from contextlib import contextmanager
import fcntl
from pathlib import Path
from typing import Any

from app.algorithms.sensor import kmeans as kmeans_sensor
from app.algorithms.sensor import sensitivity
from app.native.wndb.s42_sensor_placement import create_sensor_placement
from app.services.sensor_placement import (
    SensorPlacementConflictError,
    SensorPlacementValidationError,
    validate_sensor_placement_nodes,
)
from app.services.tjnetwork import dump_inp


def _sensor_inp_path(name: str) -> Path:
    if (
        not name
        or name in {".", ".."}
        or "/" in name
        or "\\" in name
        or "\x00" in name
    ):
        raise SensorPlacementValidationError("管网名称不是有效的项目标识")
    return Path("db_inp") / f"{name}.db.inp"


@contextmanager
def _sensor_inp_lock(name: str):
    inp_path = _sensor_inp_path(name)
    inp_path.parent.mkdir(parents=True, exist_ok=True)
    lock_path = inp_path.with_suffix(".sensor.lock")
    with lock_path.open("w", encoding="utf-8") as lock_file:
        try:
            fcntl.flock(
                lock_file.fileno(),
                fcntl.LOCK_EX | fcntl.LOCK_NB,
            )
        except BlockingIOError as exc:
            raise SensorPlacementConflictError(
                "当前项目已有监测点优化任务正在运行，请稍后重试"
            ) from exc
        try:
            yield inp_path
        finally:
            fcntl.flock(lock_file.fileno(), fcntl.LOCK_UN)


def _create_validated_placement(
    name: str,
    *,
    scheme_name: str,
    min_diameter: int,
    username: str,
    sensor_location: list[str],
) -> dict[str, Any]:
    validate_sensor_placement_nodes(name, sensor_location)
    return create_sensor_placement(
        name,
        scheme_name=scheme_name,
        min_diameter=min_diameter,
        username=username,
        sensor_location=sensor_location,
    )


def pressure_sensor_placement_sensitivity(
    name: str,
    scheme_name: str,
    sensor_number: int,
    min_diameter: int,
    username: str,
) -> dict[str, Any]:
    """
    基于改进灵敏度法进行压力监测点优化布置
    :param name: 数据库名称
    :param scheme_name: 监测优化布置方案名称
    :param sensor_number: 传感器数目
    :param min_diameter: 最小管径
    :param username: 用户名
    :return: 新建的监测点方案
    """
    with _sensor_inp_lock(name):
        sensor_location = sensitivity.get_ID(
            name=name,
            sensor_num=sensor_number,
            min_diameter=min_diameter,
        )
    return _create_validated_placement(
        name,
        scheme_name=scheme_name,
        min_diameter=min_diameter,
        username=username,
        sensor_location=sensor_location,
    )


# 2025/08/21
# 基于kmeans聚类法进行压力监测点优化布置
def pressure_sensor_placement_kmeans(
    name: str,
    scheme_name: str,
    sensor_number: int,
    min_diameter: int,
    username: str,
) -> dict[str, Any]:
    """
    基于聚类法进行压力监测点优化布置
    :param name: 数据库名称（注意，此处数据库名称也是inp文件名称，inp文件与pg库名要一样）
    :param scheme_name: 监测优化布置方案名称
    :param sensor_number: 传感器数目
    :param min_diameter: 最小管径
    :param username: 用户名
    :return: 新建的监测点方案
    """
    # dump_inp
    with _sensor_inp_lock(name) as inp_path:
        dump_inp(name, str(inp_path), "2")
        sensor_location = kmeans_sensor.kmeans_sensor_placement(
            name=name,
            sensor_num=sensor_number,
            min_diameter=min_diameter,
        )
    return _create_validated_placement(
        name,
        scheme_name=scheme_name,
        min_diameter=min_diameter,
        username=username,
        sensor_location=sensor_location,
    )