import copy
import json
import re
from pathlib import Path
from typing import Optional


class CreditDebugService:
    """处理征信解析接口的调试标记、参数校验与响应封装。"""

    VALID_MODEL = "LXCUSTALL"
    VALID_HTYPES = {"PERSON", "ENTERPRISE"}

    def __init__(self, template_path: str):
        self.template_path = template_path
        self.templates = self._load_templates()

    def validate_request(self, model: Optional[str], h_type: Optional[str], file_present: bool):
        if not model:
            return self.build_missing_param_response("model")
        if not file_present:
            return self.build_missing_param_response("file")
        if not h_type:
            return self.build_missing_param_response("hType")

        error_code = self.detect_error_marker(model)
        if error_code:
            return self.build_error_response(error_code)

        if model != self.VALID_MODEL:
            return self.build_error_response("ERR_10002")
        if h_type not in self.VALID_HTYPES:
            return self.build_error_response("ERR_10003")
        return None

    def build_success_response(self, payload: dict) -> dict:
        response = copy.deepcopy(self.templates["success"])
        response["payload"] = payload
        return response

    def build_missing_param_response(self, param_name: str) -> dict:
        response = self.build_error_response("ERR_99999")
        response["message"] = response["message"].replace("XX", param_name)
        return response

    def build_error_response(self, error_code: str) -> dict:
        return copy.deepcopy(self.templates["errors"][error_code])

    def detect_error_marker(self, model: str) -> Optional[str]:
        matched = re.search(r"error_(ERR_\d+)", model)
        if not matched:
            return None
        error_code = matched.group(1)
        if error_code in self.templates["errors"]:
            return error_code
        return None

    def _load_templates(self) -> dict:
        template_file = Path(self.template_path)
        if not template_file.is_absolute():
            template_file = Path(__file__).resolve().parent.parent / template_file
        return json.loads(template_file.read_text(encoding="utf-8"))