# Copyright (c) 2012 Google Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#     * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
#     * Neither the Google name nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

"""
This is an implementation of the Port interface that overrides other
ports and changes the Driver binary to "MockDRT".

The MockDRT objects emulate what a real DRT would do. In particular, they
return the output a real DRT would return for a given test, assuming that
test actually passes (except for reftests, which currently cause the
MockDRT to crash).
"""

import base64
import logging
import optparse
import os
import sys

# Since we execute this script directly as part of the unit tests, we need to ensure
# that Tools/Scripts is in sys.path for the next imports to work correctly.
script_dir = os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
if script_dir not in sys.path:
    sys.path.append(script_dir)

from webkitpy.common.system.systemhost import SystemHost
from webkitpy.port.driver import DriverInput, DriverOutput, DriverProxy
from webkitpy.port.factory import PortFactory

_log = logging.getLogger(__name__)


class MockDRTPort(object):
    port_name = 'mock'

    @classmethod
    def determine_full_port_name(cls, host, options, port_name):
        return port_name

    def __init__(self, host, port_name, **kwargs):
        self.__delegate = PortFactory(host).get(port_name.replace('mock-', ''), **kwargs)

    def __getattr__(self, name):
        return getattr(self.__delegate, name)

    def check_build(self):
        return True

    def check_sys_deps(self):
        return True

    def create_driver(self, worker_number, no_timeout=False):
        # The magic of the MockDRTPort is that we create a driver that has a
        # cmd_line() method monkey-patched to invoke this script instead of DRT.
        return DriverProxy(self, worker_number, self._mocked_driver_maker, pixel_tests=self.get_option('pixel_tests'), no_timeout=no_timeout)

    @staticmethod
    def _mocked_driver_maker(port, worker_number, pixel_tests, no_timeout=False):
        path_to_this_file = port.host.filesystem.abspath(__file__.replace('.pyc', '.py'))
        driver = port.__delegate._driver_class()(port, worker_number, pixel_tests, no_timeout)
        driver.cmd_line = port._overriding_cmd_line(driver.cmd_line,
                                                    port.__delegate._path_to_driver(),
                                                    sys.executable,
                                                    path_to_this_file,
                                                    port.__delegate.name())
        return driver

    @staticmethod
    def _overriding_cmd_line(original_cmd_line, driver_path, python_exe, this_file, port_name):
        def new_cmd_line(pixel_tests, per_test_args):
            cmd_line = original_cmd_line(pixel_tests, per_test_args)
            index = cmd_line.index(driver_path)
            cmd_line[index:index + 1] = [python_exe, this_file, '--platform', port_name]
            return cmd_line

        return new_cmd_line

    def start_helper(self, pixel_tests=False):
        pass

    def start_http_server(self, number_of_servers):
        pass

    def start_websocket_server(self):
        pass

    def stop_helper(self):
        pass

    def stop_http_server(self):
        pass

    def stop_websocket_server(self):
        pass

    def show_results_html_file(self, results_filename):
        pass


def main(argv, host, stdin, stdout, stderr):
    """Run the tests."""

    options, args = parse_options(argv)
    drt = MockDRT(options, args, host, stdin, stdout, stderr)
    return drt.run()


def parse_options(argv):
    # FIXME: We have to do custom arg parsing instead of using the optparse
    # module.  First, Chromium and non-Chromium DRTs have a different argument
    # syntax.  Chromium uses --pixel-tests=<path>, and non-Chromium uses
    # --pixel-tests as a boolean flag. Second, we don't want to have to list
    # every command line flag DRT accepts, but optparse complains about
    # unrecognized flags. At some point it might be good to share a common
    # DRT options class between this file and webkit.py and chromium.py
    # just to get better type checking.
    platform_index = argv.index('--platform')
    platform = argv[platform_index + 1]

    pixel_tests = '--pixel-tests' in argv
    return (optparse.Values({'platform': platform, 'pixel_tests': pixel_tests}), argv)


class MockDRT(object):
    def __init__(self, options, args, host, stdin, stdout, stderr):
        self._options = options
        self._args = args
        self._host = host
        self._stdout = stdout
        self._stdin = stdin
        self._stderr = stderr

        port_name = None
        if options.platform:
            port_name = options.platform
        self._port = PortFactory(host).get(port_name=port_name, options=options)
        self._driver = self._port.create_driver(0)

    def run(self):
        while True:
            line = self._stdin.readline()
            if not line:
                return 0
            driver_input = self.input_from_line(line)
            dirname, basename = self._port.split_test(driver_input.test_name)
            is_reftest = (self._port.reference_files(driver_input.test_name) or
                          self._port.is_reference_html_file(self._port._filesystem, dirname, basename))
            output = self.output_for_test(driver_input, is_reftest)
            self.write_test_output(driver_input, output, is_reftest)

    def input_from_line(self, line):
        vals = line.strip().split("'")
        if len(vals) == 1:
            uri = vals[0]
            checksum = None
        else:
            uri = vals[0]
            checksum = vals[1]
        if uri.startswith('http://') or uri.startswith('https://'):
            test_name = self._driver.uri_to_test(uri)
        else:
            test_name = self._port.relative_test_filename(uri)

        return DriverInput(test_name, 0, checksum, self._options.pixel_tests)

    def output_for_test(self, test_input, is_reftest):
        port = self._port
        actual_text = port.expected_text(test_input.test_name)
        actual_audio = port.expected_audio(test_input.test_name)
        actual_image = None
        actual_checksum = None
        if is_reftest:
            # Make up some output for reftests.
            actual_text = 'reference text\n'
            actual_checksum = 'mock-checksum'
            actual_image = 'blank'
            if test_input.test_name.endswith('-mismatch.html'):
                actual_text = 'not reference text\n'
                actual_checksum = 'not-mock-checksum'
                actual_image = 'not blank'
        elif self._options.pixel_tests and test_input.image_hash:
            actual_checksum = port.expected_checksum(test_input.test_name)
            actual_image = port.expected_image(test_input.test_name)

        return DriverOutput(actual_text, actual_image, actual_checksum, actual_audio)

    def write_test_output(self, test_input, output, is_reftest):
        if output.audio:
            self._stdout.write('Content-Type: audio/wav\n')
            self._stdout.write('Content-Transfer-Encoding: base64\n')
            self._stdout.write(base64.b64encode(output.audio))
        else:
            self._stdout.write('Content-Type: text/plain\n')
            # FIXME: Note that we don't ensure there is a trailing newline!
            # This mirrors actual (Mac) DRT behavior but is a bug.
            if output.text:
                self._stdout.write(output.text)

        self._stdout.write('#EOF\n')

        if self._options.pixel_tests and output.image_hash:
            self._stdout.write('\n')
            self._stdout.write('ActualHash: %s\n' % output.image_hash)
            self._stdout.write('ExpectedHash: %s\n' % test_input.image_hash)
            if output.image_hash != test_input.image_hash:
                self._stdout.write('Content-Type: image/png\n')
                self._stdout.write('Content-Length: %s\n' % len(output.image))
                self._stdout.write(output.image)
        self._stdout.write('#EOF\n')
        self._stdout.flush()
        self._stderr.write('#EOF\n')
        self._stderr.flush()

if __name__ == '__main__':
    # Note that the Mock in MockDRT refers to the fact that it is emulating a
    # real DRT, and as such, it needs access to a real SystemHost, not a MockSystemHost.
    sys.exit(main(sys.argv[1:], SystemHost(), sys.stdin, sys.stdout, sys.stderr))