From 40e5fcb07e317efdcc4a12f9c517c5613fc45944 Mon Sep 17 00:00:00 2001
From: Matt Snider <matt.snider@alum.utoronto.ca>
Date: Fri, 16 Nov 2018 02:11:57 +0100
Subject: [PATCH] Handle recurring tasks from date_string (recur)

---
 migrate.py | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 54 insertions(+), 4 deletions(-)

diff --git a/migrate.py b/migrate.py
index f5b0ca1..6f9a892 100644
--- a/migrate.py
+++ b/migrate.py
@@ -1,4 +1,5 @@
 import click
+import re
 from datetime import datetime
 from taskw import TaskWarrior
 from todoist.api import TodoistAPI
@@ -40,14 +41,15 @@ def migrate(interactive, no_sync):
         ]
         entry = taskwarrior_date(task['date_added'])
         due = taskwarrior_date(task['due_date_utc'])
+        recur = taskwarrior_recur(task['date_string'])
 
         if interactive and not click.confirm(f"Import '{name}'?"):
             continue
 
-        add_task(tid, name, project, tags, priority, entry, due)
+        add_task(tid, name, project, tags, priority, entry, due, recur)
 
 
-def add_task(tid, name, project, tags, priority, entry, due):
+def add_task(tid, name, project, tags, priority, entry, due, recur):
     """Add a taskwarrior task from todoist task
 
     Returns the taskwarrior task.
@@ -55,7 +57,7 @@ def add_task(tid, name, project, tags, priority, entry, due):
     info(f"Importing '{name}' ({project}) - ", nl=False)
     try:
         tw_task = taskwarrior.task_add(name, project=project, tags=tags,
-                priority=priority, entry=entry, due=due)
+                priority=priority, entry=entry, due=due, recur=recur)
     except:
         error('FAILED')
     else:
@@ -83,7 +85,7 @@ def taskwarrior_priority(priority):
     return PRIORITIES[priority]
 
 def taskwarrior_date(date):
-    """ Converts a date from Todist to taskwarrior
+    """ Converts a date from Todoist to taskwarrior
 
     Todoist: Fri 26 Sep 2014 08:25:05 +0000 (what is this called)?
     taskwarrior: ISO-8601
@@ -92,6 +94,54 @@ def taskwarrior_date(date):
         return None
     return datetime.strptime(date, '%a %d %b %Y %H:%M:%S %z').isoformat()
 
+
+def taskwarrior_recur(desc):
+    """ Converts a repeating interval from Todoist to taskwarrior.
+
+    Field:
+    - Todoist: date_string
+    - taskwarrior: recur
+
+    Examples:
+    - every other `interval` `period` -> 2 `period`
+    - every `interval` `period`       -> `interval` `period`
+    - every `day of week`             -> weekly
+
+    _Note_: just because Todoist sets `date_string` doesn't mean
+    that the task is repeating. Mostly it just indicates that the
+    user input via string and not date selector.
+    """
+    if not desc:
+        return
+    return _match_every(desc) or _match_weekly(desc)
+
+
+RE_INTERVAL = 'other|\d+'
+RE_PERIOD = 'day|week|month|year'
+RE_REPEAT_EVERY = re.compile(
+    f'^\s*every\s+((?P<interval>{RE_INTERVAL})\s+)?(?P<period>{RE_PERIOD})s?\s*$'
+)
+
+def _match_every(desc):
+    match =  RE_REPEAT_EVERY.match(desc.lower())
+    if not match:
+        return
+
+    interval = match.group('interval')
+    period = match.group('period')
+    if interval == 'other':
+        interval = 2
+    return f'{interval} {period}'
+
+
+RE_REPEAT_WEEKLY = re.compile(
+    '^\s*every\s+(mon|monday|tues|tuesday|weds|wednesday|thurs|thursday|fri|friday|sat|saturday|sun|sunday)\s*'
+)
+
+def _match_weekly(desc):
+    return ('weekly' if RE_REPEAT_WEEKLY.match(desc.lower()) else None)
+
+
 """ Entrypoint """
 
 if __name__ == '__main__':