from StringIO import StringIO
from util.registry.filelike import FilelikeStreamConcat, LimitingStream, StreamSlice

def somegenerator():
  yield 'some'
  yield 'cool'
  yield 'file-contents'

def test_parts():
  gens = iter([StringIO(s) for s in somegenerator()])
  fileobj = FilelikeStreamConcat(gens)

  assert fileobj.read(2) == 'so'
  assert fileobj.read(3) == 'mec'
  assert fileobj.read(7) == 'oolfile'
  assert fileobj.read(-1) == '-contents'

def test_entire():
  gens = iter([StringIO(s) for s in somegenerator()])
  fileobj = FilelikeStreamConcat(gens)
  assert fileobj.read(-1) == 'somecoolfile-contents'

def test_nolimit():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj)
  assert stream.read(-1) == 'this is a cool test'
  assert len('this is a cool test') == stream.tell()

def test_simplelimit():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj, 4)
  assert stream.read(-1) == 'this'
  assert 4 == stream.tell()

def test_simplelimit_readdefined():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj, 4)
  assert stream.read(2) == 'th'
  assert 2 == stream.tell()

def test_nolimit_readdefined():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj, -1)
  assert stream.read(2) == 'th'
  assert 2 == stream.tell()

def test_limit_multiread():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj, 7)
  assert stream.read(4) == 'this'
  assert stream.read(3) == ' is'
  assert stream.read(2) == ''
  assert 7 == stream.tell()

def test_limit_multiread2():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj, 7)
  assert stream.read(4) == 'this'
  assert stream.read(-1) == ' is'
  assert 7 == stream.tell()

def test_seek():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj)
  stream.seek(2)

  assert stream.read(2) == 'is'
  assert 4 == stream.tell()

def test_seek_withlimit():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj, 3)
  stream.seek(2)

  assert stream.read(2) == 'i'
  assert 3 == stream.tell()

def test_seek_pastlimit():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj, 3)
  stream.seek(4)

  assert stream.read(1) == ''
  assert 3 == stream.tell()

def test_seek_to_tell():
  fileobj = StringIO('this is a cool test')
  stream = LimitingStream(fileobj, 3)
  stream.seek(stream.tell())

  assert stream.read(4) == 'thi'
  assert 3 == stream.tell()

def test_none_read():
  class NoneReader(object):
    def read(self, size=None):
      return None

  stream = StreamSlice(NoneReader(), 0)
  assert stream.read(-1) == None
  assert stream.tell() == 0

def test_noslice():
  fileobj = StringIO('this is a cool test')
  stream = StreamSlice(fileobj, 0)
  assert stream.read(-1) == 'this is a cool test'
  assert len('this is a cool test') == stream.tell()

def test_startindex():
  fileobj = StringIO('this is a cool test')
  stream = StreamSlice(fileobj, 5)
  assert stream.read(-1) == 'is a cool test'
  assert len('is a cool test') == stream.tell()

def test_startindex_limitedread():
  fileobj = StringIO('this is a cool test')
  stream = StreamSlice(fileobj, 5)
  assert stream.read(4) == 'is a'
  assert 4 == stream.tell()

def test_slice():
  fileobj = StringIO('this is a cool test')
  stream = StreamSlice(fileobj, 5, 9)
  assert stream.read(-1) == 'is a'
  assert len('is a') == stream.tell()

def test_slice_explictread():
  fileobj = StringIO('this is a cool test')
  stream = StreamSlice(fileobj, 5, 9)
  assert stream.read(2) == 'is'
  assert stream.read(5) == ' a'
  assert len('is a') == stream.tell()