from django.contrib.auth.context_processors import PermWrapper

from boards import utils


PARAMETER_TRUNCATED = 'truncated'

DIFF_TYPE_HTML = 'html'
DIFF_TYPE_JSON = 'json'


class Exporter():
    @staticmethod
    def export(post, request, include_last_update) -> str:
        pass


class HtmlExporter(Exporter):
    @staticmethod
    def export(post, request, include_last_update):
        if request is not None and PARAMETER_TRUNCATED in request.GET:
            truncated = True
            reply_link = False
        else:
            truncated = False
            reply_link = True

        return post.get_view(truncated=truncated, reply_link=reply_link,
                perms=PermWrapper(request.user))


class JsonExporter(Exporter):
    @staticmethod
    def export(post, request, include_last_update):
        post_json = {
            'id': post.id,
            'title': post.title,
            'text': post.get_raw_text(),
            }
        if post.attachments.exists():
            post_image = post.get_first_image()
            post_json['image'] = post_image.file.url
            post_json['image_preview'] = post_image.get_preview_url()
        if include_last_update:
            post_json['bump_time'] = utils.datetime_to_epoch(
                post.get_thread().bump_time)
        return post_json


EXPORTERS = {
    DIFF_TYPE_HTML: HtmlExporter,
    DIFF_TYPE_JSON: JsonExporter,
}


def get_exporter(export_type: str) -> Exporter:
    return EXPORTERS[export_type]()