"""Textual pilot tests for cv4pve_tui.app; spec: docs/plans/guest-tui-mvp.md ("UI contract").

All cli functions are monkeypatched: cv4pve-cli is never executed.
"""

import subprocess
import threading

import pytest
from textual.screen import ModalScreen
from textual.widgets import Button, DataTable, Input, Select, Static

from cv4pve_tui import cli
from cv4pve_tui.app import ConfirmScreen, EditScreen, GuestApp

VM = {"vmid": 108, "name": "docker", "node": "mainframe", "type": "qemu", "status": "running",
      "maxcpu": 4, "maxmem": 8192 * 2**20, "maxdisk": 10 * 2**30}  # fmt: skip
CT = {"vmid": 100, "name": "backrest", "node": "mainframe", "type": "lxc", "status": "stopped",
      "maxcpu": 1, "maxmem": 512 * 2**20, "maxdisk": 8 * 2**30}  # fmt: skip


class Fake:
    """Recorder standing in for the cli module functions the app calls."""

    def __init__(self):
        self.guests = [VM, CT]
        self.pending = []
        self.disk_map = {"scsi0": "10G"}
        self.list_calls = 0
        self.actions, self.sets, self.resizes, self.pending_calls = [], [], [], []
        self.action_error = None
        self.action_hook = None
        self.live_status, self.status_calls = {}, []

    def list_guests(self):
        self.list_calls += 1
        return list(self.guests)

    def guest_config(self, guest):
        return {"cores": guest["maxcpu"]}

    def disks(self, config, kind):
        return dict(self.disk_map)

    def action(self, name, guest):
        self.actions.append((name, guest["vmid"]))
        if self.action_hook:
            self.action_hook()
        if self.action_error:
            raise self.action_error

    def set_resources(self, guest, cores=None, memory_mb=None):
        given = {"cores": cores, "memory_mb": memory_mb}
        self.sets.append({k: v for k, v in given.items() if v is not None})

    def resize_disk(self, guest, disk, grow_gb):
        self.resizes.append((guest["vmid"], disk, grow_gb))

    def pending_keys(self, guest):
        self.pending_calls.append(guest["vmid"])
        return list(self.pending)

    def status(self, guest):
        self.status_calls.append(guest["vmid"])
        return self.live_status.get(guest["vmid"], guest["status"])


@pytest.fixture
def fake(monkeypatch):
    f = Fake()
    for name in ("list_guests", "guest_config", "disks", "action", "set_resources",
                 "resize_disk", "pending_keys", "status"):  # fmt: skip
        monkeypatch.setattr(cli, name, getattr(f, name))
    return f


def make_app():
    app = GuestApp()
    app.seen = []  # (message, severity) of every notify
    original = app.notify

    def spy(message, **kwargs):
        app.seen.append((str(message), kwargs.get("severity", "information")))
        return original(message, **kwargs)

    app.notify = spy
    return app


async def settle(app, pilot):
    await pilot.pause()
    await app.workers.wait_for_complete()
    await pilot.pause()


def text_of(screen):
    return " ".join(str(w.render()) for w in screen.query(Static))


def errors(app):
    return [m for m, sev in app.seen if sev == "error"]


async def press_button(app, pilot, selector):
    app.screen.query_one(selector, Button).press()
    await settle(app, pilot)


# --- table ------------------------------------------------------------------


async def test_table_loads_one_row_per_guest_in_list_order(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        table = app.query_one("#guests", DataTable)
        assert table.row_count == 2
        assert [k.value for k in table.rows] == ["108", "100"]
        cells = [str(c) for c in table.get_row("108")]
        assert "docker" in cells and "mainframe" in cells and "running" in cells
        assert "8192" in cells  # memory in MiB


async def test_refresh_key_reloads_guests(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        before = fake.list_calls
        fake.guests = [CT]
        await pilot.press("g")
        await settle(app, pilot)
        assert fake.list_calls == before + 1
        assert app.query_one("#guests", DataTable).row_count == 1


# --- lifecycle actions ------------------------------------------------------


async def test_start_runs_without_confirm_and_refreshes_table(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        before = fake.list_calls
        await pilot.press("s")
        await settle(app, pilot)
        assert fake.actions == [("start", 108)]
        assert not isinstance(app.screen, ModalScreen)
        assert fake.list_calls > before


async def test_action_targets_the_cursor_row(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        await pilot.press("down", "s")
        await settle(app, pilot)
        assert fake.actions == [("start", 100)]


@pytest.mark.parametrize(
    "key,name", [("S", "shutdown"), ("x", "stop"), ("r", "reboot")]
)
async def test_confirmed_action_calls_cli_only_after_yes(fake, key, name):
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        await pilot.press(key)
        await pilot.pause()
        assert isinstance(app.screen, ConfirmScreen)
        assert "docker" in text_of(app.screen) and "108" in text_of(app.screen)
        assert fake.actions == []
        await press_button(app, pilot, "#yes")
        assert fake.actions == [(name, 108)]


@pytest.mark.parametrize("key", ["S", "x", "r"])
async def test_declined_action_does_not_call_cli(fake, key):
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        await pilot.press(key)
        await pilot.pause()
        await press_button(app, pilot, "#no")
        assert fake.actions == []
        assert not isinstance(app.screen, ModalScreen)


async def test_stop_confirm_says_hard_power_off(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        await pilot.press("x")
        await pilot.pause()
        assert "hard power-off" in text_of(app.screen).lower()


@pytest.mark.parametrize("key", ["s", "S", "x", "r", "e"])
async def test_keys_on_empty_table_do_nothing(fake, key):
    fake.guests = []
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        await pilot.press(key)
        await settle(app, pilot)
        assert fake.actions == [] and fake.sets == [] and fake.resizes == []
        assert not isinstance(app.screen, ModalScreen)


async def test_cli_error_is_notified_with_summary(fake, monkeypatch):
    with monkeypatch.context() as m:  # build a real CliError through cli.run
        m.setattr(cli.subprocess, "run", lambda argv, **kw: subprocess.CompletedProcess(
            argv, 5, "UPID:mainframe:0:0:0:qmstart:108:root@pam:\nstart failed: no quorum\n", ""))  # fmt: skip
        with pytest.raises(cli.CliError) as exc:
            cli.run("do", "start")
    fake.action_error = exc.value
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        await pilot.press("s")
        await settle(app, pilot)
        assert any(exc.value.summary in m for m in errors(app))
        assert not any("UPID" in m for m in errors(app))


async def test_busy_guest_refuses_second_action(fake):
    started, release = threading.Event(), threading.Event()
    fake.action_hook = lambda: (started.set(), release.wait(10))
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        try:
            await pilot.press("s")
            for _ in range(200):
                if started.is_set():
                    break
                await pilot.pause(0.01)
            assert started.is_set()
            assert app.seen, "a working notice is expected while the action runs"
            await pilot.press("s")
            await pilot.pause()
            assert fake.actions == [("start", 108)]
        finally:
            release.set()
        await settle(app, pilot)
        assert fake.actions == [("start", 108)]


# --- edit flow --------------------------------------------------------------


async def open_edit(app, pilot):
    await settle(app, pilot)
    await pilot.press("e")
    await settle(app, pilot)
    assert isinstance(app.screen, EditScreen)


def fill(app, **values):
    for key, value in values.items():
        w = app.screen.query_one(f"#{key}", Select if key == "disk" else Input)
        w.value = value


async def test_edit_applies_only_given_fields_as_ints(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        fill(app, cores="8")
        await press_button(app, pilot, "#apply")
        assert fake.sets == [{"cores": 8}]
        await pilot.press("e")
        await settle(app, pilot)
        fill(app, cores="2", memory="4096")
        await press_button(app, pilot, "#apply")
        assert fake.sets[-1] == {"cores": 2, "memory_mb": 4096}
        assert all(isinstance(v, int) for v in fake.sets[-1].values())


@pytest.mark.parametrize("field", ["cores", "memory"])
@pytest.mark.parametrize("bad", ["abc", "0", "-4", "2.5"])
async def test_edit_invalid_resource_input_errors_without_cli_call(fake, field, bad):
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        fill(app, **{field: bad})
        await press_button(app, pilot, "#apply")
        assert errors(app)
        assert fake.sets == [] and fake.resizes == []


@pytest.mark.parametrize("bad", ["abc", "0", "-1"])
async def test_edit_invalid_grow_errors_without_cli_call(fake, bad):
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        fill(app, disk="scsi0", grow=bad)
        await press_button(app, pilot, "#apply")
        assert errors(app)
        assert fake.resizes == []


async def test_edit_with_empty_fields_changes_nothing(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        await press_button(app, pilot, "#apply")
        assert fake.sets == [] and fake.resizes == []


async def test_edit_cancel_changes_nothing(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        fill(app, cores="8")
        await press_button(app, pilot, "#cancel")
        assert fake.sets == [] and fake.resizes == []
        assert not isinstance(app.screen, ModalScreen)


async def test_grow_needs_confirm_then_resizes(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        fill(app, disk="scsi0", grow="5")
        await press_button(app, pilot, "#apply")
        assert isinstance(app.screen, ConfirmScreen)
        assert fake.resizes == []
        await press_button(app, pilot, "#yes")
        assert fake.resizes == [(108, "scsi0", 5)]


async def test_grow_declined_does_not_resize(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        fill(app, disk="scsi0", grow="5")
        await press_button(app, pilot, "#apply")
        await press_button(app, pilot, "#no")
        assert fake.resizes == []


@pytest.mark.parametrize(
    "pending,expect_notice", [(["memory"], True), (["cores"], True), ([], False)]
)
async def test_pending_cores_or_memory_notifies_reboot(fake, pending, expect_notice):
    fake.pending = pending
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        fill(app, memory="4096")
        await press_button(app, pilot, "#apply")
        assert fake.pending_calls == [108]
        assert any("reboot" in m.lower() for m, _ in app.seen) is expect_notice


# --- review findings: robustness --------------------------------------------


async def test_guest_without_size_fields_still_listed(fake):
    # e.g. a guest on an unreachable node: the API omits maxcpu/maxmem/maxdisk
    fake.guests = [
        {
            "vmid": 999,
            "name": "ghost",
            "node": "down",
            "type": "qemu",
            "status": "unknown",
        }
    ]
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        assert app.query_one("#guests", DataTable).row_count == 1


async def test_unexpected_error_in_action_is_notified_not_fatal(fake):
    fake.action_error = KeyError("key")
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        await pilot.press("s")
        await settle(app, pilot)
        assert errors(app)
        assert app.is_running and app.busy == set()


async def test_unexpected_error_in_listing_is_notified_not_fatal(fake, monkeypatch):
    def broken():
        raise ValueError("bad json")

    monkeypatch.setattr(cli, "list_guests", broken)
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        assert errors(app) and app.is_running


async def test_pending_check_failure_does_not_skip_confirmed_grow(fake, monkeypatch):
    def broken(guest):
        raise cli.CliError("Error: boom")

    monkeypatch.setattr(cli, "pending_keys", broken)
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        fill(app, memory="4096", disk="scsi0", grow="5")
        await press_button(app, pilot, "#apply")
        await press_button(app, pilot, "#yes")
        assert fake.sets == [{"memory_mb": 4096}]
        assert fake.resizes == [(108, "scsi0", 5)]


async def test_declining_grow_cancels_whole_edit(fake):
    app = make_app()
    async with app.run_test() as pilot:
        await open_edit(app, pilot)
        fill(app, cores="8", disk="scsi0", grow="5")
        await press_button(app, pilot, "#apply")
        await press_button(app, pilot, "#no")
        assert fake.sets == [] and fake.resizes == []


@pytest.mark.parametrize("key", ["S", "e"])
async def test_escape_closes_modal_without_cli_call(fake, key):
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        await pilot.press(key)
        await settle(app, pilot)
        assert isinstance(app.screen, ModalScreen)
        await pilot.press("escape")
        await settle(app, pilot)
        assert not isinstance(app.screen, ModalScreen)
        assert fake.actions == [] and fake.sets == []


async def test_table_shows_live_status_after_action_not_lagging_list(fake):
    # /cluster/resources lags a few seconds behind; the acted-on guest must show live status
    app = make_app()
    async with app.run_test() as pilot:
        await settle(app, pilot)
        fake.live_status = {108: "stopped"}  # list_guests still says "running"
        await pilot.press("S")
        await settle(app, pilot)
        await press_button(app, pilot, "#yes")
        assert fake.status_calls == [108]
        assert "stopped" in [
            str(c) for c in app.query_one("#guests", DataTable).get_row("108")
        ]