"""A library of helper functions for the Cheroot test suite."""

from __future__ import absolute_import, division, print_function
__metaclass__ = type

import datetime
import logging
import os
import sys
import time
import threading
import types

from six.moves import http_client

import six

import cheroot.server
import cheroot.wsgi

from cheroot.test import webtest

log = logging.getLogger(__name__)
thisdir = os.path.abspath(os.path.dirname(__file__))


config = {
    'bind_addr': ('127.0.0.1', 54583),
    'server': 'wsgi',
    'wsgi_app': None,
}


class CherootWebCase(webtest.WebCase):
    """Helper class for a web app test suite."""

    script_name = ''
    scheme = 'http'

    available_servers = {
        'wsgi': cheroot.wsgi.Server,
        'native': cheroot.server.HTTPServer,
    }

    @classmethod
    def setup_class(cls):
        """Create and run one HTTP server per class."""
        conf = config.copy()
        conf.update(getattr(cls, 'config', {}))

        s_class = conf.pop('server', 'wsgi')
        server_factory = cls.available_servers.get(s_class)
        if server_factory is None:
            raise RuntimeError('Unknown server in config: %s' % conf['server'])
        cls.httpserver = server_factory(**conf)

        cls.HOST, cls.PORT = cls.httpserver.bind_addr
        if cls.httpserver.ssl_adapter is None:
            ssl = ''
            cls.scheme = 'http'
        else:
            ssl = ' (ssl)'
            cls.HTTP_CONN = http_client.HTTPSConnection
            cls.scheme = 'https'

        v = sys.version.split()[0]
        log.info('Python version used to run this test script: %s' % v)
        log.info('Cheroot version: %s' % cheroot.__version__)
        log.info('HTTP server version: %s%s' % (cls.httpserver.protocol, ssl))
        log.info('PID: %s' % os.getpid())

        if hasattr(cls, 'setup_server'):
            # Clear the wsgi server so that
            # it can be updated with the new root
            cls.setup_server()
            cls.start()

    @classmethod
    def teardown_class(cls):
        """Cleanup HTTP server."""
        if hasattr(cls, 'setup_server'):
            cls.stop()

    @classmethod
    def start(cls):
        """Load and start the HTTP server."""
        threading.Thread(target=cls.httpserver.safe_start).start()
        while not cls.httpserver.ready:
            time.sleep(0.1)

    @classmethod
    def stop(cls):
        """Terminate HTTP server."""
        cls.httpserver.stop()
        td = getattr(cls, 'teardown', None)
        if td:
            td()

    date_tolerance = 2

    def assertEqualDates(self, dt1, dt2, seconds=None):
        """Assert abs(dt1 - dt2) is within Y seconds."""
        if seconds is None:
            seconds = self.date_tolerance

        if dt1 > dt2:
            diff = dt1 - dt2
        else:
            diff = dt2 - dt1
        if not diff < datetime.timedelta(seconds=seconds):
            raise AssertionError('%r and %r are not within %r seconds.' %
                                 (dt1, dt2, seconds))


class Request:
    """HTTP request container."""

    def __init__(self, environ):
        """Initialize HTTP request."""
        self.environ = environ


class Response:
    """HTTP response container."""

    def __init__(self):
        """Initialize HTTP response."""
        self.status = '200 OK'
        self.headers = {'Content-Type': 'text/html'}
        self.body = None

    def output(self):
        """Generate iterable response body object."""
        if self.body is None:
            return []
        elif isinstance(self.body, six.text_type):
            return [self.body.encode('iso-8859-1')]
        elif isinstance(self.body, six.binary_type):
            return [self.body]
        else:
            return [x.encode('iso-8859-1') for x in self.body]


class Controller:
    """WSGI app for tests."""

    def __call__(self, environ, start_response):
        """WSGI request handler."""
        req, resp = Request(environ), Response()
        try:
            # Python 3 supports unicode attribute names
            # Python 2 encodes them
            handler = self.handlers[environ['PATH_INFO']]
        except KeyError:
            resp.status = '404 Not Found'
        else:
            output = handler(req, resp)
            if (output is not None
                and not any(resp.status.startswith(status_code)
                            for status_code in ('204', '304'))):
                resp.body = output
                try:
                    resp.headers.setdefault('Content-Length', str(len(output)))
                except TypeError:
                    if not isinstance(output, types.GeneratorType):
                        raise
        start_response(resp.status, resp.headers.items())
        return resp.output()
