#!/usr/bin/env python
"""Notes format parser."""

import sets

class Note(list): 
   """A class for holding a note."""

   Date, Meta, Data = 0, 1, 2

   def __init__(cls, date, meta, data): 
      assert isinstance(meta, sets.Set)
      list.__init__(cls, (date, meta, data))

   def __iadd__(self, items): 
      self[Note.Meta] |= sets.Set(items)
      return self

   def __isub__(self, items): 
      self[Note.Meta] -= sets.Set(items)
      return self

class Notes(dict): 
   """A class for holding parsed notes."""

   def __init__(self, s=None): 
      if s: self.feed(s)

   def __str__(self): 
      return self.serialize()

   def feed(self, s): 
      s = s.replace('\r\n', '\n')
      s = s.replace('\r', '\n')

      lines = s.splitlines()
      for (i, line) in enumerate(lines): 
         line = line.lstrip()
         if line and not line.startswith('#'): 
            date, meta, data = tuple(line.split('\t'))
            meta = [n for n in meta.split(' ') if n]
            self[i] = Note(date, sets.Set(meta), data)
      return True

   def serialize(self, format=None): 
      if format is None: 
         format = '%(date)s\t%(meta)s\t%(data)s\n'

      keys = self.keys()
      keys.sort()
      result = ''
      for key in keys: 
         date, meta, data = tuple(self[key])
         meta = ' '.join(meta)
         result += format % vars()
      return result

   def queryKeywords(self, *args): 
      keywords = sets.Set(args)
      return [note for note in self.values() 
              if keywords <= note[Note.Meta]]

   def tail(self, n=None): 
      if n is None: 
         n = 10
      assert n > 0

      keys = self.keys()
      keys.sort()
      keys = keys[-n:]
      result = Notes()
      for key in keys: 
         result[key] = self[key]
      return result

   def dialogue(self): 
      while 1: 
         try: command = raw_input('>>> ')
         except (KeyboardInterrupt, EOFError): 
            break

         if command == 'quit': 
            break
         elif command in ('print', 'show', 'display', 'view', 'serialize'): 
            print self
         elif command.startswith('tail'): 
            command, n = command.split(' ')
            n = int(n)
            schema = '%(meta)s: %(data)s (%(date)s)\n'
            print self.tail(n).serialize(schema)
         else: print "Unknown command: %s" % command

def test(): 
   s = """
2003-11-05T09:15:00+0000		scribbledygook
2003-11-08T13:19:17+0000	@@	update FOAF file with maker information
2003-11-10T04:50:34+0000		mount -t vfat -o [...]
"""
   import time
   t = time.clock()
   n = Notes(s) #  * 10000)
   print time.clock() - t
   print n
   print n.queryKeywords('@@')
   print n.queryKeywords('@@', 'project')
   note = n.queryKeywords('project')[0]
   note -= ['@@']
   note += ['hmm']
   print note
   print n.serialize()

def mainTest(): 
   s = """
2003-11-05T09:15:00+0000		scribbledygook
2003-11-08T13:19:17+0000	@@	update FOAF file with maker information
2003-11-10T04:50:34+0000		mount -t vfat -o [...]
"""
   notes = Notes(s)
   notes.dialogue()

def main(): 
   print __doc__
   mainTest()
   # notes[i][Meta] |= sets.Set(['blargh'])
   # notes[i] -= ['todo']
   # notes[i] += ['done', '2003-05-15']

if __name__=="__main__": 
   main()