"""
__init__.py -
auther: tanlie
date: 2026/8/30
"""
import logging
import traceback
from fastapi import FastAPI, Request, HTTPException
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse

from app.mobile import register_mobile_routes
from app.core.response import error_response

# Basic logging configuration for the app; applications may override this
logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(name)s: %(message)s")
logger = logging.getLogger("app")


def create_app():
    app = FastAPI()
    register_mobile_routes(app)

    @app.exception_handler(RequestValidationError)
    async def validation_exception_handler(request: Request, exc: RequestValidationError):
        # Build a friendly, JSON-serializable summary of validation errors
        errors = []
        for e in exc.errors():
            loc = e.get("loc", [])
            # remove leading location indicators like 'body', 'query', 'path', 'header'
            if loc and len(loc) > 0 and str(loc[0]) in ("body", "query", "path", "header"):
                loc_parts = loc[1:]
            else:
                loc_parts = loc
            # join remaining location parts into a dotted path for readability
            loc_str = ".".join([str(p) for p in loc_parts if p is not None]) if loc_parts else ""
            errors.append({"field": loc_str, "message": e.get("msg", "")})

        # Log validation details for debugging
        logger.info("Validation error for %s: %s", request.url.path, errors)

        return JSONResponse(
            status_code=422,
            content=error_response(msg="参数校验失败", code=422, data=errors),
        )

    @app.exception_handler(HTTPException)
    async def http_exception_handler(request: Request, exc: HTTPException):
        # Use HTTPException's status_code and detail
        detail = exc.detail if exc.detail is not None else ""
        logger.warning("HTTPException for %s: %s", request.url.path, detail)
        return JSONResponse(
            status_code=getattr(exc, "status_code", 500),
            content=error_response(msg=str(detail), code=getattr(exc, "status_code", 500)),
        )

    @app.exception_handler(Exception)
    async def generic_exception_handler(request: Request, exc: Exception):
        # Map common ValueError to a friendlier 400 parameter error
        if isinstance(exc, ValueError):
            # Log with stack for debugging
            tb = "".join(traceback.format_exception(type(exc), exc, exc.__traceback__))
            logger.warning("ValueError on %s: %s\n%s", request.url.path, str(exc), tb)
            return JSONResponse(
                status_code=400,
                content=error_response(msg=str(exc) or "参数错误", code=400),
            )

        # Generic fallback to avoid leaking internal stack traces
        # Log full stack trace for internal debugging
        tb = "".join(traceback.format_exception(type(exc), exc, exc.__traceback__))
        logger.error("Unhandled exception on %s: %s\n%s", request.url.path, str(exc), tb)

        return JSONResponse(
            status_code=500,
            content=error_response(msg="服务器内部错误", code=500),
        )

    return app