"""ORCH-1 resilience tests: preflight, 429-classifier, backoff, circuit breaker.

No real claude/Popen is ever spawned: preflight subprocess and launcher.launch_job
are mocked. DB is a fresh per-test sqlite file.
"""
import os
import tempfile

import pytest

_test_db = os.path.join(tempfile.gettempdir(), "test_orchestrator_resilience.db")
os.environ["ORCH_DB_PATH"] = _test_db
os.environ["ORCH_REPOS_DIR"] = tempfile.gettempdir()
os.environ["ORCH_GITEA_TOKEN"] = "test-token"
os.environ["ORCH_PLANE_API_TOKEN"] = "test-token"

import src.db as db
from src.db import (
    init_db, enqueue_job, claim_next_job, get_job, count_running_jobs,
    mark_job_transient,
)
from src import preflight, error_classifier
from src.error_classifier import classify_text, parse_retry_after, classify_log_file
from src.queue_worker import QueueWorker, CircuitBreaker
from src.agents.launcher import AgentLauncher


@pytest.fixture(autouse=True)
def fresh_db(tmp_path, monkeypatch):
    monkeypatch.setattr(db.settings, "db_path", str(tmp_path / "res.db"))
    init_db()
    preflight.reset_cache()
    yield


# ---------------------------------------------------------------------------
# A. Preflight
# ---------------------------------------------------------------------------
class TestPreflight:
    @pytest.fixture(autouse=True)
    def _isolate_auth_gate(self, monkeypatch):
        # ORCH-044: preflight.check() also runs a token-free auth gate reading
        # <AGENT_HOME>/.claude/.credentials.json (AgentLauncher.AGENT_HOME, not the
        # process HOME). In a clean CI runner those creds are absent, so the gate
        # returns (False, ...) and version-branch assertions would fail for purely
        # environmental reasons. Stub the gate green; auth is covered by
        # tests/test_preflight_auth.py. Production default (preflight_check_auth=True)
        # is unchanged.
        monkeypatch.setattr(preflight, "_check_auth", lambda: (True, "auth ok (test stub)"))

    def test_fail_when_bin_missing(self, monkeypatch):
        monkeypatch.setattr(preflight, "_claude_bin", lambda: "/no/such/claude")
        ok, reason = preflight.check(force=True)
        assert ok is False
        assert "not found" in reason.lower()

    def test_ok_when_version_succeeds(self, monkeypatch, tmp_path):
        fake_bin = tmp_path / "claude"
        fake_bin.write_text("#!/bin/sh\necho v1\n")
        monkeypatch.setattr(preflight, "_claude_bin", lambda: str(fake_bin))
        monkeypatch.setattr(preflight, "_run_version", lambda b: (True, "1.2.3"))
        ok, reason = preflight.check(force=True)
        assert ok is True

    def test_cache_does_not_recheck_within_ttl(self, monkeypatch, tmp_path):
        fake_bin = tmp_path / "claude"
        fake_bin.write_text("x")
        monkeypatch.setattr(preflight, "_claude_bin", lambda: str(fake_bin))
        monkeypatch.setattr(db.settings, "preflight_cache_ttl", 999)

        calls = {"n": 0}

        def counting_version(b):
            calls["n"] += 1
            return True, "ok"

        monkeypatch.setattr(preflight, "_run_version", counting_version)
        preflight.reset_cache()
        preflight.check()           # first -> runs version
        preflight.check()           # cached -> no extra version call
        preflight.check()
        assert calls["n"] == 1

    def test_force_bypasses_cache(self, monkeypatch, tmp_path):
        fake_bin = tmp_path / "claude"
        fake_bin.write_text("x")
        monkeypatch.setattr(preflight, "_claude_bin", lambda: str(fake_bin))
        calls = {"n": 0}
        monkeypatch.setattr(preflight, "_run_version",
                            lambda b: (calls.__setitem__("n", calls["n"] + 1), (True, "ok"))[1])
        preflight.reset_cache()
        preflight.check()
        preflight.check(force=True)
        assert calls["n"] == 2

    def test_worker_does_not_claim_when_preflight_fails(self, monkeypatch):
        # Preflight FAIL -> job stays queued, launch_job never called.
        monkeypatch.setattr("src.queue_worker.preflight.check",
                            lambda *a, **k: (False, "down"))
        called = {"launch": False}
        monkeypatch.setattr("src.queue_worker.launcher.launch_job",
                            lambda job: called.__setitem__("launch", True))
        jid = enqueue_job("analyst", "r")
        QueueWorker(max_concurrency=1, poll_interval=0.01)._drain_once()
        assert called["launch"] is False
        assert get_job(jid)["status"] == "queued"
        assert count_running_jobs() == 0


# ---------------------------------------------------------------------------
# B. Error classifier
# ---------------------------------------------------------------------------
class TestClassifier:
    @pytest.mark.parametrize("text", [
        "Error: 429 Too Many Requests",
        "anthropic rate limit exceeded",
        "overloaded_error: server is overloaded",
        "API quota exhausted",
        "503 Service Unavailable",
        "connection reset by peer",
    ])
    def test_transient_patterns(self, text):
        assert classify_text(text) == "transient"

    @pytest.mark.parametrize("text", [
        "Traceback: KeyError 'foo'",
        "SyntaxError: invalid syntax",
        "assertion failed in test",
        "",
    ])
    def test_permanent_patterns(self, text):
        assert classify_text(text) == "permanent"

    def test_retry_after_header(self):
        assert parse_retry_after("HTTP/1.1 429\nRetry-After: 42\n") == 42

    def test_retry_after_json(self):
        assert parse_retry_after('{"error":{"type":"rate_limit","retry_after": 7}}') == 7

    def test_retry_after_absent(self):
        assert parse_retry_after("just an error") is None

    def test_classify_log_file(self, tmp_path):
        p = tmp_path / "run.log"
        p.write_text("...lots of output...\n429 rate limit. Retry-After: 30\n")
        kind, ra = classify_log_file(str(p))
        assert kind == "transient"
        assert ra == 30

    def test_classify_missing_file_is_permanent(self):
        kind, ra = classify_log_file("/no/such/log")
        assert kind == "permanent"
        assert ra is None


# ---------------------------------------------------------------------------
# C. Backoff + available_at gating
# ---------------------------------------------------------------------------
class TestBackoff:
    def test_backoff_grows_exponentially(self):
        lr = AgentLauncher()
        # base=10, cap=600 (defaults)
        b1 = lr._backoff_seconds(1)
        b2 = lr._backoff_seconds(2)
        b3 = lr._backoff_seconds(3)
        assert b1 == 20      # 2^1*10
        assert b2 == 40      # 2^2*10
        assert b3 == 80      # 2^3*10
        assert b2 > b1 and b3 > b2

    def test_backoff_capped(self):
        lr = AgentLauncher()
        assert lr._backoff_seconds(20) == 600  # capped at backoff_max_seconds

    def test_retry_after_respected_when_larger(self):
        lr = AgentLauncher()
        # transient_attempts=1 -> base backoff 20; Retry-After=120 wins.
        assert lr._backoff_seconds(1, retry_after=120) == 120

    def test_retry_after_ignored_when_smaller(self):
        lr = AgentLauncher()
        assert lr._backoff_seconds(3, retry_after=5) == 80  # backoff bigger

    def test_transient_requeue_sets_future_available_at_and_claim_skips(self):
        jid = enqueue_job("developer", "r")
        claim_next_job()
        # Big backoff -> available_at far in the future.
        mark_job_transient(jid, 3600, error="429")
        job = get_job(jid)
        assert job["status"] == "queued"
        assert job["transient_attempts"] == 1
        assert job["available_at"] is not None
        # claim must NOT pick it up while available_at is in the future.
        assert claim_next_job() is None

    def test_transient_requeue_claimable_when_due(self):
        jid = enqueue_job("developer", "r")
        claim_next_job()
        mark_job_transient(jid, -5, error="429")  # available_at in the past
        c = claim_next_job()
        assert c is not None and c["id"] == jid


# ---------------------------------------------------------------------------
# D. Launcher transient/permanent finalize (no Popen)
# ---------------------------------------------------------------------------
class TestFinalizeClassified:
    def test_transient_failure_backoff_requeue(self, tmp_path, monkeypatch):
        monkeypatch.setattr("src.notifications.send_telegram", lambda *a, **k: None)
        log = tmp_path / "1.log"
        log.write_text("Error 429 rate limit exceeded\n")
        jid = enqueue_job("developer", "r", max_attempts=2)
        claim_next_job()
        AgentLauncher()._finalize_job(jid, "developer", run_id=1, exit_code=1,
                                      output_path=str(log))
        job = get_job(jid)
        assert job["status"] == "queued"
        assert job["transient_attempts"] == 1
        assert job["available_at"] is not None     # backoff-gated
        assert job["attempts"] == 1                 # code-fault budget NOT burned

    def test_permanent_failure_uses_normal_attempts(self, tmp_path, monkeypatch):
        monkeypatch.setattr("src.notifications.send_telegram", lambda *a, **k: None)
        log = tmp_path / "2.log"
        log.write_text("Traceback: ValueError\n")
        jid = enqueue_job("developer", "r", max_attempts=2)
        claim_next_job()
        AgentLauncher()._finalize_job(jid, "developer", run_id=2, exit_code=1,
                                      output_path=str(log))
        job = get_job(jid)
        assert job["status"] == "queued"
        assert job["transient_attempts"] == 0       # not transient
        assert job["available_at"] is None          # no backoff for code-fault

    def test_transient_exhausts_to_failed(self, tmp_path, monkeypatch):
        monkeypatch.setattr("src.notifications.send_telegram", lambda *a, **k: None)
        monkeypatch.setattr(db.settings, "transient_max_attempts", 2)
        log = tmp_path / "3.log"
        log.write_text("overloaded_error\n")
        lr = AgentLauncher()
        jid = enqueue_job("developer", "r")
        claim_next_job()
        lr._finalize_job(jid, "developer", 1, exit_code=1, output_path=str(log))
        assert get_job(jid)["status"] == "queued"   # transient 1 -> requeue
        # force claimable and retry
        mark_job_transient(jid, -1)                  # makes it due; transient=2 now
        claim_next_job()
        lr._finalize_job(jid, "developer", 2, exit_code=1, output_path=str(log))
        assert get_job(jid)["status"] == "failed"    # transient budget exhausted


# ---------------------------------------------------------------------------
# E. Circuit breaker
# ---------------------------------------------------------------------------
class TestCircuitBreaker:
    def test_opens_after_threshold(self):
        cb = CircuitBreaker(threshold=3, pause_seconds=300)
        assert cb.allow_claim() is True
        cb.record_transient()
        cb.record_transient()
        assert cb.state == "closed"
        cb.record_transient()                 # 3rd -> open
        assert cb.state == "open"
        assert cb.allow_claim() is False      # paused, no CLI calls

    def test_recovered_resets_streak(self):
        cb = CircuitBreaker(threshold=3)
        cb.record_transient()
        cb.record_transient()
        cb.record_recovered()
        assert cb.consecutive_transient == 0
        assert cb.state == "closed"

    def test_half_open_after_pause_then_closed_on_success(self, monkeypatch):
        cb = CircuitBreaker(threshold=2, pause_seconds=300)
        cb.record_transient()
        cb.record_transient()                 # open
        assert cb.state == "open"
        # Simulate the pause elapsing.
        cb.opened_at -= 301
        assert cb.allow_claim() is True       # -> half-open (probe)
        assert cb.state == "half-open"
        cb.record_recovered()                 # probe succeeded
        assert cb.state == "closed"

    def test_half_open_reopens_on_transient(self):
        cb = CircuitBreaker(threshold=2, pause_seconds=300)
        cb.record_transient(); cb.record_transient()   # open
        cb.opened_at -= 301
        cb.allow_claim()                      # half-open
        assert cb.state == "half-open"
        cb.record_transient()                 # probe failed -> re-open
        assert cb.state == "open"

    def test_breaker_blocks_worker_claim(self, monkeypatch):
        monkeypatch.setattr("src.queue_worker.preflight.check",
                            lambda *a, **k: (True, "ok"))
        called = {"launch": False}
        monkeypatch.setattr("src.queue_worker.launcher.launch_job",
                            lambda job: called.__setitem__("launch", True))
        cb = CircuitBreaker(threshold=1, pause_seconds=300)
        cb.record_transient()                 # open immediately
        w = QueueWorker(max_concurrency=1, poll_interval=0.01, breaker=cb)
        enqueue_job("analyst", "r")
        w._drain_once()
        assert called["launch"] is False      # breaker open -> no claim, no CLI