# Copyright (c) 2009 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 name of Google Inc. 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,
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import os
import shutil
import tempfile
import threading
import unittest

from webkitpy.common.system.executive import ScriptError
from webkitpy.tool.bot.queueengine import QueueEngine, QueueEngineDelegate

class LoggingDelegate(QueueEngineDelegate):
    def __init__(self, test):
        self._test = test
        self._callbacks = []
        self._run_before = False

    expected_callbacks = [
        'queue_log_path',
        'begin_work_queue',
        'should_continue_work_queue',
        'next_work_item',
        'should_proceed_with_work_item',
        'work_item_log_path',
        'process_work_item',
        'should_continue_work_queue'
    ]

    def record(self, method_name):
        self._callbacks.append(method_name)

    def queue_log_path(self):
        self.record("queue_log_path")
        return os.path.join(self._test.temp_dir, "queue_log_path")

    def work_item_log_path(self, work_item):
        self.record("work_item_log_path")
        return os.path.join(self._test.temp_dir, "work_log_path", "%s.log" % work_item)

    def begin_work_queue(self):
        self.record("begin_work_queue")

    def should_continue_work_queue(self):
        self.record("should_continue_work_queue")
        if not self._run_before:
            self._run_before = True
            return True
        return False

    def next_work_item(self):
        self.record("next_work_item")
        return "work_item"

    def should_proceed_with_work_item(self, work_item):
        self.record("should_proceed_with_work_item")
        self._test.assertEquals(work_item, "work_item")
        fake_patch = { 'bug_id' : 42 }
        return (True, "waiting_message", fake_patch)

    def process_work_item(self, work_item):
        self.record("process_work_item")
        self._test.assertEquals(work_item, "work_item")

    def handle_unexpected_error(self, work_item, message):
        self.record("handle_unexpected_error")
        self._test.assertEquals(work_item, "work_item")


class ThrowErrorDelegate(LoggingDelegate):
    def __init__(self, test, error_code):
        LoggingDelegate.__init__(self, test)
        self.error_code = error_code

    def process_work_item(self, work_item):
        self.record("process_work_item")
        raise ScriptError(exit_code=self.error_code)


class NotSafeToProceedDelegate(LoggingDelegate):
    def should_proceed_with_work_item(self, work_item):
        self.record("should_proceed_with_work_item")
        self._test.assertEquals(work_item, "work_item")
        return False


class FastQueueEngine(QueueEngine):
    def __init__(self, delegate):
        QueueEngine.__init__(self, "fast-queue", delegate, threading.Event())

    # No sleep for the wicked.
    seconds_to_sleep = 0

    def _sleep(self, message):
        pass


class QueueEngineTest(unittest.TestCase):
    def test_trivial(self):
        delegate = LoggingDelegate(self)
        work_queue = QueueEngine("trivial-queue", delegate, threading.Event())
        work_queue.run()
        self.assertEquals(delegate._callbacks, LoggingDelegate.expected_callbacks)
        self.assertTrue(os.path.exists(os.path.join(self.temp_dir, "queue_log_path")))
        self.assertTrue(os.path.exists(os.path.join(self.temp_dir, "work_log_path", "work_item.log")))

    def test_unexpected_error(self):
        delegate = ThrowErrorDelegate(self, 3)
        work_queue = QueueEngine("error-queue", delegate, threading.Event())
        work_queue.run()
        expected_callbacks = LoggingDelegate.expected_callbacks[:]
        work_item_index = expected_callbacks.index('process_work_item')
        # The unexpected error should be handled right after process_work_item starts
        # but before any other callback.  Otherwise callbacks should be normal.
        expected_callbacks.insert(work_item_index + 1, 'handle_unexpected_error')
        self.assertEquals(delegate._callbacks, expected_callbacks)

    def test_handled_error(self):
        delegate = ThrowErrorDelegate(self, QueueEngine.handled_error_code)
        work_queue = QueueEngine("handled-error-queue", delegate, threading.Event())
        work_queue.run()
        self.assertEquals(delegate._callbacks, LoggingDelegate.expected_callbacks)

    def test_not_safe_to_proceed(self):
        delegate = NotSafeToProceedDelegate(self)
        work_queue = FastQueueEngine(delegate)
        work_queue.run()
        expected_callbacks = LoggingDelegate.expected_callbacks[:]
        next_work_item_index = expected_callbacks.index('next_work_item')
        # We slice out the common part of the expected callbacks.
        # We add 2 here to include should_proceed_with_work_item, which is
        # a pain to search for directly because it occurs twice.
        expected_callbacks = expected_callbacks[:next_work_item_index + 2]
        expected_callbacks.append('should_continue_work_queue')
        self.assertEquals(delegate._callbacks, expected_callbacks)

    def setUp(self):
        self.temp_dir = tempfile.mkdtemp(suffix="work_queue_test_logs")

    def tearDown(self):
        shutil.rmtree(self.temp_dir)


if __name__ == '__main__':
    unittest.main()
