Prompt-optimizer/tests/unit/test_logging.py

"""Unit tests for structured logging configuration."""
from __future__ import annotations

import json
import logging
from pathlib import Path

from prometheus.cli.logging_setup import configure_logging, get_logger


class TestConfigureLogging:
    def _count_handlers(self, name: str = "prometheus") -> int:
        return len(logging.getLogger(name).handlers)

    def test_default_creates_console_handler(self) -> None:
        configure_logging(level=logging.INFO)
        prom = logging.getLogger("prometheus")
        assert len(prom.handlers) == 1
        assert isinstance(prom.handlers[0], logging.StreamHandler)
        prom.handlers.clear()

    def test_json_format_produces_valid_json(self, capsys) -> None:
        configure_logging(level=logging.INFO, log_format="json")
        logger = get_logger("test_json")
        logger.info("hello", extra={"structured": {"key": "value"}})

        captured = capsys.readouterr()
        # Output goes to stderr
        line = captured.err.strip().split("\n")[-1]
        data = json.loads(line)
        assert data["message"] == "hello"
        assert data["structured"]["key"] == "value"
        assert data["level"] == "INFO"
        assert "timestamp" in data

        logging.getLogger("prometheus").handlers.clear()

    def test_text_format_includes_structured_extras(self, capsys) -> None:
        configure_logging(level=logging.INFO, log_format="text")
        logger = get_logger("test_text")
        logger.info("msg", extra={"structured": {"foo": "bar"}})

        captured = capsys.readouterr()
        assert "foo=bar" in captured.err

        logging.getLogger("prometheus").handlers.clear()

    def test_debug_level_shows_debug_messages(self, capsys) -> None:
        configure_logging(level=logging.DEBUG)
        logger = get_logger("test_debug")
        logger.debug("debug msg")

        captured = capsys.readouterr()
        assert "debug msg" in captured.err

        logging.getLogger("prometheus").handlers.clear()

    def test_warning_level_hides_debug_messages(self, capsys) -> None:
        configure_logging(level=logging.WARNING)
        logger = get_logger("test_warn")
        logger.debug("should not appear")
        logger.info("also hidden")

        captured = capsys.readouterr()
        assert "should not appear" not in captured.err
        assert "also hidden" not in captured.err

        logging.getLogger("prometheus").handlers.clear()

    def test_file_handler_writes_to_file(self, tmp_path: Path) -> None:
        log_file = tmp_path / "test.log"
        configure_logging(level=logging.INFO, log_file=str(log_file))
        logger = get_logger("test_file")
        logger.info("file message")

        prom = logging.getLogger("prometheus")
        # Flush handlers
        for h in prom.handlers:
            h.flush()
        prom.handlers.clear()

        content = log_file.read_text()
        assert "file message" in content

    def test_json_file_output(self, tmp_path: Path) -> None:
        log_file = tmp_path / "test.json.log"
        configure_logging(level=logging.INFO, log_format="json", log_file=str(log_file))
        logger = get_logger("test_json_file")
        logger.info("json file msg", extra={"structured": {"x": 1}})

        prom = logging.getLogger("prometheus")
        for h in prom.handlers:
            h.flush()
        prom.handlers.clear()

        content = log_file.read_text().strip()
        data = json.loads(content)
        assert data["message"] == "json file msg"
        assert data["structured"]["x"] == 1

    def test_reconfigure_clears_old_handlers(self) -> None:
        configure_logging(level=logging.INFO)
        configure_logging(level=logging.DEBUG)
        prom = logging.getLogger("prometheus")
        assert len(prom.handlers) == 1
        prom.handlers.clear()

    def test_propagate_false_prevents_duplicate_output(self, capsys) -> None:
        configure_logging(level=logging.INFO)
        prom = logging.getLogger("prometheus")
        assert prom.propagate is False
        prom.handlers.clear()


class TestGetLogger:
    def test_returns_child_of_prometheus(self) -> None:
        logger = get_logger("mymodule")
        assert logger.name == "prometheus.mymodule"

    def test_inherits_level_from_parent(self) -> None:
        configure_logging(level=logging.DEBUG)
        logger = get_logger("child")
        assert logger.getEffectiveLevel() <= logging.DEBUG
        logging.getLogger("prometheus").handlers.clear()


class TestJsonFormatter:
    def test_exception_included(self, capsys) -> None:
        configure_logging(level=logging.ERROR, log_format="json")
        logger = get_logger("test_exc")
        try:
            raise ValueError("boom")
        except ValueError:
            logger.error("failed", exc_info=True)

        captured = capsys.readouterr()
        line = captured.err.strip().split("\n")[-1]
        data = json.loads(line)
        assert "ValueError: boom" in data["exception"]

        logging.getLogger("prometheus").handlers.clear()


class TestLoggingCLIIntegration:
    """Tests for CLI flags that configure logging."""

    def test_verbose_flag_enables_info(self, tmp_path: Path) -> None:
        """Simulate what -v does — configure_logging at INFO level."""
        configure_logging(level=logging.INFO)
        logger = get_logger("evolution")
        logger.info("test message")

        prom = logging.getLogger("prometheus")
        assert len(prom.handlers) == 1
        prom.handlers.clear()

    def test_debug_flag_enables_debug(self) -> None:
        """Simulate what --debug does — configure_logging at DEBUG level."""
        configure_logging(level=logging.DEBUG)
        logger = get_logger("evolution")
        logger.debug("debug message")

        prom = logging.getLogger("prometheus")
        assert prom.level == logging.DEBUG
        prom.handlers.clear()

    def test_log_format_invalid_rejected(self) -> None:
        """Invalid log_format should be caught by OptimizationConfig validator."""
        from pydantic import ValidationError
        from prometheus.application.dto import OptimizationConfig

        import pytest

        with pytest.raises(ValidationError, match="log_format must be one of"):
            OptimizationConfig(
                seed_prompt="a",
                task_description="b",
                log_format="xml",
            )

    def test_log_format_text_and_json_accepted(self) -> None:
        """Both text and json log_format values should be valid."""
        from prometheus.application.dto import OptimizationConfig

        for fmt in ("text", "json"):
            config = OptimizationConfig(
                seed_prompt="a", task_description="b", log_format=fmt,
            )
            assert config.log_format == fmt