import logging
from dataclasses import dataclass

import trimesh

logger = logging.getLogger("app.services.file_parser")


@dataclass
class FileInfo:
    volume_cm3: float
    surface_area_cm2: float
    bounding_box_mm: dict[str, float]
    is_watertight: bool
    triangle_count: int


SUPPORTED_EXTENSIONS = {".stl", ".3mf", ".obj"}


def parse_3d_file(file_path: str, file_extension: str) -> FileInfo:
    """Parse a 3D file and return geometric properties."""
    ext = file_extension.lower().lstrip(".")
    logger.info("Parsing 3D file: path=%s, extension=%s", file_path, ext)

    logger.debug("Loading mesh with trimesh (file_type=%s)...", ext)
    mesh = trimesh.load(file_path, file_type=ext)
    logger.debug("Trimesh loaded object type: %s", type(mesh).__name__)

    if isinstance(mesh, trimesh.Scene):
        meshes = list(mesh.dump())
        logger.info("File is a Scene with %d geometries, concatenating...", len(meshes))
        if not meshes:
            logger.error("Scene contains no geometries")
            raise ValueError("Файл не содержит 3D-геометрии")
        mesh = trimesh.util.concatenate(meshes)
        logger.debug("Concatenated into single Trimesh")

    if not isinstance(mesh, trimesh.Trimesh):
        logger.error("Could not extract Trimesh object, got: %s", type(mesh).__name__)
        raise ValueError("Не удалось извлечь 3D-геометрию из файла")

    volume_cm3 = abs(mesh.volume) / 1000.0
    surface_area_cm2 = mesh.area / 100.0
    bbox = {
        "x": round(float(mesh.bounding_box.extents[0]), 2),
        "y": round(float(mesh.bounding_box.extents[1]), 2),
        "z": round(float(mesh.bounding_box.extents[2]), 2),
    }
    is_watertight = bool(mesh.is_watertight)
    triangle_count = len(mesh.faces)

    logger.info("Parse result: volume=%.2f cm3, area=%.2f cm2, bbox=%s, watertight=%s, triangles=%d",
                volume_cm3, surface_area_cm2, bbox, is_watertight, triangle_count)

    return FileInfo(
        volume_cm3=volume_cm3,
        surface_area_cm2=surface_area_cm2,
        bounding_box_mm=bbox,
        is_watertight=is_watertight,
        triangle_count=triangle_count,
    )