"""

Web application

(from web.py)

"""

import webapi as web

import webapi, wsgi, utils

import debugerror

import httpserver

from utils import lstrips, safeunicode

import sys

import urllib

import traceback

import itertools

import os

import types

from exceptions import SystemExit

try:

    import wsgiref.handlers

except ImportError:

    pass # don't break people with old Pythons

__all__ = [

    "application", "auto_application",

    "subdir_application", "subdomain_application", 

    "loadhook", "unloadhook",

    "autodelegate"

]

class application:

    """

    Application to delegate requests based on path.

        >>> urls = ("/hello", "hello")

        >>> app = application(urls, globals())

        >>> class hello:

        ...     def GET(self): return "hello"

        >>>

        >>> app.request("/hello").data

        'hello'

    """

    def __init__(self, mapping=(), fvars={}, autoreload=None):

        if autoreload is None:

            autoreload = web.config.get('debug', False)

        self.init_mapping(mapping)

        self.fvars = fvars

        self.processors = []

        self.add_processor(loadhook(self._load))

        self.add_processor(unloadhook(self._unload))

        if autoreload:

            def main_module_name():

                mod = sys.modules['__main__']

                file = getattr(mod, '__file__', None) # make sure this works even from python interpreter

                return file and os.path.splitext(os.path.basename(file))[0]

            def modname(fvars):

                """find name of the module name from fvars."""

                file, name = fvars.get('__file__'), fvars.get('__name__')

                if file is None or name is None:

                    return None

                if name == '__main__':

                    # Since the __main__ module can't be reloaded, the module has 

                    # to be imported using its file name.                    

                    name = main_module_name()

                return name

            mapping_name = utils.dictfind(fvars, mapping)

            module_name = modname(fvars)

            def reload_mapping():

                """loadhook to reload mapping and fvars."""

                mod = __import__(module_name, None, None, [''])

                mapping = getattr(mod, mapping_name, None)

                if mapping:

                    self.fvars = mod.__dict__

                    self.init_mapping(mapping)

            self.add_processor(loadhook(Reloader()))

            if mapping_name and module_name:

                self.add_processor(loadhook(reload_mapping))

            # load __main__ module usings its filename, so that it can be reloaded.

            if main_module_name() and '__main__' in sys.argv:

                try:

                    __import__(main_module_name())

                except ImportError:

                    pass

    def _load(self):

        web.ctx.app_stack.append(self)

    def _unload(self):

        web.ctx.app_stack = web.ctx.app_stack[:-1]

        if web.ctx.app_stack:

            # this is a sub-application, revert ctx to earlier state.

            oldctx = web.ctx.get('_oldctx')

            if oldctx:

                web.ctx.home = oldctx.home

                web.ctx.homepath = oldctx.homepath

                web.ctx.path = oldctx.path

                web.ctx.fullpath = oldctx.fullpath

    def _cleanup(self):

        # Threads can be recycled by WSGI servers.

        # Clearing up all thread-local state to avoid interefereing with subsequent requests.

        utils.ThreadedDict.clear_all()

    def init_mapping(self, mapping):

        self.mapping = list(utils.group(mapping, 2))

    def add_mapping(self, pattern, classname):

        self.mapping.append((pattern, classname))

    def add_processor(self, processor):

        """

        Adds a processor to the application. 

            >>> urls = ("/(.*)", "echo")

            >>> app = application(urls, globals())

            >>> class echo:

            ...     def GET(self, name): return name

            ...

            >>>

            >>> def hello(handler): return "hello, " +  handler()

            ...

            >>> app.add_processor(hello)

            >>> app.request("/web.py").data

            'hello, web.py'

        """

        self.processors.append(processor)

    def request(self, localpart='/', method='GET', data=None,

                host="0.0.0.0:8080", headers=None, https=False, **kw):

        """Makes request to this application for the specified path and method.

        Response will be a storage object with data, status and headers.

            >>> urls = ("/hello", "hello")

            >>> app = application(urls, globals())

            >>> class hello:

            ...     def GET(self): 

            ...         web.header('Content-Type', 'text/plain')

            ...         return "hello"

            ...

            >>> response = app.request("/hello")

            >>> response.data

            'hello'

            >>> response.status

            '200 OK'

            >>> response.headers['Content-Type']

            'text/plain'

        To use https, use https=True.

            >>> urls = ("/redirect", "redirect")

            >>> app = application(urls, globals())

            >>> class redirect:

            ...     def GET(self): raise web.seeother("/foo")

            ...

            >>> response = app.request("/redirect")

            >>> response.headers['Location']

            'http://0.0.0.0:8080/foo'

            >>> response = app.request("/redirect", https=True)

            >>> response.headers['Location']

            'https://0.0.0.0:8080/foo'

        The headers argument specifies HTTP headers as a mapping object

        such as a dict.

            >>> urls = ('/ua', 'uaprinter')

            >>> class uaprinter:

            ...     def GET(self):

            ...         return 'your user-agent is ' + web.ctx.env['HTTP_USER_AGENT']

            ... 

            >>> app = application(urls, globals())

            >>> app.request('/ua', headers = {

            ...      'User-Agent': 'a small jumping bean/1.0 (compatible)'

            ... }).data

            'your user-agent is a small jumping bean/1.0 (compatible)'

        """

        path, maybe_query = urllib.splitquery(localpart)

        query = maybe_query or ""

        if 'env' in kw:

            env = kw['env']

        else:

            env = {}

        env = dict(env, HTTP_HOST=host, REQUEST_METHOD=method, PATH_INFO=path, QUERY_STRING=query, HTTPS=str(https))

        headers = headers or {}

        for k, v in headers.items():

            env['HTTP_' + k.upper().replace('-', '_')] = v

        if 'HTTP_CONTENT_LENGTH' in env:

            env['CONTENT_LENGTH'] = env.pop('HTTP_CONTENT_LENGTH')

        if 'HTTP_CONTENT_TYPE' in env:

            env['CONTENT_TYPE'] = env.pop('HTTP_CONTENT_TYPE')

        if method not in ["HEAD", "GET"]:

            data = data or ''

            import StringIO

            if isinstance(data, dict):

                q = urllib.urlencode(data)

            else:

                q = data

            env['wsgi.input'] = StringIO.StringIO(q)

            if not env.get('CONTENT_TYPE', '').lower().startswith('multipart/') and 'CONTENT_LENGTH' not in env:

                env['CONTENT_LENGTH'] = len(q)

        response = web.storage()

        def start_response(status, headers):

            response.status = status

            response.headers = dict(headers)

            response.header_items = headers

        response.data = "".join(self.wsgifunc()(env, start_response))

        return response

    def browser(self):

        import browser

        return browser.AppBrowser(self)

    def handle(self):

        fn, args = self._match(self.mapping, web.ctx.path)

        return self._delegate(fn, self.fvars, args)

    def handle_with_processors(self):

        def process(processors):

            try:

                if processors:

                    p, processors = processors[0], processors[1:]

                    return p(lambda: process(processors))

                else:

                    return self.handle()

            except web.HTTPError:

                raise

            except (KeyboardInterrupt, SystemExit):

                raise

            except:

                print >> web.debug, traceback.format_exc()

                raise self.internalerror()

        # processors must be applied in the resvere order. (??)

        return process(self.processors)

    def wsgifunc(self, *middleware):

        """Returns a WSGI-compatible function for this application."""

        def peep(iterator):

            """Peeps into an iterator by doing an iteration

            and returns an equivalent iterator.

            """

            # wsgi requires the headers first

            # so we need to do an iteration

            # and save the result for later

            try:

                firstchunk = iterator.next()

            except StopIteration:

                firstchunk = ''

            return itertools.chain([firstchunk], iterator)    

        def is_generator(x): return x and hasattr(x, 'next')

        def wsgi(env, start_resp):

            # clear threadlocal to avoid inteference of previous requests

            self._cleanup()

            self.load(env)

            try:

                # allow uppercase methods only

                if web.ctx.method.upper() != web.ctx.method:

                    raise web.nomethod()

                result = self.handle_with_processors()

                if is_generator(result):

                    result = peep(result)

                else:

                    result = [result]

            except web.HTTPError, e:

                result = [e.data]

            result = web.safestr(iter(result))

            status, headers = web.ctx.status, web.ctx.headers

            start_resp(status, headers)

            def cleanup():

                self._cleanup()

                yield '' # force this function to be a generator

            return itertools.chain(result, cleanup())

        for m in middleware: 

            wsgi = m(wsgi)

        return wsgi

    def run(self, *middleware):

        """

        Starts handling requests. If called in a CGI or FastCGI context, it will follow

        that protocol. If called from the command line, it will start an HTTP

        server on the port named in the first command line argument, or, if there

        is no argument, on port 8080.

        `middleware` is a list of WSGI middleware which is applied to the resulting WSGI

        function.

        """

        return wsgi.runwsgi(self.wsgifunc(*middleware))

    def stop(self):

        """Stops the http server started by run.

        """

        if httpserver.server:

            httpserver.server.stop()

            httpserver.server = None

    def cgirun(self, *middleware):

        """

        Return a CGI handler. This is mostly useful with Google App Engine.

        There you can just do:

            main = app.cgirun()

        """

        wsgiapp = self.wsgifunc(*middleware)

        try:

            from google.appengine.ext.webapp.util import run_wsgi_app

            return run_wsgi_app(wsgiapp)

        except ImportError:

            # we're not running from within Google App Engine

            return wsgiref.handlers.CGIHandler().run(wsgiapp)

    def load(self, env):

        """Initializes ctx using env."""

        ctx = web.ctx

        ctx.clear()

        ctx.status = '200 OK'

        ctx.headers = []

        ctx.output = ''

        ctx.environ = ctx.env = env

        ctx.host = env.get('HTTP_HOST')

        if env.get('wsgi.url_scheme') in ['http', 'https']:

            ctx.protocol = env['wsgi.url_scheme']

        elif env.get('HTTPS', '').lower() in ['on', 'true', '1']:

            ctx.protocol = 'https'

        else:

            ctx.protocol = 'http'

        ctx.homedomain = ctx.protocol + '://' + env.get('HTTP_HOST', '[unknown]')

        ctx.homepath = os.environ.get('REAL_SCRIPT_NAME', env.get('SCRIPT_NAME', ''))

        ctx.home = ctx.homedomain + ctx.homepath

        #@@ home is changed when the request is handled to a sub-application.

        #@@ but the real home is required for doing absolute redirects.

        ctx.realhome = ctx.home

        ctx.ip = env.get('REMOTE_ADDR')

        ctx.method = env.get('REQUEST_METHOD')

        ctx.path = env.get('PATH_INFO')

        # http://trac.lighttpd.net/trac/ticket/406 requires:

        if env.get('SERVER_SOFTWARE', '').startswith('lighttpd/'):

            ctx.path = lstrips(env.get('REQUEST_URI').split('?')[0], ctx.homepath)

            # Apache and CherryPy webservers unquote the url but lighttpd doesn't. 

            # unquote explicitly for lighttpd to make ctx.path uniform across all servers.

            ctx.path = urllib.unquote(ctx.path)

        if env.get('QUERY_STRING'):

            ctx.query = '?' + env.get('QUERY_STRING', '')

        else:

            ctx.query = ''

        ctx.fullpath = ctx.path + ctx.query

        for k, v in ctx.iteritems():

            # convert all string values to unicode values and replace 

            # malformed data with a suitable replacement marker.

            if isinstance(v, str):

                ctx[k] = v.decode('utf-8', 'replace') 

        # status must always be str

        ctx.status = '200 OK'

        ctx.app_stack = []

    def _delegate(self, f, fvars, args=[]):

        def handle_class(cls):

            meth = web.ctx.method

            if meth == 'HEAD' and not hasattr(cls, meth):

                meth = 'GET'

            if not hasattr(cls, meth):

                raise web.nomethod(cls)

            tocall = getattr(cls(), meth)

            return tocall(*args)

        def is_class(o): return isinstance(o, (types.ClassType, type))

        if f is None:

            raise web.notfound()

        elif isinstance(f, application):

            return f.handle_with_processors()

        elif is_class(f):

            return handle_class(f)

        elif isinstance(f, basestring):

            if f.startswith('redirect '):

                url = f.split(' ', 1)[1]

                if web.ctx.method == "GET":

                    x = web.ctx.env.get('QUERY_STRING', '')

                    if x:

                        url += '?' + x

                raise web.redirect(url)

            elif '.' in f:

                mod, cls = f.rsplit('.', 1)

                mod = __import__(mod, None, None, [''])

                cls = getattr(mod, cls)

            else:

                cls = fvars[f]

            return handle_class(cls)

        elif hasattr(f, '__call__'):

            return f()

        else:

            return web.notfound()

    def _match(self, mapping, value):

        for pat, what in mapping:

            if isinstance(what, application):

                if value.startswith(pat):

                    f = lambda: self._delegate_sub_application(pat, what)

                    return f, None

                else:

                    continue

            elif isinstance(what, basestring):

                what, result = utils.re_subm('^' + pat + '$', what, value)

            else:

                result = utils.re_compile('^' + pat + '$').match(value)

            if result: # it's a match

                return what, [x for x in result.groups()]

        return None, None

    def _delegate_sub_application(self, dir, app):

        """Deletes request to sub application `app` rooted at the directory `dir`.

        The home, homepath, path and fullpath values in web.ctx are updated to mimic request

        to the subapp and are restored after it is handled. 

        @@Any issues with when used with yield?

        """

        web.ctx._oldctx = web.storage(web.ctx)

        web.ctx.home += dir

        web.ctx.homepath += dir

        web.ctx.path = web.ctx.path[len(dir):]

        web.ctx.fullpath = web.ctx.fullpath[len(dir):]

        return app.handle_with_processors()

    def get_parent_app(self):

        if self in web.ctx.app_stack:

            index = web.ctx.app_stack.index(self)

            if index > 0:

                return web.ctx.app_stack[index-1]

    def notfound(self):

        """Returns HTTPError with '404 not found' message"""

        parent = self.get_parent_app()

        if parent:

            return parent.notfound()

        else:

            return web._NotFound()

    def internalerror(self):

        """Returns HTTPError with '500 internal error' message"""

        parent = self.get_parent_app()

        if parent:

            return parent.internalerror()

        elif web.config.get('debug'):

            import debugerror

            return debugerror.debugerror()

        else:

            return web._InternalError()

class auto_application(application):

    """Application similar to `application` but urls are constructed 

    automatiacally using metaclass.

        >>> app = auto_application()

        >>> class hello(app.page):

        ...     def GET(self): return "hello, world"

        ...

        >>> class foo(app.page):

        ...     path = '/foo/.*'

        ...     def GET(self): return "foo"

        >>> app.request("/hello").data

        'hello, world'

        >>> app.request('/foo/bar').data

        'foo'

    """

    def __init__(self):

        application.__init__(self)

        class metapage(type):

            def __init__(klass, name, bases, attrs):

                type.__init__(klass, name, bases, attrs)

                path = attrs.get('path', '/' + name)

                # path can be specified as None to ignore that class

                # typically required to create a abstract base class.

                if path is not None:

                    self.add_mapping(path, klass)

        class page:

            path = None

            __metaclass__ = metapage

        self.page = page

# The application class already has the required functionality of subdir_application

subdir_application = application

class subdomain_application(application):

    """

    Application to delegate requests based on the host.

        >>> urls = ("/hello", "hello")

        >>> app = application(urls, globals())

        >>> class hello:

        ...     def GET(self): return "hello"

        >>>

        >>> mapping = (r"hello\.example\.com", app)

        >>> app2 = subdomain_application(mapping)

        >>> app2.request("/hello", host="hello.example.com").data

        'hello'

        >>> response = app2.request("/hello", host="something.example.com")

        >>> response.status

        '404 Not Found'

        >>> response.data

        'not found'

    """

    def handle(self):

        host = web.ctx.host.split(':')[0] #strip port

        fn, args = self._match(self.mapping, host)

        return self._delegate(fn, self.fvars, args)

    def _match(self, mapping, value):

        for pat, what in mapping:

            if isinstance(what, basestring):

                what, result = utils.re_subm('^' + pat + '$', what, value)

            else:

                result = utils.re_compile('^' + pat + '$').match(value)

            if result: # it's a match

                return what, [x for x in result.groups()]

        return None, None

def loadhook(h):

    """

    Converts a load hook into an application processor.

        >>> app = auto_application()

        >>> def f(): "something done before handling request"

        ...

        >>> app.add_processor(loadhook(f))

    """

    def processor(handler):

        h()

        return handler()

    return processor

def unloadhook(h):

    """

    Converts an unload hook into an application processor.

        >>> app = auto_application()

        >>> def f(): "something done after handling request"

        ...

        >>> app.add_processor(unloadhook(f))    

    """

    def processor(handler):

        try:

            result = handler()

            is_generator = result and hasattr(result, 'next')

        except:

            # run the hook even when handler raises some exception

            h()

            raise

        if is_generator:

            return wrap(result)

        else:

            h()

            return result

    def wrap(result):

        def next():

            try:

                return result.next()

            except:

                # call the hook at the and of iterator

                h()

                raise

        result = iter(result)

        while True:

            yield next()

    return processor

def autodelegate(prefix=''):

    """

    Returns a method that takes one argument and calls the method named prefix+arg,

    calling `notfound()` if there isn't one. Example:

        urls = ('/prefs/(.*)', 'prefs')

        class prefs:

            GET = autodelegate('GET_')

            def GET_password(self): pass

            def GET_privacy(self): pass

    `GET_password` would get called for `/prefs/password` while `GET_privacy` for 

    `GET_privacy` gets called for `/prefs/privacy`.

    If a user visits `/prefs/password/change` then `GET_password(self, '/change')`

    is called.

    """

    def internal(self, arg):

        if '/' in arg:

            first, rest = arg.split('/', 1)

            func = prefix + first

            args = ['/' + rest]

        else:

            func = prefix + arg

            args = []

        if hasattr(self, func):

            try:

                return getattr(self, func)(*args)

            except TypeError:

                raise web.notfound()

        else:

            raise web.notfound()

    return internal

class Reloader:

    """Checks to see if any loaded modules have changed on disk and, 

    if so, reloads them.

    """

    """File suffix of compiled modules."""

    if sys.platform.startswith('java'):

        SUFFIX = '$py.class'

    else:

        SUFFIX = '.pyc'

    def __init__(self):

        self.mtimes = {}

    def __call__(self):

        for mod in sys.modules.values():

            self.check(mod)

    def check(self, mod):

        # jython registers java packages as modules but they either

        # don't have a __file__ attribute or its value is None

        if not (mod and hasattr(mod, '__file__') and mod.__file__):

            return

        try: 

            mtime = os.stat(mod.__file__).st_mtime

        except (OSError, IOError):

            return

        if mod.__file__.endswith(self.__class__.SUFFIX) and os.path.exists(mod.__file__[:-1]):

            mtime = max(os.stat(mod.__file__[:-1]).st_mtime, mtime)

        if mod not in self.mtimes:

            self.mtimes[mod] = mtime

        elif self.mtimes[mod] < mtime:

            try: 

                reload(mod)

                self.mtimes[mod] = mtime

            except ImportError: 

                pass

if __name__ == "__main__":

    import doctest

    doctest.testmod()