# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1264298153 -3600
# Node ID 0340bf1c9f224fce6aee499f51879b7a1af3475c
# Parent  fdf1ec151ab6b90fdabd9c721f820862f2730da4
Introduced abstractions for event pages, months and dates with substantial
modifications made to the rest of the code to handle these correctly.

diff -r fdf1ec151ab6 -r 0340bf1c9f22 EventAggregatorSupport.py
--- a/EventAggregatorSupport.py	Mon Jan 18 01:00:35 2010 +0100
+++ b/EventAggregatorSupport.py	Sun Jan 24 02:55:53 2010 +0100
@@ -2,7 +2,7 @@
 """
     MoinMoin - EventAggregator library
 
-    @copyright: 2008, 2009 by Paul Boddie <paul@boddie.org.uk>
+    @copyright: 2008, 2009, 2010 by Paul Boddie <paul@boddie.org.uk>
     @copyright: 2000-2004 Juergen Hermann <jh@web.de>,
                 2005-2008 MoinMoin:ThomasWaldmann.
     @license: GNU GPL (v2 or later), see COPYING.txt for details.
@@ -65,8 +65,74 @@
             category_regexp = re.compile(u'^%s$' % ur'(?P<all>Category(?P<key>(?!Template)\S+))', re.UNICODE)
         return category_regexp
 
+# Textual representations.
+
+def getHTTPTimeString(tmtuple):
+    return "%s, %02d %s %04d %02d:%02d:%02d GMT" % (
+        weekday_labels[tmtuple.tm_wday],
+        tmtuple.tm_mday,
+        month_labels[tmtuple.tm_mon -1], # zero-based labels
+        tmtuple.tm_year,
+        tmtuple.tm_hour,
+        tmtuple.tm_min,
+        tmtuple.tm_sec
+        )
+
+def getSimpleWikiText(text):
+
+    """
+    Return the plain text representation of the given 'text' which may employ
+    certain Wiki syntax features, such as those providing verbatim or monospaced
+    text.
+    """
+
+    # NOTE: Re-implementing support for verbatim text and linking avoidance.
+
+    return "".join([s for s in verbatim_regexp.split(text) if s is not None])
+
+def getEncodedWikiText(text):
+
+    "Encode the given 'text' in a verbatim representation."
+
+    return "<<Verbatim(%s)>>" % text
+
+def getPrettyTitle(title):
+
+    "Return a nicely formatted version of the given 'title'."
+
+    return title.replace("_", " ").replace("/", u" » ")
+
+def getMonthLabel(month):
+
+    "Return an unlocalised label for the given 'month'."
+
+    return month_labels[month - 1] # zero-based labels
+
+def getDayLabel(weekday):
+
+    "Return an unlocalised label for the given 'weekday'."
+
+    return weekday_labels[weekday]
+
 # Action support functions.
 
+def getPageRevision(page):
+
+    "Return the revision details dictionary for the given 'page'."
+
+    # From Page.edit_info...
+
+    if hasattr(page, "editlog_entry"):
+        line = page.editlog_entry()
+    else:
+        line = page._last_edited(page.request) # MoinMoin 1.5.x and 1.6.x
+
+    timestamp = line.ed_time_usecs
+    mtime = wikiutil.version2timestamp(long(timestamp)) # must be long for py 2.2.x
+    return {"timestamp" : time.gmtime(mtime), "comment" : line.comment}
+
+# Category discovery and searching.
+
 def getCategories(request):
 
     """
@@ -95,35 +161,12 @@
     mapping.sort()
     return mapping
 
-def getPageRevision(page):
-
-    # From Page.edit_info...
-
-    if hasattr(page, "editlog_entry"):
-        line = page.editlog_entry()
-    else:
-        line = page._last_edited(page.request) # MoinMoin 1.5.x and 1.6.x
-
-    timestamp = line.ed_time_usecs
-    mtime = wikiutil.version2timestamp(long(timestamp)) # must be long for py 2.2.x
-    return {"timestamp" : time.gmtime(mtime), "comment" : line.comment}
+def getCategoryPages(pagename, request):
 
-def getHTTPTimeString(tmtuple):
-    return "%s, %02d %s %04d %02d:%02d:%02d GMT" % (
-        weekday_labels[tmtuple.tm_wday],
-        tmtuple.tm_mday,
-        month_labels[tmtuple.tm_mon -1], # zero-based labels
-        tmtuple.tm_year,
-        tmtuple.tm_hour,
-        tmtuple.tm_min,
-        tmtuple.tm_sec
-        )
-
-# The main activity functions.
-
-def getPages(pagename, request):
-
-    "Return the links minus category links for 'pagename' using the 'request'."
+    """
+    Return the pages associated with the given category 'pagename' using the
+    'request'.
+    """
 
     query = search.QueryParser().parse_query('category:%s' % pagename)
     if isMoin15():
@@ -139,46 +182,191 @@
             pages.append(page)
     return pages
 
-def getSimpleWikiText(text):
+# The main activity functions.
+
+class EventPage:
+
+    "An event page."
+
+    def __init__(self, page):
+        self.page = page
+        self.details = None
+        self.body = None
+        self.categories = None
+
+    def copyPage(self, page):
+
+        "Copy the body of the given 'page'."
+
+        self.body = page.getBody()
+
+    def getPageURL(self, request):
+
+        "Using 'request', return the URL of this page."
 
-    """
-    Return the plain text representation of the given 'text' which may employ
-    certain Wiki syntax features, such as those providing verbatim or monospaced
-    text.
-    """
+        page = self.page
+
+        if isMoin15():
+            return request.getQualifiedURL(page.url(request))
+        else:
+            return request.getQualifiedURL(page.url(request, relative=0))
+
+    def getFormat(self):
+
+        "Get the format used on this page."
 
-    # NOTE: Re-implementing support for verbatim text and linking avoidance.
+        if isMoin15():
+            return "wiki" # page.pi_format
+        else:
+            return self.page.pi["format"]
+
+    def getRevisions(self):
+
+        "Return a list of page revisions."
+
+        return self.page.getRevList()
+
+    def getPageRevision(self):
 
-    return "".join([s for s in verbatim_regexp.split(text) if s is not None])
+        "Return the revision details dictionary for this page."
+
+        return getPageRevision(self.page)
+
+    def getPageName(self):
+
+        "Return the page name."
+
+        return self.page.page_name
 
-def getEncodedWikiText(text):
+    def getPrettyPageName(self):
+
+        "Return a nicely formatted title/name for this page."
+
+        return getPrettyPageName(self.page)
+
+    def getBody(self):
+
+        "Get the current page body."
 
-    "Encode the given 'text' in a verbatim representation."
+        if self.body is None:
+            self.body = self.page.get_raw_body()
+        return self.body
+
+    def getEventDetails(self):
+
+        "Return a dictionary of event details from this page."
+
+        if self.details is None:
+            self.details = {}
 
-    return "<<Verbatim(%s)>>" % text
+            if self.getFormat() == "wiki":
+                for match in definition_list_regexp.finditer(self.getBody()):
+
+                    # Skip commented-out items.
 
-def getFormat(page):
+                    if match.group("optcomment"):
+                        continue
+
+                    # Permit case-insensitive list terms.
+
+                    term = match.group("term").lower()
+                    desc = match.group("desc")
+
+                    # Special value type handling.
 
-    "Get the format used on 'page'."
+                    # Dates.
+
+                    if term in ("start", "end"):
+                        desc = getDate(desc)
+
+                    # Lists (whose elements may be quoted).
+
+                    elif term in ("topics", "categories"):
+                        desc = [getSimpleWikiText(value.strip()) for value in desc.split(",")]
+
+                    # Labels which may well be quoted.
+
+                    elif term in ("title", "summary", "description"):
+                        desc = getSimpleWikiText(desc)
+
+                    if desc is not None:
+                        self.details[term] = desc
+
+        return self.details
+
+    def getCategoryMembership(self):
 
-    if isMoin15():
-        return "wiki" # page.pi_format
-    else:
-        return page.pi["format"]
+        "Get the category names from this page."
+
+        if self.categories is None:
+            body = self.getBody()
+            match = category_membership_regexp.search(body)
+            self.categories = match.findall().split()
+
+        return self.categories
+
+    def getEventSummary(self, event_parent=None):
 
-def getEventDetails(page):
+        """
+        Return either the given title or summary of the event described by this
+        page, according to the page's event details, or using the pretty version
+        of the page name.
+
+        If the optional 'event_parent' is specified, any page beneath the given
+        'event_parent' page in the page hierarchy will omit this parent information
+        if its name is used as the summary.
+        """
+
+        event_details = self.getEventDetails()
 
-    "Return a dictionary of event details from the given 'page'."
+        if event_details.has_key("title"):
+            return event_details["title"]
+        elif event_details.has_key("summary"):
+            return event_details["summary"]
+        else:
+            # If appropriate, remove the parent details and "/" character.
+
+            title = self.getPageName()
 
-    event_details = {}
+            if event_parent is not None and title.startswith(event_parent):
+                title = title[len(event_parent.rstrip("/")) + 1:]
+
+            return getPrettyTitle(title)
+
+    def setEventDetails(self, event_details):
+
+        "Set the 'event_details' for this page."
+
+        self.details = event_details
+
+    def setCategoryMembership(self, category_names):
 
-    if getFormat(page) == "wiki":
-        for match in definition_list_regexp.finditer(page.get_raw_body()):
+        """
+        Set the category membership for the page using the specified
+        'category_names'.
+        """
+
+        self.categories = category_names
+
+    def flushEventDetails(self):
+
+        "Flush the current event details to this page's body text."
 
-            # Skip commented-out items.
+        new_body_parts = []
+        end_of_last_match = 0
+        body = self.getBody()
+        event_details = self.getEventDetails()
+
+        for match in definition_list_regexp.finditer(body):
 
-            if match.group("optcomment"):
-                continue
+            # Add preceding text to the new body.
+
+            new_body_parts.append(body[end_of_last_match:match.start()])
+            end_of_last_match = match.end()
+
+            # Get the matching regions, adding the term to the new body.
+
+            new_body_parts.append(match.group("wholeterm"))
 
             # Permit case-insensitive list terms.
 
@@ -187,276 +375,62 @@
 
             # Special value type handling.
 
-            # Dates.
-
-            if term in ("start", "end"):
-                desc = getDate(desc)
-
-            # Lists (whose elements may be quoted).
-
-            elif term in ("topics", "categories"):
-                desc = [getSimpleWikiText(value.strip()) for value in desc.split(",")]
-
-            # Labels which may well be quoted.
-
-            elif term in ("title", "summary", "description"):
-                desc = getSimpleWikiText(desc)
+            if event_details.has_key(term):
 
-            if desc is not None:
-                event_details[term] = desc
-
-    return event_details
-
-def setEventDetails(body, event_details):
-
-    """
-    Set the event details in the given page 'body' using the 'event_details'
-    dictionary, returning the new body text.
-    """
-
-    new_body_parts = []
-    end_of_last_match = 0
-
-    for match in definition_list_regexp.finditer(body):
+                # Dates.
 
-        # Add preceding text to the new body.
-
-        new_body_parts.append(body[end_of_last_match:match.start()])
-        end_of_last_match = match.end()
-
-        # Get the matching regions, adding the term to the new body.
-
-        new_body_parts.append(match.group("wholeterm"))
-
-        # Permit case-insensitive list terms.
-
-        term = match.group("term").lower()
-        desc = match.group("desc")
-
-        # Special value type handling.
+                if term in ("start", "end"):
+                    desc = desc.replace("YYYY-MM-DD", str(event_details[term]))
 
-        if event_details.has_key(term):
-
-            # Dates.
-
-            if term in ("start", "end"):
-                desc = desc.replace("YYYY-MM-DD", event_details[term])
+                # Lists (whose elements may be quoted).
 
-            # Lists (whose elements may be quoted).
-
-            elif term in ("topics", "categories"):
-                desc = ", ".join(getEncodedWikiText(event_details[term]))
-
-            # Labels which may well be quoted.
-
-            elif term in ("title", "summary"):
-                desc = getEncodedWikiText(event_details[term])
+                elif term in ("topics", "categories"):
+                    desc = ", ".join(getEncodedWikiText(event_details[term]))
 
-            # Text which need not be quoted, but it will be Wiki text.
-
-            elif term in ("description",):
-                desc = event_details[term]
-
-        new_body_parts.append(desc)
-
-    else:
-        new_body_parts.append(body[end_of_last_match:])
-
-    return "".join(new_body_parts)
-
-def setCategoryMembership(body, category_names):
+                # Labels which may well be quoted.
 
-    """
-    Set the category membership in the given page 'body' using the specified
-    'category_names' and returning the new body text.
-    """
+                elif term in ("title", "summary"):
+                    desc = getEncodedWikiText(event_details[term])
 
-    match = category_membership_regexp.search(body)
-    if match:
-        return "".join([body[:match.start()], " ".join(category_names), body[match.end():]])
-    else:
-        return body
-
-def getEventSummary(event_page, event_details, event_parent=None):
-
-    """
-    Return either the given title or summary of the event described by the given
-    'event_page', according to the given 'event_details', or return the pretty
-    version of the page name.
+                # Text which need not be quoted, but it will be Wiki text.
 
-    If the optional 'event_parent' is specified, any page beneath the given
-    'event_parent' page in the page hierarchy will omit this parent information
-    if its name is used as the summary.
-    """
-
-    if event_details.has_key("title"):
-        return event_details["title"]
-    elif event_details.has_key("summary"):
-        return event_details["summary"]
-    else:
-        # If appropriate, remove the parent details and "/" character.
-
-        title = event_page.page_name
+                elif term in ("description",):
+                    desc = event_details[term]
 
-        if event_parent is not None and title.startswith(event_parent):
-            title = title[len(event_parent.rstrip("/")) + 1:]
-
-        return getPrettyTitle(title)
-
-def getDate(s):
-
-    "Parse the string 's', extracting and returning a date string."
+            new_body_parts.append(desc)
 
-    m = date_regexp.search(s)
-    if m:
-        return tuple(map(int, m.groups()))
-    else:
-        return None
-
-def getMonth(s):
-
-    "Parse the string 's', extracting and returning a month string."
+        else:
+            new_body_parts.append(body[end_of_last_match:])
 
-    m = month_regexp.search(s)
-    if m:
-        return tuple(map(int, m.groups()))
-    else:
-        return None
-
-def getCurrentMonth():
-
-    "Return the current month as a (year, month) tuple."
-
-    today = datetime.date.today()
-    return (today.year, today.month)
+        self.body = "".join(new_body_parts)
 
-def getCurrentYear():
-
-    "Return the current year."
-
-    today = datetime.date.today()
-    return today.year
+    def flushCategoryMembership(self):
 
-def monthupdate(date, n):
-
-    "Return 'date' updated by 'n' months."
-
-    if n < 0:
-        fn = prevmonth
-    else:
-        fn = nextmonth
+        "Flush the category membership to the page body."
 
-    i = 0
-    while i < abs(n):
-        date = fn(date)
-        i += 1
-        
-    return date
-
-def daterange(first, last, step=1):
-
-    """
-    Get the range of dates starting at 'first' and ending on 'last', using the
-    specified 'step'.
-    """
-
-    results = []
+        body = self.getBody()
+        category_names = self.getCategoryMembership()
+        match = category_membership_regexp.search(body)
 
-    months_only = len(first) == 2
-    start_year = first[0]
-    end_year = last[0]
+        if match:
+            self.body = "".join([body[:match.start()], " ".join(category_names), body[match.end():]])
 
-    for year in range(start_year, end_year + step, step):
-        if step == 1 and year < end_year:
-            end_month = 12
-        elif step == -1 and year > end_year:
-            end_month = 1
-        else:
-            end_month = last[1]
-
-        if step == 1 and year > start_year:
-            start_month = 1
-        elif step == -1 and year < start_year:
-            start_month = 12
-        else:
-            start_month = first[1]
+    def saveChanges(self):
 
-        for month in range(start_month, end_month + step, step):
-            if months_only:
-                results.append((year, month))
-            else:
-                if step == 1 and month < end_month:
-                    _wd, end_day = calendar.monthrange(year, month)
-                elif step == -1 and month > end_month:
-                    end_day = 1
-                else:
-                    end_day = last[2]
-
-                if step == 1 and month > start_month:
-                    start_day = 1
-                elif step == -1 and month < start_month:
-                    _wd, start_day = calendar.monthrange(year, month)
-                else:
-                    start_day = first[2]
+        "Save changes to the event."
 
-                for day in range(start_day, end_day + step, step):
-                    results.append((year, month, day))
-
-    return results
-
-def nextdate(date):
-
-    "Return the date following the given 'date'."
-
-    year, month, day = date
-    _wd, end_day = calendar.monthrange(year, month)
-    if day == end_day:
-        if month == 12:
-            return (year + 1, 1, 1)
-        else:
-            return (year, month + 1, 1)
-    else:
-        return (year, month, day + 1)
+        self.flushEventDetails()
+        self.flushCategoryMembership()
+        self.page.saveText(self.getBody(), 0)
 
-def prevdate(date):
-
-    "Return the date preceding the given 'date'."
-
-    year, month, day = date
-    if day == 1:
-        if month == 1:
-            return (year - 1, 12, 31)
-        else:
-            _wd, end_day = calendar.monthrange(year, month - 1)
-            return (year, month - 1, end_day)
-    else:
-        return (year, month, day - 1)
-
-def nextmonth(date):
-
-    "Return the (year, month) tuple following 'date'."
+    def linkToPage(self, request, text, query_string=None):
 
-    year, month = date
-    if month == 12:
-        return (year + 1, 1)
-    else:
-        return year, month + 1
-
-def prevmonth(date):
-
-    "Return the (year, month) tuple preceding 'date'."
+        """
+        Using 'request', return a link to this page with the given link 'text'
+        and optional 'query_string'.
+        """
 
-    year, month = date
-    if month == 1:
-        return (year - 1, 12)
-    else:
-        return year, month - 1
-
-def span(start, end):
-
-    "Return the difference between 'start' and 'end'."
-
-    return end[0] - start[0], end[1] - start[1]
+        return linkToPage(request, self.page, text, query_string)
 
 def getEvents(request, category_names, calendar_start=None, calendar_end=None):
 
@@ -489,7 +463,7 @@
 
         # Get the pages and page names in the category.
 
-        pages_in_category = getPages(category_name, request)
+        pages_in_category = getCategoryPages(category_name, request)
 
         # Visit each page in the category.
 
@@ -505,20 +479,19 @@
 
             # Get a real page, not a result page.
 
-            real_page_in_category = Page(request, pagename)
-            event_details = getEventDetails(real_page_in_category)
+            event_page = EventPage(Page(request, pagename))
+            event_details = event_page.getEventDetails()
 
-            # Define the event as the page together with its details.
+            # Remember the event page.
 
-            event = (real_page_in_category, event_details)
-            events.append(event)
+            events.append(event_page)
 
             # Test for the suitability of the event.
 
             if event_details.has_key("start") and event_details.has_key("end"):
 
-                start_month = event_details["start"][:2]
-                end_month = event_details["end"][:2]
+                start_month = event_details["start"].as_month()
+                end_month = event_details["end"].as_month()
 
                 # Compare the months of the dates to the requested calendar
                 # window, if any.
@@ -526,7 +499,7 @@
                 if (calendar_start is None or end_month >= calendar_start) and \
                     (calendar_end is None or start_month <= calendar_end):
 
-                    all_shown_events.append(event)
+                    all_shown_events.append(event_page)
 
                     if earliest is None or start_month < earliest:
                         earliest = start_month
@@ -538,10 +511,10 @@
                     first = max(start_month, calendar_start or start_month)
                     last = min(end_month, calendar_end or end_month)
 
-                    for event_month in daterange(first, last):
+                    for event_month in first.months_until(last):
                         if not shown_events.has_key(event_month):
                             shown_events[event_month] = []
-                        shown_events[event_month].append(event)
+                        shown_events[event_month].append(event_page)
 
     return events, shown_events, all_shown_events, earliest, latest
 
@@ -549,25 +522,26 @@
 
     """
     Using 'request', set timestamp details in the details dictionary of each of
-    the 'events': a list of the form (event_page, event_details).
+    the 'events'.
 
     Retutn the latest timestamp found.
     """
 
     latest = None
 
-    for event_page, event_details in events:
+    for event_page in events:
+        event_details = event_page.getEventDetails()
 
         # Get the initial revision of the page.
 
-        revisions = event_page.getRevList()
-        event_page_initial = Page(request, event_page.page_name, rev=revisions[-1])
+        revisions = event_page.getRevisions()
+        event_page_initial = Page(request, event_page.getPageName(), rev=revisions[-1])
 
         # Get the created and last modified times.
 
         initial_revision = getPageRevision(event_page_initial)
         event_details["created"] = initial_revision["timestamp"]
-        latest_revision = getPageRevision(event_page)
+        latest_revision = event_page.getPageRevision()
         event_details["last-modified"] = latest_revision["timestamp"]
         event_details["sequence"] = len(revisions) - 1
         event_details["last-comment"] = latest_revision["comment"]
@@ -579,15 +553,10 @@
 
 def compareEvents(event1, event2):
 
-    """
-    Compare 'event1' and 'event2' by start and end date, where both parameters
-    are of the following form:
+    "Compare 'event1' and 'event2' by start and end date."
 
-    (event_page, event_details)
-    """
-
-    event_page1, event_details1 = event1
-    event_page2, event_details2 = event2
+    event_details1 = event1.getEventDetails()
+    event_details2 = event2.getEventDetails()
     return cmp(
         (event_details1["start"], event_details1["end"]),
         (event_details2["start"], event_details2["end"])
@@ -597,9 +566,7 @@
 
     """
     Return a list with the given 'events' ordered according to their start and
-    end dates. Each list element must be of the following form:
-
-    (event_page, event_details)
+    end dates.
     """
 
     ordered_events = events[:]
@@ -651,8 +618,8 @@
 
     # Get event details.
 
-    for event in events:
-        event_page, event_details = event
+    for event_page in events:
+        event_details = event_page.getEventDetails()
 
         # Test for the event in the period.
 
@@ -662,7 +629,7 @@
 
             event_start = max(event_details["start"], start)
             event_end = min(event_details["end"], end)
-            event_coverage = set(daterange(event_start, event_end))
+            event_coverage = set(event_start.days_until(event_end))
 
             # Update the overall coverage.
 
@@ -676,7 +643,7 @@
                 # element, add it alongside existing events.
 
                 if not coverage.intersection(event_coverage):
-                    covered_events.append(event)
+                    covered_events.append(event_page)
                     all_events[i] = coverage.union(event_coverage), covered_events
                     break
 
@@ -684,10 +651,185 @@
             # marked alongside existing events.
 
             else:
-                all_events.append((event_coverage, [event]))
+                all_events.append((event_coverage, [event_page]))
 
     return full_coverage, all_events
 
+# Date-related functions.
+
+class Period:
+
+    "A simple period of time."
+
+    def __init__(self, data):
+        self.data = data
+
+    def months(self):
+        return self.data[0] * 12 + self.data[1]
+
+class Month:
+
+    "A simple year-month representation."
+
+    def __init__(self, data):
+        self.data = tuple(data)
+
+    def __repr__(self):
+        return "%s(%r)" % (self.__class__.__name__, self.data)
+
+    def __str__(self):
+        return "%04d-%02d" % self.as_tuple()[:2]
+
+    def __hash__(self):
+        return hash(self.as_tuple())
+
+    def as_tuple(self):
+        return self.data
+
+    def as_date(self, day):
+        return Date(self.as_tuple() + (day,))
+
+    def year(self):
+        return self.data[0]
+
+    def month(self):
+        return self.data[1]
+
+    def month_properties(self):
+
+        """
+        Return the weekday of the 1st of the month, along with the number of
+        days, as a tuple.
+        """
+
+        year, month = self.data
+        return calendar.monthrange(year, month)
+
+    def month_update(self, n=1):
+
+        "Return the month updated by 'n' months."
+
+        year, month = self.data
+        return Month((year + (month - 1 + n) / 12, (month - 1 + n) % 12 + 1))
+
+    def next_month(self):
+
+        "Return the month following this one."
+
+        return self.month_update(1)
+
+    def previous_month(self):
+
+        "Return the month preceding this one."
+
+        return self.month_update(-1)
+
+    def __sub__(self, start):
+
+        """
+        Return the difference in years and months between this month and the
+        'start' month as a period.
+        """
+
+        return Period([(x - y) for x, y in zip(self.data, start.data)])
+
+    def __cmp__(self, other):
+        return cmp(self.data, other.data)
+
+    def until(self, end, nextfn, prevfn):
+        month = self
+        months = [month]
+        if month < end:
+            while month < end:
+                month = nextfn(month)
+                months.append(month)
+        elif month > end:
+            while month > end:
+                month = prevfn(month)
+                months.append(month)
+        return months
+
+    def months_until(self, end):
+        return self.until(end, Month.next_month, Month.previous_month)
+
+class Date(Month):
+
+    "A simple year-month-day representation."
+
+    def __str__(self):
+        return "%04d-%02d-%02d" % self.as_tuple()[:3]
+
+    def as_month(self):
+        return Month(self.data[:2])
+
+    def day(self):
+        return self.data[2]
+
+    def next_day(self):
+
+        "Return the date following this one."
+
+        year, month, day = self.data
+        _wd, end_day = calendar.monthrange(year, month)
+        if day == end_day:
+            if month == 12:
+                return Date((year + 1, 1, 1))
+            else:
+                return Date((year, month + 1, 1))
+        else:
+            return Date((year, month, day + 1))
+
+    def previous_day(self):
+
+        "Return the date preceding this one."
+
+        year, month, day = self.data
+        if day == 1:
+            if month == 1:
+                return Date((year - 1, 12, 31))
+            else:
+                _wd, end_day = calendar.monthrange(year, month - 1)
+                return Date((year, month - 1, end_day))
+        else:
+            return Date((year, month, day - 1))
+
+    def days_until(self, end):
+        return self.until(end, Date.next_day, Date.previous_day)
+
+def getDate(s):
+
+    "Parse the string 's', extracting and returning a date string."
+
+    m = date_regexp.search(s)
+    if m:
+        return Date(map(int, m.groups()))
+    else:
+        return None
+
+def getMonth(s):
+
+    "Parse the string 's', extracting and returning a month string."
+
+    m = month_regexp.search(s)
+    if m:
+        return Month(map(int, m.groups()))
+    else:
+        return None
+
+def getCurrentMonth():
+
+    "Return the current month as a (year, month) tuple."
+
+    today = datetime.date.today()
+    return Month((today.year, today.month))
+
+def getCurrentYear():
+
+    "Return the current year."
+
+    today = datetime.date.today()
+    return today.year
+
 # User interface functions.
 
 def getParameter(request, name, default=None):
@@ -704,6 +846,9 @@
         return "%s-%s" % (calendar_name, argname)
 
 def getParameterMonth(arg):
+
+    "Interpret 'arg', recognising keywords and simple arithmetic operations."
+
     n = None
 
     if arg.startswith("current"):
@@ -712,12 +857,12 @@
             n = int(arg[7:])
 
     elif arg.startswith("yearstart"):
-        date = (getCurrentYear(), 1)
+        date = Month((getCurrentYear(), 1))
         if len(arg) > 10:
             n = int(arg[9:])
 
     elif arg.startswith("yearend"):
-        date = (getCurrentYear(), 12)
+        date = Month((getCurrentYear(), 12))
         if len(arg) > 8:
             n = int(arg[7:])
 
@@ -725,11 +870,17 @@
         date = getMonth(arg)
 
     if n is not None:
-        date = monthupdate(date, n)
+        date = date.month_update(n)
 
     return date
 
 def getFormMonth(request, calendar_name, argname):
+
+    """
+    Return the month from the 'request' for the calendar with the given
+    'calendar_name' using the parameter having the given 'argname'.
+    """
+
     arg = getQualifiedParameter(request, calendar_name, argname)
     if arg is not None:
         return getParameterMonth(arg)
@@ -737,13 +888,22 @@
         return None
 
 def getFormMonthPair(request, yeararg, montharg):
+
+    """
+    Return the month from the 'request' for the calendar with the given
+    'calendar_name' using the parameters having the given 'yeararg' and
+    'montharg' names.
+    """
+
     year = getParameter(request, yeararg)
     month = getParameter(request, montharg)
     if year and month:
-        return (int(year), int(month))
+        return Month((int(year), int(month)))
     else:
         return None
 
+# Page-related functions.
+
 def getPrettyPageName(page):
 
     "Return a nicely formatted title/name for the given 'page'."
@@ -755,24 +915,6 @@
 
     return getPrettyTitle(title)
 
-def getPrettyTitle(title):
-
-    "Return a nicely formatted version of the given 'title'."
-
-    return title.replace("_", " ").replace("/", u" » ")
-
-def getMonthLabel(month):
-
-    "Return an unlocalised label for the given 'month'."
-
-    return month_labels[month - 1] # zero-based labels
-
-def getDayLabel(weekday):
-
-    "Return an unlocalised label for the given 'weekday'."
-
-    return weekday_labels[weekday]
-
 def linkToPage(request, page, text, query_string=None):
 
     """
@@ -790,13 +932,4 @@
     else:
         return page.link_to_raw(request, text, query_string)
 
-def getPageURL(request, page):
-
-    "Using 'request', return the URL of 'page'."
-
-    if isMoin15():
-        return request.getQualifiedURL(page.url(request))
-    else:
-        return request.getQualifiedURL(page.url(request, relative=0))
-
 # vim: tabstop=4 expandtab shiftwidth=4
diff -r fdf1ec151ab6 -r 0340bf1c9f22 actions/EventAggregatorNewEvent.py
--- a/actions/EventAggregatorNewEvent.py	Mon Jan 18 01:00:35 2010 +0100
+++ b/actions/EventAggregatorNewEvent.py	Sun Jan 24 02:55:53 2010 +0100
@@ -2,7 +2,7 @@
 """
     MoinMoin - EventAggregatorNewEvent Action
 
-    @copyright: 2008, 2009 by Paul Boddie <paul@boddie.org.uk>
+    @copyright: 2008, 2009, 2010 by Paul Boddie <paul@boddie.org.uk>
     @copyright: 2000-2004 Juergen Hermann <jh@web.de>,
                 2003-2008 MoinMoin:ThomasWaldmann,
                 2004-2006 MoinMoin:AlexanderSchremmer,
@@ -229,7 +229,7 @@
         if not page.exists():
             return 0, _("Event template not available.")
 
-        body = page.get_raw_body()
+        event_page = EventAggregatorSupport.EventPage(page)
 
         # Use any parent page information.
 
@@ -245,15 +245,18 @@
         if new_page.exists():
             return 0, _("The specified page already exists. Please choose another name.")
 
-        if EventAggregatorSupport.getFormat(page) == "wiki":
+        new_event_page = EventAggregatorSupport.EventPage(new_page)
+        new_event_page.copyPage(event_page)
+
+        if new_event_page.getFormat() == "wiki":
             event_details = {
                 "start" : start_date, "end" : end_date,
                 "title" : title, "summary" : title,
                 "description" : description
                 }
-            body = EventAggregatorSupport.setEventDetails(body, event_details)
-            body = EventAggregatorSupport.setCategoryMembership(body, category_pagenames)
-            new_page.saveText(body, 0)
+            new_event_page.setEventDetails(event_details)
+            new_event_page.setCategoryMembership(category_pagenames)
+            new_event_page.saveChanges()
 
         # Redirect and return success.
 
diff -r fdf1ec151ab6 -r 0340bf1c9f22 actions/EventAggregatorSummary.py
--- a/actions/EventAggregatorSummary.py	Mon Jan 18 01:00:35 2010 +0100
+++ b/actions/EventAggregatorSummary.py	Sun Jan 24 02:55:53 2010 +0100
@@ -2,7 +2,7 @@
 """
     MoinMoin - EventAggregatorSummary Action
 
-    @copyright: 2008, 2009 by Paul Boddie <paul@boddie.org.uk>
+    @copyright: 2008, 2009, 2010 by Paul Boddie <paul@boddie.org.uk>
     @copyright: 2000-2004 Juergen Hermann <jh@web.de>,
                 2003-2008 MoinMoin:ThomasWaldmann,
                 2004-2006 MoinMoin:AlexanderSchremmer,
@@ -219,12 +219,13 @@
         request.write("PRODID:-//MoinMoin//EventAggregatorSummary\r\n")
         request.write("VERSION:2.0\r\n")
 
-        for event_page, event_details in all_shown_events:
+        for event_page in all_shown_events:
+            event_details = event_page.getEventDetails()
 
             # Get the summary details.
 
-            event_summary = EventAggregatorSupport.getEventSummary(event_page, event_details)
-            link = EventAggregatorSupport.getPageURL(request, event_page)
+            event_summary = event_page.getEventSummary()
+            link = event_page.getPageURL(request)
 
             # Output the event details.
 
@@ -234,8 +235,8 @@
             request.write("DTSTAMP:%04d%02d%02dT%02d%02d%02dZ\r\n" % event_details["created"][:6])
             request.write("LAST-MODIFIED:%04d%02d%02dT%02d%02d%02dZ\r\n" % event_details["last-modified"][:6])
             request.write("SEQUENCE:%d\r\n" % event_details["sequence"])
-            request.write("DTSTART;VALUE=DATE:%04d%02d%02d\r\n" % event_details["start"])
-            request.write("DTEND;VALUE=DATE:%04d%02d%02d\r\n" % EventAggregatorSupport.nextdate(event_details["end"]))
+            request.write("DTSTART;VALUE=DATE:%04d%02d%02d\r\n" % event_details["start"].as_tuple())
+            request.write("DTEND;VALUE=DATE:%04d%02d%02d\r\n" % event_details["end"].next_day().as_tuple())
             request.write("SUMMARY:%s\r\n" % getQuotedText(event_summary))
 
             # Optional details.
@@ -265,21 +266,21 @@
  
         # Sort all_shown_events by start date, reversed:
         #
-        #  * events are tuples: (real_page_in_category, event_details)
         #  * event_details are dictionaries, with the "start" entry providing
         #    the start date
         #
-        # So we use as sorting key the "start" key from the event details (the
-        # second element of the tuple).
+        # So we use as sorting key the "start" key from the event details.
 
-        all_shown_events.sort(key=lambda x: x[1]["start"], reverse=True)
+        ordered_events = EventAggregatorSupport.getOrderedEvents(all_shown_events)
+        ordered_events.reverse()
 
-        for event_page, event_details in all_shown_events:
+        for event_page in ordered_events:
+            event_details = event_page.getEventDetails()
 
             # Get the summary details.
 
-            event_summary = EventAggregatorSupport.getEventSummary(event_page, event_details)
-            link = EventAggregatorSupport.getPageURL(request, event_page)
+            event_summary = event_page.getEventSummary()
+            link = event_page.getPageURL(request)
 
             request.write('<item>\r\n')
             request.write('<title>%s</title>\r\n' % wikiutil.escape(event_summary))
diff -r fdf1ec151ab6 -r 0340bf1c9f22 macros/EventAggregator.py
--- a/macros/EventAggregator.py	Mon Jan 18 01:00:35 2010 +0100
+++ b/macros/EventAggregator.py	Sun Jan 24 02:55:53 2010 +0100
@@ -53,18 +53,17 @@
 
             # Store the view parameters.
 
-            span = EventAggregatorSupport.span(first, last)
-            self.number_of_months = span[0] * 12 + span[1] + 1
+            self.number_of_months = (last - first).months() + 1
 
-            self.previous_month_start = EventAggregatorSupport.prevmonth(first)
-            self.next_month_start = EventAggregatorSupport.nextmonth(first)
-            self.previous_month_end = EventAggregatorSupport.prevmonth(last)
-            self.next_month_end = EventAggregatorSupport.nextmonth(last)
+            self.previous_month_start = first.previous_month()
+            self.next_month_start = first.next_month()
+            self.previous_month_end = last.previous_month()
+            self.next_month_end = last.next_month()
 
-            self.previous_set_start = EventAggregatorSupport.monthupdate(first, -self.number_of_months)
-            self.next_set_start = EventAggregatorSupport.monthupdate(first, self.number_of_months)
-            self.previous_set_end = EventAggregatorSupport.monthupdate(last, -self.number_of_months)
-            self.next_set_end = EventAggregatorSupport.monthupdate(last, self.number_of_months)
+            self.previous_set_start = first.month_update(-self.number_of_months)
+            self.next_set_start = first.month_update(self.number_of_months)
+            self.previous_set_end = last.month_update(-self.number_of_months)
+            self.next_set_end = last.month_update(self.number_of_months)
 
     def getQualifiedParameterName(self, argname):
         return EventAggregatorSupport.getQualifiedParameterName(self.calendar_name, argname)
@@ -73,7 +72,7 @@
         if month is not None:
             if prefix:
                 argname = self.getQualifiedParameterName(argname)
-            return "%s=%04d-%02d" % ((argname,) + month)
+            return "%s=%s" % (argname, month)
         else:
             return ""
 
@@ -155,7 +154,7 @@
 
         return "".join(output)
 
-    def writeMonthHeading(self, year, month):
+    def writeMonthHeading(self, year_month):
         page = self.page
         request = page.request
         fmt = page.formatter
@@ -163,6 +162,7 @@
 
         output = []
 
+        year, month = year_month.as_tuple()
         month_label = _(EventAggregatorSupport.getMonthLabel(month))
 
         # Prepare navigation links.
@@ -193,11 +193,9 @@
             # A link leading to this month being at the top of the calendar.
 
             full_month_label = "%s %s" % (month_label, year)
-            end_month = EventAggregatorSupport.monthupdate((year, month), self.number_of_months - 1)
+            end_month = year_month.month_update(self.number_of_months - 1)
 
-            month_link = self.getNavigationLink(
-                (year, month), end_month
-                )
+            month_link = self.getNavigationLink(year_month, end_month)
 
             output.append(fmt.span(on=1, css_class="previous-month"))
             output.append(linkToPage(request, page, "<<", previous_set_link))
@@ -224,12 +222,13 @@
 
         return "".join(output)
 
-    def writeDayNumberLinked(self, day, month, year):
+    def writeDayNumberLinked(self, date):
         page = self.page
         request = page.request
         fmt = page.formatter
         _ = request.getText
 
+        year, month, day = date.as_tuple()
         output = []
 
         # Prepare navigation details for the calendar shown with the new event
@@ -411,8 +410,9 @@
 
         # Show the events in order.
 
-        for event_page, event_details in ordered_events:
-            event_summary = EventAggregatorSupport.getEventSummary(event_page, event_details, parent_name)
+        for event_page in ordered_events:
+            event_summary = event_page.getEventSummary(parent_name)
+            event_details = event_page.getEventDetails()
 
             # Prepare CSS classes with category-related styling.
 
@@ -432,13 +432,13 @@
 
             output.append(fmt.table_cell(on=1, attrs=attrs))
             output.append(fmt.span(on=1))
-            output.append(fmt.text("%04d-%02d-%02d" % event_details["start"]))
+            output.append(fmt.text(str(event_details["start"])))
             output.append(fmt.span(on=0))
 
             if event_details["start"] != event_details["end"]:
                 output.append(fmt.text(" - "))
                 output.append(fmt.span(on=1))
-                output.append(fmt.text("%04d-%02d-%02d" % event_details["end"]))
+                output.append(fmt.text(str(event_details["end"])))
                 output.append(fmt.span(on=0))
 
             output.append(fmt.table_cell(on=0))
@@ -455,7 +455,7 @@
             # Link to the page using the summary.
 
             output.append(fmt.table_cell(on=1, attrs=attrs))
-            output.append(linkToPage(request, event_page, event_summary))
+            output.append(event_page.linkToPage(request, event_summary))
             output.append(fmt.table_cell(on=0))
 
             output.append(fmt.table_row(on=0))
@@ -477,7 +477,7 @@
 
         # Visit all months in the requested range, or across known events.
 
-        for year, month in EventAggregatorSupport.daterange(first, last):
+        for month in first.months_until(last):
 
             # Either output a calendar view...
 
@@ -493,7 +493,7 @@
                 # Either write a month heading or produce links for navigable
                 # calendars.
 
-                output.append(view.writeMonthHeading(year, month))
+                output.append(view.writeMonthHeading(month))
 
                 output.append(fmt.table_cell(on=0))
                 output.append(fmt.table_row(on=0))
@@ -511,7 +511,7 @@
 
                 # Process the days of the month.
 
-                start_weekday, number_of_days = calendar.monthrange(year, month)
+                start_weekday, number_of_days = month.month_properties()
 
                 # The start weekday is the weekday of day number 1.
                 # Find the first day of the week, counting from below zero, if
@@ -525,11 +525,11 @@
                     # Find events in this week and determine how to mark them on the
                     # calendar.
 
-                    week_start = (year, month, max(first_day, 1))
-                    week_end = (year, month, min(first_day + 6, number_of_days))
+                    week_start = month.as_date(max(first_day, 1))
+                    week_end = month.as_date(min(first_day + 6, number_of_days))
 
                     week_coverage, week_events = EventAggregatorSupport.getCoverage(
-                        week_start, week_end, shown_events.get((year, month), []))
+                        week_start, week_end, shown_events.get(month, []))
 
                     # Output a week, starting with the day numbers.
 
@@ -537,7 +537,7 @@
 
                     for weekday in range(0, 7):
                         day = first_day + weekday
-                        date = (year, month, day)
+                        date = month.as_date(day)
 
                         # Output out-of-month days.
 
@@ -559,7 +559,7 @@
                             # Output the day number, making a link to a new event
                             # action.
 
-                            output.append(view.writeDayNumberLinked(day, month, year))
+                            output.append(view.writeDayNumberLinked(date))
 
                             # End of day.
 
@@ -576,7 +576,6 @@
 
                         for weekday in range(0, 7):
                             day = first_day + weekday
-                            date = (year, month, day)
 
                             # Output out-of-month days.
 
@@ -606,7 +605,7 @@
 
                             for weekday in range(0, 7):
                                 day = first_day + weekday
-                                date = (year, month, day)
+                                date = month.as_date(day)
 
                                 # Skip out-of-month days.
 
@@ -624,7 +623,9 @@
 
                                 # Get event details for the current day.
 
-                                for event_page, event_details in events:
+                                for event_page in events:
+                                    event_details = event_page.getEventDetails()
+
                                     if not (event_details["start"] <= date <= event_details["end"]):
                                         continue
 
@@ -632,7 +633,7 @@
 
                                     starts_today = event_details["start"] == date
                                     ends_today = event_details["end"] == date
-                                    event_summary = EventAggregatorSupport.getEventSummary(event_page, event_details, parent_name)
+                                    event_summary = event_page.getEventSummary(parent_name)
 
                                     # Generate a colour for the event.
 
@@ -678,10 +679,10 @@
 
                                             else:
                                                 if event_details["end"] <= week_end:
-                                                    event_length = event_details["end"][2] - day + 1
+                                                    event_length = event_details["end"].day() - day + 1
                                                     colspan = (event_length - 2) * 3 + 4
                                                 else:
-                                                    event_length = week_end[2] - day + 1
+                                                    event_length = week_end.day() - day + 1
                                                     colspan = (event_length - 1) * 3 + 2
 
                                                 event_day_type = "event-day-multiple"
@@ -711,10 +712,10 @@
 
                                             else:
                                                 if event_details["end"] <= week_end:
-                                                    event_length = event_details["end"][2] - day + 1
+                                                    event_length = event_details["end"].day() - day + 1
                                                     colspan = (event_length - 1) * 3 + 2
                                                 else:
-                                                    event_length = week_end[2] - day + 1
+                                                    event_length = week_end.day() - day + 1
                                                     colspan = event_length * 3
 
                                                 event_day_type = "event-day-multiple"
@@ -757,13 +758,13 @@
 
                                             output.append(fmt.div(on=1, css_class="event-summary-box"))
                                             output.append(fmt.div(on=1, css_class="event-summary", style=style))
-                                            output.append(linkToPage(request, event_page, event_summary))
+                                            output.append(event_page.linkToPage(request, event_summary))
                                             output.append(fmt.div(on=0))
 
                                             # Add a pop-up element for long summaries.
 
                                             output.append(fmt.div(on=1, css_class="event-summary-popup", style=style))
-                                            output.append(linkToPage(request, event_page, event_summary))
+                                            output.append(event_page.linkToPage(request, event_summary))
                                             output.append(fmt.div(on=0))
 
                                             output.append(fmt.div(on=0))
@@ -824,7 +825,7 @@
                 # Either write a month heading or produce links for navigable
                 # calendars.
 
-                output.append(view.writeMonthHeading(year, month))
+                output.append(view.writeMonthHeading(month))
 
                 output.append(fmt.div(on=0))
 
@@ -832,30 +833,31 @@
 
                 # Get the events in order.
 
-                ordered_events = EventAggregatorSupport.getOrderedEvents(shown_events.get((year, month), []))
+                ordered_events = EventAggregatorSupport.getOrderedEvents(shown_events.get(month, []))
 
                 # Show the events in order.
 
-                for event_page, event_details in ordered_events:
-                    event_summary = EventAggregatorSupport.getEventSummary(event_page, event_details, parent_name)
+                for event_page in ordered_events:
+                    event_details = event_page.getEventDetails()
+                    event_summary = event_page.getEventSummary(parent_name)
 
                     output.append(fmt.listitem(on=1, attr={"class" : "event-listing"}))
 
                     # Link to the page using the summary.
 
                     output.append(fmt.paragraph(on=1))
-                    output.append(linkToPage(request, event_page, event_summary))
+                    output.append(event_page.linkToPage(request, event_summary))
                     output.append(fmt.paragraph(on=0))
 
                     # Start and end dates.
 
                     output.append(fmt.paragraph(on=1))
                     output.append(fmt.span(on=1))
-                    output.append(fmt.text("%04d-%02d-%02d" % event_details["start"]))
+                    output.append(fmt.text(str(event_details["start"])))
                     output.append(fmt.span(on=0))
                     output.append(fmt.text(" - "))
                     output.append(fmt.span(on=1))
-                    output.append(fmt.text("%04d-%02d-%02d" % event_details["end"]))
+                    output.append(fmt.text(str(event_details["end"])))
                     output.append(fmt.span(on=0))
                     output.append(fmt.paragraph(on=0))