# Copyright (C) 2010 Google Inc. All rights reserved.
#
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# modification, are permitted provided that the following conditions are
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import cPickle
import logging

from webkitpy.layout_tests.models import test_expectations

_log = logging.getLogger(__name__)

def is_reftest_failure(failure_list):
    failure_types = [type(f) for f in failure_list]
    return set((FailureReftestMismatch, FailureReftestMismatchDidNotOccur, FailureReftestNoImagesGenerated)).intersection(failure_types)

# FIXME: This is backwards.  Each TestFailure subclass should know what
# test_expectation type it corresponds too.  Then this method just
# collects them all from the failure list and returns the worst one.
def determine_result_type(failure_list):
    """Takes a set of test_failures and returns which result type best fits
    the list of failures. "Best fits" means we use the worst type of failure.

    Returns:
      one of the test_expectations result types - PASS, FAIL, CRASH, etc."""

    if not failure_list or len(failure_list) == 0:
        return test_expectations.PASS

    failure_types = [type(f) for f in failure_list]
    if FailureCrash in failure_types:
        return test_expectations.CRASH
    elif FailureTimeout in failure_types:
        return test_expectations.TIMEOUT
    elif FailureEarlyExit in failure_types:
        return test_expectations.SKIP
    elif (FailureMissingResult in failure_types or
          FailureMissingImage in failure_types or
          FailureMissingImageHash in failure_types or
          FailureMissingAudio in failure_types):
        return test_expectations.MISSING
    else:
        is_text_failure = FailureTextMismatch in failure_types
        is_image_failure = (FailureImageHashIncorrect in failure_types or
                            FailureImageHashMismatch in failure_types)
        is_audio_failure = (FailureAudioMismatch in failure_types)
        if is_text_failure and is_image_failure:
            return test_expectations.IMAGE_PLUS_TEXT
        elif is_text_failure:
            return test_expectations.TEXT
        elif is_image_failure or is_reftest_failure(failure_list):
            return test_expectations.IMAGE
        elif is_audio_failure:
            return test_expectations.AUDIO
        else:
            raise ValueError("unclassifiable set of failures: "
                             + str(failure_types))


class TestFailure(object):
    """Abstract base class that defines the failure interface."""

    @staticmethod
    def loads(s):
        """Creates a TestFailure object from the specified string."""
        return cPickle.loads(s)

    def message(self):
        """Returns a string describing the failure in more detail."""
        raise NotImplementedError

    def __eq__(self, other):
        return self.__class__.__name__ == other.__class__.__name__

    def __ne__(self, other):
        return self.__class__.__name__ != other.__class__.__name__

    def __hash__(self):
        return hash(self.__class__.__name__)

    def dumps(self):
        """Returns the string/JSON representation of a TestFailure."""
        return cPickle.dumps(self)

    def driver_needs_restart(self):
        """Returns True if we should kill DumpRenderTree/WebKitTestRunner before the next test."""
        return False

    def write_failure(self, writer, driver_output, expected_driver_output, port):
        assert isinstance(self, (FailureTimeout, FailureReftestNoImagesGenerated))


class FailureText(TestFailure):
    def write_failure(self, writer, driver_output, expected_driver_output, port):
        writer.write_text_files(driver_output.text, expected_driver_output.text)
        writer.create_text_diff_and_write_result(driver_output.text, expected_driver_output.text)


class FailureAudio(TestFailure):
    def write_failure(self, writer, driver_output, expected_driver_output, port):
        writer.write_audio_files(driver_output.audio, expected_driver_output.audio)
        writer.create_audio_diff_and_write_result(driver_output.audio, expected_driver_output.audio)


class FailureTimeout(TestFailure):
    def __init__(self, is_reftest=False):
        super(FailureTimeout, self).__init__()
        self.is_reftest = is_reftest

    def message(self):
        return "test timed out"

    def driver_needs_restart(self):
        return True


class FailureCrash(TestFailure):
    def __init__(self, is_reftest=False, process_name='DumpRenderTree', pid=None):
        super(FailureCrash, self).__init__()
        self.process_name = process_name
        self.pid = pid
        self.is_reftest = is_reftest

    def message(self):
        if self.pid:
            return "%s crashed [pid=%d]" % (self.process_name, self.pid)
        return self.process_name + " crashed"

    def driver_needs_restart(self):
        return True

    def write_failure(self, writer, driver_output, expected_driver_output, port):
        crashed_driver_output = expected_driver_output if self.is_reftest else driver_output
        writer.write_crash_log(crashed_driver_output.crash_log)


class FailureMissingResult(FailureText):
    def message(self):
        return "-expected.txt was missing"


class FailureTextMismatch(FailureText):
    def message(self):
        return "text diff"


class FailureMissingImageHash(TestFailure):
    def message(self):
        return "-expected.png was missing an embedded checksum"

    def write_failure(self, writer, driver_output, expected_driver_output, port):
        writer.write_image_files(driver_output.image, expected_driver_output.image)


class FailureMissingImage(TestFailure):
    def message(self):
        return "-expected.png was missing"

    def write_failure(self, writer, driver_output, expected_driver_output, port):
        writer.write_image_files(driver_output.image, expected_image=None)


class FailureImageHashMismatch(TestFailure):
    def __init__(self, diff_percent=0):
        super(FailureImageHashMismatch, self).__init__()
        self.diff_percent = diff_percent

    def message(self):
        return "image diff"

    def write_failure(self, writer, driver_output, expected_driver_output, port):
        writer.write_image_files(driver_output.image, expected_driver_output.image)
        writer.write_image_diff_files(driver_output.image_diff)


class FailureImageHashIncorrect(TestFailure):
    def message(self):
        return "-expected.png embedded checksum is incorrect"


class FailureReftestMismatch(TestFailure):
    def __init__(self, reference_filename=None):
        super(FailureReftestMismatch, self).__init__()
        self.reference_filename = reference_filename
        self.diff_percent = None

    def message(self):
        return "reference mismatch"

    def write_failure(self, writer, driver_output, expected_driver_output, port):
        writer.write_image_files(driver_output.image, expected_driver_output.image)
        # FIXME: This work should be done earlier in the pipeline (e.g., when we compare images for non-ref tests).
        # FIXME: We should always have 2 images here.
        if driver_output.image and expected_driver_output.image:
            diff_image, diff_percent, err_str = port.diff_image(expected_driver_output.image, driver_output.image, tolerance=0)
            if diff_image:
                writer.write_image_diff_files(diff_image)
                self.diff_percent = diff_percent
            else:
                _log.warn('ref test mismatch did not produce an image diff.')
        writer.write_reftest(self.reference_filename)


class FailureReftestMismatchDidNotOccur(TestFailure):
    def __init__(self, reference_filename=None):
        super(FailureReftestMismatchDidNotOccur, self).__init__()
        self.reference_filename = reference_filename

    def message(self):
        return "reference mismatch didn't happen"

    def write_failure(self, writer, driver_output, expected_driver_output, port):
        writer.write_image_files(driver_output.image, expected_image=None)
        writer.write_reftest(self.reference_filename)

class FailureReftestNoImagesGenerated(TestFailure):
    def __init__(self, reference_filename=None):
        super(FailureReftestNoImagesGenerated, self).__init__()
        self.reference_filename = reference_filename

    def message(self):
        return "reference didn't generate pixel results."


class FailureMissingAudio(FailureAudio):
    def message(self):
        return "expected audio result was missing"


class FailureAudioMismatch(FailureAudio):
    def message(self):
        return "audio mismatch"


class FailureEarlyExit(TestFailure):
    def message(self):
        return "skipped due to early exit"


# Convenient collection of all failure classes for anything that might
# need to enumerate over them all.
ALL_FAILURE_CLASSES = (FailureTimeout, FailureCrash, FailureMissingResult,
                       FailureTextMismatch, FailureMissingImageHash,
                       FailureMissingImage, FailureImageHashMismatch,
                       FailureImageHashIncorrect, FailureReftestMismatch,
                       FailureReftestMismatchDidNotOccur, FailureReftestNoImagesGenerated,
                       FailureMissingAudio, FailureAudioMismatch,
                       FailureEarlyExit)