"""Tests for the agent-health.sh restart circuit breaker.

Drives the real shell functions (sourced with AGENT_HEALTH_LIB_ONLY=1)
against a scratch STATE_DIR/LOG: futile-restart counting, circuit open,
half-open probe after cooldown, and reset on success.
"""
import subprocess
import tempfile
import unittest
from pathlib import Path

REPO_ROOT = Path(__file__).resolve().parent.parent
SCRIPT = REPO_ROOT / "bin" / "agent-health.sh"


def _run(state_dir, log, snippet):
    prog = (
        "source '%s'\n"
        "STATE_DIR='%s'; LOG='%s'\n"
        "%s\n" % (SCRIPT, state_dir, log, snippet)
    )
    env = {"AGENT_HEALTH_LIB_ONLY": "1", "PATH": "/usr/bin:/bin"}
    return subprocess.run(["bash", "-c", prog], capture_output=True,
                          text=True, env=env, timeout=30)


class CircuitBreaker(unittest.TestCase):
    def setUp(self):
        self.tmp = tempfile.TemporaryDirectory()
        self.state = str(Path(self.tmp.name) / "state")
        Path(self.state).mkdir()
        self.log = str(Path(self.tmp.name) / "log")

    def tearDown(self):
        self.tmp.cleanup()

    def bash(self, snippet):
        return _run(self.state, self.log, snippet)

    def test_allows_when_closed(self):
        r = self.bash("circuit_allows def")
        self.assertEqual(r.returncode, 0, r.stderr)

    def test_allows_below_threshold(self):
        r = self.bash("circuit_note_restart def fail\n"
                      "circuit_note_restart def fail\n"
                      "circuit_allows def")
        self.assertEqual(r.returncode, 0, r.stderr)
        self.assertEqual((Path(self.state) / "futile-def").read_text().strip(), "2")

    def test_opens_after_threshold_and_alerts(self):
        r = self.bash("circuit_note_restart def fail\n"
                      "circuit_note_restart def fail\n"
                      "circuit_note_restart def fail")
        self.assertEqual(r.returncode, 0, r.stderr)
        self.assertTrue((Path(self.state) / "circuit-def").exists())
        self.assertIn("ALERT", r.stdout)
        self.assertIn("ALERT", Path(self.log).read_text())
        r2 = self.bash("circuit_allows def")
        self.assertNotEqual(r2.returncode, 0)
        self.assertIn("CIRCUIT OPEN", Path(self.log).read_text())

    def test_half_open_after_cooldown(self):
        old = "echo $(( $(date +%%s) - 1900 )) > '%s/circuit-def'" % self.state
        r = self.bash(old + "\ncircuit_allows def")
        self.assertEqual(r.returncode, 0, r.stderr)
        self.assertIn("half-open", Path(self.log).read_text())

    def test_ok_resets(self):
        r = self.bash("circuit_note_restart def fail\n"
                      "circuit_note_restart def fail\n"
                      "circuit_note_restart def fail\n"
                      "circuit_note_restart def ok")
        self.assertEqual(r.returncode, 0, r.stderr)
        self.assertFalse((Path(self.state) / "futile-def").exists())
        self.assertFalse((Path(self.state) / "circuit-def").exists())

    def test_per_agent_isolation(self):
        r = self.bash("circuit_note_restart def fail\n"
                      "circuit_note_restart def fail\n"
                      "circuit_note_restart def fail\n"
                      "circuit_allows pip")
        self.assertEqual(r.returncode, 0, r.stderr)


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