"""The expectations grammar is undocumented, so the examples are the spec."""

import xml.etree.ElementTree as ET

import pytest

from mcbebop.protocol import xml_index
from mcbebop.protocol.expectations import expectations_for, parse_expectation_text
from mcbebop.protocol.types import Direction


def test_every_block_is_parsed_and_only_sendable_commands_carry_one():
    with_expectations = [c for c in xml_index.all_commands() if c.expectations]
    assert len(with_expectations) == 82
    assert all(c.direction is Direction.TO_DRONE for c in with_expectations)


def test_delayed_blocks():
    delayed = [c.full_name for c in xml_index.all_commands() if any(e.delayed for e in c.expectations)]
    assert sorted(delayed) == ["ardrone3.Network.WifiScan", "ardrone3.Network.WifiAuthChannel"][::-1]


def test_bare_reference():
    (expectation,) = parse_expectation_text("#0-3-0")
    assert expectation.ids == (0, 3, 0)
    assert expectation.fields == {}
    assert expectation.alternatives == ()
    assert expectation.delayed is False


def test_this_dot_argname_means_the_drone_echoes_what_was_sent():
    (expectation,) = xml_index.get("common.Settings.ProductName").expectations
    assert expectation.ids == (0, 3, 2)
    assert expectation.fields == {"name": "this.name"}


def test_whitespace_separated_references_are_all_expected():
    expectations = xml_index.get("common.Settings.AutoCountry").expectations
    assert len(expectations) == 2
    assert expectations[0].ids == (0, 3, 7)
    assert expectations[0].fields == {"automatic": "this.automatic"}
    assert expectations[1].ids == (0, 3, 6)
    assert all(e.alternatives == () for e in expectations)


def test_pipe_prefixed_references_are_alternatives():
    (expectation,) = xml_index.get("ardrone3.Piloting.NavigateHome").expectations
    assert expectation.ids == (1, 4, 3)
    assert expectation.fields == {"state": "inProgress", "reason": "userRequest"}
    assert len(expectation.alternatives) == 2
    assert [a.fields["state"] for a in expectation.alternatives] == ["pending", "available"]
    assert all(a.ids == (1, 4, 3) for a in expectation.alternatives)


def test_alternatives_can_name_different_commands():
    # StopPilotedPOI is confirmed by whichever POI event version is in play.
    (expectation,) = xml_index.get("ardrone3.Piloting.StopPilotedPOI").expectations
    assert expectation.ids == (1, 4, 14)
    assert [a.ids for a in expectation.alternatives] == [(1, 4, 22)]


def test_literal_enum_member_values():
    (expectation,) = xml_index.get("ardrone3.Piloting.StartPilotedPOI").expectations
    assert expectation.fields["status"] == "RUNNING"
    assert expectation.fields["latitude"] == "this.latitude"
    assert expectation.alternatives[0].fields["status"] == "PENDING"


def test_takeoff_expects_two_states_not_one_of_two():
    expectations = xml_index.get("ardrone3.Piloting.TakeOff").expectations
    assert [e.fields["state"] for e in expectations] == ["motor_ramping", "takingoff"]


def test_delayed_flag_reaches_the_alternatives_too():
    parsed = parse_expectation_text("#1-14-0 |#1-14-1", delayed=True)
    assert parsed[0].delayed is True
    assert parsed[0].alternatives[0].delayed is True


def test_spaced_pipe_still_parses():
    (expectation,) = parse_expectation_text("#0-1-2 | #0-1-3")
    assert [a.ids for a in expectation.alternatives] == [(0, 1, 3)]


def test_empty_block_is_empty_not_an_error():
    assert parse_expectation_text("\n\t\t\t") == ()


def test_leading_alternative_is_rejected():
    with pytest.raises(ValueError, match="starts with an alternative"):
        parse_expectation_text("|#0-1-2")


def test_text_without_a_reference_is_rejected():
    with pytest.raises(ValueError, match="no #p-c-m reference"):
        parse_expectation_text("ProductNameChanged")


def test_malformed_field_is_rejected():
    with pytest.raises(ValueError, match="is not 'name: value'"):
        parse_expectation_text("#0-3-2(name)")


def test_unknown_expectations_child_is_rejected():
    cmd = ET.fromstring(
        "<cmd name='X' id='0'><expectations><eventually>#0-0-0</eventually></expectations></cmd>"
    )
    with pytest.raises(ValueError, match="unknown expectations child"):
        expectations_for(cmd)


def test_commands_without_a_block_have_an_empty_tuple():
    assert xml_index.get("ardrone3.Piloting.PCMD").expectations == ()