"""Scope evaluation for the All PCs policy target.

These are pure unit tests: policyscope has no db or Flask dependency, so the
whole grammar can be exercised with plain dicts. build_endpoint_context needs
only duck-typed stand-ins for a Computer row.
"""
import pytest

from plugins.computers.services.policyresolver import build_endpoint_context
from plugins.computers.services.policyscope import (
    ScopeError,
    evaluate_scope,
    validate_scope,
)


class FakeComputerType:
    def __init__(self, icon):
        self.icon = icon


class FakeComputer:
    """Minimal stand-in for a Computer row, no db required."""

    def __init__(self, computertypeid=None, icon=None, installedapps=()):
        self.computertypeid = computertypeid
        self.computertype = FakeComputerType(icon) if icon is not None else None
        self.installedapps = installedapps


def test_allpcs_is_a_valid_scope_node():
    validate_scope({'type': 'allpcs'})


def test_allpcs_matches_an_ordinary_pc():
    context = {'computertypeid': 1, 'appids': set(), 'isserver': False}
    assert evaluate_scope({'type': 'allpcs'}, context) is True


def test_allpcs_does_not_match_a_server():
    """The whole point of the option: servers are excluded."""
    context = {'computertypeid': 4, 'appids': set(), 'isserver': True}
    assert evaluate_scope({'type': 'allpcs'}, context) is False


def test_allpcs_matches_an_endpoint_with_no_type_designation():
    """An untyped endpoint is an ordinary PC until something says otherwise."""
    context = {'computertypeid': None, 'appids': set()}
    assert evaluate_scope({'type': 'allpcs'}, context) is True


def test_true_still_matches_a_server():
    """'true' keeps its old meaning so existing policies do not silently shift."""
    context = {'computertypeid': 4, 'appids': set(), 'isserver': True}
    assert evaluate_scope({'type': 'true'}, context) is True


def test_allpcs_composes_with_other_nodes():
    """AND of allpcs and an app still excludes a server running that app."""
    scope = {
        'type': 'and',
        'nodes': [{'type': 'allpcs'}, {'type': 'app', 'id': 7}],
    }
    pc = {'computertypeid': 1, 'appids': {7}, 'isserver': False}
    server = {'computertypeid': 4, 'appids': {7}, 'isserver': True}
    assert evaluate_scope(scope, pc) is True
    assert evaluate_scope(scope, server) is False


def test_context_marks_a_server_icon_type_as_a_server():
    computer = FakeComputer(computertypeid=4, icon='server')
    assert build_endpoint_context(computer)['isserver'] is True


def test_context_does_not_mark_a_desktop_type_as_a_server():
    computer = FakeComputer(computertypeid=1, icon='desktop')
    assert build_endpoint_context(computer)['isserver'] is False


def test_context_handles_a_computer_with_no_type():
    computer = FakeComputer()
    assert build_endpoint_context(computer)['isserver'] is False


def test_an_unknown_node_type_is_still_rejected():
    with pytest.raises(ScopeError):
        validate_scope({'type': 'allpc'})