import io
import unittest
from unittest.mock import patch

from scripts.run_seeded_snake_tournament import ENGINE_USER_AGENT, run_game

class _Completed:
  returncode = 0
  stdout = "INFO Game completed after 42 turns. Prism was the winner.\n"

class _OutputFile:

  def __init__(self, *args, **kwargs):
    self.file = io.BytesIO(
      b'{"turn":0}\n'
      b'{"winnerId":"snake-id","winnerName":"Prism","isDraw":false}\n'
    )
    self.name = "arena-output.jsonl"

  def __enter__(self):
    return self

  def __exit__(self, *args):
    self.file.close()

  def seek(self, offset):
    return self.file.seek(offset)

  def __iter__(self):
    return iter(self.file)

class TestSeededSnakeTournament(unittest.TestCase):

  def test_proxy_identifies_requests_as_battlesnake_engine(self):
    self.assertIn("BattlesnakeEngine", ENGINE_USER_AGENT)

  @patch("scripts.run_seeded_snake_tournament.subprocess.run", return_value=_Completed())
  @patch("scripts.run_seeded_snake_tournament.tempfile.NamedTemporaryFile", _OutputFile)
  def test_run_game_reads_official_engine_result(self, run):
    result = run_game(
      cli="battlesnake", seed=7, game_type="standard", map_name="standard",
      players=[("Apex", "http://host:9001"), ("Prism", "http://host:9002")],
      width=11, height=11, timeout_ms=500,
    )

    self.assertEqual(result, {
      "seed": 7, "winner": "Prism", "draw": False, "turns": 42,
    })
    command = run.call_args.args[0]
    self.assertIn("--seed", command)
    self.assertIn("--output", command)

if __name__ == "__main__":
  unittest.main()