From c6b767445cd497caa53445195705158a97cec2ce Mon Sep 17 00:00:00 2001
From: Paul Lamere <Paul.Lamere@gmail.com>
Date: Sun, 21 Feb 2016 09:02:51 -0500
Subject: [PATCH] Added reltime

---
 server/reltime.py | 161 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 161 insertions(+)
 create mode 100644 server/reltime.py

diff --git a/server/reltime.py b/server/reltime.py
new file mode 100644
index 0000000..0161bcb
--- /dev/null
+++ b/server/reltime.py
@@ -0,0 +1,161 @@
+'''
+    A relative time parser
+
+    parsers english time strings and returns the number of seconds that the 
+    input represents.  Throws a
+    ValueError if the input can't be parsed as a time string.
+
+    Some examples:
+
+    parse_to_rel_time("1 month") -> 2592000
+    parse_to_rel_time("2 days 2 hours") -> 180000
+    parse_to_rel_time("3 years 2 months 2 days") -> 99964800
+    parse_to_rel_time("3 years 2 months and 2 days ago") -> 99964800
+    parse_to_rel_time("3 years, 2 months and 22 days ago!") -> 101692800
+    parse_to_rel_time("  3    years,  2 months and 22 days ago!   ") -> 101692800
+    parse_to_rel_time("1 h 3 w 2 d") -> 1990800
+    parse_to_rel_time("last week") -> 604800
+    parse_to_rel_time("six weeks") -> 3628800
+    parse_to_rel_time("a week ago") -> 604800
+    parse_to_rel_time("twenty days ago") -> 1728000
+
+'''
+
+import re
+
+#    1m
+#    5Y3M2W4D3h2m2s
+#    5 years 3 months 2 weeks 4 days 3 hours 2 mins 2 secs
+#    5 Y 3 M 2 W 4 D 3h 2 m 2 s
+
+def parse_to_rel_time(str):
+    stop_words = set(['and', 'ago', 'since'])
+    delta_types = {
+        'second':1,
+        'sec':1,
+        'secs':1,
+        'seconds':1,
+        'second':1,
+        'minute':60,
+
+        'm':60,
+        'min':60,
+        'minute':60,
+        'minutes':60,
+
+        'h':3600,
+        'hr':3600,
+        'hrs':3600,
+        'hour':3600,
+        'hours':3600,
+
+        'day':60 * 60 * 24,
+        'd':60 * 60 * 24,
+        'days':60 * 60 * 24,
+
+        'fortnight':60 * 60 * 2 * 7,
+
+        'week':60 * 60 * 24 * 7,
+        'weeks':60 * 60 * 24 * 7,
+        'wks':60 * 60 * 24 * 7,
+        'w':60 * 60 * 24 * 7,
+
+        'month':60 * 60 * 24 * 30,
+        'months':60 * 60 * 24 * 30,
+        'mth':60 * 60 * 24 * 30,
+        'mths':60 * 60 * 24 * 30,
+        'mnth':60 * 60 * 24 * 30,
+        'mnths':60 * 60 * 24 * 30,
+
+        'year':60 * 60 * 24 * 365,
+        'years':60 * 60 * 24 * 365,
+        'yr':60 * 60 * 24 * 365,
+        'yrs':60 * 60 * 24 * 365,
+        'y':60 * 60 * 24 * 365,
+    }
+
+    num_subs = {
+        'last': 1, 'a': 1, 'one': 1, 'two': 2, 'three': 3,
+        'four': 4, 'five': 5, 'six': 6, 'seven': 7, 'eight': 8,
+        'nine': 9, 'ten': 10, 'eleven': 11, 'twelve': 12, 'thirteen': 13,
+        'fourteen': 14, 'fifteen': 15, 'sixteen': 16, 'seventeen': 17,
+        'eighteen': 18, 'nineteen': 19, 'twenty': 20,
+    }
+
+    delta = 0
+    words = re.findall(r"[\w]+", str)
+    words = [w for w in words if w not in stop_words]
+    if len(words) % 2 == 1:
+        raise ValueError('bad time format: ' + str)
+        
+    for i in xrange(0, len(words), 2):
+        snum = words[i]
+        type = words[i + 1].lower()
+
+        if snum in num_subs:
+            num = num_subs[snum]
+        else:
+            try:
+                num = int(snum)
+            except:
+                raise ValueError('number expected, but found ' + snum + ' instead in ' + str)
+
+        if type in delta_types:
+            delta += delta_types[type] * num
+        else:
+            raise ValueError('type expected, but found ' + type + ' instead in ' + str)
+
+    return delta
+
+if __name__ == '__main__':
+    HOUR = 60 * 60
+    DAY = 60 * 60 * 24
+    WEEK = 60 * 60 * 24 * 7
+    MONTH = 60 * 60 * 24 * 30
+    YEAR = 60 * 60 * 24 * 365
+
+    tests = [
+        ("1 month",  1 * MONTH),
+        ("2 days 2 hours", 2 * DAY + 2 * HOUR),
+        ("3 years 2 months 2 days", 3 * YEAR + 2 * MONTH + 2 * DAY),
+        ("3 years 2 months and 2 days ago", 3 * YEAR + 2 * MONTH + 2 * DAY),
+        ("3 years, 2 months and 22 days ago!", 3 * YEAR + 2 * MONTH + 22 * DAY),
+        ("  3        years,    2 months and 22 days ago!   ", 3 * YEAR + 2 * MONTH + 22 * DAY),
+        ("1 h 3 w 2 d", 1 * HOUR + 3 * WEEK + 2 * DAY),
+        ("last week",  1 * WEEK),
+        ("last year and 3 weeks ago",  1 * YEAR + 3 * WEEK),
+        ("six weeks",  6 * WEEK),
+        ("a week ago",  1 * WEEK),
+        ("twenty days ago",  20 * DAY),
+        ("6 mnths, 2 wks",  6 * MONTH + 2 * WEEK),
+    ]
+
+    bad_patterns = [
+        "1",
+    ]
+
+    for stest, res in tests:
+        time = parse_to_rel_time(stest)
+        if time == res:
+            print "GOOD", stest, time
+        else:
+            print "BAD", stest, res, time
+
+    print
+    print 'testing bad patterns'
+    for bp in bad_patterns:
+        try:
+            time = parse_to_rel_time(bp)
+            print 'BAD', 'unexpected parse of', bp
+        except ValueError as e:
+            print 'GOOD', e
+
+    print "some time examples"
+    for stest, res in tests:
+        print 'parse_to_rel_time("' + stest + '")', '->', res
+
+    print "some time examples"
+    for stest, res in tests:
+        print "<li>" + stest + "</li>"
+    print
+