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

import bpy


ARMATURE_NAME = "WebGapArmatureSeparateArmature"
OBJECT_NAME = "WebGapArmatureSeparateObject"
SELECTED_BONE = "WebGapArmatureSeparateSelected"
RETAINED_BONE = "WebGapArmatureSeparateRetained"
SEPARATED_OBJECT = "WebGapArmatureSeparateObject.001"


def vector(value):
    return [round(float(component), 6) for component in value]


def find_object(name):
    obj = bpy.data.objects.get(name)
    if obj is None or obj.type != "ARMATURE":
        raise RuntimeError(f"missing armature object {name}")
    return obj


def state_report():
    values = []
    for obj in sorted((value for value in bpy.data.objects if value.type == "ARMATURE"), key=lambda value: value.name):
        armature = obj.data
        if armature.name != ARMATURE_NAME and not armature.name.startswith(f"{ARMATURE_NAME}."):
            continue
        if obj.mode != "EDIT":
            bpy.context.view_layer.objects.active = obj
            obj.select_set(True)
            bpy.ops.object.mode_set(mode="EDIT")
        bones = []
        for bone in armature.edit_bones:
            bones.append({"name": bone.name, "selected": bool(bone.select), "head": vector(bone.head), "tail": vector(bone.tail), "parent": bone.parent.name if bone.parent else None})
        bpy.ops.object.mode_set(mode="OBJECT")
        values.append({"object": obj.name, "armature": armature.name, "activeBone": armature.edit_bones.active.name if armature.edit_bones.active else None, "bones": bones})
    return {"objects": values}


def stable(value):
    return {"objects": [{"object": item["object"], "armature": item["armature"], "activeBone": item["activeBone"], "bones": sorted(item["bones"], key=lambda bone: bone["name"])} for item in value["objects"]]}


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --factory-startup --python check-action-armature-separate-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 = find_object(OBJECT_NAME)
    bpy.context.view_layer.objects.active = source
    source.select_set(True)
    if source.mode != "EDIT":
        bpy.ops.object.mode_set(mode="EDIT")
    before = state_report()
    source_state = next(item for item in before["objects"] if item["object"] == OBJECT_NAME)
    selected = {bone["name"] for bone in source_state["bones"] if bone["selected"]}
    if selected == {SELECTED_BONE} and len(before["objects"]) == 1:
        already_applied = False
    elif len(before["objects"]) == 2 and {item["object"] for item in before["objects"]} == {OBJECT_NAME, SEPARATED_OBJECT}:
        already_applied = True
    else:
        raise RuntimeError(f"unexpected armature.separate state: {before}")
    bpy.context.view_layer.objects.active = source
    source.select_set(True)
    if source.mode != "EDIT":
        bpy.ops.object.mode_set(mode="EDIT")
    poll = bool(bpy.ops.armature.separate.poll())
    if not poll:
        raise RuntimeError("ARMATURE_OT_separate poll failed")
    if not already_applied:
        result = bpy.ops.armature.separate()
        if result != {"FINISHED"}:
            raise RuntimeError(f"ARMATURE_OT_separate returned {result}")
    after = state_report()
    names = {item["object"] for item in after["objects"]}
    if names != {OBJECT_NAME, SEPARATED_OBJECT}:
        raise RuntimeError(f"armature.separate object mismatch: {after}")
    original = next(item for item in after["objects"] if item["object"] == OBJECT_NAME)
    separated = next(item for item in after["objects"] if item["object"] == SEPARATED_OBJECT)
    if [bone["name"] for bone in original["bones"]] != [RETAINED_BONE] or [bone["name"] for bone in separated["bones"]] != [SELECTED_BONE]:
        raise RuntimeError(f"armature.separate bone partition mismatch: {after}")
    bpy.context.view_layer.objects.active = source
    descriptor, temporary = tempfile.mkstemp(prefix="m16-armature-separate-reopen-", suffix=".blend")
    os.close(descriptor)
    temporary_path = pathlib.Path(temporary)
    try:
        bpy.ops.wm.save_as_mainfile(filepath=str(temporary_path), check_existing=False, compress=True)
        bpy.ops.wm.open_mainfile(filepath=str(temporary_path), load_ui=False)
        reopened = state_report()
        if stable(reopened) != stable(after):
            raise RuntimeError(f"armature.separate save/reopen drift: {after} != {reopened}")
        shutil.copyfile(temporary_path, fixture)
        report = {"schemaVersion": 1, "task": "M16-GAP-00258", "operation": "ARMATURE_SEPARATE_DESKTOP", "fixture": str(fixture), "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(), "before": before, "after": reopened, "sourceObject": OBJECT_NAME, "separatedObject": SEPARATED_OBJECT, "selectedBone": SELECTED_BONE, "retainedBone": RETAINED_BONE, "operatorStatus": "FINISHED" if not already_applied else "SKIPPED_ALREADY_APPLIED", "mainMutation": "SELECTED_BONES_SEPARATED" if not already_applied else "SELECTED_BONES_ALREADY_SEPARATED", "poll": poll, "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(f"armature-separate-desktop-ok source={OBJECT_NAME} separated={SEPARATED_OBJECT} saveReopen=exact")
    finally:
        temporary_path.unlink(missing_ok=True)


if __name__ == "__main__":
    try:
        main()
    except Exception as error:
        print(f"armature-separate-desktop-failed: {error}")
        raise SystemExit(1)