"""run_scan service persistence, _background_scan lifecycle, stop/cancel."""
import uuid
from unittest.mock import AsyncMock, patch

import pytest
from httpx import AsyncClient
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.db.models import Node, PendingDevice, ScanRun
from app.services.scanner import _cancelled_runs, request_cancel, run_scan


@pytest.mark.asyncio
async def test_background_scan_marks_run_failed_on_exception(mem_db):
    """If run_scan() raises, the ScanRun must transition running → failed and the
    session rollback path must execute without a follow-on exception."""
    from app.api.routes.scan import _background_scan

    async with mem_db() as session:
        run = ScanRun(status="running", ranges=["10.0.0.0/24"])
        session.add(run)
        await session.commit()
        run_id = run.id

    with (
        patch("app.api.routes.scan.AsyncSessionLocal", mem_db),
        patch(
            "app.api.routes.scan.run_scan",
            new_callable=AsyncMock,
            side_effect=RuntimeError("boom"),
        ),
    ):
        await _background_scan(run_id, ["10.0.0.0/24"])

    async with mem_db() as session:
        refreshed = await session.get(ScanRun, run_id)
        assert refreshed is not None
        assert refreshed.status == "failed"


@pytest.mark.asyncio
async def test_background_scan_leaves_non_running_status_alone(mem_db):
    """If the run was already stopped/cancelled before run_scan failed, _background_scan
    must NOT overwrite that terminal status with 'failed'."""
    from app.api.routes.scan import _background_scan

    async with mem_db() as session:
        run = ScanRun(status="cancelled", ranges=["10.0.0.0/24"])
        session.add(run)
        await session.commit()
        run_id = run.id

    with (
        patch("app.api.routes.scan.AsyncSessionLocal", mem_db),
        patch(
            "app.api.routes.scan.run_scan",
            new_callable=AsyncMock,
            side_effect=RuntimeError("boom"),
        ),
    ):
        await _background_scan(run_id, ["10.0.0.0/24"])

    async with mem_db() as session:
        refreshed = await session.get(ScanRun, run_id)
        assert refreshed is not None
        assert refreshed.status == "cancelled"


@pytest.mark.asyncio
async def test_background_scan_success_path_invokes_run_scan(mem_db):
    from app.api.routes.scan import _background_scan

    async with mem_db() as session:
        run = ScanRun(status="running", ranges=["10.0.0.0/24"])
        session.add(run)
        await session.commit()
        run_id = run.id

    with (
        patch("app.api.routes.scan.AsyncSessionLocal", mem_db),
        patch("app.api.routes.scan.run_scan", new_callable=AsyncMock) as mock_run_scan,
    ):
        from app.services.scanner import DeepScanOptions
        await _background_scan(run_id, ["10.0.0.0/24"], DeepScanOptions())
        mock_run_scan.assert_awaited_once()


@pytest.mark.asyncio
async def test_list_runs_empty(client: AsyncClient, headers):
    res = await client.get("/api/v1/scan/runs", headers=headers)
    assert res.status_code == 200
    assert res.json() == []


# --- run_scan: re-scan updates existing pending devices ---

MOCK_HOST = {
    "ip": "192.168.1.50",
    "mac": "aa:bb:cc:dd:ee:ff",
    "hostname": "myhost.lan",
    "os": "Linux",
    "open_ports": [{"port": 8096, "protocol": "tcp", "banner": "Jellyfin"}],
}


@pytest.mark.asyncio
async def test_run_scan_creates_new_pending_device(db_session: AsyncSession):
    run_id = str(uuid.uuid4())
    run = ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"])
    db_session.add(run)
    await db_session.commit()

    with (
        patch("app.services.scanner._nmap_scan", return_value=[MOCK_HOST]),
        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
    ):
        await run_scan(["192.168.1.0/24"], db_session, run_id)

    result = await db_session.execute(
        select(PendingDevice).where(PendingDevice.ip == "192.168.1.50")
    )
    device = result.scalar_one_or_none()
    assert device is not None
    assert device.hostname == "myhost.lan"
    assert any(s["port"] == 8096 for s in device.services)
    assert device.suggested_type == "server"


@pytest.mark.asyncio
async def test_run_scan_keeps_stale_pending_for_canvas_nodes(db_session: AsyncSession):
    """Pending devices whose IP is already on a canvas are NOT purged — they stay
    in the inventory and are surfaced with an "In N canvas" badge."""
    node = Node(
        id=str(uuid.uuid4()),
        label="Existing Server",
        type="server",
        ip="192.168.1.50",
        status="online",
        services=[],
        pos_x=0.0,
        pos_y=0.0,
    )
    stale = PendingDevice(
        id=str(uuid.uuid4()),
        ip="192.168.1.50",
        mac=None,
        hostname=None,
        os=None,
        services=[],
        suggested_type="generic",
        status="pending",
    )
    db_session.add(node)
    db_session.add(stale)
    await db_session.commit()

    run_id = str(uuid.uuid4())
    run = ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"])
    db_session.add(run)
    await db_session.commit()

    with (
        patch("app.services.scanner._nmap_scan", return_value=[]),
        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
    ):
        await run_scan(["192.168.1.0/24"], db_session, run_id)

    result = await db_session.execute(
        select(PendingDevice).where(PendingDevice.ip == "192.168.1.50")
    )
    assert result.scalar_one_or_none() is not None


@pytest.mark.asyncio
async def test_run_scan_records_ip_already_in_canvas(db_session: AsyncSession):
    """A scanned IP that already exists as a canvas Node still produces a pending
    device (no longer suppressed)."""
    node = Node(
        id=str(uuid.uuid4()),
        label="Existing Server",
        type="server",
        ip="192.168.1.50",
        status="online",
        services=[],
        pos_x=0.0,
        pos_y=0.0,
    )
    db_session.add(node)
    await db_session.commit()

    run_id = str(uuid.uuid4())
    run = ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"])
    db_session.add(run)
    await db_session.commit()

    with (
        patch("app.services.scanner._nmap_scan", return_value=[MOCK_HOST]),
        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
    ):
        await run_scan(["192.168.1.0/24"], db_session, run_id)

    result = await db_session.execute(
        select(PendingDevice).where(PendingDevice.ip == "192.168.1.50")
    )
    device = result.scalar_one_or_none()
    assert device is not None
    assert device.status == "pending"


@pytest.mark.asyncio
async def test_run_scan_refreshes_approved_device_without_duplicating(db_session: AsyncSession):
    """Re-scanning an already-approved device updates its row in place instead of
    spawning a fresh pending duplicate, and keeps it approved."""
    approved = PendingDevice(
        id=str(uuid.uuid4()), ip="192.168.1.50", mac=None, hostname="old",
        os=None, services=[], suggested_type="server", status="approved",
    )
    db_session.add(approved)
    run_id = str(uuid.uuid4())
    db_session.add(ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"]))
    await db_session.commit()

    with (
        patch("app.services.scanner._nmap_scan", return_value=[MOCK_HOST]),
        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
    ):
        await run_scan(["192.168.1.0/24"], db_session, run_id)

    rows = (await db_session.execute(
        select(PendingDevice).where(PendingDevice.ip == "192.168.1.50")
    )).scalars().all()
    assert len(rows) == 1
    assert rows[0].status == "approved"
    assert rows[0].hostname == "myhost.lan"  # refreshed from the scan


@pytest.mark.asyncio
async def test_run_scan_collapses_existing_duplicate_rows(db_session: AsyncSession):
    """Pre-existing duplicate inventory rows for one IP are collapsed to a single
    row at scan start, even if the device is not re-discovered."""
    for status in ("approved", "pending", "pending"):
        db_session.add(PendingDevice(
            id=str(uuid.uuid4()), ip="192.168.1.77", mac=None, hostname=None,
            os=None, services=[], suggested_type="server", status=status,
        ))
    run_id = str(uuid.uuid4())
    db_session.add(ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"]))
    await db_session.commit()

    with (
        patch("app.services.scanner._nmap_scan", return_value=[]),
        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
    ):
        await run_scan(["192.168.1.0/24"], db_session, run_id)

    rows = (await db_session.execute(
        select(PendingDevice).where(PendingDevice.ip == "192.168.1.77")
    )).scalars().all()
    assert len(rows) == 1
    assert rows[0].status == "approved"  # approved row is the one kept


@pytest.mark.asyncio
async def test_run_scan_skips_hidden_device(db_session: AsyncSession):
    """Devices previously hidden by the user must not re-appear in pending on re-scan."""
    hidden = PendingDevice(
        id=str(uuid.uuid4()),
        ip="192.168.1.50",
        mac=None,
        hostname=None,
        os=None,
        services=[],
        suggested_type="generic",
        status="hidden",
    )
    db_session.add(hidden)
    await db_session.commit()

    run_id = str(uuid.uuid4())
    run = ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"])
    db_session.add(run)
    await db_session.commit()

    with (
        patch("app.services.scanner._nmap_scan", return_value=[MOCK_HOST]),
        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
    ):
        await run_scan(["192.168.1.0/24"], db_session, run_id)

    result = await db_session.execute(
        select(PendingDevice).where(
            PendingDevice.ip == "192.168.1.50",
            PendingDevice.status == "pending",
        )
    )
    assert result.scalar_one_or_none() is None


@pytest.mark.asyncio
async def test_stop_scan_requires_auth(client: AsyncClient):
    res = await client.post("/api/v1/scan/fake-id/stop")
    assert res.status_code == 401


@pytest.mark.asyncio
async def test_stop_scan_not_found(client: AsyncClient, headers):
    import uuid as _uuid
    res = await client.post(f"/api/v1/scan/{_uuid.uuid4()}/stop", headers=headers)
    assert res.status_code == 404


@pytest.mark.asyncio
async def test_stop_scan_not_running(client: AsyncClient, headers, db_session: AsyncSession):
    run = ScanRun(id=str(uuid.uuid4()), status="done", ranges=["192.168.1.0/24"])
    db_session.add(run)
    await db_session.commit()

    res = await client.post(f"/api/v1/scan/{run.id}/stop", headers=headers)
    assert res.status_code == 409


@pytest.mark.asyncio
async def test_stop_scan_success(client: AsyncClient, headers, db_session: AsyncSession):
    run = ScanRun(id=str(uuid.uuid4()), status="running", ranges=["192.168.1.0/24"])
    db_session.add(run)
    await db_session.commit()

    res = await client.post(f"/api/v1/scan/{run.id}/stop", headers=headers)
    assert res.status_code == 200
    assert res.json() == {"stopping": True}
    # run_id added to cancel set
    assert run.id in _cancelled_runs
    # status flipped eagerly so the UI reacts without waiting for a checkpoint
    await db_session.refresh(run)
    assert run.status == "cancelled"
    assert run.finished_at is not None
    # cleanup for other tests
    _cancelled_runs.discard(run.id)


@pytest.mark.asyncio
async def test_run_scan_cancelled_marks_status(db_session: AsyncSession):
    """When cancel is requested before the scan starts, status becomes 'cancelled'."""
    run_id = str(uuid.uuid4())
    run = ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"])
    db_session.add(run)
    await db_session.commit()

    request_cancel(run_id)

    with (
        patch("app.services.scanner._nmap_scan", return_value=[MOCK_HOST]) as mock_nmap,
        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
    ):
        await run_scan(["192.168.1.0/24"], db_session, run_id)
        # nmap should not have been called — cancelled before first range
        mock_nmap.assert_not_called()

    await db_session.refresh(run)
    assert run.status == "cancelled"
    assert run.finished_at is not None


@pytest.mark.asyncio
async def test_run_scan_cancelled_mid_scan_skips_remaining_cidrs(db_session: AsyncSession):
    """Cancel flag set after first CIDR is started prevents processing of the second CIDR."""
    run_id = str(uuid.uuid4())
    run = ScanRun(id=run_id, status="running", ranges=["10.0.0.0/24", "10.0.1.0/24"])
    db_session.add(run)
    await db_session.commit()

    call_count = 0

    def nmap_side_effect(target: str, port_spec: str | None = None, run_id: str | None = None):
        nonlocal call_count
        call_count += 1
        # Signal cancellation after the first CIDR scan completes
        if call_count == 1:
            request_cancel(run_id)
        return []

    with (
        patch("app.services.scanner._nmap_scan", side_effect=nmap_side_effect),
        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
    ):
        await run_scan(["10.0.0.0/24", "10.0.1.0/24"], db_session, run_id)

    assert call_count == 1  # second CIDR was skipped
    await db_session.refresh(run)
    assert run.status == "cancelled"


@pytest.mark.asyncio
async def test_run_scan_updates_existing_pending_device(db_session: AsyncSession):
    """Re-scanning the same IP updates services instead of creating a duplicate."""
    # Pre-existing pending device with no services
    existing = PendingDevice(
        id=str(uuid.uuid4()),
        ip="192.168.1.50",
        mac=None,
        hostname=None,
        os=None,
        services=[],
        suggested_type="generic",
        status="pending",
    )
    db_session.add(existing)
    await db_session.commit()

    run_id = str(uuid.uuid4())
    run = ScanRun(id=run_id, status="running", ranges=["192.168.1.0/24"])
    db_session.add(run)
    await db_session.commit()

    with (
        patch("app.services.scanner._nmap_scan", return_value=[MOCK_HOST]),
        patch("app.api.routes.status.broadcast_scan_update", new_callable=AsyncMock),
    ):
        await run_scan(["192.168.1.0/24"], db_session, run_id)

    # Should still be only one device
    result = await db_session.execute(
        select(PendingDevice).where(PendingDevice.ip == "192.168.1.50")
    )
    devices = list(result.scalars().all())
    assert len(devices) == 1
    device = devices[0]
    # Services and hostname should be updated
    assert device.hostname == "myhost.lan"
    assert any(s["port"] == 8096 for s in device.services)