from importlib.resources import files

from numpy import logical_and
from pandas import DataFrame, read_csv, Series
from .. import logging

from .base import EnergyUseSimulation, SimulationError
from .occupancy import OccupationSimulation
from ..schemas import LightingSimulationOutput
from ..types import (
    OpenBESSpecification,
    LIGHTING_TECHNOLOGIES,
    LIGHTING_BALLASTS,
    LIGHTING_CONTROL,
    ENERGY_SOURCES,
)

logger = logging.getLogger(__name__)


class LightingSimulationError(SimulationError):
    """Raised when lighting report generation fails."""


class LightingSimulation(EnergyUseSimulation):
    """Simulate lighting energy use based on building specifications and occupancy patterns.

    Lighting simulations calculate energy use based on the number of luminaires, lamp power, ballast type,
    and lighting technology for each zone in the building.
    The model also accounts for lighting control strategies (manual vs automatic)
    and calculates parasitic heat gains from lighting.
    """

    occupancy: OccupationSimulation
    _lighting_heat: float

    def __init__(
        self, spec: OpenBESSpecification, occupancy: OccupationSimulation = None
    ):
        super().__init__(spec=spec)
        try:
            self.occupancy = occupancy or OccupationSimulation(spec=spec)
        except SimulationError as exc:
            raise EnergyUseSimulationInitError(
                f"Failed to initialize LightingSimulation due to error in dependent simulation: {exc}"
            ) from exc

    def get_w_per_luminaire(self, zone: int) -> float:
        """kWh per day for a specific zone based on lighting system specifications."""
        lamp_number = getattr(self.spec, f"lighting_system_lamp_number_z{zone}")
        tech = getattr(self.spec, f"lighting_system_tech_z{zone}")
        ballast = getattr(self.spec, f"lighting_system_ballast_z{zone}")
        lamp_power = getattr(self.spec, f"lighting_system_lamp_power_z{zone}")

        try:
            if tech in [
                LIGHTING_TECHNOLOGIES.IC,
                LIGHTING_TECHNOLOGIES.HAL,
                LIGHTING_TECHNOLOGIES.LED,
            ]:
                return float(lamp_power * lamp_number)
            if ballast == LIGHTING_BALLASTS.BE and tech == LIGHTING_TECHNOLOGIES.FT_T8:
                d = read_csv(
                    str(
                        files("openbes.simulations.lighting_data") / "lamp_ft_t8_be.csv"
                    )
                )
                return float(
                    d.loc[(d["lamp_power"] == lamp_power)][
                        f"lamp_number_{lamp_number}"
                    ].values[0]
                )
            d = read_csv(
                str(
                    files("openbes.simulations.lighting_data")
                    / f"lamp_{tech.name.lower()}.csv"
                )
            )
            return float(
                d.loc[(d["lamp_power"] == lamp_power)][
                    f"lamp_number_{lamp_number}"
                ].values[0]
            )
        except (AttributeError, FileNotFoundError, KeyError, IndexError) as e:
            logger.warning(
                f"Badly matched self.spec for zone {zone} [{e.__class__.__name__}: {e}]"
            )
        except Exception as e:
            logger.error(e, exc_info=True)

        return 0.0

    def get_kwh_per_day_for_zone(self, zone: int) -> float:
        """Calculate the kWh per day for a specific zone based on lighting system specifications.
        Args:
            self.spec (OpenBESSpecification): The building specifications self.spec data class.
            zone (int): The zone number to calculate kWh/day for.
        Returns:
            float: The kWh per day for the specified zone.
        """
        power_per_luminaire = self.get_w_per_luminaire(zone)
        luminary_number = getattr(self.spec, f"lighting_system_luminary_number_z{zone}")
        if luminary_number is None:
            logger.warning(
                "Inadequate data to calculate lighting power for zone %d", zone
            )
            return 0.0

        power_per_zone = power_per_luminaire * luminary_number

        try:
            zone_number = getattr(
                self.spec, f"lighting_system_similar_zone_number_z{zone}"
            )
            operating_hours = getattr(
                self.spec, f"lighting_system_operating_hours_z{zone}"
            )
            simultaneity_factor = getattr(
                self.spec, f"lighting_system_simultaneity_factor_z{zone}"
            )

            return (
                power_per_zone
                * zone_number
                * simultaneity_factor
                * operating_hours
                / 1000.0
            )
        except AttributeError:
            logger.warning(
                "Inadequate data to calculate lighting power for zone %d", zone
            )
        except Exception as e:
            logger.error(e, exc_info=True)
        return 0.0

    def get_kwh_per_day_per_zone(self) -> DataFrame:
        """Calculate the kWh per day per zone based on lighting system specifications.
        Args:
            self.spec (OpenBESSpecification): The building specifications self.spec data class.
        Returns:
            DataFrame: A DataFrame containing kWh per day per zone.
        """
        zones = [f"Lighting system {i}" for i in range(1, 7)]
        return DataFrame(
            [self.get_kwh_per_day_for_zone(i) for i in range(1, 7)],
            index=zones,
            columns=["kWh/day"],
        )

    def get_kwh_per_month_per_zone(self) -> DataFrame:
        """
        Calculate the kWh per month per zone based on lighting system specifications and operational hours per month.
        Args:
            self.spec (OpenBESSpecification): The building specifications self.spec data class.
        Returns:
            DataFrame: kWh used by each zone in each requested month
        """
        df = self.get_kwh_per_day_per_zone()
        operational_days_df = self.occupancy.occupied_days_per_month.copy()
        cross = df["kWh/day"].values[:, None] * operational_days_df.values
        return DataFrame(cross, columns=operational_days_df.index, index=df.index)

    def get_kwh_per_month(self) -> Series:
        """
        Calculate the kWh used by lighting in each month.
        Args:
            self.spec (OpenBESSpecification): The building specifications self.spec data class.
        Returns:
            DataFrame: The energy used on lighting in the building in kWh.
        """
        per_month = self.get_kwh_per_month_per_zone().sum()
        per_month.name = "kWh/month"
        return per_month

    @property
    def lights_on(self) -> "Series[bool]":
        """Hourly lights on status.
        [Hourly Simulation column KJ]

        Lights are considered to be on during occupied hours between the specified on and off times.
        """
        if "lights_on" not in self._hours.columns:
            s = self.occupancy.is_occupied
            self._hours["lights_on"] = False
            on_time = self.spec.lighting_on_time
            off_time = self.spec.lighting_off_time
            if on_time is not None and off_time is not None:
                i = s.index.get_level_values("hour")
                lights_on = (i > on_time) & (i <= off_time)
                self._hours["lights_on"] = logical_and(s, lights_on)
        return self._hours["lights_on"]

    @property
    def lighting_ratio(self) -> "Series[float]":
        """Calculate the lighting ratio based on building specifications.
        [Hourly Simulation column KI]
        """
        if "lighting_ratio" not in self._hours.columns:
            self._hours["lighting_ratio"] = (
                self.lights_on * self.spec.lighting_simultaneity_factor
            )
        return self._hours["lighting_ratio"]

    @property
    def parasitic_heat(self) -> float:
        """Calculate the parasitic heat from lighting in W/m2.
        W,pc [Hourly Simulation column KR]

        Parasitic heat from lighting is modelled using EN 15193 Annex F which gives typical yearly values
        for school buildings.
        """
        if (
            self.spec.parameters.lighting_on_off is not None
            and not self.spec.parameters.lighting_on_off
        ):
            return 0.0
        # (emergency_kWh_per_m2_year + standby_kWh_per_m2_year) / hours_per_year * 1000 kW_per_W
        return (1 + 5) / 8760 * 1000

    @property
    def lighting_heat(self) -> float:
        """Calculate the lighting heat gains in W/m2.
        [Inputs cell C147]

        Heat from lighting is modelled using EN 15193 Annex F which gives typical yearly values
        for school buildings.

        The model accounts for differences in automatic and manual lighting controls.
        """
        if not hasattr(self, "_lighting_heat") or self._lighting_heat is None:
            if (
                self.spec.parameters.lighting_on_off is not None
                and not self.spec.parameters.lighting_on_off
            ):
                return 0.0
            FC = 1.0  # correction factor for building type (schools)
            kWh_per_year_m2 = 20.0
            tD = 1800.0  # daylight usage hours
            tN = 200.0  # night usage hours
            FD = (
                1.0 if self.spec.lighting_control == LIGHTING_CONTROL.Manual else 0.9
            )  # daylight control factor
            F0 = (
                1.0 if self.spec.lighting_control == LIGHTING_CONTROL.Manual else 0.9
            )  # general control factor
            self._lighting_heat = (
                (FC * kWh_per_year_m2 / 1000 * ((tD * FD * F0) + (tN * F0)))
                * (5 / 8760 * (8760 - (tD + tN)))
                * 1000
                / 8760
            )
        return self._lighting_heat

    @property
    def energy_use(self) -> DataFrame:
        """Lighting energy use in kWh for each hour of the year.

        NOTE: This currently averages annual energy use by lighting over each hour of the year.
         A more sensible implementation will spread the usage over occupied hours only,
         taking into account lighting on/off times and lighting ratio.
        """
        if self._energy_use[ENERGY_SOURCES.Electricity].hasnans:
            self._energy_use[ENERGY_SOURCES.Electricity] = (
                self.get_kwh_per_month().sum().sum() / len(self._energy_use)
            )
        return self._energy_use

    @property
    def report(self) -> LightingSimulationOutput:
        try:
            peak_load = 0.0
            for z in range(1, 7):
                try:
                    peak_load += (
                        self.get_w_per_luminaire(zone=z)
                        * getattr(self.spec, f"lighting_system_luminary_number_z{z}")
                    ) / 1000
                except (AttributeError, TypeError):
                    continue
            area = self.occupancy.geometry.conditioned_floor_area
            return LightingSimulationOutput(
                lighting_demand=self.energy_use.sum().sum() / area if area else None,
                lighting_peak_load=peak_load,
                lighting_load_ratio=peak_load * 1000 / area if area else None,
            )
        except Exception as exc:
            raise LightingSimulationError("Failed to generate lighting report") from exc
