"""Tests for _shared.heartbeat — Task A1."""
import json
import sys
from pathlib import Path

import pytest

# Make `_shared` importable (same pattern as test_reliable_queue.py)
sys.path.insert(0, str(Path(__file__).resolve().parent.parent.parent))

from _shared.heartbeat import WorkerStats, build_payload, render_state


def test_build_payload_has_contract_fields():
    s = WorkerStats(); s.jobs_done = 3; s.last_job_at = "2026-06-29T00:00:00Z"
    payload = json.loads(build_payload("image-render", "render", "idle", s))
    assert payload["name"] == "image-render"
    assert payload["kind"] == "render"
    assert payload["state"] == "idle"
    assert payload["jobs_done"] == 3
    assert payload["last_job_at"] == "2026-06-29T00:00:00Z"
    assert payload["ts"].endswith("Z")


def test_build_payload_merges_extra():
    payload = json.loads(build_payload("task-watcher", "watcher", "free", WorkerStats(), extra={"mode": "free"}))
    assert payload["mode"] == "free"


class _FakeRedis:
    def __init__(self, paused): self._paused = paused
    async def get(self, key): return b"1" if self._paused else None


@pytest.mark.asyncio
async def test_render_state_paused_overrides_busy():
    s = WorkerStats(); s.busy = True
    assert await render_state(_FakeRedis(paused=True), s) == "paused"


@pytest.mark.asyncio
async def test_render_state_busy_then_idle():
    s = WorkerStats(); s.busy = True
    assert await render_state(_FakeRedis(paused=False), s) == "busy"
    s.busy = False
    assert await render_state(_FakeRedis(paused=False), s) == "idle"