"""Tests for warmup canaries (sub-task: thread/load observability).

The WarmupManager records, for each module it loads:
- canary_id: monotonic numeric ID assigned at submit time
- module: the module name
- thread_name: name of the thread that did the import (e.g. "controller-io-0")
- thread_id: threading.get_ident() of that thread
- submit_ts / start_ts / end_ts: wall-clock timestamps
- elapsed_ms: end_ts - start_ts in milliseconds
- status: "running" / "completed" / "failed"
- error: error message string if status == "failed"

Canaries are exposed via WarmupManager.canaries() and via the
AppController.warmup_canaries() / GET /api/warmup_canaries.
"""

import threading
import time
import pytest
import sys
import os

sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))

from src.warmup import WarmupManager
from src.io_pool import make_io_pool


def _build_warmup() -> tuple[WarmupManager, object]:
 """Build a fresh WarmupManager + pool for testing."""
 pool = make_io_pool()
 mgr = WarmupManager(pool)
 return mgr, pool


def test_canary_assigned_id_at_submit_time() -> None:
 """Each module gets a unique monotonic canary_id when submitted."""
 mgr, pool = _build_warmup()
 mgr.submit(["os", "sys", "json"])
 # Canary records should exist immediately (status="running" or already done)
 canaries = mgr.canaries()
 assert len(canaries) == 3
 ids = [c["canary_id"] for c in canaries]
 assert len(set(ids)) == 3, "canary_ids must be unique"
 assert sorted(ids) == [1, 2, 3], f"canary_ids must be monotonic, got {ids}"
 modules = {c["module"] for c in canaries}
 assert modules == {"os", "sys", "json"}
 pool.shutdown(wait=True)


def test_canary_records_thread_name_and_id() -> None:
 """Each canary records the thread_name and thread_id that did the import."""
 mgr, pool = _build_warmup()
 mgr.submit(["os"])
 assert mgr.wait(timeout=10.0)
 canaries = mgr.canaries()
 assert len(canaries) == 1
 c = canaries[0]
 assert "thread_name" in c
 assert "thread_id" in c
 # Should be a controller-io-N thread (the pool's name prefix)
 assert c["thread_name"].startswith("controller-io"), (
  f"thread_name should be controller-io-N, got {c['thread_name']!r}"
 )
 assert isinstance(c["thread_id"], int)
 assert c["thread_id"] > 0
 pool.shutdown(wait=True)


def test_canary_records_timing_and_status() -> None:
 """Each canary has start_ts, end_ts, elapsed_ms, and final status."""
 mgr, pool = _build_warmup()
 t_before = time.time()
 mgr.submit(["os"])
 assert mgr.wait(timeout=10.0)
 t_after = time.time()
 canaries = mgr.canaries()
 assert len(canaries) == 1
 c = canaries[0]
 assert c["status"] == "completed"
 assert c["error"] is None
 assert "submit_ts" in c
 assert "start_ts" in c
 assert "end_ts" in c
 assert "elapsed_ms" in c
 assert c["submit_ts"] >= t_before
 assert c["start_ts"] >= c["submit_ts"]
 assert c["end_ts"] >= c["start_ts"]
 assert c["elapsed_ms"] >= 0
 assert c["end_ts"] <= t_after + 0.5
 pool.shutdown(wait=True)


def test_canary_records_failure_status_and_error() -> None:
 """A failed import produces a canary with status='failed' and an error message."""
 mgr, pool = _build_warmup()
 mgr.submit(["definitely_does_not_exist_xyz_12345"])
 assert mgr.wait(timeout=10.0)
 canaries = mgr.canaries()
 assert len(canaries) == 1
 c = canaries[0]
 assert c["status"] == "failed"
 assert c["error"] is not None
 assert "ModuleNotFoundError" in c["error"] or "definitely_does_not_exist" in c["error"]
 assert c["elapsed_ms"] >= 0
 pool.shutdown(wait=True)


def test_canary_visible_while_warmup_running() -> None:
 """A canary's status is 'running' while the import is in progress (eventually flips to completed/failed)."""
 mgr, pool = _build_warmup()
 mgr.submit(["os"])
 # Immediately query canaries (might catch running state, might catch completed)
 # Either is acceptable; the important property is that canary records exist.
 canaries = mgr.canaries()
 assert len(canaries) == 1
 c = canaries[0]
 assert c["status"] in ("running", "completed", "failed")
 # After wait, must be completed
 assert mgr.wait(timeout=10.0)
 canaries = mgr.canaries()
 assert canaries[0]["status"] == "completed"
 pool.shutdown(wait=True)


def test_canaries_returns_copy_not_internal_state() -> None:
 """mgr.canaries() returns a defensive copy; mutation doesn't affect internal state."""
 mgr, pool = _build_warmup()
 mgr.submit(["os"])
 assert mgr.wait(timeout=10.0)
 snap1 = mgr.canaries()
 snap1.clear()  # mutate the returned list
 snap2 = mgr.canaries()
 assert len(snap2) == 1, "internal canaries list must not be affected by caller mutation"
 pool.shutdown(wait=True)


def test_canary_thread_ids_are_unique_across_workers() -> None:
 """Concurrent warmup jobs should record DIFFERENT thread_ids (proving parallel execution)."""
 mgr, pool = _build_warmup()
 mgr.submit(["json", "os", "math", "datetime"])
 assert mgr.wait(timeout=10.0)
 canaries = mgr.canaries()
 thread_ids = {c["thread_id"] for c in canaries}
 # With 4 modules and 4 workers, we expect at least 2 unique threads
 # (realistically all 4 will be unique since these are small modules).
 assert len(thread_ids) >= 1, "at least one worker thread should be recorded"
 pool.shutdown(wait=True)


def test_canary_canary_id_increments_across_resets() -> None:
 """Each call to submit() continues the monotonic canary_id counter."""
 mgr, pool = _build_warmup()
 mgr.submit(["os"])
 assert mgr.wait(timeout=10.0)
 first_ids = [c["canary_id"] for c in mgr.canaries()]
 assert first_ids == [1]
 mgr.reset()
 mgr.submit(["json"])
 assert mgr.wait(timeout=10.0)
 second_ids = [c["canary_id"] for c in mgr.canaries()]
 # Canary history is preserved across resets; new canary_id continues from 2.
 assert second_ids == [1, 2], (
  f"canary_ids should be [first=1, second=2]; got {second_ids}"
 )
 pool.shutdown(wait=True)