"""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.operations.cache import CacheStatus
from ci_orchestrator.operations.host import DiskStatus, RunnerStatus
from ci_orchestrator.operations.vms import LiveVm
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_runners_route_renders_runner_status(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    # Stage E: the /runners partial carries only the runner statuses -- the
    # disk card was folded into the status-header Disk tile.
    _quiet_host(monkeypatch)
    app = create_app(_make_config(tmp_path))
    client = TestClient(app)

    resp = client.get("/runners")

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


def test_runners_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("/runners")

    assert resp.status_code == 200


def test_runners_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("/runners")

    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


# ── _health_summary (A3) ─────────────────────────────────────────────────

_ACTIVE_RUNNER = RunnerStatus(name="act-runner.service", active=True, sub_state="running")
_DEAD_RUNNER = RunnerStatus(name="act-runner-rust.service", active=False, sub_state="dead")
_LIVE_VM = LiveVm(
    name="job1", vmx="/x/job1.vmx", ip="10.0.0.5", guest_os="ubuntu-64",
    uptime_sec=120, is_orphan=False,
)
_ORPHAN_VM = LiveVm(
    name="job2", vmx="/x/job2.vmx", ip=None, guest_os="ubuntu-64",
    uptime_sec=99999, is_orphan=True,
)
_CACHE = CacheStatus(
    root=Path("/cache"), total_bytes=1024, entry_count=1, oldest_age_days=1, retention_days=30
)


def test_health_summary_backend_unavailable_is_vm_unknown() -> None:
    health = app_module._health_summary(
        [], backend_available=False, cache=None, disk=None, runners=[]
    )
    assert health.vm_class == "tile-unknown"
    assert health.vm_label == "unknown"


def test_health_summary_orphan_present_is_vm_warn() -> None:
    health = app_module._health_summary(
        [_LIVE_VM, _ORPHAN_VM], backend_available=True, cache=None, disk=None, runners=[]
    )
    assert health.vm_count == 2
    assert health.orphan_count == 1
    assert health.vm_class == "tile-warn"
    assert health.vm_label == "orphaned"


def test_health_summary_no_orphans_is_vm_ok() -> None:
    health = app_module._health_summary(
        [_LIVE_VM], backend_available=True, cache=None, disk=None, runners=[]
    )
    assert health.vm_class == "tile-ok"
    assert health.vm_label == "ok"


def test_health_summary_no_runners_is_unknown() -> None:
    health = app_module._health_summary(
        [], backend_available=True, cache=None, disk=None, runners=[]
    )
    assert health.runners_total == 0
    assert health.runner_class == "tile-unknown"


def test_health_summary_all_runners_active_is_ok() -> None:
    health = app_module._health_summary(
        [], backend_available=True, cache=None, disk=None, runners=[_ACTIVE_RUNNER]
    )
    assert health.runners_active == 1
    assert health.runners_total == 1
    assert health.runner_class == "tile-ok"


def test_health_summary_a_down_runner_is_bad() -> None:
    health = app_module._health_summary(
        [], backend_available=True, cache=None, disk=None,
        runners=[_ACTIVE_RUNNER, _DEAD_RUNNER],
    )
    assert health.runners_active == 1
    assert health.runners_total == 2
    assert health.runner_class == "tile-bad"
    assert health.runner_label == "down"


def test_health_summary_disk_none_is_unknown() -> None:
    health = app_module._health_summary(
        [], backend_available=True, cache=None, disk=None, runners=[]
    )
    assert health.disk_used_pct is None
    assert health.disk_class == "tile-unknown"


def test_health_summary_disk_above_critical_is_bad() -> None:
    disk = DiskStatus(path=Path("/"), total_gb=100.0, free_gb=5.0, used_pct=90.0)
    health = app_module._health_summary(
        [], backend_available=True, cache=None, disk=disk, runners=[]
    )
    assert health.disk_class == "tile-bad"
    assert health.disk_label == "critical"


def test_health_summary_disk_above_elevated_is_warn() -> None:
    disk = DiskStatus(path=Path("/"), total_gb=100.0, free_gb=25.0, used_pct=75.0)
    health = app_module._health_summary(
        [], backend_available=True, cache=None, disk=disk, runners=[]
    )
    assert health.disk_class == "tile-warn"
    assert health.disk_label == "elevated"


def test_health_summary_disk_healthy_is_ok() -> None:
    disk = DiskStatus(path=Path("/"), total_gb=100.0, free_gb=60.0, used_pct=40.0)
    health = app_module._health_summary(
        [], backend_available=True, cache=None, disk=disk, runners=[]
    )
    assert health.disk_class == "tile-ok"
    assert health.disk_label == "ok"


def test_health_summary_cache_none_is_unknown() -> None:
    health = app_module._health_summary(
        [], backend_available=True, cache=None, disk=None, runners=[]
    )
    assert health.cache_bytes is None
    assert health.cache_class == "tile-unknown"


def test_health_summary_cache_present_is_ok() -> None:
    health = app_module._health_summary(
        [], backend_available=True, cache=_CACHE, disk=None, runners=[]
    )
    assert health.cache_bytes == 1024
    assert health.cache_class == "tile-ok"


def test_dashboard_includes_status_header_tiles(
    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
    assert 'id="status-header"' in resp.text