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

import bpy


ARMATURE_NAME = "WebGapArmatureRollClearArmature"
OBJECT_NAME = "WebGapArmatureRollClearObject"
BONE_NAME = "WebGapArmatureRollClearBone"
INITIAL_ROLL = math.pi / 4.0
TARGET_ROLL = 0.0


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


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


def ensure_edit_mode():
    obj = bpy.data.objects.get(OBJECT_NAME)
    armature = bpy.data.armatures.get(ARMATURE_NAME)
    if armature is None or obj is None or obj.type != "ARMATURE" or obj.data != armature:
        raise RuntimeError("armature.roll_clear fixture is missing")
    bpy.context.view_layer.objects.active = obj
    obj.select_set(True)
    if obj.mode != "EDIT":
        bpy.ops.object.mode_set(mode="EDIT")
    return armature


def state_report():
    armature = ensure_edit_mode()
    bone = armature.edit_bones.get(BONE_NAME)
    if bone is None:
        raise RuntimeError("armature.roll_clear bone is missing")
    return {
        "object": OBJECT_NAME,
        "armature": ARMATURE_NAME,
        "activeBone": armature.edit_bones.active.name if armature.edit_bones.active else None,
        "bones": [{
            "name": bone.name,
            "roll": round(float(bone.roll), 6),
            "selected": bool(bone.select),
            "hidden": bool(bone.hide),
            "head": vector(bone.head),
            "tail": vector(bone.tail),
            "matrix": matrix_flat(bone.matrix),
        }],
    }


def stable_state(state):
    return {
        "object": state["object"],
        "armature": state["armature"],
        "activeBone": state["activeBone"],
        "bones": [{key: state["bones"][0][key] for key in ("name", "roll", "selected", "hidden", "head", "tail", "matrix")}],
    }


def validate_input(before):
    if len(before["bones"]) != 1 or before["bones"][0]["name"] != BONE_NAME:
        raise RuntimeError(f"unexpected armature.roll_clear bones: {before}")
    bone = before["bones"][0]
    if abs(bone["roll"] - INITIAL_ROLL) <= 1e-5 and bone["selected"] and not bone["hidden"]:
        return False
    if abs(bone["roll"] - TARGET_ROLL) <= 1e-5 and bone["selected"] and not bone["hidden"]:
        return True
    raise RuntimeError(f"unexpected armature.roll_clear state: {before}")


def run_operator(already_cleared):
    armature = ensure_edit_mode()
    bone = armature.edit_bones[BONE_NAME]
    bone.select = True
    armature.edit_bones.active = bone
    poll = bool(bpy.ops.armature.roll_clear.poll())
    if not poll:
        raise RuntimeError("ARMATURE_OT_roll_clear poll failed")
    if not already_cleared:
        result = bpy.ops.armature.roll_clear(roll=TARGET_ROLL)
        if result != {"FINISHED"}:
            raise RuntimeError(f"ARMATURE_OT_roll_clear returned {result}")
    roll = float(bone.roll)
    bpy.ops.object.mode_set(mode="OBJECT")
    return poll, not already_cleared, roll


def validate_after(after, roll):
    bone = after["bones"][0]
    if abs(roll - TARGET_ROLL) > 1e-5 or abs(bone["roll"] - TARGET_ROLL) > 1e-5:
        raise RuntimeError(f"armature.roll_clear did not clear roll: {after}")
    if not bone["selected"] or bone["hidden"]:
        raise RuntimeError(f"armature.roll_clear changed selection/visibility: {after}")
    if bone["head"] != [0.0, 0.0, 0.0] or bone["tail"] != [0.0, 2.0, 0.0]:
        raise RuntimeError(f"armature.roll_clear changed geometry: {after}")


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --factory-startup --python check-action-armature-roll-clear-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 = state_report()
    already_cleared = validate_input(before)
    poll, changed, roll = run_operator(already_cleared)
    after = state_report()
    validate_after(after, roll)

    bpy.ops.object.mode_set(mode="OBJECT")
    descriptor, temporary = tempfile.mkstemp(prefix="m16-armature-roll-clear-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_state(reopened) != stable_state(after):
            raise RuntimeError(f"armature.roll_clear save/reopen drift: {after} != {reopened}")
        shutil.copyfile(temporary_path, fixture)
        report = {
            "schemaVersion": 1,
            "task": "M16-GAP-00249",
            "operation": "ARMATURE_ROLL_CLEAR_DESKTOP",
            "fixture": str(fixture),
            "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
            "before": before,
            "after": reopened,
            "bone": BONE_NAME,
            "roll": round(roll, 6),
            "poll": poll,
            "operatorStatus": "FINISHED" if changed else "SKIPPED_ALREADY_APPLIED",
            "mainMutation": "ROLL_CLEARED_TO_ZERO" if changed else "ROLL_ALREADY_ZERO",
            "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-roll-clear-desktop-ok bone={BONE_NAME} roll=0 saveReopen=exact")
    finally:
        temporary_path.unlink(missing_ok=True)


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