"""설정파일(config.yaml) 스키마와 로더.

사내 관행값·발주처 기준이 필요한 TODO 항목은 §9 표를 참고. 전부 이 모듈의
기본값으로 노출되어 있으며, config.yaml로 덮어쓴다.
"""

from __future__ import annotations

import dataclasses
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any, Optional

import yaml


@dataclass
class ConnectionsPerBlock:
    min: int = 500  # TODO: 편람에 수치 규정 없음. 사내 관행값 확정 필요
    max: int = 3000


@dataclass
class DemandPerBlock:
    max_cmd: Optional[float] = None  # m3/day, null이면 미적용


@dataclass
class PartitionConfig:
    level: str = "small"  # large | medium | small
    k_min: int = 4
    k_max: int = 20
    method: str = "spectral"  # spectral | louvain
    flow_weight_alpha: float = 0.7


@dataclass
class ConstraintsConfig:
    connections_per_block: ConnectionsPerBlock = field(default_factory=ConnectionsPerBlock)
    max_pipe_length_per_block: float = 30000.0  # m, TODO
    demand_per_block: DemandPerBlock = field(default_factory=DemandPerBlock)
    elevation_band_m: float = 30.0
    large_consumer_demand_lps: float = 5.0  # TODO
    large_consumer_policy: str = "isolate"  # isolate | keep_together
    sources_in_separate_blocks: bool = True


@dataclass
class HydraulicsConfig:
    duration_hours: int = 24
    timestep_minutes: int = 60
    min_pressure_m: float = 15.0  # TODO: 수도법 시행규칙 / 상수도설계기준 확인 후 확정
    max_pressure_m: float = 71.0  # TODO
    max_water_age_hours: float = 48.0  # TODO
    allow_isolated_nodes: bool = False


@dataclass
class RefineConfig:
    max_iterations: int = 20
    moves_per_iteration: int = 50


@dataclass
class ScoringWeights:
    n_valves: float = 0.25
    n_meters: float = 0.15
    pressure_violations: float = 0.30
    max_water_age: float = 0.15
    boundary_pipe_length: float = 0.15


@dataclass
class ScoringConfig:
    weights: ScoringWeights = field(default_factory=ScoringWeights)


@dataclass
class BoundaryConfig:
    # 블록당 유입지점(유량계) 목표 개수. 편람에 수치 없음, 통상 1개 예비 포함 2개. TODO
    inlets_per_block: int = 1


@dataclass
class Config:
    crs: str = "EPSG:5186"
    partition: PartitionConfig = field(default_factory=PartitionConfig)
    constraints: ConstraintsConfig = field(default_factory=ConstraintsConfig)
    hydraulics: HydraulicsConfig = field(default_factory=HydraulicsConfig)
    refine: RefineConfig = field(default_factory=RefineConfig)
    scoring: ScoringConfig = field(default_factory=ScoringConfig)
    boundary: BoundaryConfig = field(default_factory=BoundaryConfig)

    @classmethod
    def from_yaml(cls, path: str | Path) -> "Config":
        raw = yaml.safe_load(Path(path).read_text(encoding="utf-8")) or {}
        return cls.from_dict(raw)

    @classmethod
    def from_dict(cls, raw: dict[str, Any]) -> "Config":
        cfg = cls()
        _apply(cfg, raw)
        return cfg


def _apply(instance: Any, data: dict[str, Any]) -> None:
    for key, value in data.items():
        if not hasattr(instance, key):
            continue
        current = getattr(instance, key)
        if dataclasses.is_dataclass(current) and isinstance(value, dict):
            _apply(current, value)
        else:
            setattr(instance, key, value)