#!/usr/bin/env python3
import pathlib
import sys

import bpy


def main(output: pathlib.Path) -> None:
    bpy.ops.wm.read_factory_settings(use_empty=True)
    material = bpy.data.materials.new("WebGapNodeTreeMaterial")
    material.use_nodes = True
    nodes = material.node_tree.nodes
    links = material.node_tree.links
    principled = nodes.get("Principled BSDF")
    output_node = nodes.get("Material Output")
    if principled is None or output_node is None:
        raise RuntimeError("default shader nodes are missing")
    rgb = nodes.new("ShaderNodeRGB")
    rgb.name = "WebGapRGB"
    rgb.outputs["Color"].default_value = (0.1, 0.3, 0.7, 1.0)
    links.new(rgb.outputs["Color"], principled.inputs["Base Color"])
    links.new(principled.outputs["BSDF"], output_node.inputs["Surface"])
    mesh = bpy.data.meshes.new("WebGapNodeTreeMesh")
    mesh.from_pydata([(-1.0, -1.0, 0.0), (1.0, -1.0, 0.0), (0.0, 1.0, 0.0)], [], [(0, 1, 2)])
    mesh.materials.append(material)
    obj = bpy.data.objects.new("WebGapNodeTreeObject", mesh)
    bpy.context.collection.objects.link(obj)
    bpy.ops.wm.save_as_mainfile(filepath=str(output.resolve()), check_existing=False, compress=True)


if __name__ == "__main__":
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 1:
        raise SystemExit("usage: blender -b --python M16-GAP-00016.py -- OUTPUT")
    main(pathlib.Path(arguments[0]))