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

import bpy


OPERATIONS = ("Translate", "Merge", "Dissolve", "Extrude", "Inset", "Bevel", "LoopCut")


def mesh_report(label):
    obj = bpy.data.objects.get("WBV2P2003%sObject" % label)
    if obj is None or obj.type != "MESH":
        raise RuntimeError("MESH_EDIT_INVALID: operation fixture object is missing")
    mesh = obj.data
    return {
        "objectId": "object:" + obj.name,
        "meshId": "mesh:" + mesh.name,
        "vertexCount": len(mesh.vertices),
        "edgeCount": len(mesh.edges),
        "faceCount": len(mesh.polygons),
        "triangleCount": sum(max(0, len(poly.vertices) - 2) for poly in mesh.polygons),
        "positionHash": hashlib.sha256(json.dumps([tuple(round(float(value), 6) for value in vertex.co) for vertex in mesh.vertices], separators=(",", ":")).encode()).hexdigest(),
    }


def report():
    return {label: mesh_report(label) for label in OPERATIONS}


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --python check-wbv2-p2-003-desktop.py -- FIXTURE REPORT")
    fixture, output = (pathlib.Path(value).resolve() for value in arguments)
    bpy.ops.wm.open_mainfile(filepath=str(fixture), load_ui=True)
    before = report()
    descriptor, temporary = tempfile.mkstemp(prefix="wbv2-p2-003-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=True)
        after = report()
    finally:
        pathlib.Path(temporary).unlink(missing_ok=True)
    if before != after:
        raise RuntimeError(f"MESH_EDIT_INVALID: desktop save/reopen drift: {before} != {after}")
    value = {
        "schemaVersion": 1,
        "task": "WBV2-P2-003",
        "operation": "MESH_EDIT_CORE_DESKTOP",
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "meshes": after,
        "saveReopen": "EXACT",
        "blenderVersion": bpy.app.version_string,
    }
    output.parent.mkdir(parents=True, exist_ok=True)
    output.write_text(json.dumps(value, indent=2, sort_keys=True) + "\n", encoding="utf-8")
    print("wbv2-p2-003-desktop-ok meshes=%d topology=quad saveReopen=exact" % len(after))


if __name__ == "__main__":
    main()