from webob import Response

from zope.component import queryUtility

from zope.interface import classProvides
from zope.interface import implements

from repoze.bfg.interfaces import ITemplateRenderer
from repoze.bfg.interfaces import ITemplateRendererFactory
from repoze.bfg.interfaces import ISettings

from repoze.bfg.templating import renderer_from_cache

from chameleon.core.template import TemplateFile
from chameleon.zpt.language import Parser

class TextTemplateFile(TemplateFile):
    default_parser = Parser()
    
    def __init__(self, filename, parser=None, format=None,
                 doctype=None, **kwargs):
        if parser is None:
            parser = self.default_parser
        super(TextTemplateFile, self).__init__(filename, parser, format,
                                               doctype, **kwargs)

class TextTemplateRenderer(object):
    classProvides(ITemplateRendererFactory)
    implements(ITemplateRenderer)

    def __init__(self, path, auto_reload=False):
        self.template = TextTemplateFile(
            path,
            format='text',
            auto_reload=auto_reload
            )

    def implementation(self):
        return self.template
    
    def __call__(self, **kw):
        return self.template(**kw)

def _auto_reload():
    settings = queryUtility(ISettings)
    auto_reload = settings and settings.reload_templates
    return auto_reload

def get_renderer(path):
    """ Return a callable ``ITemplateRenderer`` object representing a
    ``chameleon`` text template at the package-relative path (may also
    be absolute)."""
    auto_reload = _auto_reload()
    renderer = renderer_from_cache(path, TextTemplateRenderer,
                                   auto_reload=auto_reload)
    return renderer

def get_template(path):
    """ Return a ``chameleon`` text template at the package-relative
    path (may also be absolute)."""
    auto_reload = _auto_reload()
    renderer = renderer_from_cache(path, TextTemplateRenderer,
                                   auto_reload=auto_reload)
    return renderer.implementation()

def render_template(path, **kw):
    """ Render a ``chameleon`` text template at the package-relative
    path (may also be absolute) using the kwargs in ``*kw`` as
    top-level names and return a string."""
    auto_reload = _auto_reload()
    renderer = renderer_from_cache(path, TextTemplateRenderer,
                                   auto_reload=auto_reload)
    return renderer(**kw)

def render_template_to_response(path, **kw):
    """ Render a ``chameleon`` text template at the package-relative
    path (may also be absolute) using the kwargs in ``*kw`` as
    top-level names and return a Response object with the body as the
    template result."""
    auto_reload = _auto_reload()
    renderer = renderer_from_cache(path, TextTemplateRenderer,
                                  auto_reload=auto_reload)
    result = renderer(**kw)
    return Response(result)