from stl import mesh
import numpy as np

def create_cad_model(size):
    try:
        # Define 8 vertices of a cube
        vertices = np.array([
            [0, 0, 0],
            [size, 0, 0],
            [size, size, 0],
            [0, size, 0],
            [0, 0, size],
            [size, 0, size],
            [size, size, size],
            [0, size, size],
        ])
        
        # Define 12 triangles composing the cube
        faces = np.array([
            [0, 3, 1],
            [1, 3, 2],
            [0, 4, 7],
            [0, 7, 3],
            [4, 5, 6],
            [4, 6, 7],
            [5, 1, 2],
            [5, 2, 6],
            [2, 3, 6],
            [3, 7, 6],
            [0, 1, 5],
            [0, 5, 4],
        ])
        
        # Create the mesh
        cube_mesh = mesh.Mesh(np.zeros(faces.shape[0], dtype=mesh.Mesh.dtype))
        for i, face in enumerate(faces):
            for j in range(3):
                cube_mesh.vectors[i][j] = vertices[face[j], :]
        
        # Save to file
        stl_file = "output_cube.stl"
        cube_mesh.save(stl_file)
        return f"STL file created successfully: {stl_file}"
    except Exception as e:
        return f"Error during STL generation: {str(e)}"