#!/usr/bin/env python

from Common import *
from UserDict import UserDict
from Object import Object
from types import FloatType, ClassType

from ExceptionHandler import ExceptionHandler

from ConfigurableForServerSidePath import ConfigurableForServerSidePath

from TaskKit.Scheduler import Scheduler

from HTTPRequest import HTTPRequest
from Transaction import Transaction
from Session import Session
import URLParser
import HTTPExceptions

debug = 0


class EndResponse(Exception):
    """End response exception.

    Used to prematurely break out of the awake()/respond()/sleep()
    cycle without reporting a traceback. During servlet processing,
    if this exception is caught during awake() or respond() then sleep()
    is called and the response is sent. If caught during sleep(),
    processing ends and the response is sent.

    """
    pass


class Application(ConfigurableForServerSidePath, Object):
    """The Application singleton.

    `Application` and `AppServer` work together to setup up and dispatch
    requests. The distinction between the two is largely historical, but
    AppServer communicates directly with Adapters (or speaks protocols like
    HTTP), and Application receives the (slightly) processed input from
    AppServer and turns it into `Transaction`, `HTTPRequest`, `HTTPResponse`,
    and `Session`.

    Application is a singleton, which belongs to the AppServer. You can get
    access through the Transaction object (``transaction.application()``),
    or you can do::

        from AppServer import globalAppServer
        application = AppServer.application()

    Settings for Application are taken from ``Configs/Application.config``,
    and it is used for many global settings, even if they aren't closely tied
    to the Application object itself.

    """


    ## Init ##

    def __init__(self, server):
        """Called only by `AppServer`, sets up the Application."""

        self._server = server
        self._serverSidePath = server.serverSidePath()

        ConfigurableForServerSidePath.__init__(self)
        Object.__init__(self)

        if self.setting('PrintConfigAtStartUp'):
            self.printConfig()

        self.initVersions()

        self._shutDownHandlers = []

        # For TaskManager:
        if self._server.isPersistent():
            self._taskManager = Scheduler(1)
            self._taskManager.start()

        # Define this before initializing URLParser, so that contexts have a
        # chance to override this. Also be sure to define it before loading the
        # sessions, in case the loading of the sessions causes an exception.
        self._exceptionHandlerClass = ExceptionHandler

        # For session store:
        sessionStore = 'Session%sStore' % self.setting('SessionStore')
        exec 'from %s import %s' % (sessionStore, sessionStore)
        klass = locals()[sessionStore]
        assert isinstance(klass, ClassType) or issubclass(klass, Object)
        self._sessions = klass(self)

        print 'Current directory:', os.getcwd()

        URLParser.initApp(self)
        self._rootURLParser = URLParser.ContextParser(self)

        self.running = 1

        self.startSessionSweeper()

        try: # try to get a 404 error page from the working dir
            self._404Page = open(os.path.join(self._serverSidePath,
                "404Text.txt")).read()
        except: # if not found in the working dir,
            try: # then try the directory this file is located in
                self._404Page = open(os.path.join(
                    os.path.dirname(os.path.abspath(__file__)),
                    "404Text.txt")).read()
            except: # otherwise fall back to standard exception
                self._404Page = None


    def initVersions(self):
        """Get and store versions.

        Initialize attributes that store the Webware and WebKit versions as
        both tuples and strings. These are stored in the Properties.py files.

        """
        from MiscUtils.PropertiesObject import PropertiesObject
        props = PropertiesObject(os.path.join(self.webwarePath(),
                              'Properties.py'))
        self._webwareVersion = props['version']
        self._webwareVersionString = props['versionString']

        props = PropertiesObject(os.path.join(self.webKitPath(),
                              'Properties.py'))
        self._webKitVersion = props['version']
        self._webKitVersionString = props['versionString']


    def taskManager(self):
        """Accessor: `TaskKit.Scheduler` instance."""
        return self._taskManager

    def startSessionSweeper(self):
        """Start session sweeper.

        Starts the session sweeper, `WebKit.Tasks.SessionTask`, which deletes
        session objects (and disk copies of those objects) that have expired.

        """
        from Tasks import SessionTask
        import time
        task = SessionTask.SessionTask(self._sessions)
        tm = self.taskManager()
        sweepinterval = self.setting('SessionTimeout')*60/10
        tm.addPeriodicAction(time.time()+sweepinterval,
                     sweepinterval, task, "SessionSweeper")
        print "Session Sweeper started"

    def shutDown(self):
        """Shut down the application.

        Called by AppServer when it is shuting down.  The `__del__` function
        of Application probably won't be called due to circular references.

        """
        print "Application is shutting down..."
        self.running = 0
        if hasattr(self, '_sessSweepThread'):
            # We don't always have this, hence the 'if' above
            self._closeEvent.set()
            self._sessSweepThread.join()
            del self._sessSweepThread
        self._sessions.storeAllSessions()
        if self._server.isPersistent():
            self.taskManager().stop()
        del self._sessions
        del self._server

        # Call all registered shutdown handlers
        for shutDownHandler in self._shutDownHandlers:
            shutDownHandler()
        del self._shutDownHandlers

        print "Application has been succesfully shutdown."

    def addShutDownHandler(self, func):
        """Add a shutdown handler.

        Functions added through `addShutDownHandler` will be called when
        the AppServer is shutting down. You can use this hook to close
        database connections, clean up resources, save data to disk, etc.

        """
        self._shutDownHandlers.append(func)


    ## Config ##

    def defaultConfig(self):
        """The default Application.config."""
        return {
            'PrintConfigAtStartUp': 1,
            'LogActivity': 1,
            'ActivityLogFilename': 'Logs/Activity.csv',
            'ActivityLogColumns': [
                'request.remoteAddress', 'request.method',
                'request.uri', 'response.size',
                'servlet.name', 'request.timeStamp',
                'transaction.duration',
                'transaction.errorOccurred'
                ],
            'SessionStore': 'Dynamic',
            'SessionTimeout': 60,
            'IgnoreInvalidSession': 1,
            'UseAutomaticPathSessions': 0,
            'ShowDebugInfoOnErrors': 1,
            'IncludeFancyTraceback': 0,
            'FancyTracebackContext': 5,
            'UserErrorMessage': 'The site is having technical difficulties'
                ' with this page. An error has been logged, and the problem'
                ' will be fixed as soon as possible. Sorry!',
            'LogErrors': 1,
            'ErrorLogFilename': 'Logs/Errors.csv',
            'SaveErrorMessages': 1,
            'ErrorMessagesDir': 'ErrorMsgs',
            'EmailErrors': 0,
            'ErrorEmailServer': 'localhost',
            'ErrorEmailHeaders': {
                'From': 'webware@mydomain',
                'To': ['webware@mydomain'],
                'Reply-to': 'webware@mydomain',
                'content-type': 'text/html',
                'Subject': 'Error'
                },
            'MaxValueLengthInExceptionReport': 500,
            'RPCExceptionReturn': 'traceback',
            'ReportRPCExceptionsInWebKit': 1,
            'Contexts': {
                'default': 'Examples',
                'Admin': 'Admin',
                'Examples': 'Examples',
                'Testing': 'Testing',
                'Docs': 'Docs',
                },
            'Debug': {
                'Sessions': 0,
                },
            'EnterDebuggerOnException': 0,
            'DirectoryFile': ['index', 'Index', 'main', 'Main'],
            'UseCascadingExtensions': 1,
            'ExtensionCascadeOrder': ['.py','.psp','.kid','.html'],
            'ExtraPathInfo': 1,
            'ExtensionsToIgnore': ['.pyc', '.pyo', '.py~',
                '.psp~', '.kid~', '.html~', '.bak', '.tmpl'
                ],
            'ExtensionsToServe': [],
            'FilesToHide': ['.*','*~', '*.bak', '*.tmpl',
                '*.config', '__init__.*', '*.pyc', '*.pyo'
                ],
            'FilesToServe': [],
            'UnknownFileTypes': {
                'ReuseServlets': 1,
                'Technique': 'serveContent',
                'CacheContent': 0,
                },
        }

    def configFilename(self):
        return self.serverSidePath('Configs/Application.config')

    def configReplacementValues(self):
        return self._server.configReplacementValues()


    ## Versions ##

    def version(self):
        """Return the version of the application.

        This implementation returns '0.1'. Subclasses should
        override to return the correct version number.

        """
        # @@ 2000-05-01 ce: Maybe this could be a setting 'AppVersion'
        # @@ 2003-03 ib: Does anyone care about this?  What's this
        # version even supposed to mean?
        return '0.1'

    def webwareVersion(self):
        """Return the Webware version as a tuple."""
        return self._webwareVersion

    def webwareVersionString(self):
        """Return the Webware version as a printable string."""
        return self._webwareVersionString

    def webKitVersion(self):
        """ Return the WebKit version as a tuple."""
        # @@ 2003-03 ib: This is synced with Webware now, should be removed
        # because redundant (and not that useful anyway)
        return self._webKitVersion

    def webKitVersionString(self):
        """Return the WebKit version as a printable string."""
        return self._webKitVersionString


    ## Sessions ##

    def session(self, sessionId, default=NoDefault):
        """The session object for `sessionId`.

        Raises ``KeyError`` if session not found and no default is given.

        """
        if default is NoDefault:
            return self._sessions[sessionId]
        else:
            return self._sessions.get(sessionId, default)

    def hasSession(self, sessionId):
        """Check whether session `sessionId` exists."""
        return self._sessions.has_key(sessionId)

    def sessions(self):
        """A dictionary of all the session objects."""
        return self._sessions

    def createSessionForTransaction(self, transaction):
        """Get the session object for the transaction.

        If the session already exists, returns that, otherwise creates
        a new session.

        Finding the session ID is done in `Transaction.sessionId`.

        """
        debug = self.setting('Debug').get('Sessions')
        if debug:
            prefix = '>> [session] createSessionForTransaction:'
        sessId = transaction.request().sessionId()
        if debug:
            print prefix, 'sessId =', sessId
        if sessId:
            try:
                session = self.session(sessId)
                if debug: print prefix, 'retrieved session =', session
            except KeyError:
                sessId = None
        if not sessId:
            session = Session(transaction)
            self._sessions[session.identifier()] = session
            if debug: print prefix, 'created session =', session
        transaction.setSession(session)
        return session

    def createSessionWithID(self, transaction, sessionID):
        # Create a session object with our session ID
        sess = Session(transaction, sessionID)
        # Replace the session if it didn't already exist,
        # otherwise we just throw it away.  setdefault is an atomic
        # operation so this guarantees that 2 different
        # copies of the session with the same ID never get placed into
        # the session store, even if multiple threads are calling
        # this method simultaneously.
        transaction.application()._sessions.setdefault(sessionID, sess)


    ## Misc Access ##

    def server(self):
        """Acessor: the AppServer"""
        return self._server

    def serverSidePath(self, path=None):
        """Get the serve-side-path.

        Returns the absolute server-side path of the WebKit application.
        If the optional path is passed in, then it is joined with the
        server side directory to form a path relative to the app server.

        """
        if path:
            return os.path.normpath(
                os.path.join(self._serverSidePath, path))
        else:
            return self._serverSidePath

    def webwarePath(self):
        """The path of the ``Webware/`` directory."""
        return self._server.webwarePath()

    def webKitPath(self):
        """The Path of the ``Webware/WebKit/`` directory."""
        return self._server.webKitPath()


    def name(self):
        """The name by which this was started. Usually ``AppServer``."""
        # @@ 2003-03 ib: unconfirmed
        return sys.argv[0]


    ## Activity Log ##

    def writeActivityLog(self, transaction):
        """Write an entry to the activity log.

        Writes an entry to the script log file. Uses settings
        ``ActivityLogFilename`` and ``ActivityLogColumns``.

        """
        filename = self.serverSidePath(
            self.setting('ActivityLogFilename'))
        if os.path.exists(filename):
            file = open(filename, 'a')
        else:
            file = open(filename, 'w')
            file.write(','.join(self.setting('ActivityLogColumns'))+'\n')
        values = []
        # We use UserDict on the next line because we know it inherits
        # NamedValueAccess and reponds to valueForName()
        objects = UserDict({
            'application': self,
            'transaction': transaction,
            'request':   transaction.request(),
            'response': transaction.response(),
            'servlet':   transaction.servlet(),
            'session':   transaction._session, #don't cause creation of session
        })
        for column in self.setting('ActivityLogColumns'):
            try:
                value = objects.valueForName(column)
            except:
                value = '(unknown)'
            if type(value) is FloatType:
                # probably need more flexibility in the future
                value = '%0.2f' % value
            else:
                value = str(value)
            values.append(value)
        file.write(','.join(values)+'\n')
        file.close()

        for i in objects.keys():
            objects[i] = None


    ## Request Dispatching ##

    # These are the entry points from `AppServer`, which take a raw request,
    # turn it into a transaction, run the transaction, and clean up.

    def dispatchRawRequest(self, requestDict, strmOut):
        """Dispatch a raw request.

        Dispatch a request as passed from the Adapter through the AppServer.
        This method creates the request, response, and transaction object,
        then runs (via `runTransaction`) the transaction. It also catches any
        exceptions, which are then passed on to `handleExceptionInTransaction`.

        """
        trans = None
        try:
            request = self.createRequestForDict(requestDict)
            trans = Transaction(application=self, request=request)
            request.setTransaction(trans)
            response = request.responseClass()(trans, strmOut)
            trans.setResponse(response)
            self.runTransaction(trans)
            trans.response().deliver()
        except:
            if trans:
                trans.setErrorOccurred(1)
            if self.setting('EnterDebuggerOnException') and sys.stdin.isatty():
                import pdb
                pdb.post_mortem(sys.exc_info()[2])
            self.handleExceptionInTransaction(sys.exc_info(), trans)
            trans.response().deliver()

        if self.setting('LogActivity'):
            self.writeActivityLog(trans)
        request.clearTransaction()
        response.clearTransaction()
        return trans

    def createRequestForDict(self, requestDict):
        """Create request object for a given dictionary.

        Create a request object (subclass of `Request`) given the raw
        dictionary as passed by the adapter.

        The class of the request may be based on the contents of the
        dictionary (though only `HTTPRequest` is currently created),
        and the request will later determine the class of the response.

        Called by `dispatchRawRequest`.

        """
        format = requestDict['format']
        # Maybe an EmailAdapter would make a request with a
        # format of Email, and an EmailRequest would be
        # generated.  For now just CGI/HTTPRequest.
        assert format == 'CGI'
        return HTTPRequest(requestDict)

    def runTransaction(self, trans):
        """Run transation.

        Executes the transaction, handling HTTPException errors.
        Finds the servlet (using the root parser, probably
        `URLParser.ContextParser`, to find the servlet for the
        transaction, then calling `runTransactionViaServlet`.

        Called by `dispatchRawRequest`.

        """
        # @@ gtalvola: I'm guessing this is not the ideal place
        # @@ to put this code. But, it works.
        if self.setting('UseAutomaticPathSessions'):
            request = trans.request()
            request_has_cookie_session = request.hasCookieSession()
            request_has_path_session = request.hasPathSession()
            if request_has_cookie_session and request_has_path_session:
                self.handleUnnecessaryPathSession(trans)
                return
            elif not request_has_cookie_session and not request_has_path_session:
                self.handleMissingPathSession(trans)
                return
        servlet = None
        try:
            servlet = self._rootURLParser.findServletForTransaction(trans)
            self.runTransactionViaServlet(servlet, trans)
        except HTTPExceptions.HTTPException, err:
            err.setTransaction(trans)
            trans.response().displayError(err)
        except EndResponse:
            pass
        if servlet:
            # Return the servlet to its pool
            self.returnServlet(servlet, trans)

    def runTransactionViaServlet(self, servlet, trans):
        """Execute the transaction using the servlet.

        This is the `awake`/`respond`/`sleep` sequence of calls, or if
        the servlet supports it, a single `runTransaction` call (which is
        presumed to make the awake/respond/sleep calls on its own). Using
        `runTransaction` allows the servlet to override the basic call
        sequence, or catch errors from that sequence.

        Called by `runTransaction`.

        """
        trans.setServlet(servlet)
        if hasattr(servlet, 'runTransaction'):
            servlet.runTransaction(trans)
        else:
            # For backward compatibility (Servlet.runTransaction implements
            # this same sequence of calls, but by keeping it in the servlet
            # it's easier for the servlet to catch exceptions).
            try:
                trans.awake()
                trans.respond()
            finally:
                trans.sleep()

    def forward(self, trans, url, context=None):
        """Forward the request to a different (internal) url.

        The transaction's URL is changed to point to the new servlet,
        and the transaction is simply run again.

        Output is _not_ accumulated, so if the original servlet had any output,
        the new output will _replace_ the old output.

        You can change the request in place to control the servlet you are
        forwarding to -- using methods like `HTTPRequest.setField`.

        @@ 2003-03 ib: how does the forwarded servlet knows that it's not
        the original servlet?

        """
        # Reset the response to a "blank slate"
        trans.response().reset()

        # Include the other servlet
        self.includeURL(trans, url, context)

        # Raise an exception to end processing of this request
        raise EndResponse

    def callMethodOfServlet(self, trans, url, method, *args, **kw):
        """Call method of another servlet.

        Call a method of the servlet referred to by the url, potentially in
        a particular context (use the context keyword argument). Calls sleep()
        and awake() before and after the method call. Or, if the servlet
        defines it, then `runMethodForTransaction` is used (analogous to the
        use of `runTransaction` in `forward`).

        The entire process is similar to `forward`, except that instead of
        `respond`, `method` is called (`method` should be a string, ``*args``
        and ``**kw`` are passed as arguments to that method).

        A `context` keyword argument (as used in `forward`) is also allowed,
        though it isn't present in the method signature.

        """
        # 3-03 ib@@: Does anyone actually use this method?
        # 2003-04-08 jdh: I use callMethodOfServlet, but I don't use
        # this little context trick.  Not sure what you were referring to.
        if kw.has_key('context'):
            context = kw['context']
            del kw['context']
        else:
            context = None

        urlPath = self.resolveInternalRelativePath(trans, url, context)
        req = trans.request()
        currentPath = req.urlPath()
        currentServlet = trans._servlet
        currentServerSidePath = req._serverSidePath
        currentServerSideContextPath = req._serverSideContextPath
        currentContextName = req._contextName
        currentServerRootPath = req._serverRootPath
        currentPathInfo = req._pathInfo
        currentExtraURLPath = req._extraURLPath
        req.setURLPath(urlPath)
        req.addParent(currentServlet)

        servlet = self._rootURLParser.findServletForTransaction(trans)
        trans._servlet = servlet
        if hasattr(servlet, 'runMethodForTransaction'):
            result = servlet.runMethodForTransaction(trans, method, *args, **kw)
        else:
            servlet.awake(trans)
            result = getattr(servlet, method)(*args, **kw)
            servlet.sleep(trans)

        # Put things back
        req.setURLPath(currentPath)
        req._serverSidePath = currentServerSidePath
        req._serverSideContextPath = currentServerSideContextPath
        req._contextName = currentContextName
        req._serverRootPath = currentServerRootPath
        req._pathInfo = currentPathInfo
        req._extraURLPath = currentExtraURLPath
        req.popParent()
        trans._servlet = currentServlet

        return result

    def includeURL(self, trans, url, context=None):
        """Include another servlet.

        Include the servlet given by the url, potentially in context (or
        current context). Like `forward`, except control is ultimately
        returned to the servlet.

        """
        urlPath = self.resolveInternalRelativePath(trans, url, context)
        req = trans.request()
        currentPath = req.urlPath()
        currentServlet = trans._servlet
        currentServerSidePath = req._serverSidePath
        currentServerSideContextPath = req._serverSideContextPath
        currentContextName = req._contextName
        req.setURLPath(urlPath)
        req.addParent(currentServlet)
        # We use a try/finally to make sure everything gets restored properly
        # in the event of an exception in an included servlet.
        try:
            servlet = self._rootURLParser.findServletForTransaction(trans)
            trans._servlet = servlet
            # We will interpret an EndResponse in an included page to mean that
            # the current page may continue processing.
            try:
                servlet.runTransaction(trans)
            except EndResponse:
                pass
            self.returnServlet(servlet, trans)
        finally:
            req.popParent()
            req.setURLPath(currentPath)
            req._serverSidePath = currentServerSidePath
            req._serverSideContextPath = currentServerSideContextPath
            req._contextName = currentContextName
            trans._servlet = currentServlet

    def resolveInternalRelativePath(self, trans, url, context=None):
        """Return the absolute internal path.

        Given a URL and an optional context, return the absolute
        internal URL. URLs are assumed relative to the current URL.

        Absolute paths are returned unchanged.

        """
        req = trans.request()
        if not url.startswith('/'):
            origPath = req.urlPath()
            if origPath.endswith('/'):
                origDir = origPath
            else:
                origDir = os.path.dirname(origPath)
                if not origDir.endswith('/'):
                    origDir += '/'
            path = origDir + url
        else:
            if context is None:
                context = req._contextName
            path = '/%s%s' % (context, url)
        # Deal with .. in the path
        parts = []
        for part in path.split('/'):
            if part == '..':
                parts.pop()
            else:
                parts.append(part)
        return '/'.join(parts)

    def returnServlet(self, servlet, trans):
        servlet.close(trans)

    def handleException(self):
        """Handle exceptions.

        This should only be used in cases where there is no transaction object,
        for example if an exception occurs when attempting to save a session
        to disk.

        """
        self._exceptionHandlerClass(self, None, sys.exc_info())

    def handleExceptionInTransaction(self, excInfo, transaction):
        """Handle exception with info.

        Handles exception `excInfo` (as returned by ``sys.exc_info()``)
        that was generated by `transaction`. It may display the exception
        report, email the report, etc., handled by
        `ExceptionHandler.ExceptionHandler`.

        """
        req = transaction.request()
        editlink = req.adapterName() + "/Admin/EditFile"
        self._exceptionHandlerClass(self, transaction, excInfo,
                         {"editlink": editlink})

    def rootURLParser(self):
        """Accessor: the Rool URL parser.

        URL parsing (as defined by subclasses of `URLParser.URLParser`)
        starts here. Other parsers are called in turn by this parser.

        """
        return self._rootURLParser

    def hasContext(self, name):
        """Checks whether context `name` exist."""
        return self._rootURLParser._contexts.has_key(name)

    def addContext(self, name, path):
        """Add a context by named `name`, rooted at `path`.

        This gets imported as a package, and the last directory
        of `path` does not have to match the context name.
        (The package will be named `name`, regardless of `path`).

        Delegated to `URLParser.ContextParser`.

        """
        self._rootURLParser.addContext(name, path)

    def addServletFactory(self, factory):
        """Add a ServletFactory.

        Delegated to the `URLParser.ServletFactoryManager` singleton.

        """
        URLParser.ServletFactoryManager.addServletFactory(factory)

    def contexts(self):
        """Return a dictionary of context-name: context-path."""
        return self._rootURLParser._contexts

    def writeExceptionReport(self, handler):
        # @@ 2003-02 ib: does anyone care?
        pass

    def handleMissingPathSession(self,transaction):
        """Redirect requests without session info in the path.

        if UseAutomaticPathSessions is enabled in Application.config
        we redirect the browser to a url with SID in path
        http://gandalf/a/_SID_=2001080221301877755/Examples/
        _SID_ is extracted and removed from path in HTTPRequest.py

        This is for convinient building of webapps that must not
        depend on cookie support.

        """
        newSid = transaction.session().identifier()
        request = transaction.request()
        url = request.adapterName() + '/_SID_='+ newSid + '/' \
            + request.pathInfo() + (request.extraURLPath() or '')
        if request.queryString():
            url = url + '?' + request.queryString()
        if self.setting('Debug')['Sessions']:
            print '>> [sessions] handling UseAutomaticPathSessions,' \
                ' redirecting to', url
        transaction.response().sendRedirect(url)

    def handleUnnecessaryPathSession(self, transaction):
        """Redirect request with unnecessary session info in the path.

        This is called if it has been determined that the request has a path
        session, but also cookies. In that case we redirect to eliminate the
        unnecessary path session.

        """
        request = transaction.request()
        url = request.adapterName() + '/' + request.pathInfo() + (request.extraURLPath() or '')

        if request.queryString():
            url = url + '?' + request.queryString()
        if self.setting('Debug')['Sessions']:
            print ">> [sessions] handling unnecessary path session, redirecting to", url
        transaction.response().sendRedirect(url)


## Main ##

def main(requestDict):
    """Return a raw reponse.

    This method is mostly used by OneShotAdapter.py.

    """
    from WebUtils.HTMLForException import HTMLForException
    try:
        assert type(requestDict) is type({})
        app = Application(useSessionSweeper=0)
        return app.runRawRequest(requestDict).response().rawResponse()
    except:
        return {
            'headers': [('Content-type', 'text/html')],
            'contents': '<html><body>%s</html></body>' % HTMLForException()
        }


"""
You can run Application as a main script, in which case it expects a
single argument which is a file containing a dictionary representing
a request. This technique isn't very popular as Application itself
could raise exceptions that aren't caught. See `CGIAdapter` and
`AppServer` for a better example of how things should be done.

Largely historical.
"""

if __name__=='__main__':
    if len(sys.argv)!=2:
        sys.stderr.write('WebKit: Application: Expecting one filename argument.\n')
    requestDict = eval(open(sys.argv[1]).read())
    main(requestDict)