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e6daace5064bc275d1be93308138cf160804187b
[etc/taskwarrior.git] / tasklib / backends.py
1 import abc
2 import copy
3 import datetime
4 import json
5 import logging
6 import os
7 import re
8 import six
9 import subprocess
10
11 from .task import Task, TaskQuerySet, ReadOnlyDictView
12 from .filters import TaskWarriorFilter
13 from .serializing import local_zone
14
15 DATE_FORMAT_CALC = '%Y-%m-%dT%H:%M:%S'
16
17 logger = logging.getLogger(__name__)
18
19
20 class Backend(object):
21
22     @abc.abstractproperty
23     def filter_class(self):
24         """Returns the TaskFilter class used by this backend"""
25         pass
26
27     @abc.abstractmethod
28     def filter_tasks(self, filter_obj):
29         """Returns a list of Task objects matching the given filter"""
30         pass
31
32     @abc.abstractmethod
33     def save_task(self, task):
34         pass
35
36     @abc.abstractmethod
37     def delete_task(self, task):
38         pass
39
40     @abc.abstractmethod
41     def start_task(self, task):
42         pass
43
44     @abc.abstractmethod
45     def stop_task(self, task):
46         pass
47
48     @abc.abstractmethod
49     def complete_task(self, task):
50         pass
51
52     @abc.abstractmethod
53     def refresh_task(self, task, after_save=False):
54         """
55         Refreshes the given task. Returns new data dict with serialized
56         attributes.
57         """
58         pass
59
60     @abc.abstractmethod
61     def annotate_task(self, task, annotation):
62         pass
63
64     @abc.abstractmethod
65     def denotate_task(self, task, annotation):
66         pass
67
68     @abc.abstractmethod
69     def sync(self):
70         """Syncs the backend database with the taskd server"""
71         pass
72
73     def convert_datetime_string(self, value):
74         """
75         Converts TW syntax datetime string to a localized datetime
76         object. This method is not mandatory.
77         """
78         raise NotImplementedError
79
80
81 class TaskWarriorException(Exception):
82     pass
83
84
85 class TaskWarrior(Backend):
86
87     VERSION_2_1_0 = six.u('2.1.0')
88     VERSION_2_2_0 = six.u('2.2.0')
89     VERSION_2_3_0 = six.u('2.3.0')
90     VERSION_2_4_0 = six.u('2.4.0')
91     VERSION_2_4_1 = six.u('2.4.1')
92     VERSION_2_4_2 = six.u('2.4.2')
93     VERSION_2_4_3 = six.u('2.4.3')
94     VERSION_2_4_4 = six.u('2.4.4')
95     VERSION_2_4_5 = six.u('2.4.5')
96
97     def __init__(self, data_location=None, create=True, taskrc_location='~/.taskrc'):
98         self.taskrc_location = os.path.expanduser(taskrc_location)
99
100         # If taskrc does not exist, pass / to use defaults and avoid creating
101         # dummy .taskrc file by TaskWarrior
102         if not os.path.exists(self.taskrc_location):
103             self.taskrc_location = '/'
104
105         self._config = None
106         self.version = self._get_version()
107         self.overrides = {
108             'confirmation': 'no',
109             'dependency.confirmation': 'no',  # See TW-1483 or taskrc man page
110             'recurrence.confirmation': 'no',  # Necessary for modifying R tasks
111
112             # Defaults to on since 2.4.5, we expect off during parsing
113             'json.array': 'off',
114
115             # 2.4.3 onwards supports 0 as infite bulk, otherwise set just
116             # arbitrary big number which is likely to be large enough
117             'bulk': 0 if self.version >= self.VERSION_2_4_3 else 100000,
118         }
119
120         # Set data.location override if passed via kwarg
121         if data_location is not None:
122             data_location = os.path.expanduser(data_location)
123             if create and not os.path.exists(data_location):
124                 os.makedirs(data_location)
125             self.overrides['data.location'] = data_location
126
127         self.tasks = TaskQuerySet(self)
128
129     def _get_command_args(self, args, config_override=None):
130         command_args = ['task', 'rc:{0}'.format(self.taskrc_location)]
131         overrides = self.overrides.copy()
132         overrides.update(config_override or dict())
133         for item in overrides.items():
134             command_args.append('rc.{0}={1}'.format(*item))
135         command_args.extend([
136             x.decode('utf-8') if isinstance(x, six.binary_type)
137             else six.text_type(x) for x in args
138         ])
139         return command_args
140
141     def _get_version(self):
142         p = subprocess.Popen(
143             ['task', '--version'],
144             stdout=subprocess.PIPE,
145             stderr=subprocess.PIPE)
146         stdout, stderr = [x.decode('utf-8') for x in p.communicate()]
147         return stdout.strip('\n')
148
149     def _get_modified_task_fields_as_args(self, task):
150         args = []
151
152         def add_field(field):
153             # Add the output of format_field method to args list (defaults to
154             # field:value)
155             serialized_value = task._serialize(field, task._data[field])
156
157             # Empty values should not be enclosed in quotation marks, see
158             # TW-1510
159             if serialized_value is '':
160                 escaped_serialized_value = ''
161             else:
162                 escaped_serialized_value = six.u("'{0}'").format(
163                     serialized_value)
164
165             format_default = lambda task: six.u("{0}:{1}").format(
166                 field, escaped_serialized_value)
167
168             format_func = getattr(self, 'format_{0}'.format(field),
169                                   format_default)
170
171             args.append(format_func(task))
172
173         # If we're modifying saved task, simply pass on all modified fields
174         if task.saved:
175             for field in task._modified_fields:
176                 add_field(field)
177
178         # For new tasks, pass all fields that make sense
179         else:
180             for field in task._data.keys():
181                 # We cannot set stuff that's read only (ID, UUID, ..)
182                 if field in task.read_only_fields:
183                     continue
184                 # We do not want to do field deletion for new tasks
185                 if task._data[field] is None:
186                     continue
187                 # Otherwise we're fine
188                 add_field(field)
189
190         return args
191
192     def format_depends(self, task):
193         # We need to generate added and removed dependencies list,
194         # since Taskwarrior does not accept redefining dependencies.
195
196         # This cannot be part of serialize_depends, since we need
197         # to keep a list of all depedencies in the _data dictionary,
198         # not just currently added/removed ones
199
200         old_dependencies = task._original_data.get('depends', set())
201
202         added = task['depends'] - old_dependencies
203         removed = old_dependencies - task['depends']
204
205         # Removed dependencies need to be prefixed with '-'
206         return 'depends:' + ','.join(
207             [t['uuid'] for t in added] +
208             ['-' + t['uuid'] for t in removed]
209         )
210
211     def format_description(self, task):
212         # Task version older than 2.4.0 ignores first word of the
213         # task description if description: prefix is used
214         if self.version < self.VERSION_2_4_0:
215             return task._data['description']
216         else:
217             return six.u("description:'{0}'").format(task._data['description'] or '')
218
219     def convert_datetime_string(self, value):
220
221         if self.version >= self.VERSION_2_4_0:
222             # For strings, use 'task calc' to evaluate the string to datetime
223             # available since TW 2.4.0
224             args = value.split()
225             result = self.execute_command(['calc'] + args)
226             naive = datetime.datetime.strptime(result[0], DATE_FORMAT_CALC)
227             localized = local_zone.localize(naive)
228         else:
229             raise ValueError("Provided value could not be converted to "
230                              "datetime, its type is not supported: {}"
231                              .format(type(value)))
232
233         return localized
234
235     @property
236     def filter_class(self):
237         return TaskWarriorFilter
238
239     # Public interface
240
241     @property
242     def config(self):
243         # First, check if memoized information is available
244         if self._config:
245             return self._config
246
247         # If not, fetch the config using the 'show' command
248         raw_output = self.execute_command(
249             ['show'],
250             config_override={'verbose': 'nothing'}
251         )
252
253         config = dict()
254         config_regex = re.compile(r'^(?P<key>[^\s]+)\s+(?P<value>[^\s].+$)')
255
256         for line in raw_output:
257             match = config_regex.match(line)
258             if match:
259                 config[match.group('key')] = match.group('value').strip()
260
261         # Memoize the config dict
262         self._config = ReadOnlyDictView(config)
263
264         return self._config
265
266     def execute_command(self, args, config_override=None, allow_failure=True,
267                         return_all=False):
268         command_args = self._get_command_args(
269             args, config_override=config_override)
270         logger.debug(u' '.join(command_args))
271
272         p = subprocess.Popen(command_args, stdout=subprocess.PIPE,
273                              stderr=subprocess.PIPE)
274         stdout, stderr = [x.decode('utf-8') for x in p.communicate()]
275         if p.returncode and allow_failure:
276             if stderr.strip():
277                 error_msg = stderr.strip()
278             else:
279                 error_msg = stdout.strip()
280             error_msg += u'\nCommand used: ' + u' '.join(command_args)
281             raise TaskWarriorException(error_msg)
282
283         # Return all whole triplet only if explicitly asked for
284         if not return_all:
285             return stdout.rstrip().split('\n')
286         else:
287             return (stdout.rstrip().split('\n'),
288                     stderr.rstrip().split('\n'),
289                     p.returncode)
290
291     def enforce_recurrence(self):
292         # Run arbitrary report command which will trigger generation
293         # of recurrent tasks.
294
295         # Only necessary for TW up to 2.4.1, fixed in 2.4.2.
296         if self.version < self.VERSION_2_4_2:
297             self.execute_command(['next'], allow_failure=False)
298
299     def merge_with(self, path, push=False):
300         path = path.rstrip('/') + '/'
301         self.execute_command(['merge', path], config_override={
302             'merge.autopush': 'yes' if push else 'no',
303         })
304
305     def undo(self):
306         self.execute_command(['undo'])
307
308     # Backend interface implementation
309
310     def filter_tasks(self, filter_obj):
311         self.enforce_recurrence()
312         args = ['export'] + filter_obj.get_filter_params()
313         tasks = []
314         for line in self.execute_command(args):
315             if line:
316                 data = line.strip(',')
317                 try:
318                     filtered_task = Task(self)
319                     filtered_task._load_data(json.loads(data))
320                     tasks.append(filtered_task)
321                 except ValueError:
322                     raise TaskWarriorException('Invalid JSON: %s' % data)
323         return tasks
324
325     def save_task(self, task):
326         """Save a task into TaskWarrior database using add/modify call"""
327
328         args = [task['uuid'], 'modify'] if task.saved else ['add']
329         args.extend(self._get_modified_task_fields_as_args(task))
330         output = self.execute_command(args)
331
332         # Parse out the new ID, if the task is being added for the first time
333         if not task.saved:
334             id_lines = [l for l in output if l.startswith('Created task ')]
335
336             # Complain loudly if it seems that more tasks were created
337             # Should not happen.
338             # Expected output: Created task 1.
339             #                  Created task 1 (recurrence template).
340             if len(id_lines) != 1 or len(id_lines[0].split(' ')) not in (3, 5):
341                 raise TaskWarriorException("Unexpected output when creating "
342                                            "task: %s" % '\n'.join(id_lines))
343
344             # Circumvent the ID storage, since ID is considered read-only
345             identifier = id_lines[0].split(' ')[2].rstrip('.')
346
347             # Identifier can be either ID or UUID for completed tasks
348             try:
349                 task._data['id'] = int(identifier)
350             except ValueError:
351                 task._data['uuid'] = identifier
352
353         # Refreshing is very important here, as not only modification time
354         # is updated, but arbitrary attribute may have changed due hooks
355         # altering the data before saving
356         task.refresh(after_save=True)
357
358     def delete_task(self, task):
359         self.execute_command([task['uuid'], 'delete'])
360
361     def start_task(self, task):
362         self.execute_command([task['uuid'], 'start'])
363
364     def stop_task(self, task):
365         self.execute_command([task['uuid'], 'stop'])
366
367     def complete_task(self, task):
368         # Older versions of TW do not stop active task at completion
369         if self.version < self.VERSION_2_4_0 and task.active:
370             task.stop()
371
372         self.execute_command([task['uuid'], 'done'])
373
374     def annotate_task(self, task, annotation):
375         args = [task['uuid'], 'annotate', annotation]
376         self.execute_command(args)
377
378     def denotate_task(self, task, annotation):
379         args = [task['uuid'], 'denotate', annotation]
380         self.execute_command(args)
381
382     def refresh_task(self, task, after_save=False):
383         # We need to use ID as backup for uuid here for the refreshes
384         # of newly saved tasks. Any other place in the code is fine
385         # with using UUID only.
386         args = [task['uuid'] or task['id'], 'export']
387         output = self.execute_command(args)
388
389         def valid(output):
390             return len(output) == 1 and output[0].startswith('{')
391
392         # For older TW versions attempt to uniquely locate the task
393         # using the data we have if it has been just saved.
394         # This can happen when adding a completed task on older TW versions.
395         if (not valid(output) and self.version < self.VERSION_2_4_5
396                 and after_save):
397
398             # Make a copy, removing ID and UUID. It's most likely invalid
399             # (ID 0) if it failed to match a unique task.
400             data = copy.deepcopy(task._data)
401             data.pop('id', None)
402             data.pop('uuid', None)
403
404             taskfilter = self.filter_class(self)
405             for key, value in data.items():
406                 taskfilter.add_filter_param(key, value)
407
408             output = self.execute_command(['export'] +
409                                           taskfilter.get_filter_params())
410
411         # If more than 1 task has been matched still, raise an exception
412         if not valid(output):
413             raise TaskWarriorException(
414                 "Unique identifiers {0} with description: {1} matches "
415                 "multiple tasks: {2}".format(
416                     task['uuid'] or task['id'], task['description'], output)
417             )
418
419         return json.loads(output[0])
420
421     def sync(self):
422         self.execute_command(['sync'])