"""Shared fixtures: real captures for shape, fakes for behaviour.

Anything that must match an upstream (an agent snapshot, an engine's /metrics text, the NUT
wire protocol) is asserted against a verbatim capture in tests/fixtures/. Everything that
needs a *failure* — a dead host, a refused command, a counter reset — is a fake here.

The `live` marker is the bridge to real hardware: those tests dial the fleet, the engines,
or upsd, so they SKIP unless you pass `--live` and have set the env vars they read (see
tests/test_live_fleet.py). That keeps `uv run pytest` hermetic and offline while still
letting `uv run pytest -m live --live` catch an upstream that renamed something.
"""
from __future__ import annotations

import copy
import json
import sys
from pathlib import Path
from typing import Any

import pytest


def pytest_addoption(parser: pytest.Parser) -> None:
    parser.addoption(
        "--live",
        action="store_true",
        default=False,
        help="run tests marked `live` against the real fleet/engines/upsd (they skip otherwise)",
    )


def pytest_collection_modifyitems(config: pytest.Config, items: list[pytest.Item]) -> None:
    if config.getoption("--live"):
        return
    skip = pytest.mark.skip(reason="needs --live and a reachable target (see tests/test_live_fleet.py)")
    for item in items:
        if "live" in item.keywords:
            item.add_marker(skip)

ROOT = Path(__file__).resolve().parents[1]
SRC = ROOT / "src"
if str(SRC) not in sys.path:
    sys.path.insert(0, str(SRC))

from dashboards.rates import RateEstimator  # noqa: E402
from dashboards.sources.host import HostCollector, parse_host_snapshot  # noqa: E402
from dashboards.store import SampleStore  # noqa: E402

FIXTURES = Path(__file__).resolve().parent / "fixtures"


@pytest.fixture
def db(tmp_path: Path) -> Any:
    store = SampleStore(tmp_path / "t.sqlite3")
    try:
        yield store
    finally:
        store.close()


@pytest.fixture
def store(db: Any) -> Any:
    """Alias: some tests read better with `store`, others with `db`. Same object."""
    return db


@pytest.fixture
def agent_snapshot() -> dict[str, Any]:
    """A real driveripper snapshot (Threadripper + R9700, 48 logical CPUs)."""
    return json.loads((FIXTURES / "agent_driveripper.json").read_text())


@pytest.fixture
def agent_snapshots() -> dict[str, dict[str, Any]]:
    """Every captured host, keyed by name — fleet code paths need >1 host to mean anything."""
    out: dict[str, dict[str, Any]] = {}
    for path in sorted(FIXTURES.glob("agent_*.json")):
        out[path.stem.removeprefix("agent_")] = json.loads(path.read_text())
    return out


@pytest.fixture
def host_scrape() -> Any:
    """`host_scrape(snapshot, cpu_busy=10.0, mutate=None)` -> one parsed host payload.

    Two scrapes are needed before any rate exists (the agent reports counters; the
    dashboard owns the window), and the payload the API serves is the second one. `mutate`
    edits the snapshot before both scrapes so a test can put a value on a chosen side of
    `severity.THRESHOLDS`; `cpu_busy` sets the CPU percentage over the window directly.
    Driven from the real capture so a schema drift breaks here rather than in a browser.
    """
    def scrape(snapshot: dict[str, Any], *, name: str = "driveripper", cpu_busy: float = 10.0,
               mutate: Any = None) -> dict[str, Any]:
        snap = copy.deepcopy(snapshot)
        if mutate is not None:
            mutate(snap)
        collector = HostCollector(RateEstimator(span=60.0))
        parse_host_snapshot(name, snap, collector, now=1_000.0)
        second = copy.deepcopy(snap)
        second["ts"] = 1_010.0
        modes = second["cpu"]["modes"]
        # busy = (Δtotal - Δidle)/Δtotal, and iowait is left untouched so it rates at 0
        modes["total"] += 1_000.0
        modes["idle"] += 1_000.0 - (cpu_busy * 10.0)
        return parse_host_snapshot(name, second, collector, now=1_010.0).payload

    return scrape


@pytest.fixture
def metrics_text() -> Any:
    """metrics_text('gufo') / metrics_text('vllm') -> the captured exposition verbatim."""
    def load(engine: str) -> str:
        path = FIXTURES / f"metrics_{engine}.txt"
        if not path.exists():
            pytest.skip(f"missing fixture {path.name} — run scripts/capture-fixtures.sh --with-llm")
        return path.read_text()

    return load


@pytest.fixture
def rates() -> RateEstimator:
    return RateEstimator(span=10.0)