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

import bpy


def action_report(action):
    channels = []
    for layer in action.layers:
        for strip in layer.strips:
            for bag in strip.channelbags:
                for curve in bag.fcurves:
                    channels.append({
                        "path": curve.data_path,
                        "index": curve.array_index,
                        "frames": [round(float(keyframe.co.x), 6) for keyframe in curve.keyframe_points],
                    })
    channels.sort(key=lambda value: (value["path"], value["index"]))
    return {
        "name": action.name,
        "users": action.users,
        "fakeUser": bool(action.use_fake_user),
        "channels": channels,
    }


def state_report():
    actions = {
        action.name: action_report(action)
        for action in bpy.data.actions
        if action.name.startswith("WebGapAnimClearUseless")
    }
    used = bpy.data.objects.get("WebGapAnimClearUselessUsedObject")
    if used is None or used.animation_data is None or used.animation_data.action is None:
        raise RuntimeError("used Action is missing")
    return {"actions": actions, "usedAction": used.animation_data.action.name}


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --python check-action-clear-useless-actions-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()
    expected = {
        "WebGapAnimClearUselessUsedAction",
        "WebGapAnimClearUselessLibraryAction",
    }
    if set(before["actions"]) != expected:
        raise RuntimeError(f"clear_useless_actions did not remove only the empty Action: {before}")
    if before["usedAction"] != "WebGapAnimClearUselessUsedAction":
        raise RuntimeError(f"used Action drifted: {before}")
    if any(len(value["channels"]) != 3 for value in before["actions"].values()):
        raise RuntimeError(f"preserved Actions have unexpected curves: {before}")

    descriptor, temporary = tempfile.mkstemp(prefix="m16-anim-clear-useless-actions-reopen-", suffix=".blend")
    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 = state_report()
    finally:
        pathlib.Path(temporary).unlink(missing_ok=True)
    if before != after:
        raise RuntimeError("anim.clear_useless_actions save/reopen drift")
    report = {
        "schemaVersion": 1,
        "task": "M16-GAP-00172",
        "operation": "ANIM_CLEAR_USELESS_ACTIONS_DESKTOP",
        "fixture": str(fixture),
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "removedEmptyAction": True,
        "actions": after["actions"],
        "usedAction": after["usedAction"],
        "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("anim-clear-useless-actions-desktop-ok removedEmpty=true preserved=2 saveReopen=exact")


if __name__ == "__main__":
    main()