"""Material presets for the render backend.

Each preset is a RenderMaterial with physically-plausible values.
"""

from __future__ import annotations

from typing import Dict, List

from .render_backend import RenderMaterial

# ── Preset library ──────────────────────────────────────────────────────
# Note: Mitsuba pip installs don't include spectral metal data files,
# so metal_preset is not used. Instead, metals use material="none" with
# specular_reflectance set to the metal color.

PRESETS: Dict[str, RenderMaterial] = {
    # ── Metals ──────────────────────────────────────────────────────
    "Brushed Steel": RenderMaterial(
        name="Brushed Steel",
        color=(0.65, 0.67, 0.72),
        metallic=0.9,
        roughness=0.35,
        bsdf_type="roughconductor",
    ),
    "Polished Chrome": RenderMaterial(
        name="Polished Chrome",
        color=(0.8, 0.8, 0.8),
        metallic=1.0,
        roughness=0.05,
        bsdf_type="roughconductor",
    ),
    "Brushed Aluminum": RenderMaterial(
        name="Brushed Aluminum",
        color=(0.75, 0.75, 0.75),
        metallic=0.85,
        roughness=0.25,
        bsdf_type="roughconductor",
    ),
    "Copper": RenderMaterial(
        name="Copper",
        color=(0.95, 0.64, 0.54),
        metallic=0.95,
        roughness=0.15,
        bsdf_type="roughconductor",
    ),
    "Gold": RenderMaterial(
        name="Gold",
        color=(1.0, 0.76, 0.33),
        metallic=1.0,
        roughness=0.1,
        bsdf_type="roughconductor",
    ),
    "Blackened Steel": RenderMaterial(
        name="Blackened Steel",
        color=(0.15, 0.15, 0.17),
        metallic=0.8,
        roughness=0.4,
        bsdf_type="roughconductor",
    ),
    # ── Plastics ────────────────────────────────────────────────────
    "Matte Plastic": RenderMaterial(
        name="Matte Plastic",
        color=(0.2, 0.5, 0.8),
        metallic=0.0,
        roughness=0.6,
        bsdf_type="plastic",
        int_ior=1.5,
    ),
    "Glossy Plastic": RenderMaterial(
        name="Glossy Plastic",
        color=(0.2, 0.5, 0.8),
        metallic=0.0,
        roughness=0.1,
        bsdf_type="plastic",
        int_ior=1.5,
    ),
    "White Nylon": RenderMaterial(
        name="White Nylon",
        color=(0.85, 0.85, 0.83),
        metallic=0.0,
        roughness=0.45,
        bsdf_type="plastic",
        int_ior=1.53,
    ),
    "Black ABS": RenderMaterial(
        name="Black ABS",
        color=(0.05, 0.05, 0.05),
        metallic=0.0,
        roughness=0.35,
        bsdf_type="plastic",
        int_ior=1.54,
    ),
    "Red PA12": RenderMaterial(
        name="Red PA12",
        color=(0.75, 0.08, 0.08),
        metallic=0.0,
        roughness=0.4,
        bsdf_type="plastic",
        int_ior=1.53,
    ),
    # ── Other ───────────────────────────────────────────────────────
    "Rubber": RenderMaterial(
        name="Rubber",
        color=(0.1, 0.1, 0.1),
        metallic=0.0,
        roughness=0.9,
        bsdf_type="diffuse",
    ),
    "Ceramic White": RenderMaterial(
        name="Ceramic White",
        color=(0.92, 0.91, 0.88),
        metallic=0.0,
        roughness=0.15,
        bsdf_type="dielectric",
        int_ior=1.55,
    ),
    "Glass": RenderMaterial(
        name="Glass",
        color=(0.95, 0.95, 0.95),
        metallic=0.0,
        roughness=0.0,
        bsdf_type="dielectric",
        int_ior=1.52,
    ),
    "Wood": RenderMaterial(
        name="Wood",
        color=(0.6, 0.4, 0.2),
        metallic=0.0,
        roughness=0.7,
        bsdf_type="diffuse",
    ),
}


def get_preset(name: str) -> RenderMaterial:
    """Get a material preset by name. Falls back to default if not found."""
    if name in PRESETS:
        return PRESETS[name]
    return default_material()


def default_material() -> RenderMaterial:
    """Return the default grey material."""
    return RenderMaterial(
        name="Default",
        color=(0.7, 0.7, 0.7),
        metallic=0.0,
        roughness=0.5,
        bsdf_type="diffuse",
    )


def preset_names() -> List[str]:
    """Return sorted list of available preset names."""
    return sorted(PRESETS.keys())