# Copyright (c) 2010 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.
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# 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
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# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import fnmatch
import os
import os.path
import sys

from webkitpy.common.system.executive import ScriptError
from webkitpy.port.base import Port
from webkitpy.tool.servers.reflectionhandler import ReflectionHandler

if sys.version_info > (3, 0):
    from http.server import HTTPServer
else:
    from BaseHTTPServer import HTTPServer


STATE_NEEDS_REBASELINE = 'needs_rebaseline'
STATE_REBASELINE_FAILED = 'rebaseline_failed'
STATE_REBASELINE_SUCCEEDED = 'rebaseline_succeeded'


def _get_actual_result_files(test_file, test_config):
    test_name, _ = os.path.splitext(test_file)
    test_directory = os.path.dirname(test_file)

    test_results_directory = test_config.filesystem.join(
        test_config.results_directory, test_directory)
    actual_pattern = os.path.basename(test_name) + '-actual.*'
    actual_files = []
    for filename in test_config.filesystem.listdir(test_results_directory):
        if fnmatch.fnmatch(filename, actual_pattern):
            actual_files.append(filename)
    actual_files.sort()
    return tuple(actual_files)


def _rebaseline_test(test_file, baseline_target, baseline_move_to, test_config, log):
    test_name, _ = os.path.splitext(test_file)
    test_directory = os.path.dirname(test_name)

    log('Rebaselining %s...' % test_name)

    actual_result_files = _get_actual_result_files(test_file, test_config)
    filesystem = test_config.filesystem
    scm = test_config.scm
    layout_tests_directory = test_config.layout_tests_directory
    results_directory = test_config.results_directory
    target_expectations_directory = filesystem.join(
        layout_tests_directory, 'platform', baseline_target, test_directory)
    test_results_directory = test_config.filesystem.join(
        test_config.results_directory, test_directory)

    # If requested, move current baselines out
    current_baselines = get_test_baselines(test_file, test_config)
    if baseline_target in current_baselines and baseline_move_to != 'none':
        log('  Moving current %s baselines to %s' %
            (baseline_target, baseline_move_to))

        # See which ones we need to move (only those that are about to be
        # updated), and make sure we're not clobbering any files in the
        # destination.
        current_extensions = set(current_baselines[baseline_target].keys())
        actual_result_extensions = [
            os.path.splitext(f)[1] for f in actual_result_files]
        extensions_to_move = current_extensions.intersection(
            actual_result_extensions)

        if extensions_to_move.intersection(
            current_baselines.get(baseline_move_to, {}).keys()):
            log('    Already had baselines in %s, could not move existing '
                '%s ones' % (baseline_move_to, baseline_target))
            return False

        # Do the actual move.
        if extensions_to_move:
            if not _move_test_baselines(
                test_file,
                list(extensions_to_move),
                baseline_target,
                baseline_move_to,
                test_config,
                log):
                return False
        else:
            log('    No current baselines to move')

    log('  Updating baselines for %s' % baseline_target)
    filesystem.maybe_make_directory(target_expectations_directory)
    for source_file in actual_result_files:
        source_path = filesystem.join(test_results_directory, source_file)
        destination_file = source_file.replace('-actual', '-expected')
        destination_path = filesystem.join(
            target_expectations_directory, destination_file)
        filesystem.copyfile(source_path, destination_path)
        try:
            scm.add(destination_path)
            log('    Updated %s' % destination_file)
        except ScriptError as error:
            log('    Could not update %s in SCM, exit code %d' %
                (destination_file, error.exit_code))
            return False

    return True


def _move_test_baselines(test_file, extensions_to_move, source_platform, destination_platform, test_config, log):
    test_file_name = os.path.splitext(os.path.basename(test_file))[0]
    test_directory = os.path.dirname(test_file)
    filesystem = test_config.filesystem

    # Want predictable output order for unit tests.
    extensions_to_move.sort()

    source_directory = os.path.join(
        test_config.layout_tests_directory,
        'platform',
        source_platform,
        test_directory)
    destination_directory = os.path.join(
        test_config.layout_tests_directory,
        'platform',
        destination_platform,
        test_directory)
    filesystem.maybe_make_directory(destination_directory)

    for extension in extensions_to_move:
        file_name = test_file_name + '-expected' + extension
        source_path = filesystem.join(source_directory, file_name)
        destination_path = filesystem.join(destination_directory, file_name)
        filesystem.copyfile(source_path, destination_path)
        try:
            test_config.scm.add(destination_path)
            log('    Moved %s' % file_name)
        except ScriptError as error:
            log('    Could not update %s in SCM, exit code %d' %
                (file_name, error.exit_code))
            return False

    return True


def get_test_baselines(test_file, test_config):
    # FIXME: This seems like a hack. This only seems used to access the Port.expected_baselines logic.
    class AllPlatformsPort(Port):
        def __init__(self, host):
            super(AllPlatformsPort, self).__init__(host, 'mac')
            self._platforms_by_directory = dict([(self._webkit_baseline_path(p), p) for p in test_config.platforms])

        def baseline_search_path(self, **kwargs):
            return list(self._platforms_by_directory.keys())

        def platform_from_directory(self, directory):
            return self._platforms_by_directory[directory]

    test_path = test_config.filesystem.join(test_config.layout_tests_directory, test_file)

    host = test_config.host
    host.initialize_scm()
    all_platforms_port = AllPlatformsPort(host)

    all_test_baselines = {}
    for baseline_extension in ('.txt', '.checksum', '.png'):
        test_baselines = test_config.test_port.expected_baselines(test_file, baseline_extension)
        baselines = all_platforms_port.expected_baselines(test_file, baseline_extension, all_baselines=True)
        for platform_directory, expected_filename in baselines:
            if not platform_directory:
                continue
            if platform_directory == test_config.layout_tests_directory:
                platform = 'base'
            else:
                platform = all_platforms_port.platform_from_directory(platform_directory)
            platform_baselines = all_test_baselines.setdefault(platform, {})
            was_used_for_test = (platform_directory, expected_filename) in test_baselines
            platform_baselines[baseline_extension] = was_used_for_test

    return all_test_baselines


class RebaselineHTTPServer(HTTPServer):
    def __init__(self, httpd_port, config):
        server_name = ""
        HTTPServer.__init__(self, (server_name, httpd_port), RebaselineHTTPRequestHandler)
        self.test_config = config['test_config']
        self.results_json = config['results_json']
        self.platforms_json = config['platforms_json']


class RebaselineHTTPRequestHandler(ReflectionHandler):
    STATIC_FILE_NAMES = frozenset([
        "index.html",
        "loupe.js",
        "main.js",
        "main.css",
        "queue.js",
        "util.js",
    ])

    STATIC_FILE_DIRECTORY = os.path.join(os.path.dirname(__file__), "data", "rebaselineserver")

    def results_json(self):
        self._serve_json(self.server.results_json)

    def test_config(self):
        self._serve_json(self.server.test_config)

    def platforms_json(self):
        self._serve_json(self.server.platforms_json)

    def rebaseline(self):
        test = self.query['test'][0]
        baseline_target = self.query['baseline-target'][0]
        baseline_move_to = self.query['baseline-move-to'][0]
        test_json = self.server.results_json['tests'][test]

        if test_json['state'] != STATE_NEEDS_REBASELINE:
            self.send_error(400, "Test %s is in unexpected state: %s" % (test, test_json["state"]))
            return

        log = []
        success = _rebaseline_test(
            test,
            baseline_target,
            baseline_move_to,
            self.server.test_config,
            log=lambda l: log.append(l))

        if success:
            test_json['state'] = STATE_REBASELINE_SUCCEEDED
            self.send_response(200)
        else:
            test_json['state'] = STATE_REBASELINE_FAILED
            self.send_response(500)

        self.send_header('Content-type', 'text/plain')
        self.end_headers()
        self.wfile.write('\n'.join(log))

    def test_result(self):
        test_name, _ = os.path.splitext(self.query['test'][0])
        mode = self.query['mode'][0]
        if mode == 'expected-image':
            file_name = test_name + '-expected.png'
        elif mode == 'actual-image':
            file_name = test_name + '-actual.png'
        if mode == 'expected-checksum':
            file_name = test_name + '-expected.checksum'
        elif mode == 'actual-checksum':
            file_name = test_name + '-actual.checksum'
        elif mode == 'diff-image':
            file_name = test_name + '-diff.png'
        if mode == 'expected-text':
            file_name = test_name + '-expected.txt'
        elif mode == 'actual-text':
            file_name = test_name + '-actual.txt'
        elif mode == 'diff-text':
            file_name = test_name + '-diff.txt'
        elif mode == 'diff-text-pretty':
            file_name = test_name + '-pretty-diff.html'

        file_path = os.path.join(self.server.test_config.results_directory, file_name)
        if not os.path.isfile(file_path):
            file_path = os.path.join(self.server.test_config.results_directory, 'retries', file_name)

        # Let results be cached for 60 seconds, so that they can be pre-fetched
        # by the UI
        self._serve_file(file_path, cacheable_seconds=60)