"""
Current (linear) pricing model.

Ported from eau.py:256-354 (CurrentModel).
Pure Python + numpy, no matplotlib.
"""

from dataclasses import dataclass

from app.engine.pricing import HouseholdData


@dataclass
class LinearTariffResult:
    """Result of the linear tariff computation."""
    p0: float  # flat price per m³
    curve_volumes: list[float]
    curve_bills_rp: list[float]
    curve_bills_rs: list[float]
    curve_price_m3_rp: list[float]
    curve_price_m3_rs: list[float]


def compute_linear_tariff(
    households: list[HouseholdData],
    recettes: float,
    abop: float,
    abos: float,
    vmax: float = 2100,
    nbpts: int = 200,
) -> LinearTariffResult:
    """
    Compute the linear (current) pricing model.

    p0 = (recettes - Σ abo) / Σ volume
    """
    total_abo = 0.0
    total_volume = 0.0

    for h in households:
        abo = abos if h.status == "RS" else abop
        total_abo += abo
        total_volume += max(h.volume_m3, 1e-5)

    if total_abo >= recettes or total_volume == 0:
        p0 = 0.0
    else:
        p0 = (recettes - total_abo) / total_volume

    # Generate curves
    import numpy as np
    vv = np.linspace(1e-5, vmax, nbpts)

    bills_rp = abop + p0 * vv
    bills_rs = abos + p0 * vv
    price_m3_rp = abop / vv + p0
    price_m3_rs = abos / vv + p0

    def sanitize(arr):
        return [0.0 if (x != x or x == float('inf') or x == float('-inf')) else float(x) for x in arr]

    return LinearTariffResult(
        p0=p0,
        curve_volumes=sanitize(vv),
        curve_bills_rp=sanitize(bills_rp),
        curve_bills_rs=sanitize(bills_rs),
        curve_price_m3_rp=sanitize(price_m3_rp),
        curve_price_m3_rs=sanitize(price_m3_rs),
    )