"""Job cost and time estimation from STL geometry."""
import os

# g/cm³ per material
_DENSITY: dict[str, float] = {
    "PLA":   1.24,
    "PETG":  1.27,
    "ABS":   1.04,
    "ASA":   1.07,
    "TPU":   1.20,
    "Nylon": 1.14,
    "PC":    1.20,
}
_DEFAULT_DENSITY = 1.24


def estimate(volume_ccm: float, material: str | None) -> dict:
    """
    Returns a cost/time estimate dict for one job.

    MATERIAL_FACTOR (env, default 0.50):
      Fraction of model volume that becomes actual filament.
      '20 % infill' in the slicer does NOT mean 20 % of volume is printed —
      walls, top/bottom solid layers, and shells are 100 % solid and typically
      dominate. Empirically ~50 % of model volume is printed for typical FDM
      parts (validated against Bambu Lab Studio output).

    PRINT_SPEED_G_PER_HOUR (env, default 32):
      Average material throughput in g/h. ~32 g/h matches Bambu Lab printers
      at normal quality; slower printers (~20 g/h) can be set here.
    """
    vat_rate       = float(os.environ.get("VAT_RATE", 19))
    price_per_kg   = float(os.environ.get("FILAMENT_PRICE_PER_KG", 15))
    material_factor = float(os.environ.get("MATERIAL_FACTOR", 0.50))
    print_speed    = float(os.environ.get("PRINT_SPEED_G_PER_HOUR", 32))
    density        = _DENSITY.get(material or "", _DEFAULT_DENSITY)

    material_ccm  = volume_ccm * material_factor
    weight_g      = material_ccm * density
    print_minutes = round((weight_g / print_speed) * 60)

    filament_cost  = weight_g / 1000 * price_per_kg
    after_misprint = filament_cost * 1.20
    net_price      = after_misprint * 1.30
    gross_price    = net_price * (1 + vat_rate / 100)

    return {
        "material_ccm":     round(material_ccm, 2),
        "weight_g":         round(weight_g, 1),
        "print_minutes":    print_minutes,
        "filament_cost":    round(filament_cost, 2),
        "net_price":        round(net_price, 2),
        "gross_price":      round(gross_price, 2),
        "vat_rate":         vat_rate,
        "price_per_kg":     price_per_kg,
        "material_factor":  material_factor,
        "print_speed":      print_speed,
    }