from __future__ import annotations

from dataclasses import dataclass, field
from datetime import datetime, timezone
from enum import Enum
from typing import Any


class ObservationQuality(str, Enum):
    OK = "ok"
    STALE = "stale"
    ESTIMATED = "estimated"
    MISSING = "missing"
    ERROR = "error"


class PowerStage(str, Enum):
    ALWAYS = "always"
    SURPLUS = "surplus"
    CHEAP_GRID = "cheap_grid"
    STANDARD = "standard"
    CONSERVE = "conserve"


@dataclass(frozen=True)
class Observation:
    source: str
    metric: str
    value: int | float | str | bool | None
    unit: str = "none"
    quality: ObservationQuality = ObservationQuality.OK
    observed_at: datetime = field(default_factory=lambda: datetime.now(timezone.utc))
    received_at: datetime = field(default_factory=lambda: datetime.now(timezone.utc))
    metadata: dict[str, Any] = field(default_factory=dict)


@dataclass(frozen=True)
class Snapshot:
    created_at: datetime
    solar_power_w: float | None = None
    home_power_w: float | None = None
    battery_soc_pct: float | None = None
    grid_import_w: float | None = None
    grid_export_w: float | None = None
    cheap_window_active: bool = False
    input_quality: dict[str, ObservationQuality] = field(default_factory=dict)


@dataclass(frozen=True)
class Decision:
    created_at: datetime
    stage: PowerStage
    reasons: list[str]
    confidence: float


@dataclass(frozen=True)
class WeatherForecastPoint:
    issued_at: datetime
    target_at: datetime
    horizon_hours: int
    temperature_c: float | None
    shortwave_radiation_w_m2: float | None
    cloud_cover_pct: float | None = None
    source: str = "open_meteo"


@dataclass(frozen=True)
class WeatherForecastRun:
    issued_at: datetime
    source: str
    latitude: float
    longitude: float
    points: list[WeatherForecastPoint]


@dataclass(frozen=True)
class WeatherResolvedTruth:
    resolved_at: datetime
    temperature_c: float | None
    shortwave_radiation_w_m2: float | None
    source: str