"""mime type transformation engine for cubicweb, based on mtconverter

"""

__docformat__ = "restructuredtext en"

from logilab import mtconverter

from logilab.mtconverter.engine import TransformEngine

from logilab.mtconverter.transform import Transform

from logilab.mtconverter import (register_base_transforms,

                                 register_pil_transforms,

                                 register_pygments_transforms)

from cubicweb.utils import UStringIO

from cubicweb.uilib import rest_publish, html_publish

HTML_MIMETYPES = ('text/html', 'text/xhtml', 'application/xhtml+xml')

# CubicWeb specific transformations

class rest_to_html(Transform):

    inputs = ('text/rest', 'text/x-rst')

    output = 'text/html'

    def _convert(self, trdata):

        return rest_publish(trdata.appobject, trdata.decode())

class html_to_html(Transform):

    inputs = HTML_MIMETYPES

    output = 'text/html'

    def _convert(self, trdata):

        return html_publish(trdata.appobject, trdata.data)

# Instantiate and configure the transformation engine

mtconverter.UNICODE_POLICY = 'replace'

ENGINE = TransformEngine()

ENGINE.add_transform(rest_to_html())

ENGINE.add_transform(html_to_html())

try:

    from cubicweb.ext.tal import CubicWebContext, compile_template

except ImportError:

    HAS_TAL = False

    from cubicweb import schema

    schema.NEED_PERM_FORMATS.remove('text/cubicweb-page-template')

else:

    HAS_TAL = True

    class ept_to_html(Transform):

        inputs = ('text/cubicweb-page-template',)

        output = 'text/html'

        output_encoding = 'utf-8'

        def _convert(self, trdata):

            context = CubicWebContext()

            appobject = trdata.appobject

            context.update({'self': appobject, 'rset': appobject.cw_rset,

                            'req': appobject._cw,

                            '_' : appobject._cw._,

                            'user': appobject._cw.user})

            output = UStringIO()

            template = compile_template(trdata.encode(self.output_encoding))

            template.expand(context, output)

            return output.getvalue()

    ENGINE.add_transform(ept_to_html())

if register_pil_transforms(ENGINE, verb=False):

    HAS_PIL_TRANSFORMS = True

else:

    HAS_PIL_TRANSFORMS = False

try:

    from logilab.mtconverter.transforms import pygmentstransforms

    for mt in ('text/plain',) + HTML_MIMETYPES:

        try:

            pygmentstransforms.mimetypes.remove(mt)

        except ValueError:

            continue

    register_pygments_transforms(ENGINE, verb=False)

    def patch_convert(cls):

        def _convert(self, trdata, origconvert=cls._convert):

            try:

                trdata.appobject._cw.add_css('pygments.css')

            except AttributeError: # session has no add_css, only http request

                pass

            return origconvert(self, trdata)

        cls._convert = _convert

    patch_convert(pygmentstransforms.PygmentsHTMLTransform)

    HAS_PYGMENTS_TRANSFORMS = True

except ImportError:

    HAS_PYGMENTS_TRANSFORMS = False

register_base_transforms(ENGINE, verb=False)