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

import bpy


OBJECT_NAME = "WebGapAnimConstraintSlotObject"
CONSTRAINT_NAME = "WebGapActionSlotConstraint"
ACTION_NAME = "WebGapAnimConstraintSlotAction"
SLOT_IDENTIFIER = "OBWebGapConstraintSlot"


def state_report():
    obj = bpy.data.objects.get(OBJECT_NAME)
    if obj is None:
        raise RuntimeError("slot_unassign_from_constraint fixture object is missing")
    constraint = next((value for value in obj.constraints if value.name == CONSTRAINT_NAME), None)
    if constraint is None or constraint.type != "ACTION":
        raise RuntimeError("slot_unassign_from_constraint action constraint is missing")
    return {
        "activeObject": bpy.context.view_layer.objects.active.name if bpy.context.view_layer.objects.active else None,
        "constraint": constraint.name,
        "action": constraint.action.name if constraint.action else None,
        "actionSlot": constraint.action_slot.identifier if constraint.action_slot else None,
        "actionSlotHandle": int(constraint.action_slot_handle),
    }


def is_unassigned(state):
    return state["action"] == ACTION_NAME and state["actionSlot"] is None and state["actionSlotHandle"] == 0


def run_operator(constraint):
    window = bpy.context.window
    screen = window.screen
    area = next((candidate for candidate in screen.areas if candidate.height >= 200), None)
    region = next((candidate for candidate in area.regions if candidate.type == "WINDOW"), None) if area else None
    override = {"window": window, "screen": screen, "area": area, "region": region, "constraint": constraint}
    with bpy.context.temp_override(**{key: value for key, value in override.items() if value is not None}):
        poll = bool(bpy.ops.anim.slot_unassign_from_constraint.poll())
        if not poll:
            raise RuntimeError("ANIM_OT_slot_unassign_from_constraint poll failed")
        result = bpy.ops.anim.slot_unassign_from_constraint()
    if result != {"FINISHED"}:
        raise RuntimeError(f"ANIM_OT_slot_unassign_from_constraint returned {result}")
    return poll, result


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --factory-startup --python check-action-slot-unassign-from-constraint-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)
    obj = bpy.data.objects.get(OBJECT_NAME)
    constraint = next((value for value in obj.constraints if value.name == CONSTRAINT_NAME), None) if obj else None
    before = state_report()
    preserved = is_unassigned(before)
    if preserved:
        poll = True
        result = {"FINISHED"}
    else:
        if before["action"] != ACTION_NAME or before["actionSlot"] != SLOT_IDENTIFIER or before["actionSlotHandle"] == 0:
            raise RuntimeError(f"slot_unassign_from_constraint source state is wrong: {before}")
        poll, result = run_operator(constraint)
    after = state_report()
    if not is_unassigned(after):
        raise RuntimeError(f"slot_unassign_from_constraint did not clear the assigned slot: {after}")
    descriptor, temporary = tempfile.mkstemp(prefix="m16-anim-slot-unassign-constraint-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 reopened != after:
            raise RuntimeError(f"anim.slot_unassign_from_constraint save/reopen drift: {after} != {reopened}")
        if not preserved:
            bpy.ops.wm.save_as_mainfile(filepath=str(fixture), check_existing=False, compress=True)
        report = {
            "schemaVersion": 1,
            "task": "M16-GAP-00208",
            "operation": "ANIM_SLOT_UNASSIGN_FROM_CONSTRAINT_DESKTOP",
            "fixture": str(fixture),
            "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
            "before": before,
            "after": reopened,
            "poll": poll,
            "operatorStatus": "FINISHED",
            "mainMutation": "CONSTRAINT_SLOT_UNASSIGNED" if not preserved else "NONE_ALREADY_UNASSIGNED",
            "saveReopen": "EXACT",
            "blenderVersion": bpy.app.version_string,
        }
        if preserved:
            report["evidenceStatus"] = "PRESERVED"
        if not preserved or not output.exists():
            output.parent.mkdir(parents=True, exist_ok=True)
            output.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")
        print("anim-slot-unassign-from-constraint-desktop-ok poll=true status=FINISHED mainMutation=constraint_slot_unassigned saveReopen=exact")
    finally:
        temporary_path.unlink(missing_ok=True)


if __name__ == "__main__":
    try:
        main()
    except Exception as error:
        print(f"anim-slot-unassign-from-constraint-desktop-failed: {error}")
        raise SystemExit(1)