from __future__ import absolute_import, division, unicode_literals

from html5lib.filters.whitespace import Filter
from html5lib.constants import spaceCharacters
spaceCharacters = "".join(spaceCharacters)


def runTest(input, expected):
    output = list(Filter(input))
    errorMsg = "\n".join(["\n\nInput:", str(input),
                          "\nExpected:", str(expected),
                          "\nReceived:", str(output)])
    assert expected == output, errorMsg


def runTestUnmodifiedOutput(input):
    runTest(input, input)


def testPhrasingElements():
    runTestUnmodifiedOutput(
        [{"type": "Characters", "data": "This is a "},
         {"type": "StartTag", "name": "span", "data": []},
         {"type": "Characters", "data": "phrase"},
         {"type": "EndTag", "name": "span", "data": []},
         {"type": "SpaceCharacters", "data": " "},
         {"type": "Characters", "data": "with"},
         {"type": "SpaceCharacters", "data": " "},
         {"type": "StartTag", "name": "em", "data": []},
         {"type": "Characters", "data": "emphasised text"},
         {"type": "EndTag", "name": "em", "data": []},
         {"type": "Characters", "data": " and an "},
         {"type": "StartTag", "name": "img", "data": [["alt", "image"]]},
         {"type": "Characters", "data": "."}])


def testLeadingWhitespace():
    runTest(
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "SpaceCharacters", "data": spaceCharacters},
         {"type": "Characters", "data": "foo"},
         {"type": "EndTag", "name": "p", "data": []}],
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "SpaceCharacters", "data": " "},
         {"type": "Characters", "data": "foo"},
         {"type": "EndTag", "name": "p", "data": []}])


def testLeadingWhitespaceAsCharacters():
    runTest(
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "Characters", "data": spaceCharacters + "foo"},
         {"type": "EndTag", "name": "p", "data": []}],
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "Characters", "data": " foo"},
         {"type": "EndTag", "name": "p", "data": []}])


def testTrailingWhitespace():
    runTest(
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "Characters", "data": "foo"},
         {"type": "SpaceCharacters", "data": spaceCharacters},
         {"type": "EndTag", "name": "p", "data": []}],
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "Characters", "data": "foo"},
         {"type": "SpaceCharacters", "data": " "},
         {"type": "EndTag", "name": "p", "data": []}])


def testTrailingWhitespaceAsCharacters():
    runTest(
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "Characters", "data": "foo" + spaceCharacters},
         {"type": "EndTag", "name": "p", "data": []}],
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "Characters", "data": "foo "},
         {"type": "EndTag", "name": "p", "data": []}])


def testWhitespace():
    runTest(
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "Characters", "data": "foo" + spaceCharacters + "bar"},
         {"type": "EndTag", "name": "p", "data": []}],
        [{"type": "StartTag", "name": "p", "data": []},
         {"type": "Characters", "data": "foo bar"},
         {"type": "EndTag", "name": "p", "data": []}])


def testLeadingWhitespaceInPre():
    runTestUnmodifiedOutput(
        [{"type": "StartTag", "name": "pre", "data": []},
         {"type": "SpaceCharacters", "data": spaceCharacters},
         {"type": "Characters", "data": "foo"},
         {"type": "EndTag", "name": "pre", "data": []}])


def testLeadingWhitespaceAsCharactersInPre():
    runTestUnmodifiedOutput(
        [{"type": "StartTag", "name": "pre", "data": []},
         {"type": "Characters", "data": spaceCharacters + "foo"},
         {"type": "EndTag", "name": "pre", "data": []}])


def testTrailingWhitespaceInPre():
    runTestUnmodifiedOutput(
        [{"type": "StartTag", "name": "pre", "data": []},
         {"type": "Characters", "data": "foo"},
         {"type": "SpaceCharacters", "data": spaceCharacters},
         {"type": "EndTag", "name": "pre", "data": []}])


def testTrailingWhitespaceAsCharactersInPre():
    runTestUnmodifiedOutput(
        [{"type": "StartTag", "name": "pre", "data": []},
         {"type": "Characters", "data": "foo" + spaceCharacters},
         {"type": "EndTag", "name": "pre", "data": []}])


def testWhitespaceInPre():
    runTestUnmodifiedOutput(
        [{"type": "StartTag", "name": "pre", "data": []},
         {"type": "Characters", "data": "foo" + spaceCharacters + "bar"},
         {"type": "EndTag", "name": "pre", "data": []}])