import os
import json
from typing import Any

class TemplateEngine:
    def __init__(self, template_name: str, template_path: str = "templates/") -> None:
        self.__name = template_name
        self.__path = template_path
        self.__template_path = f"{self.__path}{self.__name}.json"
        self.__template = self.__load_template()
        
    def __load_template(self) -> dict[str, Any]:  
        with open(self.__template_path, "r", encoding="utf-8") as f:
            return json.loads(f.read())
        
    def __replace_placeholders(self, obj: Any, data: dict) -> Any:
        """Recursively replace placeholders in dict/list/string values."""
        if isinstance(obj, dict):
            return {k: self.__replace_placeholders(v, data) for k, v in obj.items()}
        elif isinstance(obj, list):
            return [self.__replace_placeholders(item, data) for item in obj]
        elif isinstance(obj, str):
            return obj.format(**data)
        else:
            return obj

    def generate(self, data: dict) -> dict[str, Any]:
        template = self.__load_template()
        return self.__replace_placeholders(template, data)