Open Media Library

oml/changelog.py

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+# -*- coding: utf-8 -*-
+# vi:si:et:sw=4:sts=4:ts=4
+
+import json
+from datetime import datetime
+
+from ed25519_utils import valid
+
+import settings
+from settings import db
+import state
+from websocket import trigger_event
+
+class Changelog(db.Model):
+    '''
+        additem               itemid    metadata from file (info) + OLID
+        edititem              itemid    name->id (i.e. olid-> OL...M)
+        removeitem            itemid
+        addlist               name
+        editlist              name {name: newname}
+        orderlists            [name, name, name]
+        removelist            name
+        additemtolist         listname itemid
+        removeitemfromlist    listname itemid
+        editusername          username
+        editcontact           string
+        addpeer               peerid peername
+        removepeer            peerid peername
+    '''
+    id = db.Column(db.Integer(), primary_key=True)
+
+    created = db.Column(db.DateTime())
+
+    user_id = db.Column(db.String(43))
+    revision = db.Column(db.BigInteger())
+    data = db.Column(db.Text())
+    sig = db.Column(db.String(96))
+
+    @classmethod
+    def record(cls, user, action, *args):
+        c = cls()
+        c.created = datetime.now()
+        c.user_id = user.id
+        c.revision = cls.query.filter_by(user_id=user.id).count()
+        c.data = json.dumps([action, args])
+        timestamp = c.timestamp
+        _data = str(c.revision) + str(timestamp) + c.data
+        c.sig = settings.sk.sign(_data, encoding='base64')
+        db.session.add(c)
+        db.session.commit()
+        if state.online:
+            state.nodes.queue('online', 'pushChanges', [c.json()])
+
+    @property
+    def timestamp(self):
+        return self.created.strftime('%s')
+
+    @classmethod
+    def apply_change(cls, user, change, rebuild=False):
+        revision, timestamp, sig, data = change
+        last = Changelog.query.filter_by(user_id=user.id).order_by('-revision').first()
+        next_revision = last.revision + 1 if last else 0
+        if revision == next_revision:
+            _data = str(revision) + str(timestamp) + data
+            if rebuild:
+                sig = settings.sk.sign(_data, encoding='base64')
+            if valid(user.id, _data, sig):
+                c = cls()
+                c.created = datetime.now()
+                c.user_id = user.id
+                c.revision = revision
+                c.data = data
+                c.sig = sig
+                action, args = json.loads(data)
+                print 'apply change', action
+                if getattr(c, 'action_' + action)(user, timestamp, *args):
+                    print 'change applied'
+                    db.session.add(c)
+                    db.session.commit()
+                    return True
+            else:
+                print 'INVLAID SIGNATURE ON CHANGE', change
+                raise Exception, 'invalid signature'
+        else:
+            print 'revsion does not match! got', revision, 'expecting', next_revision
+            return False
+
+    def __repr__(self):
+        return self.data
+
+    def verify(self):
+        _data = str(self.revision) + str(self.timestamp) + self.data
+        return valid(self.user_id, _data, self.sig)
+
+    def json(self):
+        return [self.revision, self.timestamp, self.sig, self.data]
+
+    @classmethod
+    def restore(cls, user_id, path=None):
+        from user.models import User
+        user = User.get_or_create(user_id)
+        if not path:
+            path = '/tmp/oml_changelog_%s.json' % user_id
+        with open(path, 'r') as fd:
+            for change in fd:
+                change = json.loads(change)
+                cls.apply_change(user, change, user_id == settings.USER_ID)
+
+    @classmethod
+    def export(cls, user_id, path=None):
+        if not path:
+            path = '/tmp/oml_changelog_%s.json' % user_id
+        with open(path, 'w') as fd:
+            for c in cls.query.filter_by(user_id=user_id).order_by('revision'):
+                fd.write(json.dumps(c.json()) + '\n')
+
+    def action_additem(self, user, timestamp, itemid, info):
+        from item.models import Item
+        i = Item.get(itemid)
+        if i and i.timestamp > timestamp:
+            return True
+        if not i:
+            i = Item.get_or_create(itemid, info)
+        i.users.append(user)
+        i.update()
+        return True
+
+    def action_edititem(self, user, timestamp, itemid, meta):
+        from item.models import Item
+        i = Item.get(itemid)
+        if i.timestamp > timestamp:
+            return True
+        key = meta.keys()[0]
+        if not meta[key] and i.meta.get('mainid') == key:
+            print 'remove id mapping', key, meta[key], 'currently', i.meta[key]
+            i.update_mainid(key, meta[key])
+        elif meta[key] and (i.meta.get('mainid') != key or meta[key] != i.meta.get(key)):
+            print 'new mapping', key, meta[key], 'currently', i.meta.get('mainid'), i.meta.get(i.meta.get('mainid'))
+            i.update_mainid(key, meta[key])
+        return True
+
+    def action_removeitem(self, user, timestamp, itemid):
+        from item.models import Item
+        i = Item.get(itemid)
+        if not i or i.timestamp > timestamp:
+            return True
+        i.users.remove(user)
+        if i.users:
+            i.update()
+        else:
+            db.session.delete(i)
+            db.session.commit()
+        return True
+
+    def action_addlist(self, user, timestamp, name, query=None):
+        from user.models import List
+        l = List.create(user.id, name)
+        return True
+
+    def action_editlist(self, user, timestamp, name, new):
+        from user.models import List
+        l = List.get_or_create(user.id, name)
+        if 'name' in new:
+            l.name = new['name']
+        l.save()
+        return True
+
+    def action_orderlists(self, user, timestamp, lists):
+        from user.models import List
+        position = 0
+        for name in lists:
+            l = List.get_or_create(user.id, name)
+            l.position = position
+            l.save()
+            position += 1
+        return True
+
+    def action_removelist(self, user, timestamp, name):
+        from user.models import List
+        l = List.get(user.id, name)
+        if l:
+            l.remove()
+        return True
+
+    def action_addlistitem(self, user, timestamp, name, itemid):
+        from item.models import Item
+        from user.models import List
+        l = List.get(user.id, name)
+        i = Item.get(itemid)
+        if l and i:
+            i.lists.append(l)
+            i.update()
+        return True
+
+    def action_removelistitem(self, user, timestamp, name, itemid):
+        from item.models import Item
+        from user.models import List
+        l = List.get(user.id, name)
+        i = Item.get(itemid)
+        if l and i:
+            i.lists.remove(l)
+            i.update()
+        return True
+
+    def action_editusername(self, user, timestamp, username):
+        user.info['username'] = username
+        user.save()
+        return True
+
+    def action_editcontact(self, user, timestamp, contact):
+        user.info['contact'] = contact
+        user.save()
+        return True
+
+    def action_adduser(self, user, timestamp, peerid, username):
+        from user.models import User
+        if not 'users' in user.info:
+            user.info['users'] = {}
+        user.info['users'][peerid] = username
+        user.save()
+        User.get_or_create(peerid)
+        #fixme, add username to user?
+        return True
+
+    def action_removeuser(self, user, timestamp, peerid):
+        if 'users' in user.info and peerid in user.info['users']:
+            del user.info['users'][peerid]
+            user.save()
+            #fixme, remove from User table if no other connection exists
+        return True