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

import bpy


TEXT_NAME = "WBV2-P1-002-SceneIRContract"


def read_contract():
    text = bpy.data.texts.get(TEXT_NAME)
    if text is None:
        raise RuntimeError("SCENEIR_CONTRACT_INVALID: contract text is missing")
    source = text.as_string()
    return source, json.loads(source)


def scene_summary():
    obj = bpy.data.objects.get("WBV2P1002CubeObject")
    if obj is None or obj.type != "MESH":
        raise RuntimeError("SCENEIR_CONTRACT_INVALID: cube object is missing")
    mesh = obj.data
    mesh.calc_loop_triangles()
    positions = [value for vertex in mesh.vertices for value in vertex.co]
    normalized_positions = [int(value) if value == int(value) else round(value, 6) for value in positions]
    return {
        "objectId": "object:" + obj.name,
        "meshId": "mesh:" + mesh.name,
        "vertexCount": len(mesh.vertices),
        "triangleCount": len(mesh.loop_triangles),
        "positionHash": hashlib.sha256(json.dumps(normalized_positions, separators=(",", ":")).encode("utf-8")).hexdigest(),
    }


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --python check-wbv2-p1-002-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)
    source, before = read_contract()
    summary = scene_summary()
    descriptor, temporary = tempfile.mkstemp(prefix="wbv2-p1-002-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_source, after = read_contract()
        after_summary = scene_summary()
    finally:
        pathlib.Path(temporary).unlink(missing_ok=True)
    if before != after or source != after_source or summary != after_summary:
        raise RuntimeError("SCENEIR_CONTRACT_INVALID: desktop save/reopen drift")
    value = {
        "schemaVersion": 1,
        "task": "WBV2-P1-002",
        "operation": "SCENEIR_STABLE_IDS_BINARY_DELTA_DESKTOP",
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "contract": after,
        "summary": after_summary,
        "sourceSha256": hashlib.sha256(after_source.encode("utf-8")).hexdigest(),
        "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(f"wbv2-p1-002-desktop-ok mesh={after_summary['meshId']} vertices={after_summary['vertexCount']} triangles={after_summary['triangleCount']} saveReopen=exact")


if __name__ == "__main__":
    main()