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

import bpy


ARMATURE_NAME = "WebGapArmatureCalculateRollArmature"
OBJECT_NAME = "WebGapArmatureCalculateRollObject"
BONE_NAME = "WebGapArmatureCalculateRollBone"
EXPECTED_ROLL = math.pi / 2.0


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 state_report():
    armature = bpy.data.armatures.get(ARMATURE_NAME)
    obj = bpy.data.objects.get(OBJECT_NAME)
    if armature is None or obj is None or obj.type != "ARMATURE" or obj.data != armature:
        raise RuntimeError("armature.calculate_roll fixture is missing")
    bones = [
        {
            "name": bone.name,
            "head": vector(bone.head_local),
            "tail": vector(bone.tail_local),
            "matrix": matrix_flat(bone.matrix_local),
        }
        for bone in armature.bones
    ]
    bones.sort(key=lambda value: value["name"])
    return {"object": OBJECT_NAME, "armature": ARMATURE_NAME, "bones": bones}


def run_operator(before):
    if [bone["name"] for bone in before["bones"]] != [BONE_NAME]:
        raise RuntimeError(f"unexpected calculate_roll input: {before}")
    bpy.context.view_layer.objects.active = bpy.data.objects[OBJECT_NAME]
    bpy.data.objects[OBJECT_NAME].select_set(True)
    if bpy.context.object.mode != "EDIT":
        bpy.ops.object.mode_set(mode="EDIT")
    armature = bpy.data.armatures[ARMATURE_NAME]
    edit_bone = armature.edit_bones[BONE_NAME]
    already_calculated = abs(abs(edit_bone.roll) - EXPECTED_ROLL) <= 1e-5
    edit_bone.select = True
    armature.bones.active = armature.bones[BONE_NAME]
    poll = bool(bpy.ops.armature.calculate_roll.poll())
    if not poll:
        raise RuntimeError("ARMATURE_OT_calculate_roll poll failed")
    if not already_calculated:
        result = bpy.ops.armature.calculate_roll(type="GLOBAL_POS_X", axis_flip=False, axis_only=False)
        if result != {"FINISHED"}:
            raise RuntimeError(f"ARMATURE_OT_calculate_roll returned {result}")
    roll = float(edit_bone.roll)
    bpy.ops.object.mode_set(mode="OBJECT")
    return poll, not already_calculated, roll


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --factory-startup --python check-action-armature-calculate-roll-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()
    poll, changed, roll = run_operator(before)
    after = state_report()
    if len(after["bones"]) != 1 or after["bones"][0]["name"] != BONE_NAME:
        raise RuntimeError(f"calculate_roll changed unexpected bones: {before} -> {after}")
    if abs(abs(roll) - EXPECTED_ROLL) > 1e-5:
        raise RuntimeError(f"calculate_roll did not produce the expected roll: {roll}")
    expected_matrix = [0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, -1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0]
    for actual, expected in zip(after["bones"][0]["matrix"], expected_matrix):
        if abs(actual - expected) > 1e-5:
            raise RuntimeError(f"calculate_roll matrix mismatch: {after}")

    descriptor, temporary = tempfile.mkstemp(prefix="m16-armature-calculate-roll-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"armature.calculate_roll save/reopen drift: {after} != {reopened}")
        shutil.copyfile(temporary_path, fixture)
        report = {
            "schemaVersion": 1,
            "task": "M16-GAP-00219",
            "operation": "ARMATURE_CALCULATE_ROLL_DESKTOP",
            "fixture": str(fixture),
            "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
            "before": before,
            "after": reopened,
            "alreadyCalculated": not changed,
            "roll": round(roll, 6),
            "poll": poll,
            "operatorStatus": "FINISHED" if changed else "SKIPPED_ALREADY_APPLIED",
            "mainMutation": "ROLL_CALCULATED_GLOBAL_POS_X" if changed else "ALREADY_ROLL_CALCULATED_GLOBAL_POS_X",
            "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("armature-calculate-roll-desktop-ok poll=true roll=global-pos-x saveReopen=exact")
    finally:
        temporary_path.unlink(missing_ok=True)


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