from __future__ import annotations

from dataclasses import dataclass
from math import pi


MM_TO_M = 1.0e-3
M_TO_MM = 1.0e3
M3_TO_CM3 = 1.0e6
M3_PER_S_TO_L_PER_MIN = 60_000.0


def circular_area(diameter_m: float) -> float:
    if diameter_m < 0.0:
        raise ValueError("diameter_m must be non-negative.")
    return pi * diameter_m * diameter_m / 4.0


def mm_to_m(value: float) -> float:
    return value * MM_TO_M


def m_to_mm(value: float) -> float:
    return value * M_TO_MM


@dataclass(frozen=True)
class AmesimPistonGeometry:
    """Geometry relations used by AMESim PNRP17 pneumatic piston variables."""

    piston_diameter_m: float
    rod_diameter_m: float = 0.0
    zero_length_m: float = 0.0

    @property
    def piston_area_m2(self) -> float:
        return circular_area(self.piston_diameter_m)

    @property
    def rod_area_m2(self) -> float:
        return circular_area(self.rod_diameter_m)

    @property
    def annulus_area_m2(self) -> float:
        return self.piston_area_m2 - self.rod_area_m2

    def chamber_length_m(self, port4_displacement_m: float, port5_displacement_m: float) -> float:
        return self.zero_length_m + port5_displacement_m - port4_displacement_m

    def chamber_length_mm(self, port4_displacement_m: float, port5_displacement_m: float) -> float:
        return m_to_mm(self.chamber_length_m(port4_displacement_m, port5_displacement_m))

    @property
    def chamber_area_m2(self) -> float:
        return self.annulus_area_m2

    def chamber_volume_m3(self, port4_displacement_m: float, port5_displacement_m: float) -> float:
        return self.chamber_area_m2 * self.chamber_length_m(
            port4_displacement_m,
            port5_displacement_m,
        )

    def chamber_volume_cm3(self, port4_displacement_m: float, port5_displacement_m: float) -> float:
        return self.chamber_volume_m3(port4_displacement_m, port5_displacement_m) * M3_TO_CM3

    def chamber_volume_rate_m3_s(self, port4_velocity_m_s: float, port5_velocity_m_s: float) -> float:
        return self.chamber_area_m2 * (port5_velocity_m_s - port4_velocity_m_s)

    def chamber_volume_rate_l_min(self, port4_velocity_m_s: float, port5_velocity_m_s: float) -> float:
        return self.chamber_volume_rate_m3_s(
            port4_velocity_m_s,
            port5_velocity_m_s,
        ) * M3_PER_S_TO_L_PER_MIN


@dataclass(frozen=True)
class AmesimElasticEndstop:
    """Contact force part of AMESim LSTP00A elastic endstop."""

    contact_stiffness_n_per_m: float
    contact_damping_n_per_m_per_s: float = 0.0
    gap0_m: float = 0.0

    def penetration_m_from_gap_mm(self, gap_mm: float) -> float:
        return max(-(mm_to_m(gap_mm) - self.gap0_m), 0.0)

    def static_contact_force(self, gap_mm: float) -> float:
        return self.contact_stiffness_n_per_m * self.penetration_m_from_gap_mm(gap_mm)

    def contact_force(self, gap_mm: float, penetration_velocity_m_s: float = 0.0) -> float:
        if self.penetration_m_from_gap_mm(gap_mm) <= 0.0:
            return 0.0
        damping_force = self.contact_damping_n_per_m_per_s * penetration_velocity_m_s
        return max(self.static_contact_force(gap_mm) + damping_force, 0.0)