"""Tests for DebugLogger (backend/managers/debug_logger.py).

DebugLogger is a classmethod-based utility.  Its _error_log class variable
persists across tests, so every test that modifies it must call
DebugLogger.clear_errors() in teardown (handled by the autouse fixture).
"""

import sys
from pathlib import Path
import pytest

sys.path.insert(0, str(Path(__file__).parent.parent))

from backend.managers.debug_logger import DebugLogger


# ── Fixtures ──────────────────────────────────────────────────────────────────

@pytest.fixture(autouse=True)
def clear_error_log():
    """Reset the shared _error_log class variable before and after each test."""
    DebugLogger.clear_errors()
    yield
    DebugLogger.clear_errors()


# ── log_error() ───────────────────────────────────────────────────────────────

class TestLogError:
    """Tests for log_error(): appends the message to the in-memory error list."""

    def test_log_error_appends_to_error_log(self):
        DebugLogger.log_error("something broke")
        assert "something broke" in DebugLogger.get_errors()

    def test_log_error_multiple_messages_all_stored(self):
        DebugLogger.log_error("first error")
        DebugLogger.log_error("second error")
        errors = DebugLogger.get_errors()
        assert "first error" in errors
        assert "second error" in errors

    def test_log_error_preserves_order(self):
        DebugLogger.log_error("alpha")
        DebugLogger.log_error("beta")
        errors = DebugLogger.get_errors()
        assert errors.index("alpha") < errors.index("beta")


# ── get_errors() ──────────────────────────────────────────────────────────────

class TestGetErrors:
    """Tests for get_errors(): returns the current in-memory error list."""

    def test_get_errors_empty_initially(self):
        assert DebugLogger.get_errors() == []

    def test_get_errors_reflects_logged_errors(self):
        DebugLogger.log_error("boom")
        assert len(DebugLogger.get_errors()) == 1


# ── clear_errors() ────────────────────────────────────────────────────────────

class TestClearErrors:
    """Tests for clear_errors(): wipes the in-memory error list."""

    def test_clear_errors_empties_list(self):
        DebugLogger.log_error("will be cleared")
        DebugLogger.clear_errors()
        assert DebugLogger.get_errors() == []

    def test_clear_errors_on_empty_list_does_not_raise(self):
        DebugLogger.clear_errors()  # already empty from autouse fixture


# ── format_debug_output() ─────────────────────────────────────────────────────

class TestFormatDebugOutput:
    """Tests for format_debug_output(): renders return_code, stdout, and stderr."""

    def test_contains_execution_result_header(self):
        result = DebugLogger.format_debug_output({"return_code": 0, "stdout": "", "stderr": ""})
        assert "=== Execution Result ===" in result

    def test_exit_code_zero_appears_in_output(self):
        result = DebugLogger.format_debug_output({"return_code": 0, "stdout": "", "stderr": ""})
        assert "Exit Code: 0" in result

    def test_nonzero_exit_code_appears_in_output(self):
        result = DebugLogger.format_debug_output({"return_code": 1, "stdout": "", "stderr": ""})
        assert "Exit Code: 1" in result

    def test_stdout_included_when_present(self):
        result = DebugLogger.format_debug_output({"return_code": 0, "stdout": "Hello", "stderr": ""})
        assert "Hello" in result

    def test_stderr_included_when_present(self):
        result = DebugLogger.format_debug_output({"return_code": 1, "stdout": "", "stderr": "NameError"})
        assert "NameError" in result

    def test_empty_stdout_shows_none_placeholder(self):
        result = DebugLogger.format_debug_output({"return_code": 0, "stdout": "", "stderr": ""})
        assert "(none)" in result

    def test_missing_keys_do_not_raise(self):
        # format_debug_output uses .get() so absent keys fall back to defaults.
        result = DebugLogger.format_debug_output({})
        assert isinstance(result, str)