# -*- coding: utf-8 -*-

import io

from django.conf import settings
from django.template.backends.base import BaseEngine
from django.template.backends.utils import csrf_input_lazy, csrf_token_lazy
from django.template.engine import Engine
from docutils import core

from .directives import register_pygments_directive

try:
    from django.template.base import TemplateDoesNotExist
except ImportError:  # >= 1.9
    from django.template.exceptions import TemplateDoesNotExist


class Docutils(BaseEngine):
    app_dirname = "templates"

    def __init__(self, params):
        params = params.copy()
        self.options = params.pop("OPTIONS").copy()
        self.options.setdefault("debug", settings.DEBUG)
        self.options.setdefault("file_charset", settings.FILE_CHARSET)
        super(Docutils, self).__init__(params)
        self.engine = Engine(self.dirs, self.app_dirs, **self.options)

    def from_string(self, template_code):
        return DocutilsTemplate(template_code, self.options)

    def get_template(self, template_name):
        for template_file in self.iter_template_filenames(template_name):
            try:
                with io.open(template_file, encoding=settings.FILE_CHARSET) as fp:
                    template_code = fp.read()
            except IOError:
                continue

            return DocutilsTemplate(template_code, self.options)
        else:
            raise TemplateDoesNotExist(template_name)


class DocutilsTemplate(object):
    def __init__(self, source, options):
        self.source = source
        self.options = options

    def render(self, context=None, request=None):
        context = self.options
        if request is not None:
            context["request"] = request
            context["csrf_input"] = csrf_input_lazy(request)
            context["csrf_token"] = csrf_token_lazy(request)
        context = {"source": self.source, "writer_name": "html"}

        return core.publish_parts(**context)["html_body"]


register_pygments_directive()
