"""Wrapper for mod_wsgi, for use as a CherryPy HTTP server.

To autostart modwsgi, the "apache" executable or script must be
on your system path, or you must override the global APACHE_PATH.
On some platforms, "apache" may be called "apachectl" or "apache2ctl"--
create a symlink to them if needed.


KNOWN BUGS
==========

1. Apache processes Range headers automatically; CherryPy's truncated
    output is then truncated again by Apache. See test_core.testRanges.
    This was worked around in http://www.cherrypy.dev/changeset/1319.
2. Apache does not allow custom HTTP methods like CONNECT as per the spec.
    See test_core.testHTTPMethods.
3. Max request header and body settings do not work with Apache.
4. Apache replaces status "reason phrases" automatically. For example,
    CherryPy may set "304 Not modified" but Apache will write out
    "304 Not Modified" (capital "M").
5. Apache does not allow custom error codes as per the spec.
6. Apache (or perhaps modpython, or modpython_gateway) unquotes %xx in the
    Request-URI too early.
7. mod_wsgi will not read request bodies which use the "chunked"
    transfer-coding (it passes REQUEST_CHUNKED_ERROR to ap_setup_client_block
    instead of REQUEST_CHUNKED_DECHUNK, see Apache2's http_protocol.c and
    mod_python's requestobject.c).
8. When responding with 204 No Content, mod_wsgi adds a Content-Length
    header for you.
9. When an error is raised, mod_wsgi has no facility for printing a
    traceback as the response content (it's sent to the Apache log instead).
10. Startup and shutdown of Apache when running mod_wsgi seems slow.
"""

import os
import re
import sys
import time

import portend

from cheroot.test import webtest

import cherrypy
from cherrypy.test import helper

curdir = os.path.abspath(os.path.dirname(__file__))


def read_process(cmd, args=''):
    pipein, pipeout = os.popen4('%s %s' % (cmd, args))
    try:
        firstline = pipeout.readline()
        if (re.search(r'(not recognized|No such file|not found)', firstline,
                      re.IGNORECASE)):
            raise IOError('%s must be on your system path.' % cmd)
        output = firstline + pipeout.read()
    finally:
        pipeout.close()
    return output


if sys.platform == 'win32':
    APACHE_PATH = 'httpd'
else:
    APACHE_PATH = 'apache'

CONF_PATH = 'test_mw.conf'

conf_modwsgi = r"""
# Apache2 server conf file for testing CherryPy with modpython_gateway.

ServerName 127.0.0.1
DocumentRoot "/"
Listen %(port)s

AllowEncodedSlashes On
LoadModule rewrite_module modules/mod_rewrite.so
RewriteEngine on
RewriteMap escaping int:escape

LoadModule log_config_module modules/mod_log_config.so
LogFormat "%%h %%l %%u %%t \"%%r\" %%>s %%b \"%%{Referer}i\" \"%%{User-agent}i\"" combined
CustomLog "%(curdir)s/apache.access.log" combined
ErrorLog "%(curdir)s/apache.error.log"
LogLevel debug

LoadModule wsgi_module modules/mod_wsgi.so
LoadModule env_module modules/mod_env.so

WSGIScriptAlias / "%(curdir)s/modwsgi.py"
SetEnv testmod %(testmod)s
""" # noqa E501


class ModWSGISupervisor(helper.Supervisor):

    """Server Controller for ModWSGI and CherryPy."""

    using_apache = True
    using_wsgi = True
    template = conf_modwsgi

    def __str__(self):
        return 'ModWSGI Server on %s:%s' % (self.host, self.port)

    def start(self, modulename):
        mpconf = CONF_PATH
        if not os.path.isabs(mpconf):
            mpconf = os.path.join(curdir, mpconf)

        with open(mpconf, 'wb') as f:
            output = (self.template %
                      {'port': self.port, 'testmod': modulename,
                       'curdir': curdir})
            f.write(output)

        result = read_process(APACHE_PATH, '-k start -f %s' % mpconf)
        if result:
            print(result)

        # Make a request so mod_wsgi starts up our app.
        # If we don't, concurrent initial requests will 404.
        portend.occupied('127.0.0.1', self.port, timeout=5)
        webtest.openURL('/ihopetheresnodefault', port=self.port)
        time.sleep(1)

    def stop(self):
        """Gracefully shutdown a server that is serving forever."""
        read_process(APACHE_PATH, '-k stop')


loaded = False


def application(environ, start_response):
    global loaded
    if not loaded:
        loaded = True
        modname = 'cherrypy.test.' + environ['testmod']
        mod = __import__(modname, globals(), locals(), [''])
        mod.setup_server()

        cherrypy.config.update({
            'log.error_file': os.path.join(curdir, 'test.error.log'),
            'log.access_file': os.path.join(curdir, 'test.access.log'),
            'environment': 'test_suite',
            'engine.SIGHUP': None,
            'engine.SIGTERM': None,
        })
    return cherrypy.tree(environ, start_response)
