"""
All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
its licensors.

For complete copyright and license terms please see the LICENSE at the root of this
distribution (the "License"). All use of this software is governed by the License,
or, if provided, by the license below or the license accompanying this file. Do not
remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
"""

import json
import logging
import os
import time
import shutil
import subprocess
import sys

logger = logging.getLogger(__name__)


class PlatformDriver:

    def __init__(self, project_json_path, project_launcher_tests_folder, test_names, screenshots_folder, screenshots_interval):
        self.project_json_path = project_json_path
        self.project_launcher_tests_folder = project_launcher_tests_folder
        self.test_names = test_names
        self.screenshots_folder = screenshots_folder
        self.screenshots_interval = screenshots_interval

    def read_json_data(self, path):
        """Read a json file and return the data"""
        try:
            with open(path) as json_file:
                json_data = json.load(json_file)
        except Exception, e:
            logger.error("Failed to read json file: '{}'".format(path))
            logger.error("Exception: '{}'".format(e))
            sys.exit(1)
        return json_data

    def read_project_name(self):
        project_data = self.read_json_data(self.project_json_path)
        return project_data['project_name']


    def run_test(self, map, dynamic_slice, timeout, pass_string, fail_string):
        """ Meant to be overridden in derived classes. """
        return True

    def run_launcher_tests(self):
        """Discovers all of the available tests in launcher_tests.json and runs them.
        """
        # Delete the old screenshots folder if it exists
        if os.path.exists(self.screenshots_folder):
            shutil.rmtree(self.screenshots_folder)
        
        # Read the launcher_tests.json file.
        launcher_tests_data = self.read_json_data(os.path.join(self.project_launcher_tests_folder, 'launcher_tests.json'))

        # Run each of the tests found in the launcher_tests.json file.
        ok = True
        for launcher_test_data in launcher_tests_data['launcher_tests']:
        
            # Skip over this test if specific tests are specified and this is not one of them.
            if self.test_names and launcher_test_data.get('name').lower() not in [x.lower() for x in self.test_names]:
                continue
        
            ok = ok and self.run_test(
                launcher_test_data.get('name'),
                launcher_test_data.get('map'),
                launcher_test_data.get('dynamic_slice'),
                launcher_test_data.get('timeout'),
                launcher_test_data.get('pass_string', 'AUTO_LAUNCHER_TEST_COMPLETE'),
                launcher_test_data.get('fail_string', 'AUTO_LAUNCHER_TEST_FAIL'))
        return ok

    def monitor_process_output(self, test_name, command, pass_string, fail_string, timeout, log_file=None):

        self.process = subprocess.Popen(command, stdout=subprocess.PIPE)

        # On windows, function was failing (I think) because it checked the poll before the process
        # had a chance to start, so added a short delay to give it some time to startup.
        # It also failed if the log_file was open()'d when it didn't exist yet.
        # Delay seems to have fixed the problem. 0.25 sec was too short.
        time.sleep(0.5)

        if log_file:
            # The process we're starting sends it's output to the log file instead of stdout
            # so we need to monitor that instead of the stdout.
            fp = open(log_file)

        # Detect log output messages or timeout exceeded
        start = time.time()
        last_time = start
        screenshot_time_remaining = self.screenshots_interval
        screenshot_index = 0
        logger.info('Waiting for test to complete.')
        message = ""
        result = False
        while True:
            if log_file:
                line = fp.readline()
            else:
                line = self.process.stdout.readline()
            if line == '' and self.process.poll() is not None:
                break
            if line:
                logger.info(line.rstrip())
                if pass_string in line:
                    message = "Detected {}. Test completed.".format(pass_string)
                    result = True
                    break
                if fail_string in line:
                    message = "Detected {}. Test failed.".format(fail_string)
                    break
                if time.time() - start > timeout:
                    message = "Timeout of {} reached. Test failed.".format(timeout)
                    break

            rc = self.process.poll()
            cur_time = time.time()
            screenshot_time_remaining = screenshot_time_remaining - (cur_time - last_time)
            last_time = cur_time
            if screenshot_time_remaining <= 0:
                self.take_screenshot(os.path.join(self.screenshots_folder, "{}_screen{}".format(test_name.replace(' ', '_'), screenshot_index)))
                screenshot_index = screenshot_index + 1
                screenshot_time_remaining = self.screenshots_interval

        logger.info(message)

        if log_file:
            fp.close()

        return result