Podstawowy DiffHandler.
[redakcja.git] / apps / api / handlers / library_handlers.py
index 591d4e9..9751fef 100644 (file)
@@ -1,33 +1,73 @@
 # -*- encoding: utf-8 -*-
 # -*- encoding: utf-8 -*-
+import os.path
+
+import logging
+log = logging.getLogger('platforma.api.library')
 
 __author__= "Łukasz Rekucki"
 __date__ = "$2009-09-25 15:49:50$"
 __doc__ = "Module documentation."
 
 from piston.handler import BaseHandler, AnonymousBaseHandler
 
 __author__= "Łukasz Rekucki"
 __date__ = "$2009-09-25 15:49:50$"
 __doc__ = "Module documentation."
 
 from piston.handler import BaseHandler, AnonymousBaseHandler
+from django.http import HttpResponse
 
 import re
 from datetime import date
 
 from django.core.urlresolvers import reverse
 from django.utils import simplejson as json
 
 import re
 from datetime import date
 
 from django.core.urlresolvers import reverse
 from django.utils import simplejson as json
+from django.db import IntegrityError
 
 import librarian
 import librarian.html
 
 import librarian
 import librarian.html
-from librarian import dcparser
+import difflib
+from librarian import dcparser, parser
 
 
-from wlrepo import RevisionNotFound, LibraryException, DocumentAlreadyExists
-from explorer.models import PullRequest
+from wlrepo import *
+from api.models import PullRequest
+from explorer.models import GalleryForDocument
 
 # internal imports
 import api.forms as forms
 import api.response as response
 
 # internal imports
 import api.forms as forms
 import api.response as response
-from api.utils import validate_form, hglibrary
-from api.models import PartCache
+from api.utils import validate_form, hglibrary, natural_order
+from api.models import PartCache, PullRequest
+
+#
+import settings
+
+
+def is_prq(username):
+    return username.startswith('$prq-')
+
+def prq_for_user(username):
+    try:
+        return PullRequest.objects.get(id=int(username[5:]))
+    except:
+        return None
+
+def check_user(request, user):
+    log.info("user: %r, perm: %r" % (request.user, request.user.get_all_permissions()) )
+    #pull request
+    if is_prq(user):
+        if not request.user.has_perm('api.view_prq'):
+            yield response.AccessDenied().django_response({
+                'reason': 'access-denied',
+                'message': "You don't have enough priviliges to view pull requests."
+            })
+    # other users
+    elif request.user.username != user:
+        if not request.user.has_perm('api.view_other_document'):
+            yield response.AccessDenied().django_response({
+                'reason': 'access-denied',
+                'message': "You don't have enough priviliges to view other people's document."
+            })
+    pass
 
 #
 # Document List Handlers
 #
 
 #
 # Document List Handlers
 #
+# TODO: security check
 class BasicLibraryHandler(AnonymousBaseHandler):
     allowed_methods = ('GET',)
 
 class BasicLibraryHandler(AnonymousBaseHandler):
     allowed_methods = ('GET',)
 
@@ -37,10 +77,11 @@ class BasicLibraryHandler(AnonymousBaseHandler):
         document_list = [{
             'url': reverse('document_view', args=[docid]),
             'name': docid } for docid in lib.documents() ]
         document_list = [{
             'url': reverse('document_view', args=[docid]),
             'name': docid } for docid in lib.documents() ]
-
         return {'documents' : document_list}
         
         return {'documents' : document_list}
         
-
+#
+# This handler controlls the document collection
+#
 class LibraryHandler(BaseHandler):
     allowed_methods = ('GET', 'POST')
     anonymous = BasicLibraryHandler
 class LibraryHandler(BaseHandler):
     allowed_methods = ('GET', 'POST')
     anonymous = BasicLibraryHandler
@@ -51,34 +92,37 @@ class LibraryHandler(BaseHandler):
 
         documents = {}
         
 
         documents = {}
         
-        for docid in lib.documents():
+        for docid in lib.documents():            
             documents[docid] = {
                 'url': reverse('document_view', args=[docid]),
                 'name': docid,
                 'parts': []
             }
 
             documents[docid] = {
                 'url': reverse('document_view', args=[docid]),
                 'name': docid,
                 'parts': []
             }
 
-        related = PartCache.objects.defer('part_id')\
+        parts = PartCache.objects.defer('part_id')\
             .values_list('part_id', 'document_id').distinct()
             .values_list('part_id', 'document_id').distinct()
+       
+        document_tree = dict(documents)
 
 
-        for part, docid in related:
+        for part, docid in parts:
             # this way, we won't display broken links
             if not documents.has_key(part):
             # this way, we won't display broken links
             if not documents.has_key(part):
+                log.info("NOT FOUND: %s", part)
                 continue
 
                 continue
 
-            child = documents[part]
             parent = documents[docid]
             parent = documents[docid]
+            child = documents[part]
+
+            # not top-level anymore
+            document_tree.pop(part)
+            parent['parts'].append(child)
+        
+        for doc in documents.itervalues():
+            doc['parts'].sort(key=natural_order(lambda d: d['name']))
             
             
-            if isinstance(parent, dict): # the parent is top-level
-                documents.pop(part)                
-                parent['parts'].append(child)
-                documents[part] = child['parts']
-            else: # not top-level
-                parent.append(child)
-            
-        return {
-            'documents': [d for d in documents.itervalues() if isinstance(d, dict)]
-        }
+        return {'documents': sorted(document_tree.itervalues(),
+            key=natural_order(lambda d: d['name']) ) }
+
 
     @validate_form(forms.DocumentUploadForm, 'POST')
     @hglibrary
 
     @validate_form(forms.DocumentUploadForm, 'POST')
     @hglibrary
@@ -90,6 +134,9 @@ class LibraryHandler(BaseHandler):
         else:            
             data = request.FILES['ocr_file'].read().decode('utf-8')
 
         else:            
             data = request.FILES['ocr_file'].read().decode('utf-8')
 
+        if data is None:
+            return response.BadRequest().django_response('You must pass ocr_data or ocr_file.')
+
         if form.cleaned_data['generate_dc']:
             data = librarian.wrap_text(data, unicode(date.today()))
 
         if form.cleaned_data['generate_dc']:
             data = librarian.wrap_text(data, unicode(date.today()))
 
@@ -98,17 +145,17 @@ class LibraryHandler(BaseHandler):
         try:
             lock = lib.lock()            
             try:
         try:
             lock = lib.lock()            
             try:
-                print "DOCID", docid                
+                log.info("DOCID %s", docid)
                 doc = lib.document_create(docid)
                 # document created, but no content yet
                 doc = lib.document_create(docid)
                 # document created, but no content yet
-
                 try:
                     doc = doc.quickwrite('xml', data.encode('utf-8'),
                         '$AUTO$ XML data uploaded.', user=request.user.username)
                 except Exception,e:
                 try:
                     doc = doc.quickwrite('xml', data.encode('utf-8'),
                         '$AUTO$ XML data uploaded.', user=request.user.username)
                 except Exception,e:
+                    import traceback
                     # rollback branch creation
                     lib._rollback()
                     # rollback branch creation
                     lib._rollback()
-                    raise LibraryException("Exception occured:" + repr(e))
+                    raise LibraryException(traceback.format_exc())
 
                 url = reverse('document_view', args=[doc.id])
 
 
                 url = reverse('document_view', args=[doc.id])
 
@@ -121,12 +168,16 @@ class LibraryHandler(BaseHandler):
             finally:
                 lock.release()
         except LibraryException, e:
             finally:
                 lock.release()
         except LibraryException, e:
-            return response.InternalError().django_response(\
-                {'exception': repr(e) })                
+            import traceback
+            return response.InternalError().django_response({
+                "reason": traceback.format_exc()
+            })
         except DocumentAlreadyExists:
             # Document is already there
         except DocumentAlreadyExists:
             # Document is already there
-            return response.EntityConflict().django_response(\
-                {"reason": "Document %s already exists." % docid})
+            return response.EntityConflict().django_response({
+                "reason": "already-exists",
+                "message": "Document already exists." % docid
+            })
 
 #
 # Document Handlers
 
 #
 # Document Handlers
@@ -143,14 +194,34 @@ class BasicDocumentHandler(AnonymousBaseHandler):
 
         result = {
             'name': doc.id,
 
         result = {
             'name': doc.id,
-            'html_url': reverse('dochtml_view', args=[doc.id,doc.revision]),
-            'text_url': reverse('doctext_view', args=[doc.id,doc.revision]),
-            'dc_url': reverse('docdc_view', args=[doc.id,doc.revision]),
+            'html_url': reverse('dochtml_view', args=[doc.id]),
+            'text_url': reverse('doctext_view', args=[doc.id]),
+            'dc_url': reverse('docdc_view', args=[doc.id]),
             'public_revision': doc.revision,
         }
 
         return result
 
             'public_revision': doc.revision,
         }
 
         return result
 
+
+class DiffHandler(BaseHandler):
+    allowed_methods = ('GET',)
+    
+    @hglibrary
+    def read(self, request, source_revision, target_revision, lib):
+        '''Return diff between source_revision and target_revision)'''
+        source_document = lib.document_for_rev(source_revision)
+        target_document = lib.document_for_rev(target_revision)
+        print source_document,
+        print target_document
+        diff = difflib.unified_diff(
+            source_document.data('xml').splitlines(True),
+            target_document.data('xml').splitlines(True),
+            'source',
+            'target')
+        
+        return ''.join(list(diff))
+
+
 #
 # Document Meta Data
 #
 #
 # Document Meta Data
 #
@@ -158,52 +229,168 @@ class DocumentHandler(BaseHandler):
     allowed_methods = ('GET', 'PUT')
     anonymous = BasicDocumentHandler
 
     allowed_methods = ('GET', 'PUT')
     anonymous = BasicDocumentHandler
 
+    @validate_form(forms.DocumentRetrieveForm, 'GET')
     @hglibrary
     @hglibrary
-    def read(self, request, docid, lib):
+    def read(self, request, form, docid, lib):
         """Read document's meta data"""       
         """Read document's meta data"""       
-        try:
-            doc = lib.document(docid)
-            udoc = doc.take(request.user.username)
-        except RevisionNotFound:
-            return request.EnityNotFound().django_response()
-
-        # is_shared = udoc.ancestorof(doc)
-        # is_uptodate = is_shared or shared.ancestorof(document)
+        log.info(u"User '%s' wants to %s(%s) as %s" % \
+            (request.user.username, docid, form.cleaned_data['revision'], form.cleaned_data['user']) )
 
 
-        result = {
-            'name': udoc.id,
-            'html_url': reverse('dochtml_view', args=[udoc.id,udoc.revision]),
-            'text_url': reverse('doctext_view', args=[udoc.id,udoc.revision]),
-            'dc_url': reverse('docdc_view', args=[udoc.id,udoc.revision]),
-            #'gallery_url': reverse('docdc_view', args=[udoc.id,udoc.revision]),
-            'user_revision': udoc.revision,
-            'public_revision': doc.revision,            
-        }       
+        user = form.cleaned_data['user'] or request.user.username
+        rev = form.cleaned_data['revision'] or 'latest'
 
 
-        return result
+        for error in check_user(request, user):
+            return error
+            
+        try:
+            doc = lib.document(docid, user, rev=rev)
+        except RevisionMismatch, e:
+            # the document exists, but the revision is bad
+            return response.EntityNotFound().django_response({
+                'reason': 'revision-mismatch',
+                'message': e.message,
+                'docid': docid,
+                'user': user,
+            })
+        except RevisionNotFound, e:
+            # the user doesn't have this document checked out
+            # or some other weird error occured
+            # try to do the checkout
+            try:
+                if user == request.user.username:
+                    mdoc = lib.document(docid)
+                    doc = mdoc.take(user)
+                elif is_prq(user):
+                    prq = prq_for_user(user)
+                    # commiter's document
+                    prq_doc = lib.document_for_rev(prq.source_revision)
+                    doc = prq_doc.take(user)
+                else:
+                    return response.EntityNotFound().django_response({
+                        'reason': 'document-not-found',
+                        'message': e.message,
+                        'docid': docid,
+                        'user': user,
+                    })
+            except RevisionNotFound, e:
+                return response.EntityNotFound().django_response({
+                    'reason': 'document-not-found',
+                    'message': e.message,
+                    'docid': docid,
+                    'user': user
+                })
 
 
-    @hglibrary
-    def update(self, request, docid, lib):
-        """Update information about the document, like display not"""
-        return
+        return {
+            'name': doc.id,
+            'user': user,
+            'html_url': reverse('dochtml_view', args=[doc.id]),
+            'text_url': reverse('doctext_view', args=[doc.id]),
+            # 'dc_url': reverse('docdc_view', args=[doc.id]),
+            'gallery_url': reverse('docgallery_view', args=[doc.id]),
+            'merge_url': reverse('docmerge_view', args=[doc.id]),
+            'revision': doc.revision,
+            'timestamp': doc.revision.timestamp,
+            # 'public_revision': doc.revision,
+            # 'public_timestamp': doc.revision.timestamp,
+        }   
+
+    
+#    @hglibrary
+#    def update(self, request, docid, lib):
+#        """Update information about the document, like display not"""
+#        return
 #
 #
 #
 class DocumentHTMLHandler(BaseHandler):
 #
 #
 #
 class DocumentHTMLHandler(BaseHandler):
-    allowed_methods = ('GET', 'PUT')
+    allowed_methods = ('GET')
 
 
+    @validate_form(forms.DocumentRetrieveForm, 'GET')
     @hglibrary
     @hglibrary
-    def read(self, request, docid, revision, lib):
+    def read(self, request, form, docid, lib, stylesheet='partial'):
         """Read document as html text"""
         try:
         """Read document as html text"""
         try:
-            if revision == 'latest':
-                document = lib.document(docid)
-            else:
-                document = lib.document_for_rev(revision)
+            revision = form.cleaned_data['revision']
+            user = form.cleaned_data['user'] or request.user.username
+            document = lib.document_for_rev(revision)
+
+            if document.id != docid:
+                return response.BadRequest().django_response({
+                    'reason': 'name-mismatch',
+                    'message': 'Provided revision is not valid for this document'
+                })
 
 
-            return librarian.html.transform(document.data('xml'), is_file=False)
-        except RevisionNotFound:
-            return response.EntityNotFound().django_response()
+            if document.owner != user:
+                return response.BadRequest().django_response({
+                    'reason': 'user-mismatch',
+                    'message': "Provided revision doesn't belong to user %s" % user
+                })
+
+            for error in check_user(request, user):
+                return error
+
+            return librarian.html.transform(document.data('xml'), is_file=False, \
+                parse_dublincore=False, stylesheet=stylesheet,\
+                options={
+                    "with-paths": 'boolean(1)',                    
+                })
+                
+        except (EntryNotFound, RevisionNotFound), e:
+            return response.EntityNotFound().django_response({
+                'reason': 'not-found', 'message': e.message})
+        except librarian.ParseError, e:
+            return response.InternalError().django_response({
+                'reason': 'xml-parse-error', 'message': e.message })
+
+#
+# Image Gallery
+#
+
+class DocumentGalleryHandler(BaseHandler):
+    allowed_methods = ('GET')
+    
+    
+    def read(self, request, docid):
+        """Read meta-data about scans for gallery of this document."""
+        galleries = []
+        from urllib import quote
+
+        for assoc in GalleryForDocument.objects.filter(document=docid):
+            dirpath = os.path.join(settings.MEDIA_ROOT, assoc.subpath)
+
+            if not os.path.isdir(dirpath):
+                log.warn(u"[WARNING]: missing gallery %s", dirpath)
+                continue
+
+            gallery = {'name': assoc.name, 'pages': []}
+            
+            for file in os.listdir(dirpath):
+                if not isinstance(file, unicode):
+                    try:
+                        file = file.decode('utf-8')
+                    except:
+                        log.warn(u"File %r in gallery %r is not unicode. Ommiting."\
+                            % (file, dirpath) )
+                        file = None
+
+                if file is not None:
+                    name, ext = os.path.splitext(os.path.basename(file))
+
+                    if ext.lower() not in [u'.png', u'.jpeg', u'.jpg']:
+                        log.warn(u"Ignoring: %s %s", name, ext)
+                        url = None
+
+                    url = settings.MEDIA_URL + assoc.subpath + u'/' + file
+                
+                if url is None:
+                    url = settings.MEDIA_URL + u'/missing.png'
+                    
+                gallery['pages'].append( quote(url.encode('utf-8')) )
+
+#            gallery['pages'].sort()
+            galleries.append(gallery)
+
+        return galleries
 
 #
 # Document Text View
 
 #
 # Document Text View
@@ -213,34 +400,79 @@ XINCLUDE_REGEXP = r"""<(?:\w+:)?include\s+[^>]*?href=("|')wlrepo://(?P<link>[^\1
 #
 #
 #
 #
 #
 #
+
 class DocumentTextHandler(BaseHandler):
 class DocumentTextHandler(BaseHandler):
-    allowed_methods = ('GET', 'PUT')
+    allowed_methods = ('GET', 'POST')
 
 
+    @validate_form(forms.TextRetrieveForm, 'GET')
     @hglibrary
     @hglibrary
-    def read(self, request, docid, revision, lib):
-        """Read document as raw text"""               
+    def read(self, request, form, docid, lib):
+        """Read document as raw text"""        
         try:
         try:
-            if revision == 'latest':
-                document = lib.document(docid)
-            else:
-                document = lib.document_for_rev(revision)
+            revision = form.cleaned_data['revision']
+            part = form.cleaned_data['part']
+            user = form.cleaned_data['user'] or request.user.username            
             
             
-            # TODO: some finer-grained access control
-            return document.data('xml')
-        except RevisionNotFound:
-            return response.EntityNotFound().django_response()
+            document = lib.document_for_rev(revision)
+            
+            if document.id != docid:
+                return response.BadRequest().django_response({
+                    'reason': 'name-mismatch',
+                    'message': 'Provided revision is not valid for this document'
+                })
+
+            if document.owner != user:
+                return response.BadRequest().django_response({
+                    'reason': 'user-mismatch',
+                    'message': "Provided revision doesn't belong to user %s" % user
+                })
 
 
+            for error in check_user(request, user):
+                return error
+            
+            if not part:                
+                return document.data('xml')
+            
+            xdoc = parser.WLDocument.from_string(document.data('xml'),\
+                parse_dublincore=False)
+            ptext = xdoc.part_as_text(part)
+
+            if ptext is None:
+                return response.EntityNotFound().django_response({
+                      'reason': 'no-part-in-document'                     
+                })
+
+            return ptext
+        except librarian.ParseError, e:
+            return response.EntityNotFound().django_response({
+                'reason': 'invalid-document-state',
+                'exception': type(e),
+                'message': e.message
+            })
+        except (EntryNotFound, RevisionNotFound), e:
+            return response.EntityNotFound().django_response({
+                'reason': 'not-found',
+                'exception': type(e), 'message': e.message
+            })   
+
+    @validate_form(forms.TextUpdateForm, 'POST')
     @hglibrary
     @hglibrary
-    def update(self, request, docid, revision, lib):
+    def create(self, request, form, docid, lib):
         try:
         try:
-            data = request.PUT['contents']            
-
-            if request.PUT.has_key('message'):
-                msg = u"$USER$ " + request.PUT['message']
-            else:
-                msg = u"$AUTO$ XML content update."
+            revision = form.cleaned_data['revision']
+            msg = form.cleaned_data['message']
+            user = form.cleaned_data['user'] or request.user.username
 
 
-            current = lib.document(docid, request.user.username)
+            # do not allow changing not owned documents
+            # (for now... )
+            
+            
+            if user != request.user.username:
+                return response.AccessDenied().django_response({
+                    'reason': 'insufficient-priviliges',
+                })
+            
+            current = lib.document(docid, user)
             orig = lib.document_for_rev(revision)
 
             if current != orig:
             orig = lib.document_for_rev(revision)
 
             if current != orig:
@@ -248,11 +480,28 @@ class DocumentTextHandler(BaseHandler):
                         "reason": "out-of-date",
                         "provided_revision": orig.revision,
                         "latest_revision": current.revision })
                         "reason": "out-of-date",
                         "provided_revision": orig.revision,
                         "latest_revision": current.revision })
+            
+            if form.cleaned_data.has_key('contents'):
+                data = form.cleaned_data['contents']
+            else:                               
+                chunks = form.cleaned_data['chunks']
+                xdoc = parser.WLDocument.from_string(current.data('xml'))
+                errors = xdoc.merge_chunks(chunks)
+
+                if len(errors):
+                    return response.EntityConflict().django_response({
+                            "reason": "invalid-chunks",
+                            "message": "Unable to merge following parts into the document: %s " % ",".join(errors)
+                    })
+
+                data = xdoc.serialize()
 
             # try to find any Xinclude tags
             includes = [m.groupdict()['link'] for m in (re.finditer(\
                 XINCLUDE_REGEXP, data, flags=re.UNICODE) or []) ]
 
 
             # try to find any Xinclude tags
             includes = [m.groupdict()['link'] for m in (re.finditer(\
                 XINCLUDE_REGEXP, data, flags=re.UNICODE) or []) ]
 
+            log.info("INCLUDES: %s", includes)
+
             # TODO: provide useful routines to make this simpler
             def xml_update_action(lib, resolve):
                 try:
             # TODO: provide useful routines to make this simpler
             def xml_update_action(lib, resolve):
                 try:
@@ -280,16 +529,18 @@ class DocumentTextHandler(BaseHandler):
 
             ndoc = None
             ndoc = current.invoke_and_commit(\
 
             ndoc = None
             ndoc = current.invoke_and_commit(\
-                xml_update_action, lambda d: (msg, current.owner) )
+                xml_update_action, lambda d: (msg, user) )
 
             try:
                 # return the new revision number
                 return response.SuccessAllOk().django_response({
                     "document": ndoc.id,
 
             try:
                 # return the new revision number
                 return response.SuccessAllOk().django_response({
                     "document": ndoc.id,
+                    "user": user,
                     "subview": "xml",
                     "previous_revision": current.revision,
                     "subview": "xml",
                     "previous_revision": current.revision,
-                    "updated_revision": ndoc.revision,
-                    "url": reverse("doctext_view", args=[ndoc.id, ndoc.revision])
+                    "revision": ndoc.revision,
+                    'timestamp': ndoc.revision.timestamp,
+                    "url": reverse("doctext_view", args=[ndoc.id])
                 })
             except Exception, e:
                 if ndoc: lib._rollback()
                 })
             except Exception, e:
                 if ndoc: lib._rollback()
@@ -304,63 +555,74 @@ class DocumentTextHandler(BaseHandler):
 #
 # @requires librarian
 #
 #
 # @requires librarian
 #
-class DocumentDublinCoreHandler(BaseHandler):
-    allowed_methods = ('GET', 'PUT')
-
-    @hglibrary
-    def read(self, request, docid, revision, lib):
-        """Read document as raw text"""        
-        try:
-            if revision == 'latest':
-                doc = lib.document(docid)
-            else:
-                doc = lib.document_for_rev(revision)
-            
-            bookinfo = dcparser.BookInfo.from_string(doc.data('xml'))
-            return bookinfo.serialize()
-        except RevisionNotFound:
-            return response.EntityNotFound().django_response()
-
-    @hglibrary
-    def update(self, request, docid, revision, lib):
-        try:
-            bi_json = request.PUT['contents']            
-            if request.PUT.has_key('message'):
-                msg = u"$USER$ " + request.PUT['message']
-            else:
-                msg = u"$AUTO$ Dublin core update."
-
-            current = lib.document(docid, request.user.username)
-            orig = lib.document_for_rev(revision)
-
-            if current != orig:
-                return response.EntityConflict().django_response({
-                        "reason": "out-of-date",
-                        "provided": orig.revision,
-                        "latest": current.revision })
-
-            xmldoc = parser.WLDocument.from_string(current.data('xml'))
-            document.book_info = dcparser.BookInfo.from_json(bi_json)
-
-            # zapisz
-            ndoc = current.quickwrite('xml', \
-                document.serialize().encode('utf-8'),\
-                message=msg, user=request.user.username)
-
-            try:
-                # return the new revision number
-                return {
-                    "document": ndoc.id,
-                    "subview": "dc",
-                    "previous_revision": current.revision,
-                    "updated_revision": ndoc.revision,
-                    "url": reverse("docdc_view", args=[ndoc.id, ndoc.revision])
-                }
-            except Exception, e:
-                if ndoc: lib._rollback()
-                raise e
-        except RevisionNotFound:
-            return response.EntityNotFound().django_response()
+#class DocumentDublinCoreHandler(BaseHandler):
+#    allowed_methods = ('GET', 'POST')
+#
+#    @hglibrary
+#    def read(self, request, docid, lib):
+#        """Read document as raw text"""
+#        try:
+#            revision = request.GET.get('revision', 'latest')
+#
+#            if revision == 'latest':
+#                doc = lib.document(docid)
+#            else:
+#                doc = lib.document_for_rev(revision)
+#
+#
+#            if document.id != docid:
+#                return response.BadRequest().django_response({'reason': 'name-mismatch',
+#                    'message': 'Provided revision is not valid for this document'})
+#
+#            bookinfo = dcparser.BookInfo.from_string(doc.data('xml'))
+#            return bookinfo.serialize()
+#        except (EntryNotFound, RevisionNotFound), e:
+#            return response.EntityNotFound().django_response({
+#                'exception': type(e), 'message': e.message})
+#
+#    @hglibrary
+#    def create(self, request, docid, lib):
+#        try:
+#            bi_json = request.POST['contents']
+#            revision = request.POST['revision']
+#
+#            if request.POST.has_key('message'):
+#                msg = u"$USER$ " + request.PUT['message']
+#            else:
+#                msg = u"$AUTO$ Dublin core update."
+#
+#            current = lib.document(docid, request.user.username)
+#            orig = lib.document_for_rev(revision)
+#
+#            if current != orig:
+#                return response.EntityConflict().django_response({
+#                        "reason": "out-of-date",
+#                        "provided": orig.revision,
+#                        "latest": current.revision })
+#
+#            xmldoc = parser.WLDocument.from_string(current.data('xml'))
+#            document.book_info = dcparser.BookInfo.from_json(bi_json)
+#
+#            # zapisz
+#            ndoc = current.quickwrite('xml', \
+#                document.serialize().encode('utf-8'),\
+#                message=msg, user=request.user.username)
+#
+#            try:
+#                # return the new revision number
+#                return {
+#                    "document": ndoc.id,
+#                    "subview": "dc",
+#                    "previous_revision": current.revision,
+#                    "revision": ndoc.revision,
+#                    'timestamp': ndoc.revision.timestamp,
+#                    "url": reverse("docdc_view", args=[ndoc.id])
+#                }
+#            except Exception, e:
+#                if ndoc: lib._rollback()
+#                raise e
+#        except RevisionNotFound:
+#            return response.EntityNotFound().django_response()
 
 class MergeHandler(BaseHandler):
     allowed_methods = ('POST',)
 
 class MergeHandler(BaseHandler):
     allowed_methods = ('POST',)
@@ -369,75 +631,101 @@ class MergeHandler(BaseHandler):
     @hglibrary
     def create(self, request, form, docid, lib):
         """Create a new document revision from the information provided by user"""
     @hglibrary
     def create(self, request, form, docid, lib):
         """Create a new document revision from the information provided by user"""
+        revision = form.cleaned_data['revision']
 
 
-        target_rev = form.cleaned_data['target_revision']
-
+        # fetch the main branch document
         doc = lib.document(docid)
         doc = lib.document(docid)
-        udoc = doc.take(request.user.username)
 
 
-        if target_rev == 'latest':
-            target_rev = udoc.revision
+        # fetch the base document
+        user_doc = lib.document_for_rev(revision)
+        base_doc = user_doc.latest()
 
 
-        if str(udoc.revision) != target_rev:
-            # user think doesn't know he has an old version
-            # of his own branch.
-            
-            # Updating is teorericly ok, but we need would
-            # have to force a refresh. Sharing may be not safe,
-            # 'cause it doesn't always result in update.
-
-            # In other words, we can't lie about the resource's state
-            # So we should just yield and 'out-of-date' conflict
-            # and let the client ask again with updated info.
-
-            # NOTE: this could result in a race condition, when there
-            # are 2 instances of the same user editing the same document.
-            # Instance "A" trying to update, and instance "B" always changing
-            # the document right before "A". The anwser to this problem is
-            # for the "A" to request a merge from 'latest' and then
-            # check the parent revisions in response, if he actually
-            # merge from where he thinks he should. If not, the client SHOULD
-            # update his internal state.
+        if base_doc != user_doc:
             return response.EntityConflict().django_response({
             return response.EntityConflict().django_response({
-                    "reason": "out-of-date",
-                    "provided": target_rev,
-                    "latest": udoc.revision })
-
-        if not request.user.has_perm('explorer.book.can_share'):
-            # User is not permitted to make a merge, right away
-            # So we instead create a pull request in the database
-            prq = PullRequest(
-                comitter=request.user,
-                document=docid,
-                source_revision = str(udoc.revision),
-                status="N",
-                comment = form.cleaned_data['comment'] or '$AUTO$ Document shared.'
-            )
-
-            prq.save()
-            return response.RequestAccepted().django_response(\
-                ticket_status=prq.status, \
-                ticket_uri=reverse("pullrequest_view", args=[prq.id]) )
+                "reason": "out-of-date",
+                "provided": str(user_doc.revision),
+                "latest": str(base_doc.revision)
+            })      
 
         if form.cleaned_data['type'] == 'update':
             # update is always performed from the file branch
             # to the user branch
 
         if form.cleaned_data['type'] == 'update':
             # update is always performed from the file branch
             # to the user branch
-            success, changed = udoc.update(request.user.username)
+            user_doc_new = base_doc.update(request.user.username)
+                
+            # shared document is the same
+            doc_new = doc
 
         if form.cleaned_data['type'] == 'share':
 
         if form.cleaned_data['type'] == 'share':
-            success, changed = udoc.share(form.cleaned_data['comment'])
+            if not base_doc.up_to_date():
+                return response.BadRequest().django_response({
+                    "reason": "not-fast-forward",
+                    "message": "You must first update yout branch to the latest version."
+                })
 
 
-        if not success:
-            return response.EntityConflict().django_response()
+            # check for unresolved conflicts            
+            if base_doc.has_conflict_marks():
+                return response.BadRequest().django_response({
+                    "reason": "unresolved-conflicts",
+                    "message": "There are unresolved conflicts in your file. Fix them, and try again."
+                })
 
 
-        if not changed:
-            return response.SuccessNoContent().django_response()
+            if not request.user.has_perm('api.share_document'):
+                # User is not permitted to make a merge, right away
+                # So we instead create a pull request in the database
+                try:
+                    prq, created = PullRequest.objects.get_or_create(
+                        comitter = request.user,
+                        document = docid,
+                        status = "N",
+                        defaults = {
+                            'source_revision': str(base_doc.revision),
+                            'comment': form.cleaned_data['message'] or '$AUTO$ Document shared.',
+                        }
+                    )
+
+                    # there can't be 2 pending request from same user
+                    # for the same document
+                    if not created:
+                        prq.source_revision = str(base_doc.revision)
+                        prq.comment = prq.comment + 'u\n\n' + (form.cleaned_data['message'] or u'')
+                        prq.save()
+
+                    return response.RequestAccepted().django_response(\
+                        ticket_status=prq.status, \
+                        ticket_uri=reverse("pullrequest_view", args=[prq.id]) )
+                except IntegrityError:
+                    return response.EntityConflict().django_response({
+                        'reason': 'request-already-exist'
+                    })
+
+            changed = base_doc.share(form.cleaned_data['message'])
+
+            # update shared version if needed
+            if changed:
+                doc_new = doc.latest()
+            else:
+                doc_new = doc
 
 
-        new_udoc = udoc.latest()
+            # the user wersion is the same
+            user_doc_new = base_doc
 
 
+        # The client can compare parent_revision to revision
+        # to see if he needs to update user's view        
+        # Same goes for shared view
+        
         return response.SuccessAllOk().django_response({
         return response.SuccessAllOk().django_response({
-            "name": udoc.id,
-            "parent_user_resivion": udoc.revision,
-            "parent_revision": doc.revision,
-            "revision": udoc.revision,
-        })
+            "name": user_doc_new.id,
+            "user": user_doc_new.owner,
+
+            "revision": user_doc_new.revision,
+            'timestamp': user_doc_new.revision.timestamp,
+
+            "parent_revision": user_doc.revision,
+            "parent_timestamp": user_doc.revision.timestamp,
+
+            "shared_revision": doc_new.revision,
+            "shared_timestamp": doc_new.revision.timestamp,
+
+            "shared_parent_revision": doc.revision,
+            "shared_parent_timestamp": doc.revision.timestamp,
+        })
\ No newline at end of file