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"

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

    def validate_request(
        self,
        serial_num: Optional[str],
        org_code: Optional[str],
        run_type: Optional[str],
        remote_path: Optional[str],
        model: Optional[str],
    ):
        if not serial_num:
            return self.build_missing_param_response("serialNum")
        if not org_code:
            return self.build_missing_param_response("orgCode")
        if not run_type:
            return self.build_missing_param_response("runType")
        if not remote_path:
            return self.build_missing_param_response("remotePath")
        if not model:
            return self.build_missing_param_response("model")

        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")
        return None

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

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

    def build_error_response(self, error_code: str) -> dict:
        return self.wrap_mapping_response(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 wrap_mapping_response(self, mapping_output_fields: dict) -> dict:
        return {
            "success": True,
            "code": 10000,
            "data": {
                "mappingOutputFields": mapping_output_fields,
            },
        }

    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"))