Refactoring PRAW generators.

rtv/content_generators.py

@@ -0,0 +1,135 @@
+from datetime import datetime, timedelta
+
+
+def clean(unicode_string):
+    """
+    Convert unicode string into ascii-safe characters.
+    """
+
+    return unicode_string.encode('ascii', 'replace').replace('\\', '')
+
+
+def humanize_timestamp(utc_timestamp, verbose=False):
+    """
+    Convert a utc timestamp into a human readable relative-time.
+    """
+
+    timedelta = datetime.utcnow() - datetime.utcfromtimestamp(utc_timestamp)
+
+    seconds = int(timedelta.total_seconds())
+    if seconds < 60:
+        return 'moments ago' if verbose else '0min'
+    minutes = seconds / 60
+    if minutes < 60:
+        return ('%d minutes ago' % minutes) if verbose else ('%dmin' % minutes)
+    hours = minutes / 60
+    if hours < 24:
+        return ('%d hours ago' % hours) if verbose else ('%dhr' % hours)
+    days = hours / 24
+    if days < 30:
+        return ('%d days ago' % days) if verbose else ('%dday' % days)
+    months = days / 30.4
+    if months < 12:
+        return ('%d months ago' % months) if verbose else ('%dmonth' % months)
+    years = months / 12
+    return ('%d years ago' % years) if verbose else ('%dyr' % years)
+
+
+class SubmissionGenerator(object):
+    """
+    Facilitates navigating through the comments in a PRAW submission.
+    """
+
+    def __init__(self, submission):
+
+        self.submission = submission
+
+    @staticmethod
+    def flatten_comments(submission):
+        """
+        Flatten a PRAW comment tree while preserving the nested level of each
+        comment via the `nested_level` attribute.
+        """
+
+        stack = submission[:]
+        for item in stack:
+            item.nested_level = 0
+
+        retval = []
+        while stack:
+            item = stack.pop(0)
+            nested = getattr(item, 'replies', None)
+            if nested:
+                for n in nested:
+                    n.nested_level = item.nested_level + 1
+                stack[0:0] = nested
+            retval.append(item)
+        return retval
+
+
+class SubredditGenerator(object):
+    """
+    Grabs a subreddit from PRAW lazily and store in an internal list for repeat
+    access.
+
+    params:
+        session (praw.Reddit): Active reddit connection
+        subreddit (str): Subreddit to connect to, None defaults to front page.
+    """
+
+    def __init__(self, reddit_session, subreddit=None):
+
+        self.r = reddit_session
+        self.r.config.decode_html_entities = True
+
+        if subreddit is None:
+            self._submissions = self.r.get_front_page(limit=None)
+        else:
+            self._submissions = self.r.get_subreddit(subreddit, limit=None)
+
+        self._submission_data = []
+
+    @staticmethod
+    def strip_praw_submission(sub):
+        """
+        Parse through a submission and return a dict with data ready to be
+        displayed through the terminal.
+        """
+
+        is_selfpost = lambda s: s.startswith('http://www.reddit.com/r/')
+
+        data = {}
+        data['title'] = clean(sub.title)
+        data['created'] = humanize_timestamp(sub.created_utc)
+        data['comments'] = '{} comments'.format(sub.num_comments)
+        data['score'] = '{} pts'.format(sub.score)
+        data['author'] = clean(sub.author.name)
+        data['subreddit'] = clean(sub.subreddit.url)
+        data['url'] = ('(selfpost)' if is_selfpost(sub.url) else clean(sub.url))
+
+        return data
+
+    def get(self, index, n_cols):
+        """
+        Grab the `i`th submission, with the title field formatted to fit inside
+        of a window of width `n`
+        """
+
+        assert(index >= 0)
+
+        while index >= len(self._submission_data):
+            data = self._strip_praw_submission(self._submissions.next())
+            self._submission_data.append(data)
+
+        # Modifies the original original dict, faster than copying
+        data = self._submission_data[index]
+        data['split_title'] = textwrap.wrap(data['title'], width=n_cols)
+        data['n_rows'] = len(data['split_title']) + 3
+
+        return data
+
+    def iterate(self, index, n_cols):
+
+        while True:
+            yield self.get(index, n_cols)
+            index += 1