"""Unit tests for apply_task_to_simulation() mapping helper."""
from __future__ import annotations

from datetime import UTC, datetime
from unittest.mock import MagicMock

from backend.app.services.c2.mapping import apply_task_to_simulation


def _make_task(output: str | None = "whoami output", mapping_applied: bool = False) -> MagicMock:
    task = MagicMock()
    task.output = output
    task.mapping_applied = mapping_applied
    return task


def _make_sim(execution_result: str | None = None) -> MagicMock:
    sim = MagicMock()
    sim.execution_result = execution_result
    sim.updated_at = None
    return sim


class TestApplyTaskToSimulation:
    def test_appends_output_to_empty_simulation(self):
        task = _make_task(output="whoami output")
        sim = _make_sim(execution_result=None)

        apply_task_to_simulation(task, sim)

        assert sim.execution_result == "whoami output"
        assert task.mapping_applied is True

    def test_appends_with_newline_separator(self):
        task = _make_task(output="second result")
        sim = _make_sim(execution_result="first result")

        apply_task_to_simulation(task, sim)

        assert sim.execution_result == "first result\nsecond result"

    def test_idempotent_when_already_applied(self):
        task = _make_task(output="some output", mapping_applied=True)
        sim = _make_sim(execution_result="existing")

        apply_task_to_simulation(task, sim)

        # execution_result must not be modified.
        assert sim.execution_result == "existing"

    def test_no_op_when_output_is_empty_string(self):
        task = _make_task(output="")
        sim = _make_sim(execution_result="existing")

        apply_task_to_simulation(task, sim)

        assert sim.execution_result == "existing"
        # Still marks mapping_applied so we don't revisit it.
        assert task.mapping_applied is True

    def test_no_op_when_output_is_none(self):
        task = _make_task(output=None)
        sim = _make_sim(execution_result="existing")

        apply_task_to_simulation(task, sim)

        assert sim.execution_result == "existing"
        assert task.mapping_applied is True

    def test_strips_trailing_newlines_from_existing(self):
        """Existing execution_result with trailing newlines should not cause double blank lines."""
        task = _make_task(output="new output")
        sim = _make_sim(execution_result="old output\n\n")

        apply_task_to_simulation(task, sim)

        assert sim.execution_result == "old output\nnew output"

    def test_updated_at_is_set_on_sim(self):
        task = _make_task(output="something")
        sim = _make_sim(execution_result=None)
        before = datetime.now(UTC)

        apply_task_to_simulation(task, sim)

        assert sim.updated_at is not None
        assert sim.updated_at >= before

    def test_multiple_tasks_accumulate(self):
        sim = _make_sim(execution_result=None)
        tasks = [_make_task(output=f"result {i}") for i in range(3)]

        for t in tasks:
            apply_task_to_simulation(t, sim)

        lines = sim.execution_result.split("\n")
        assert lines == ["result 0", "result 1", "result 2"]