"""Exercise real Sequencer UI ticks, rebuild, render, then render again in one editor."""
import json
import os
import traceback

import unreal

from ue_workshop import render
from ue_workshop.paths import PROJECT

unreal.EditorPythonScripting.set_keep_python_script_alive(True)
# The test owns shutdown; allow multiple renders in the same editor process.
os.environ["WORKSHOP_BATCH"] = "0"
code = (PROJECT / "exercises/my_shot.py").read_text(encoding="utf-8")
code = code.replace("RENDER = True", "RENDER = False")
state = {"stage": 0, "ticks": 0, "outputs": []}


def build():
    namespace = {"__name__": "__main__"}
    exec(compile(code, "my_shot.py", "exec"), namespace)
    return namespace


namespace = build()


def tick(delta):
    global namespace
    state["ticks"] += 1
    try:
        if state["stage"] in {0, 2} and state["ticks"] >= 30:
            # The previous sequence editor has ticked before its actors and
            # bindings are replaced, matching repeated Execute Python Script.
            next_stage = state["stage"] + 1
            # Asset saves can pump Slate recursively. Do not re-enter the test.
            state["stage"] = -1
            namespace = build()
            output = render.start(namespace["shot"], mp4=True)
            state["outputs"].append(output)
            state["stage"] = next_stage
        elif state["stage"] in {1, 3} and not render.is_rendering():
            result = json.loads((state["outputs"][-1] / "result.json").read_text())
            assert result["success"], result
            if state["stage"] == 3:
                finish({"success": True, "renders": [str(path) for path in state["outputs"]]})
            else:
                unreal.LevelSequenceEditorBlueprintLibrary.open_level_sequence(namespace["shot"].asset)
                state["stage"] = 2
                state["ticks"] = 0
    except Exception:
        finish({"success": False, "error": traceback.format_exc()})


def finish(result):
    unreal.unregister_slate_post_tick_callback(handle)
    render._write_status(result)
    unreal.log("[Workshop UI test] " + str(result))
    unreal.EditorPythonScripting.set_keep_python_script_alive(False)


handle = unreal.register_slate_post_tick_callback(tick)