#!/usr/bin/env python3
"""Check a fresh, physical arrows-first Steam Big Picture run of Cthulhu."""

import argparse
import json
from pathlib import Path


def check_log(path: Path) -> None:
    records = [json.loads(line) for line in path.read_text().splitlines() if line.strip()]
    starts = [index for index, record in enumerate(records)
              if record.get("message") == "starting Cthulhu"]
    if not starts:
        raise ValueError("no Cthulhu startup in log")
    records = records[starts[-1]:]

    steam_pid = None
    steam_document = False
    first_link = None
    first_caret = None
    tab_focus = False
    home = power = confirm = cancel = False
    links_before_arrow = set()
    for record in records:
        message = record.get("message")
        if message == "X11 foreground ownership changed":
            pid = record.get("pid") or 0
            if first_link is not None and pid and pid != steam_pid and not cancel:
                raise ValueError("foreground left Steam before the dialog check finished")
            if first_link is None and pid:
                steam_pid = pid
            continue
        if message == "suspended for XTerm focus handoff" and first_link is not None and not cancel:
            raise ValueError("focus switched away from Steam before the dialog check finished")
        if (message == "delivering accessible presentation" and
                record.get("role") == "document web" and
                record.get("utterance", "").startswith("Steam Big Picture Mode")):
            steam_document = True
        if message == "document caret navigation completed" and record.get("moved") is True:
            if first_link is not None and first_caret is None:
                first_caret = record.get("time")
            continue
        if message != "delivering accessible presentation" or record.get("cause") != "object:state-changed:focused":
            continue
        role = record.get("role")
        utterance = record.get("utterance", "")
        if role == "link" and utterance and steam_document:
            if first_link is None:
                first_link = record.get("time")
                links_before_arrow.add(utterance)
            elif first_caret is None:
                links_before_arrow.add(utterance)
            else:
                tab_focus = True
        if first_caret is None:
            continue
        if role == "menu item" and utterance == "Home, menu item":
            home = True
        elif role == "menu item" and utterance == "Power, menu item":
            power = home
        elif role == "button" and utterance == "Confirm, button":
            confirm = power
        elif role == "button" and utterance == "Cancel, button":
            cancel = confirm
            if cancel:
                break

    if not steam_document or first_link is None:
        raise ValueError("Steam never exposed its document and an initial focused link")
    if len(links_before_arrow) != 1:
        raise ValueError("focus moved between links before the first browse arrow; test arrows first")
    if first_caret is None:
        raise ValueError("no successful browse arrow after Steam became ready")
    if not tab_focus:
        raise ValueError("no focused link after the first arrow and Tab")
    if not home or not power:
        raise ValueError("Escape did not expose Home and Power")
    if not confirm or not cancel:
        raise ValueError("Power did not expose both Confirm and Cancel buttons")


def main() -> None:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("log", type=Path, help="fresh Cthulhu debug log")
    arguments = parser.parse_args()
    try:
        check_log(arguments.log)
    except (OSError, ValueError, json.JSONDecodeError) as error:
        parser.exit(1, f"Steam Big Picture check failed: {error}\n")
    print("Steam Big Picture arrows-first focus, menu, and dialog check passed")


if __name__ == "__main__":
    main()