_IS_DOCUMENT(epub_document));
+
+    /*
+     * We'll only check the first page for a supplied night mode stylesheet.
+     * Odds are, if this one has it, all others have it too.
+     */
+	contentListNode *node = epub_document->contentList->data;
+    gchar* stylesheetfilename = epub_document_get_alternate_stylesheet((gchar*)node->value) ;
+
+    if (stylesheetfilename == NULL) {
+        gchar *style = "body {color:rgb(255,255,255);\
+                        background-color:rgb(0,0,0);\
+                        text-align:justify;\
+                        line-spacing:1.8;\
+                        margin-top:0px;\
+                        margin-bottom:4px;\
+                        margin-right:50px;\
+                        margin-left:50px;\
+                        text-indent:3em;}\
+                        h1, h2, h3, h4, h5, h6\
+                        {color:white;\
+                        text-align:center;\
+                        font-style:italic;\
+                        font-weight:bold;}";
+
+        gchar *csspath = g_strdup_printf("%s/atrilnightstyle.css",epub_document->documentdir);
+
+        
+        GFile *styles = g_file_new_for_path (csspath);
+        GOutputStream *outstream = (GOutputStream*)g_file_create(styles,G_FILE_CREATE_PRIVATE,NULL,NULL);
+        if ( g_output_stream_write((GOutputStream*)outstream,style,strlen(style),NULL,NULL) == -1 )
+        {
+            return ;
+        }
+        g_output_stream_close((GOutputStream*)outstream,NULL,NULL);
+        g_object_unref(styles) ;
+        g_object_unref(outstream) ;
+        //add this stylesheet to each document, for later.
+        g_list_foreach(epub_document->contentList,(GFunc)add_night_sheet,csspath);
+        g_free(csspath);
+    }
+    g_free(stylesheetfilename);
+}
+
+static void
+epub_document_toggle_night_mode(EvDocument *document,gboolean night)
+{
+    EpubDocument *epub_document = EPUB_DOCUMENT(document);
+
+    g_return_if_fail(EPUB_IS_DOCUMENT(epub_document));
+    if (night) 
+        g_list_foreach(epub_document->contentList,(GFunc)change_to_night_sheet,NULL);
+    else
+        g_list_foreach(epub_document->contentList,(GFunc)change_to_day_sheet,NULL);
+}
+
+static gchar*
+epub_document_set_document_title(gchar *containeruri)
+{
+	gchar *contentfilename = g_filename_from_uri(containeruri, NULL, NULL);
+	open_xml_document(containeruri);
+	gchar *doctitle;
+	set_xml_root_node(NULL);
+
+	xmlNodePtr title = xml_get_pointer_to_node((xmlChar*)"title",NULL,NULL);
+
+	doctitle = (gchar*)xml_get_data_from_node(title, XML_KEYWORD, NULL);
+	xml_free_doc();
+
+	return doctitle;
+}
+
+static void
+page_set_function(linknode *Link, GList *contentList)
+{
+	GList *listiter = contentList;
+	contentListNode *pagedata;
+
+	guint flag=0;
+	while (!flag) {
+		pagedata = listiter->data;
+		if (link_present_on_page(Link->pagelink, pagedata->value)) {
+			flag=1;
+			Link->page = pagedata->index - 1;
+		}
+		listiter = listiter->next;
+	}
+
+	if (Link->children) {
+		g_list_foreach(Link->children,(GFunc)page_set_function,contentList);
+	}
+}
+
+static void
+epub_document_set_index_pages(GList *index,GList *contentList)
+{
+	g_list_foreach(index,(GFunc)page_set_function,contentList);
+}
+
+
+static void
+add_mathjax_script_node_to_file(gchar *filename, gchar *data)
+{
+	xmlDocPtr mathdocument = xmlParseFile (filename);
+	xmlNodePtr mathroot = xmlDocGetRootElement(mathdocument);
+
+	if (mathroot == NULL)
+		return;
+
+	xmlNodePtr head = mathroot->children;
+
+	while(head != NULL) {
+		if (!xmlStrcmp(head->name,(xmlChar*)"head")) {
+			break;
+		}
+		head = head->next;
+	}
+
+	if (xmlStrcmp(head->name,(xmlChar*)"head")) {
+		return ;
+	}
+
+	xmlNodePtr script = xmlNewTextChild (head,NULL,(xmlChar*)"script",(xmlChar*)"");
+	xmlNewProp(script,(xmlChar*)"type",(xmlChar*)"text/javascript");
+	xmlNewProp(script,(xmlChar*)"src",(xmlChar*)data);
+
+	xmlSaveFormatFile(filename, mathdocument, 0);
+	xmlFreeDoc (mathdocument);
+}
+
+static void
+epub_document_add_mathJax(gchar* containeruri,gchar* documentdir)
+{
+	gchar *containerfilename= g_filename_from_uri(containeruri,NULL,NULL);
+	gchar *backenddir = ev_backends_manager_get_backends_dir();
+	GString *mathjaxdir = g_string_new(backenddir);
+	g_string_append_printf(mathjaxdir,"/epub/MathJax");
+
+	gchar *mathjaxref = g_filename_to_uri(mathjaxdir->str,NULL,NULL);
+	gchar *nodedata = g_strdup_printf("%s/MathJax.js?config=TeX-AMS-MML_SVG",mathjaxref);
+
+	open_xml_document(containerfilename);
+	set_xml_root_node(NULL);
+	xmlNodePtr manifest = xml_get_pointer_to_node((xmlChar*)"manifest",NULL,NULL);
+
+	xmlNodePtr item = manifest->xmlChildrenNode;
+
+	while (item != NULL) {
+		if (xmlStrcmp(item->name,(xmlChar*)"item")) {
+			item = item->next;
+			continue;
+		}
+
+		xmlChar *mathml = xml_get_data_from_node(item,XML_ATTRIBUTE, (xmlChar*)"properties");
+
+		if (mathml != NULL &&
+		    !xmlStrcmp(mathml, (xmlChar*)"mathml") ) {
+			gchar *href = (gchar*)xml_get_data_from_node(item, XML_ATTRIBUTE, (xmlChar*)"href");
+			gchar *filename = g_strdup_printf("%s/%s",documentdir,href);
+
+			add_mathjax_script_node_to_file(filename,nodedata);
+			g_free(href);
+			g_free(filename);
+		}
+		g_free(mathml);
+		item = item->next;
+	}
+	xml_free_doc();
+	g_free(backenddir);
+	g_free(mathjaxref);
+	g_free(containerfilename);
+	g_free(nodedata);
+	g_string_free(mathjaxdir,TRUE);
+}
+
+static gboolean
+epub_document_load (EvDocument* document,
+                    const char* uri,
+                    GError**    error)
+{
+	EpubDocument *epub_document = EPUB_DOCUMENT(document);
+	GError* err = NULL ;
+	gchar* containeruri ;
+	GString *containerpath ;
+	gchar* contentOpfUri ;
+	if ( check_mime_type (uri,&err) == FALSE )
+	{
+		/*Error would've been set by the function*/
+		g_propagate_error(error,err);
+		return FALSE;
+	}
+
+	extract_epub_from_container (uri,epub_document,&err);
+
+	if ( err )
+	{
+		g_propagate_error( error,err );
+		return FALSE;
+	}
+
+	/*FIXME : can this be different, ever?*/
+	containerpath = g_string_new(epub_document->tmp_archive_dir);
+	g_string_append_printf(containerpath,"/META-INF/container.xml");
+	containeruri = g_filename_to_uri(containerpath->str,NULL,&err);
+
+	if ( err )
+	{
+		g_propagate_error(error,err);
+		return FALSE;
+	}
+	contentOpfUri = get_uri_to_content (containeruri,&err,epub_document);
+
+	if ( contentOpfUri == NULL )
+	{
+		g_propagate_error(error,err);
+		return FALSE;
+	}
+
+	epub_document->docTitle = epub_document_set_document_title(contentOpfUri);
+	epub_document->index = setup_document_index(epub_document,contentOpfUri);
+		
+	epub_document->contentList = setup_document_content_list (contentOpfUri,&err,epub_document->documentdir);
+
+	epub_document_set_index_pages(epub_document->index, epub_document->contentList);
+	epub_document_add_mathJax(contentOpfUri,epub_document->documentdir);
+	if ( epub_document->contentList == NULL )
+	{
+		g_propagate_error(error,err);
+		return FALSE;
+	}
+
+	return TRUE ;
+}
+
+static void
+epub_document_init (EpubDocument *epub_document)
+{
+    epub_document->archivename = NULL ;
+    epub_document->tmp_archive_dir = NULL ;
+    epub_document->contentList = NULL ;
+	epub_document->documentdir = NULL;
+	epub_document->index = NULL;
+	epub_document->docTitle = NULL;
+}
+
+static void
+epub_document_finalize (GObject *object)
+{
+	EpubDocument *epub_document = EPUB_DOCUMENT (object);
+	
+	if (epub_document->epubDocument != NULL) {
+		if (epub_remove_temporary_dir (epub_document->tmp_archive_dir) == -1)
+			g_warning (_("There was an error deleting “%s”."),
+				   epub_document->tmp_archive_dir);
+	}
+	
+	if ( epub_document->contentList ) {
+            g_list_free_full(epub_document->contentList,(GDestroyNotify)free_tree_nodes);
+			epub_document->contentList = NULL;
+	}
+
+	if (epub_document->index) {
+		g_list_free_full(epub_document->index,(GDestroyNotify)free_link_nodes);
+		epub_document->index = NULL;
+	}
+
+	if ( epub_document->tmp_archive_dir) {
+		g_free (epub_document->tmp_archive_dir);
+		epub_document->tmp_archive_dir = NULL;
+	}
+
+	if (epub_document->docTitle) {
+		g_free(epub_document->docTitle);
+		epub_document->docTitle = NULL;
+	}
+	if ( epub_document->archivename) {
+		g_free (epub_document->archivename);
+		epub_document->archivename = NULL;
+	}
+	if ( epub_document->documentdir) {
+		g_free (epub_document->documentdir);
+		epub_document->documentdir = NULL;
+	}
+	G_OBJECT_CLASS (epub_document_parent_class)->finalize (object);
+}
+
+static void
+epub_document_class_init (EpubDocumentClass *klass)
+{
+	GObjectClass    *gobject_class = G_OBJECT_CLASS (klass);
+	EvDocumentClass *ev_document_class = EV_DOCUMENT_CLASS (klass);
+	
+	gobject_class->finalize = epub_document_finalize;
+	ev_document_class->load = epub_document_load;
+	ev_document_class->save = epub_document_save;
+	ev_document_class->get_n_pages = epub_document_get_n_pages;
+	ev_document_class->get_info = epub_document_get_info; 
+	ev_document_class->get_page = epub_document_get_page;
+	ev_document_class->toggle_night_mode = epub_document_toggle_night_mode;
+    ev_document_class->check_add_night_sheet = epub_document_check_add_night_sheet;
+}
\ No newline at end of file