[doneit] / src / toolbox.py

import sys
import StringIO
import urllib
from xml.dom import minidom
import datetime


class Optional(object):
        """
        Taglines:
        Even you don't have to worry about knowing when to perform None checks
        When the NULL object pattern just isn't good enough

        >>> a = Optional()
        >>> a.is_good()
        False
        >>> a.get_nothrow("Blacksheep")
        'Blacksheep'
        >>> a.set("Lamb")
        >>> a.is_good()
        True
        >>> a.get_nothrow("Blacksheep"), a.get(), a()
        ('Lamb', 'Lamb', 'Lamb')
        >>> a.clear()
        >>> a.is_good()
        False
        >>> a.get_nothrow("Blacksheep")
        'Blacksheep'
        >>>
        >>> b = Optional("Lamb")
        >>> a.set("Lamb")
        >>> a.is_good()
        True
        >>> a.get_nothrow("Blacksheep"), a.get(), a()
        ('Lamb', 'Lamb', 'Lamb')
        >>> a.clear()
        >>> a.is_good()
        False
        >>> a.get_nothrow("Blacksheep")
        'Blacksheep'
        """

        class NonExistent(object):
                pass

        def __init__(self, value = NonExistent):
                self._value = value

        def set(self, value):
                self._value = value

        def clear(self):
                self._value = self.NonExistent

        def is_good(self):
                return self._value is not self.NonExistent

        def get_nothrow(self, default = None):
                return self._value if self.is_good() else default

        def get(self):
                if not self.is_good():
                        raise ReferenceError("Optional not initialized")
                return self._value

        def __call__(self):
                # Implemented to imitate weakref
                return self.get()

        def __str__(self):
                return str(self.get_nothrow(""))

        def __repr__(self):
                return "<Optional at %x; to %r>" % (
                        id(self), self.get_nothrow("Nothing")
                )


def open_anything(source, alternative=None):
        """URI, filename, or string --> stream

        This function lets you define parsers that take any input source
        (URL, pathname to local or network file, or actual data as a string)
        and deal with it in a uniform manner.  Returned object is guaranteed
        to have all the basic stdio read methods (read, readline, readlines).
        Just .close() the object when you're done with it.
        """
        if hasattr(source, "read"):
                return source

        if source == '-':
                return sys.stdin

        # try to open with urllib (if source is http, ftp, or file URL)
        try:
                return urllib.urlopen(source)
        except (IOError, OSError):
                ##pass
                print "ERROR with URL ("+source+")!\n"

        # try to open with native open function (if source is pathname)
        try:
                return open(source)
        except (IOError, OSError):
                ##pass
                print "ERROR with file!\n"

        # treat source as string
        if alternative == None:
                print 'LAST RESORT.  String is "'+source+'"\n'
                return StringIO.StringIO(str(source))
        else:
                print 'LAST RESORT.  String is "'+alternative+'"\n'
                return StringIO.StringIO(str(alternative))


def load_xml(source, alternative=None):
        """load XML input source, return parsed XML document

        - a URL of a remote XML file ("http://diveintopython.org/kant.xml")
        - a filename of a local XML file ("~/diveintopython/common/py/kant.xml")
        - standard input ("-")
        - the actual XML document, as a string
        """
        sock = open_anything(source, alternative)
        try:
                xmldoc = minidom.parse(sock).documentElement
        except (IOError, OSError):
                print "ERROR with data"
                sock.close()
                sock = open_anything('<response method="getProjects"><project projName="ERROR!"/></response>')
                xmldoc = minidom.parse(sock).documentElement
        sock.close()
        return xmldoc


def is_same_year(targetDate, todaysDate = datetime.datetime.today()):
        return targetDate.year == todaysDate.year


def is_same_month(targetDate, todaysDate = datetime.datetime.today()):
        return targetDate.month == todaysDate.month


def is_same_day(targetDate, todaysDate = datetime.datetime.today()):
        return targetDate.day == todaysDate.day


def to_fuzzy_date(targetDate, todaysDate = datetime.datetime.today()):
        """
        Conert a date/time/datetime object to a fuzzy date

        >>> todaysDate = datetime.date(2009, 4, 16)
        >>> to_fuzzy_date(datetime.date(1, 4, 6), todaysDate)
        'Forever ago'
        >>> to_fuzzy_date(datetime.date(2008, 4, 13), todaysDate)
        'Last year'
        >>> to_fuzzy_date(datetime.date(2009, 4, 13), todaysDate)
        'Last Monday'
        >>> to_fuzzy_date(datetime.date(2009, 4, 20), todaysDate)
        'This Monday'
        >>> to_fuzzy_date(datetime.date(2010, 4, 13), todaysDate)
        'Next year'
        >>> to_fuzzy_date(datetime.date(2012, 12, 12), todaysDate)
        'Forever from now'
        """
        delta = targetDate - todaysDate
        days = abs(delta.days)
        noDifference = datetime.timedelta()
        isFuture = noDifference < delta
        directionBy1 = "Next" if isFuture else "Last"
        directionByN = "Later" if isFuture else "Earlier"

        yearDelta = abs(targetDate.year - todaysDate.year)
        if 1 < yearDelta:
                directionByInf = "from now" if isFuture else "ago"
                return "Forever %s" % directionByInf
        elif 1 == yearDelta:
                return "%s year" % directionBy1

        monthDelta = abs(targetDate.month - todaysDate.month)
        if 1 < monthDelta:
                return "%s this year" % directionByN
        elif 1 == monthDelta:
                return "%s month" % directionBy1

        dayDelta = abs(targetDate.day - todaysDate.day)
        if 14 < dayDelta:
                return "%s this month" % directionByN
        elif 1 < dayDelta:
                directionInWeek = "This" if isFuture else "Last"
                days = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]
                return "%s %s" % (directionInWeek, days[targetDate.weekday()])
        elif 1 == dayDelta:
                return "%s day" % directionBy1
        else:
                return "Today"