# 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.
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# in the documentation and/or other materials provided with the
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import datetime
import os
import shutil
import tempfile
import threading
import unittest

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


class LoggingDelegate(QueueEngineDelegate):
    def __init__(self, test):
        self._test = test
        self._callbacks = []
        self._run_before = False
        self.stop_message = None

    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',
        'stop_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")
        return True

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

    def stop_work_queue(self, message):
        self.record("stop_work_queue")
        self.stop_message = message


class RaisingDelegate(LoggingDelegate):
    def __init__(self, test, exception):
        LoggingDelegate.__init__(self, test)
        self._exception = exception

    def process_work_item(self, work_item):
        self.record("process_work_item")
        raise self._exception


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)
        self._run_engine(delegate)
        self.assertEquals(delegate.stop_message, "Delegate terminated queue.")
        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 = RaisingDelegate(self, ScriptError(exit_code=3))
        self._run_engine(delegate)
        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 = RaisingDelegate(self, ScriptError(exit_code=QueueEngine.handled_error_code))
        self._run_engine(delegate)
        self.assertEquals(delegate._callbacks, LoggingDelegate.expected_callbacks)

    def _run_engine(self, delegate, engine=None, termination_message=None):
        if not engine:
            engine = QueueEngine("test-queue", delegate, threading.Event())
        if not termination_message:
            termination_message = "Delegate terminated queue."
        expected_stderr = "\n%s\n" % termination_message
        OutputCapture().assert_outputs(self, engine.run, [], expected_stderr=expected_stderr)

    def _test_terminating_queue(self, exception, termination_message):
        work_item_index = LoggingDelegate.expected_callbacks.index('process_work_item')
        # The terminating error should be handled right after process_work_item.
        # There should be no other callbacks after stop_work_queue.
        expected_callbacks = LoggingDelegate.expected_callbacks[:work_item_index + 1]
        expected_callbacks.append("stop_work_queue")

        delegate = RaisingDelegate(self, exception)
        self._run_engine(delegate, termination_message=termination_message)

        self.assertEquals(delegate._callbacks, expected_callbacks)
        self.assertEquals(delegate.stop_message, termination_message)

    def test_terminating_error(self):
        self._test_terminating_queue(KeyboardInterrupt(), "User terminated queue.")
        self._test_terminating_queue(TerminateQueue(), "TerminateQueue exception received.")

    def test_not_safe_to_proceed(self):
        delegate = NotSafeToProceedDelegate(self)
        self._run_engine(delegate, engine=FastQueueEngine(delegate))
        expected_callbacks = LoggingDelegate.expected_callbacks[:]
        expected_callbacks.remove('work_item_log_path')
        expected_callbacks.remove('process_work_item')
        self.assertEquals(delegate._callbacks, expected_callbacks)

    def test_now(self):
        """Make sure there are no typos in the QueueEngine.now() method."""
        engine = QueueEngine("test", None, None)
        self.assertTrue(isinstance(engine._now(), datetime.datetime))

    def test_sleep_message(self):
        engine = QueueEngine("test", None, None)
        engine._now = lambda: datetime.datetime(2010, 1, 1)
        expected_sleep_message = "MESSAGE Sleeping until 2010-01-01 00:02:00 (2 mins)."
        self.assertEqual(engine._sleep_message("MESSAGE"), expected_sleep_message)

    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()