"""Tests for the read-only (W4) web dashboard app.

In-process only: routes call ``operations/`` + a backend injected via
FastAPI dependency override -- no real ``vmrun`` subprocess is ever
spawned. ``shutil.disk_usage``/``shutil.which`` are monkeypatched so no
real host state (disk, systemd) leaks into the assertions either.
"""

from __future__ import annotations

import shutil
from collections import namedtuple
from pathlib import Path
from typing import Any

import pytest
from fastapi.testclient import TestClient

import ci_orchestrator.web.app as app_module
from ci_orchestrator.backends.errors import BackendNotAvailable
from ci_orchestrator.backends.protocol import VmHandle
from ci_orchestrator.config import BackendConfig, CargoCacheConfig, Config, Paths
from ci_orchestrator.web.app import create_app, get_backend

_DiskUsage = namedtuple("_DiskUsage", ["total", "used", "free"])


def _fake_disk_usage(_path: Any) -> _DiskUsage:
    gb = 1024**3
    return _DiskUsage(total=100 * gb, used=40 * gb, free=60 * gb)


def _make_config(root: Path) -> Config:
    return Config(
        paths=Paths(
            root=root,
            templates=root / "templates",
            build_vms=root / "build-vms",
            artifacts=root / "artifacts",
            keys=root / "keys",
        ),
        backend=BackendConfig(),
        cargo_cache=CargoCacheConfig(
            enabled=True, root=root / "cache" / "cargo", retention_days=30
        ),
    )


class _FakeBackend:
    """Stub ``VmBackend`` -- proves no real ``vmrun`` is ever invoked."""

    def __init__(self, handles: list[VmHandle], ip: str | None = "192.168.79.201") -> None:
        self._handles = handles
        self._ip = ip
        self.list_running_calls = 0
        self.get_ip_calls = 0

    def list_running(self) -> list[VmHandle]:
        self.list_running_calls += 1
        return self._handles

    def get_ip(self, handle: VmHandle, timeout: float = 0.0) -> str | None:
        self.get_ip_calls += 1
        return self._ip


class _BoomBackend:
    """Backend whose ``list_running`` raises something other than ``BackendError``."""

    def list_running(self) -> list[VmHandle]:
        raise RuntimeError("boom")

    def get_ip(self, handle: VmHandle, timeout: float = 0.0) -> str | None:
        return None


def _quiet_host(monkeypatch: pytest.MonkeyPatch) -> None:
    """No real disk/systemctl calls from ``operations.host`` during a test."""
    monkeypatch.setattr(shutil, "disk_usage", _fake_disk_usage)
    monkeypatch.setattr(shutil, "which", lambda _name: None)


# ── /healthz ──────────────────────────────────────────────────────────────


def test_healthz_returns_ok(tmp_path: Path) -> None:
    app = create_app(_make_config(tmp_path))
    client = TestClient(app)

    resp = client.get("/healthz")

    assert resp.status_code == 200
    assert resp.json() == {"status": "ok"}


# ── / (dashboard) ────────────────────────────────────────────────────────


def test_dashboard_renders_all_four_cards(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    _quiet_host(monkeypatch)
    app = create_app(_make_config(tmp_path))
    app.dependency_overrides[get_backend] = lambda: _FakeBackend([])
    client = TestClient(app)

    resp = client.get("/")

    assert resp.status_code == 200
    for needle in ("Live VMs", "Cargo cache", "Disk", "Runners"):
        assert needle in resp.text


def test_dashboard_shows_backend_unavailable_notice_when_backend_is_none(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    _quiet_host(monkeypatch)
    app = create_app(_make_config(tmp_path))
    app.dependency_overrides[get_backend] = lambda: None
    client = TestClient(app)

    resp = client.get("/")

    assert resp.status_code == 200
    assert "unavailable" in resp.text.lower()


# ── /vms ──────────────────────────────────────────────────────────────────


def test_vms_route_renders_injected_vm_and_never_touches_real_vmrun(tmp_path: Path) -> None:
    vmx = tmp_path / "build-vms" / "job1" / "job1.vmx"
    fake = _FakeBackend([VmHandle(identifier=str(vmx), name="job1")])
    app = create_app(_make_config(tmp_path))
    app.dependency_overrides[get_backend] = lambda: fake
    client = TestClient(app)

    resp = client.get("/vms")

    assert resp.status_code == 200
    assert "job1" in resp.text
    assert fake.list_running_calls == 1


def test_vms_route_degrades_when_backend_is_none(tmp_path: Path) -> None:
    app = create_app(_make_config(tmp_path))
    app.dependency_overrides[get_backend] = lambda: None
    client = TestClient(app)

    resp = client.get("/vms")

    assert resp.status_code == 200
    assert "unavailable" in resp.text.lower()


def test_vms_route_degrades_on_unexpected_backend_error(tmp_path: Path) -> None:
    app = create_app(_make_config(tmp_path))
    app.dependency_overrides[get_backend] = lambda: _BoomBackend()
    client = TestClient(app)

    resp = client.get("/vms")

    assert resp.status_code == 200


def test_get_backend_degrades_to_none_when_vmrun_missing(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    def _raise(_config: Config) -> Any:
        raise BackendNotAvailable("vmrun not found")

    monkeypatch.setattr(app_module, "load_backend", _raise)
    app = create_app(_make_config(tmp_path))
    client = TestClient(app)

    resp = client.get("/vms")

    assert resp.status_code == 200
    assert "unavailable" in resp.text.lower()


# ── /cache ────────────────────────────────────────────────────────────────


def test_cache_route_renders_status(tmp_path: Path) -> None:
    app = create_app(_make_config(tmp_path))
    client = TestClient(app)

    resp = client.get("/cache")

    assert resp.status_code == 200
    assert "Cargo cache" in resp.text


def test_cache_route_degrades_when_operations_raises(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    def _boom(_config: Config) -> Any:
        raise RuntimeError("boom")

    monkeypatch.setattr(app_module, "cargo_cache_status", _boom)
    app = create_app(_make_config(tmp_path))
    client = TestClient(app)

    resp = client.get("/cache")

    assert resp.status_code == 200


# ── /host ─────────────────────────────────────────────────────────────────


def test_host_route_renders_disk_and_runner_status(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    _quiet_host(monkeypatch)
    app = create_app(_make_config(tmp_path))
    client = TestClient(app)

    resp = client.get("/host")

    assert resp.status_code == 200
    assert "Disk" in resp.text
    assert "Runners" in resp.text
    assert "act-runner.service" in resp.text
    assert "act-runner-rust.service" in resp.text


def test_host_route_degrades_when_disk_status_raises(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    def _boom(_path: Path) -> Any:
        raise RuntimeError("boom")

    monkeypatch.setattr(app_module, "disk_status", _boom)
    monkeypatch.setattr(shutil, "which", lambda _name: None)
    app = create_app(_make_config(tmp_path))
    client = TestClient(app)

    resp = client.get("/host")

    assert resp.status_code == 200


def test_host_route_degrades_when_runner_status_raises(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    def _boom(_names: list[str]) -> Any:
        raise RuntimeError("boom")

    _quiet_host(monkeypatch)
    monkeypatch.setattr(app_module, "runner_status", _boom)
    app = create_app(_make_config(tmp_path))
    client = TestClient(app)

    resp = client.get("/host")

    assert resp.status_code == 200


# ── static mount ─────────────────────────────────────────────────────────


def test_static_mount_serves_app_css(tmp_path: Path) -> None:
    app = create_app(_make_config(tmp_path))
    client = TestClient(app)

    resp = client.get("/static/app.css")

    assert resp.status_code == 200