import os
import hashlib
from django.template import TemplateDoesNotExist
from django.template.loaders.base import Loader
from myapp.template_plugins import registry
 
class PluginLoader(Loader):
    def __init__(self, engine):
        super().__init__(engine)
        self.template_plugins = registry.get_template_sources()
    
    def get_template_sources(self, template_name):
        for plugin in self.template_plugins:
            if plugin.can_handle(template_name):
                source = plugin.fetch_source(template_name)
                if source:
                    contents, path = source
                    yield self._make_origin(path, template_name, plugin.name)
    
    def _make_origin(self, path, template_name, source_name):
        return f"{source_name}:{template_name}"
    
    def load_template(self, template_name, dirs=None):
        for origin in self.get_template_sources(template_name):
            try:
                contents = origin.split(':')[1] if ':' in origin else None
                for plugin in self.template_plugins:
                    if plugin.name == origin.split(':')[0]:
                        template_string = plugin.render_template(template_name)
                        return self.compile_template(template_string), origin
            except Exception as e:
                continue
        raise TemplateDoesNotExist(template_name)
 
class TemplatePlugin:
    def __init__(self, name, priority=50):
        self.name = name
        self.priority = priority
    
    def can_handle(self, template_name):
        return template_name.startswith(f"{self.name}:")
    
    def fetch_source(self, template_name):
        raise NotImplementedError
    
    def render_template(self, template_name):
        raise NotImplementedError