lazy: Properly override getattr calls

[etc/taskwarrior.git] / tasklib / task.py

diff --git a/tasklib/task.py b/tasklib/task.py
index b78ed32fb4aa0aee25e9c17a4f74302ff66f39e7..5eabc65178d2ae930835d6508a04ad45f0eafe0c 100644 (file)
--- a/tasklib/task.py
+++ b/tasklib/task.py
@@ -1,94 +1,426 @@
+from __future__ import print_function

 import copy
 import copy

-import datetime
+import importlib

 import json
 import json

+import logging

 import os
 import os

-import subprocess
-import tempfile
-import uuid
+import six
+import sys

 
 

+from .serializing import SerializingObject

 
 DATE_FORMAT = '%Y%m%dT%H%M%SZ'
 
 DATE_FORMAT = '%Y%m%dT%H%M%SZ'

-

 REPR_OUTPUT_SIZE = 10
 REPR_OUTPUT_SIZE = 10

-

 PENDING = 'pending'
 PENDING = 'pending'

+COMPLETED = 'completed'

 
 

+logger = logging.getLogger(__name__)

 
 

-class TaskWarriorException(Exception):
-    pass

 
 

+class ReadOnlyDictView(object):
+    """
+    Provides simplified read-only view upon dict object.
+    """
+
+    def __init__(self, viewed_dict):
+        self.viewed_dict = viewed_dict

 
 

-class Task(object):
+    def __getitem__(self, key):
+        return copy.deepcopy(self.viewed_dict.__getitem__(key))

 
 

-    class DoesNotExist(Exception):
-        pass
+    def __contains__(self, k):
+        return self.viewed_dict.__contains__(k)
+
+    def __iter__(self):
+        for value in self.viewed_dict:
+            yield copy.deepcopy(value)
+
+    def __len__(self):
+        return len(self.viewed_dict)
+
+    def __unicode__(self):
+        return six.u('ReadOnlyDictView: {0}'.format(repr(self.viewed_dict)))
+
+    __repr__ = __unicode__
+
+    def get(self, key, default=None):
+        return copy.deepcopy(self.viewed_dict.get(key, default))
+
+    def items(self):
+        return [copy.deepcopy(v) for v in self.viewed_dict.items()]
+
+    def values(self):
+        return [copy.deepcopy(v) for v in self.viewed_dict.values()]

 
 

-    def __init__(self, warrior, data={}):
-        self.warrior = warrior
-        self._data = data
+
+class TaskResource(SerializingObject):
+    read_only_fields = []
+
+    def _load_data(self, data):
+        self._data = dict((key, self._deserialize(key, value))
+                          for key, value in data.items())
+        # We need to use a copy for original data, so that changes
+        # are not propagated.
+        self._original_data = copy.deepcopy(self._data)
+
+    def _update_data(self, data, update_original=False, remove_missing=False):
+        """
+        Low level update of the internal _data dict. Data which are coming as
+        updates should already be serialized. If update_original is True, the
+        original_data dict is updated as well.
+        """
+        self._data.update(dict((key, self._deserialize(key, value))
+                               for key, value in data.items()))
+
+        # In certain situations, we want to treat missing keys as removals
+        if remove_missing:
+            for key in set(self._data.keys()) - set(data.keys()):
+                self._data[key] = None
+
+        if update_original:
+            self._original_data = copy.deepcopy(self._data)

 
     def __getitem__(self, key):
 
     def __getitem__(self, key):

-        return self._get_field(key)
+        # This is a workaround to make TaskResource non-iterable
+        # over simple index-based iteration
+        try:
+            int(key)
+            raise StopIteration
+        except ValueError:
+            pass
+
+        if key not in self._data:
+            self._data[key] = self._deserialize(key, None)
+
+        return self._data.get(key)
+
+    def __setitem__(self, key, value):
+        if key in self.read_only_fields:
+            raise RuntimeError('Field \'%s\' is read-only' % key)

 
 

-    def __setitem__(self, key, val):
-        self._data[key] = val
+        # Normalize the user input before saving it
+        value = self._normalize(key, value)
+        self._data[key] = value
+
+    def __str__(self):
+        s = six.text_type(self.__unicode__())
+        if not six.PY3:
+            s = s.encode('utf-8')
+        return s
+
+    def __repr__(self):
+        return str(self)
+
+    def export_data(self):
+        """
+        Exports current data contained in the Task as JSON
+        """
+
+        # We need to remove spaces for TW-1504, use custom separators
+        data_tuples = ((key, self._serialize(key, value))
+                       for key, value in six.iteritems(self._data))
+
+        # Empty string denotes empty serialized value, we do not want
+        # to pass that to TaskWarrior.
+        data_tuples = filter(lambda t: t[1] is not '', data_tuples)
+        data = dict(data_tuples)
+        return json.dumps(data, separators=(',', ':'))
+
+    @property
+    def _modified_fields(self):
+        writable_fields = set(self._data.keys()) - set(self.read_only_fields)
+        for key in writable_fields:
+            new_value = self._data.get(key)
+            old_value = self._original_data.get(key)
+
+            # Make sure not to mark data removal as modified field if the
+            # field originally had some empty value
+            if key in self._data and not new_value and not old_value:
+                continue
+
+            if new_value != old_value:
+                yield key
+
+    @property
+    def modified(self):
+        return bool(list(self._modified_fields))
+
+
+class TaskAnnotation(TaskResource):
+    read_only_fields = ['entry', 'description']
+
+    def __init__(self, task, data=None):
+        self.task = task
+        self._load_data(data or dict())
+        super(TaskAnnotation, self).__init__(task.backend)
+
+    def remove(self):
+        self.task.remove_annotation(self)

 
     def __unicode__(self):
 
     def __unicode__(self):

-        return self._data.get('description')
+        return self['description']
+
+    def __eq__(self, other):
+        # consider 2 annotations equal if they belong to the same task, and
+        # their data dics are the same
+        return self.task == other.task and self._data == other._data

 
 

-    def _get_field(self, key):
-        hydrate_func = getattr(self, 'deserialize_{0}'.format(key), lambda x:x)
-        return hydrate_func(self._data.get(key))
+    __repr__ = __unicode__

 
 

-    def _set_field(self, key, value):
-        dehydrate_func = getattr(self, 'serialize_{0}'.format(key), lambda x:x)
-        self._data[key] = dehydrate_func(value)

 
 

-    def serialize_due(self, date):
-        return date.strftime(DATE_FORMAT)
+class Task(TaskResource):
+    read_only_fields = ['id', 'entry', 'urgency', 'uuid', 'modified']

 
 

-    def deserialize_due(self, date_str):
-        if not date_str:
-            return None
-        return datetime.datetime.strptime(date_str, DATE_FORMAT)
+    class DoesNotExist(Exception):
+        pass
+
+    class CompletedTask(Exception):
+        """
+        Raised when the operation cannot be performed on the completed task.
+        """
+        pass

 
 

-    def regenerate_uuid(self):
-        self['uuid'] = str(uuid.uuid4())
+    class DeletedTask(Exception):
+        """
+        Raised when the operation cannot be performed on the deleted task.
+        """
+        pass
+
+    class ActiveTask(Exception):
+        """
+        Raised when the operation cannot be performed on the active task.
+        """
+        pass
+
+    class InactiveTask(Exception):
+        """
+        Raised when the operation cannot be performed on an inactive task.
+        """
+        pass
+
+    class NotSaved(Exception):
+        """
+        Raised when the operation cannot be performed on the task, because
+        it has not been saved to TaskWarrior yet.
+        """
+        pass
+
+    @classmethod
+    def from_input(cls, input_file=sys.stdin, modify=None, backend=None):
+        """
+        Creates a Task object, directly from the stdin, by reading one line.
+        If modify=True, two lines are used, first line interpreted as the
+        original state of the Task object, and second line as its new,
+        modified value. This is consistent with the TaskWarrior's hook
+        system.
+
+        Object created by this method should not be saved, deleted
+        or refreshed, as t could create a infinite loop. For this
+        reason, TaskWarrior instance is set to None.
+
+        Input_file argument can be used to specify the input file,
+        but defaults to sys.stdin.
+        """
+
+        # Detect the hook type if not given directly
+        name = os.path.basename(sys.argv[0])
+        modify = name.startswith('on-modify') if modify is None else modify
+
+        # Create the TaskWarrior instance if none passed
+        if backend is None:
+            backends = importlib.import_module('tasklib.backends')
+            hook_parent_dir = os.path.dirname(os.path.dirname(sys.argv[0]))
+            backend = backends.TaskWarrior(data_location=hook_parent_dir)
+
+        # TaskWarrior instance is set to None
+        task = cls(backend)
+
+        # Load the data from the input
+        task._load_data(json.loads(input_file.readline().strip()))
+
+        # If this is a on-modify event, we are provided with additional
+        # line of input, which provides updated data
+        if modify:
+            task._update_data(json.loads(input_file.readline().strip()),
+                              remove_missing=True)
+
+        return task
+
+    def __init__(self, backend, **kwargs):
+        super(Task, self).__init__(backend)
+
+        # Check that user is not able to set read-only value in __init__
+        for key in kwargs.keys():
+            if key in self.read_only_fields:
+                raise RuntimeError('Field \'%s\' is read-only' % key)
+
+        # We serialize the data in kwargs so that users of the library
+        # do not have to pass different data formats via __setitem__ and
+        # __init__ methods, that would be confusing
+
+        # Rather unfortunate syntax due to python2.6 comaptiblity
+        self._data = dict((key, self._normalize(key, value))
+                          for (key, value) in six.iteritems(kwargs))
+        self._original_data = copy.deepcopy(self._data)
+
+        # Provide read only access to the original data
+        self.original = ReadOnlyDictView(self._original_data)
+
+    def __unicode__(self):
+        return self['description']
+
+    def __eq__(self, other):
+        if self['uuid'] and other['uuid']:
+            # For saved Tasks, just define equality by equality of uuids
+            return self['uuid'] == other['uuid']
+        else:
+            # If the tasks are not saved, compare the actual instances
+            return id(self) == id(other)
+
+    def __hash__(self):
+        if self['uuid']:
+            # For saved Tasks, just define equality by equality of uuids
+            return self['uuid'].__hash__()
+        else:
+            # If the tasks are not saved, return hash of instance id
+            return id(self).__hash__()
+
+    @property
+    def completed(self):
+        return self['status'] == six.text_type('completed')
+
+    @property
+    def deleted(self):
+        return self['status'] == six.text_type('deleted')
+
+    @property
+    def waiting(self):
+        return self['status'] == six.text_type('waiting')
+
+    @property
+    def pending(self):
+        return self['status'] == six.text_type('pending')
+
+    @property
+    def active(self):
+        return self['start'] is not None
+
+    @property
+    def saved(self):
+        return self['uuid'] is not None or self['id'] is not None
+
+    def serialize_depends(self, cur_dependencies):
+        # Check that all the tasks are saved
+        for task in (cur_dependencies or set()):
+            if not task.saved:
+                raise Task.NotSaved('Task \'%s\' needs to be saved before '
+                                    'it can be set as dependency.' % task)
+
+        return super(Task, self).serialize_depends(cur_dependencies)

 
     def delete(self):
 
     def delete(self):

-        self.warrior.delete_task(self['uuid'])
+        if not self.saved:
+            raise Task.NotSaved("Task needs to be saved before it can be deleted")
+
+        # Refresh the status, and raise exception if the task is deleted
+        self.refresh(only_fields=['status'])
+
+        if self.deleted:
+            raise Task.DeletedTask("Task was already deleted")
+
+        self.backend.delete_task(self)
+
+        # Refresh the status again, so that we have updated info stored
+        self.refresh(only_fields=['status', 'start', 'end'])
+
+    def start(self):
+        if not self.saved:
+            raise Task.NotSaved("Task needs to be saved before it can be started")
+
+        # Refresh, and raise exception if task is already completed/deleted
+        self.refresh(only_fields=['status'])
+
+        if self.completed:
+            raise Task.CompletedTask("Cannot start a completed task")
+        elif self.deleted:
+            raise Task.DeletedTask("Deleted task cannot be started")
+        elif self.active:
+            raise Task.ActiveTask("Task is already active")
+
+        self.backend.start_task(self)
+
+        # Refresh the status again, so that we have updated info stored
+        self.refresh(only_fields=['status', 'start'])
+
+    def stop(self):
+        if not self.saved:
+            raise Task.NotSaved("Task needs to be saved before it can be stopped")
+
+        # Refresh, and raise exception if task is already completed/deleted
+        self.refresh(only_fields=['status'])
+
+        if not self.active:
+            raise Task.InactiveTask("Cannot stop an inactive task")
+
+        self.backend.stop_task(self)
+
+        # Refresh the status again, so that we have updated info stored
+        self.refresh(only_fields=['status', 'start'])

 
     def done(self):
 
     def done(self):

-        self.warrior.complete_task(self['uuid'])
+        if not self.saved:
+            raise Task.NotSaved("Task needs to be saved before it can be completed")

 
 

-    def save(self, delete_first=True):
-        if self['uuid'] and delete_first:
-            self.delete()
-        if not self['uuid'] or delete_first:
-            self.regenerate_uuid()
-        self.warrior.import_tasks([self._data])
+        # Refresh, and raise exception if task is already completed/deleted
+        self.refresh(only_fields=['status'])

 
 

-    __repr__ = __unicode__
+        if self.completed:
+            raise Task.CompletedTask("Cannot complete a completed task")
+        elif self.deleted:
+            raise Task.DeletedTask("Deleted task cannot be completed")

 
 

+        self.backend.complete_task(self)

 
 

-class TaskFilter(object):
-    """
-    A set of parameters to filter the task list with.
-    """
+        # Refresh the status again, so that we have updated info stored
+        self.refresh(only_fields=['status', 'start', 'end'])

 
 

-    def __init__(self, filter_params=()):
-        self.filter_params = filter_params
+    def save(self):
+        if self.saved and not self.modified:
+            return

 
 

-    def add_filter(self, param, value):
-        self.filter_params += ((param, value),)
+        # All the actual work is done by the backend
+        self.backend.save_task(self)

 
 

-    def get_filter_params(self):
-        return self.filter_params
+    def add_annotation(self, annotation):
+        if not self.saved:
+            raise Task.NotSaved("Task needs to be saved to add annotation")

 
 

-    def clone(self):
-        c = self.__class__()
-        c.filter_params = tuple(self.filter_params)
-        return c
+        self.backend.annotate_task(self, annotation)
+        self.refresh(only_fields=['annotations'])
+
+    def remove_annotation(self, annotation):
+        if not self.saved:
+            raise Task.NotSaved("Task needs to be saved to remove annotation")
+
+        if isinstance(annotation, TaskAnnotation):
+            annotation = annotation['description']
+
+        self.backend.denotate_task(self, annotation)
+        self.refresh(only_fields=['annotations'])
+
+    def refresh(self, only_fields=None, after_save=False):
+        # Raise error when trying to refresh a task that has not been saved
+        if not self.saved:
+            raise Task.NotSaved("Task needs to be saved to be refreshed")
+
+        new_data = self.backend.refresh_task(self, after_save=after_save)
+
+        if only_fields:
+            to_update = dict(
+                [(k, new_data.get(k)) for k in only_fields])
+            self._update_data(to_update, update_original=True)
+        else:
+            self._load_data(new_data)

 
 
 class TaskQuerySet(object):
 
 
 class TaskQuerySet(object):


@@ -96,18 +428,18 @@ class TaskQuerySet(object):
     Represents a lazy lookup for a task objects.
     """
 
     Represents a lazy lookup for a task objects.
     """
 

-    def __init__(self, warrior=None, filter_obj=None):
-        self.warrior = warrior
+    def __init__(self, backend, filter_obj=None):
+        self.backend = backend

         self._result_cache = None
         self._result_cache = None

-        self.filter_obj = filter_obj or TaskFilter()
+        self.filter_obj = filter_obj or self.backend.filter_class(backend)

 
     def __deepcopy__(self, memo):
         """
         Deep copy of a QuerySet doesn't populate the cache
         """
 
     def __deepcopy__(self, memo):
         """
         Deep copy of a QuerySet doesn't populate the cache
         """

-        obj = self.__class__()
-        for k,v in self.__dict__.items():
-            if k in ('_iter','_result_cache'):
+        obj = self.__class__(backend=self.backend)
+        for k, v in self.__dict__.items():
+            if k in ('_iter', '_result_cache'):

                 obj.__dict__[k] = None
             else:
                 obj.__dict__[k] = copy.deepcopy(v, memo)
                 obj.__dict__[k] = None
             else:
                 obj.__dict__[k] = copy.deepcopy(v, memo)


@@ -150,7 +482,7 @@ class TaskQuerySet(object):
         if klass is None:
             klass = self.__class__
         filter_obj = self.filter_obj.clone()
         if klass is None:
             klass = self.__class__
         filter_obj = self.filter_obj.clone()

-        c = klass(warrior=self.warrior, filter_obj=filter_obj)
+        c = klass(backend=self.backend, filter_obj=filter_obj)

         c.__dict__.update(kwargs)
         return c
 
         c.__dict__.update(kwargs)
         return c
 


@@ -158,7 +490,7 @@ class TaskQuerySet(object):
         """
         Fetch the tasks which match the current filters.
         """
         """
         Fetch the tasks which match the current filters.
         """

-        return self.warrior._execute_filter(self.filter_obj)
+        return self.backend.filter_tasks(self.filter_obj)

 
     def all(self):
         """
 
     def all(self):
         """


@@ -169,13 +501,18 @@ class TaskQuerySet(object):
     def pending(self):
         return self.filter(status=PENDING)
 
     def pending(self):
         return self.filter(status=PENDING)
 

-    def filter(self, **kwargs):
+    def completed(self):
+        return self.filter(status=COMPLETED)
+
+    def filter(self, *args, **kwargs):

         """
         Returns a new TaskQuerySet with the given filters added.
         """
         clone = self._clone()
         """
         Returns a new TaskQuerySet with the given filters added.
         """
         clone = self._clone()

-        for param, value in kwargs.items():
-            clone.filter_obj.add_filter(param, value)
+        for f in args:
+            clone.filter_obj.add_filter(f)
+        for key, value in kwargs.items():
+            clone.filter_obj.add_filter_param(key, value)

         return clone
 
     def get(self, **kwargs):
         return clone
 
     def get(self, **kwargs):


@@ -194,65 +531,3 @@ class TaskQuerySet(object):
         raise ValueError(
             'get() returned more than one Task -- it returned {0}! '
             'Lookup parameters were {1}'.format(num, kwargs))
         raise ValueError(
             'get() returned more than one Task -- it returned {0}! '
             'Lookup parameters were {1}'.format(num, kwargs))

-
-
-class TaskWarrior(object):
-    DEFAULT_FILTERS = {
-        'status': 'pending',
-    }
-
-    def __init__(self, data_location='~/.task', create=True):
-        if not os.path.exists(data_location):
-            os.makedirs(data_location)
-        self.config = {
-            'data.location': os.path.expanduser(data_location),
-        }
-        self.tasks = TaskQuerySet(self)
-
-    def _generate_command(self, command):
-        args = ['task', 'rc:/']
-        for item in self.config.items():
-            args.append('rc.{0}={1}'.format(*item))
-        args.append(command)
-        return ' '.join(args)
-
-    def _execute_command(self, command):
-        p = subprocess.Popen(self._generate_command(command), shell=True,
-                             stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-        stdout, stderr = p.communicate()
-        if p.returncode:
-            raise TaskWarriorException(stderr.strip())
-        return stdout.strip().split('\n')
-
-    def _format_filter_kwarg(self, kwarg):
-        key, val = kwarg[0], kwarg[1]
-        key = key.replace('__', '.')
-        return '{0}:{1}'.format(key, val)
-
-    def _execute_filter(self, filter_obj):
-        filter_commands = ' '.join(map(self._format_filter_kwarg,
-                                       filter_obj.get_filter_params()))
-        command = '{0} export'.format(filter_commands)
-        tasks = []
-        for line in self._execute_command(command):
-            if line:
-                tasks.append(Task(self, json.loads(line.strip(','))))
-        return tasks
-
-    def add_task(self, description, project=None):
-        args = ['add', description]
-        if project is not None:
-            args.append('project:{0}'.format(project))
-        self._execute_command(' '.join(args))
-
-    def delete_task(self, task_id):
-        self._execute_command('{0} rc.confirmation:no delete'.format(task_id))
-
-    def complete_task(self, task_id):
-        self._execute_command('{0} done'.format(task_id))
-
-    def import_tasks(self, tasks):
-        fd, path = tempfile.mkstemp()
-        with open(path, 'w') as f:
-            f.write(json.dumps(tasks))
-        self._execute_command('import {0}'.format(path))