#!/usr/bin/env python3
import hashlib
import json
import os
import pathlib
import sys
import tempfile

import bpy


def rounded(value):
    return round(float(value), 6)


def material_report():
    material = bpy.data.materials.get("WBV2P3001PrincipledMaterial")
    cube = bpy.data.objects.get("WBV2P3001MaterialCube")
    if material is None or cube is None or cube.type != "MESH" or not material.use_nodes:
        raise RuntimeError("MATERIAL_INVALID: material fixture is missing")
    principled = material.node_tree.nodes.get("Principled BSDF")
    if principled is None:
        raise RuntimeError("MATERIAL_INVALID: Principled BSDF is missing")
    uv_layer = cube.data.uv_layers.active
    if uv_layer is None:
        raise RuntimeError("MATERIAL_INVALID: active UV layer is missing")
    uv_values = [rounded(value) for loop in uv_layer.data for value in loop.uv]
    return {
        "materialId": "material:" + material.name,
        "materialName": material.name,
        "baseColor": [rounded(value) for value in principled.inputs["Base Color"].default_value],
        "roughness": rounded(principled.inputs["Roughness"].default_value),
        "metallic": rounded(principled.inputs["Metallic"].default_value),
        "ior": rounded(principled.inputs["IOR"].default_value),
        "nodeTypes": sorted(node.bl_idname for node in material.node_tree.nodes),
        "unsupportedNode": "ShaderNodeTexNoise" in [node.bl_idname for node in material.node_tree.nodes],
        "uvLayerNames": [layer.name for layer in cube.data.uv_layers],
        "activeUVMap": uv_layer.name,
        "uvHash": hashlib.sha256(json.dumps(uv_values, separators=(",", ":")).encode()).hexdigest(),
        "uvValueCount": len(uv_values),
    }


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --python check-wbv2-p3-001-desktop.py -- FIXTURE REPORT")
    fixture, output = (pathlib.Path(value).resolve() for value in arguments)
    bpy.ops.wm.open_mainfile(filepath=str(fixture), load_ui=False)
    before = material_report()
    descriptor, temporary = tempfile.mkstemp(prefix="wbv2-p3-001-reopen-", suffix=".blend", dir=fixture.parent)
    os.close(descriptor)
    try:
        bpy.ops.wm.save_as_mainfile(filepath=temporary, check_existing=False, compress=True)
        bpy.ops.wm.open_mainfile(filepath=temporary, load_ui=False)
        after = material_report()
    finally:
        pathlib.Path(temporary).unlink(missing_ok=True)
    if before != after:
        raise RuntimeError(f"MATERIAL_INVALID: desktop save/reopen drift: {before} != {after}")
    report = {
        "schemaVersion": 1,
        "task": "WBV2-P3-001",
        "operation": "MATERIAL_PBR_UV_DESKTOP",
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "material": after,
        "saveReopen": "EXACT",
        "blenderVersion": bpy.app.version_string,
    }
    output.parent.mkdir(parents=True, exist_ok=True)
    output.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")
    print("wbv2-p3-001-desktop-ok material=%s uv=%s unsupported=retained saveReopen=exact" % (after["materialId"], after["activeUVMap"]))


if __name__ == "__main__":
    main()