"""
业务处理器注册表：意图 -> 处理器、参数校验、执行器
新增二级Agent仅需在此注册，路由零改动
"""
from typing import Callable, Awaitable, Optional
from fastapi import UploadFile, HTTPException
from service.stream_service import stream_calculation_sync, stream_review_sync, stream_comparison_sync

# 定义处理器结构体
class IntentHandler:
    def __init__(
        self,
        need_file: bool,          # 是否需要上传PDF文件
        stream_func: Callable,    # 流式生成函数
        validate: Callable[[Optional[UploadFile]], None]  # 自定义参数校验
    ):
        self.need_file = need_file
        self.stream_func = stream_func
        self.validate = validate

# -------------------------- 校验规则 --------------------------
def validate_no_file(file: Optional[UploadFile]) -> None:
    """计算需风量：禁止上传文件"""
    if file:
        raise HTTPException(status_code=400, detail="需风量计算无需上传文件")

def validate_pdf_file(file: Optional[UploadFile]) -> None:
    """配风审查：必须上传PDF文件"""
    if not file or not file.filename.endswith(".pdf"):
        raise HTTPException(status_code=400, detail="配风审查仅支持上传PDF文件")

# -------------------------- 全局注册表 --------------------------
HANDLER_REGISTRY = {
    # 意图标识 : 对应处理器
    "calc_ventilation": IntentHandler(
        need_file=False,
        stream_func=stream_calculation_sync,
        validate=validate_no_file
    ),
    "review_plan": IntentHandler(
        need_file=True,
        stream_func=stream_review_sync,
        validate=validate_pdf_file
    ),
    "check_vent_comparison": IntentHandler(
        need_file=True,
        stream_func=stream_comparison_sync,
        validate=validate_pdf_file
    )
}