chore: import upstream snapshot with attribution

agentlightning/logging.py

@@ -0,0 +1,370 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from __future__ import annotations
+
+import logging
+import os
+import platform
+import sys
+import warnings
+from logging.config import dictConfig
+from typing import Any, Dict, Optional
+
+from rich.console import Console
+
+__all__ = ["setup", "configure_logger", "setup_module"]
+
+
+def configure_logger(level: int = logging.INFO, name: str = "agentlightning") -> logging.Logger:
+    """Create or reset a namespaced logger with a consistent console format.
+
+    This helper clears any previously attached handlers before binding a single
+    `StreamHandler` that writes to standard output. The resulting logger does
+    not propagate to the root logger, preventing duplicate log emission when
+    applications compose multiple logging configurations.
+
+    !!! danger
+
+        This function is deprecated in favor of [`setup_logging`][agentlightning.setup_logging].
+
+    Args:
+        level: Logging level applied both to the logger and the installed
+            handler. Defaults to `logging.INFO`.
+        name: Dotted path for the logger instance. Defaults to
+            `"agentlightning"`.
+
+    Returns:
+        Configured logger instance ready for immediate use.
+
+    Examples:
+        ```python
+        from agentlightning import configure_logger
+
+        logger = configure_logger(level=logging.INFO)
+        logger.info("agent-lightning is ready!")
+        ```
+    """
+    warnings.warn("This function is deprecated in favor of `setup_logging`.", DeprecationWarning, stacklevel=2)
+
+    return setup_module(level=level, name=name, console=True, color=True, propagate=False)
+
+
+DEFAULT_FORMAT = "%(asctime)s [%(levelname)s] (Process-%(process)d %(name)s)   %(message)s"
+DATE_FORMAT = "%H:%M:%S"
+
+
+def _to_level_value(lvl: int | str) -> int:
+    if isinstance(lvl, int):
+        return lvl
+    val = getattr(logging, str(lvl).upper(), None)
+    if val is None:
+        raise ValueError(f"Invalid log level: {lvl}")
+    return val
+
+
+def _ensure_file_handler(
+    logger: logging.Logger,
+    filename: str,
+    *,
+    level: int,
+    formatter: Optional[logging.Formatter],
+) -> None:
+    """Attach a FileHandler to `logger` for `filename` if it doesn't already exist."""
+    abspath = os.path.abspath(filename)
+
+    # Avoid duplicates
+    for h in logger.handlers:
+        if isinstance(h, logging.FileHandler) and getattr(h, "baseFilename", None) == abspath:
+            return
+
+    # Ensure directory exists
+    dirname = os.path.dirname(abspath)
+    if dirname:
+        os.makedirs(dirname, exist_ok=True)
+
+    fh = logging.FileHandler(abspath, encoding="utf-8")
+    fh.setLevel(level)
+    if formatter is not None:
+        fh.setFormatter(formatter)
+    else:
+        fh.setFormatter(logging.Formatter(DEFAULT_FORMAT, DATE_FORMAT))
+
+    logger.addHandler(fh)
+
+
+def setup(
+    level: int | str = "INFO",
+    *,
+    console: bool = True,
+    color: bool | Dict[str, Any] = True,
+    propagate: bool = False,
+    disable_existing_loggers: bool = False,
+    capture_warnings: bool = False,
+    submodule_levels: Optional[dict[str, int | str]] = None,
+    extra_handlers: Optional[list[logging.Handler]] = None,
+    formatter: Optional[logging.Formatter] = None,
+    apply_to: Optional[list[str]] = None,
+    files: Optional[str | dict[str, str]] = None,
+) -> None:
+    """Configures logging for the `agentlightning` logger hierarchy.
+
+    This function provides a one-stop setup utility for configuring the
+    `agentlightning` root logger and optionally its submodules or external
+    loggers. It supports console logging, colored rich output, per-submodule
+    log levels, and optional handler/formatter injection.
+
+    The setup is intentionally isolated: it does not modify the global root
+    logger or loggers belonging to other libraries unless explicitly directed
+    via `apply_to`.
+
+    Args:
+        level:
+            Logging level for the base `agentlightning` logger. Accepts either
+            an integer (e.g., `logging.DEBUG`) or a string level name
+            (e.g., `"INFO"`). Defaults to `"INFO"`.
+        console:
+            Whether to attach a console handler to the logger. Defaults to
+            `True`.
+        color:
+            Enables rich-formatted output using `RichHandler` when `True`
+            or a configuration dict. If `False`, a plain text formatter is
+            used instead. Defaults to `True`.
+        propagate:
+            Whether `agentlightning` logs should propagate to ancestor
+            loggers. Defaults to `False`.
+        disable_existing_loggers:
+            Passed to `logging.config.dictConfig`. If `True`, disables all
+            existing configured loggers before applying this configuration.
+            Defaults to `False`.
+        capture_warnings:
+            If `True`, redirects Python `warnings` emitted via the `warnings`
+            module into the logging system. Defaults to `False`.
+        submodule_levels:
+            Mapping of submodule logger names to logging levels. If a specified
+            submodule level is more verbose than the base level, a warning is emitted.
+        extra_handlers:
+            A list of user-provided handlers to attach to the `agentlightning` logger.
+            Handlers are added idempotently; duplicates are not reattached.
+        formatter:
+            A formatter to apply to any handler under `agentlightning` that does not
+            already have one assigned. Useful for customizing output without overwriting
+            formatters on custom handlers.
+        apply_to:
+            A list of additional logger names to configure identically to
+            `agentlightning` base logger. Their handlers are replaced with copies of the base
+            handlers, and propagation is disabled to avoid duplicate log emission.
+        files:
+            If a string, attach a FileHandler to the base `agentlightning` logger.
+            If a dict, for each `(logger_name, filename)` pair, attach a FileHandler
+            directly to that logger.
+            Each file handler should use the logger's effective level at creation.
+
+    Notes:
+        * On Windows, this function forces UTF-8 mode in the console to prevent
+          issues with rich output or special characters.
+        * Submodule loggers can generate records below the handler's emission
+          threshold. Whether such records appear depends on both the logger's
+          level and the handler's level.
+        * `apply_to` loggers inherit the same handlers but do not propagate
+          upward, yielding isolated, consistent behavior.
+
+    Examples:
+        Basic setup:
+
+        >>> setup()
+
+        Enabling debug mode with no color:
+
+        >>> setup(level="DEBUG", color=False)
+
+        Overriding specific submodule levels:
+
+        >>> setup(submodule_levels={"agentlightning.io": "DEBUG"})
+
+        Attaching an additional file handler:
+
+        >>> fh = logging.FileHandler("app.log")
+        >>> setup(extra_handlers=[fh])
+    """
+    # Ensure UTF-8 encoding on Windows consoles
+    # Note: This change does not fully represent support for execution under the windows system.
+    # It only fixes console printing issues caused by special characters.
+    # TODO: More comprehensive Windows support may be needed in the future.
+    if platform.system() == "Windows":
+        os.environ["PYTHONUTF8"] = "1"
+
+    base_logger = setup_module(
+        level,
+        name="agentlightning",
+        console=console,
+        color=color,
+        propagate=propagate,
+        disable_existing_loggers=disable_existing_loggers,
+    )
+
+    base_level_value = base_logger.level
+
+    # Apply user-provided formatter (only to handlers without one,
+    # so we don't clobber custom extra_handlers)
+    if formatter is not None:
+        for h in base_logger.handlers:
+            if h.formatter is None:
+                h.setFormatter(formatter)
+
+    # Attach user-provided handler(s) if any, idempotently
+    if extra_handlers:
+        for h in extra_handlers:
+            if h not in base_logger.handlers:
+                base_logger.addHandler(h)
+
+    # Per-submodule levels
+    if submodule_levels:
+        for name, lvl in submodule_levels.items():
+            sub_level = _to_level_value(lvl)
+
+            # Emit a warning if submodule level is lower (more verbose) than the global/base level
+            if sub_level < base_level_value:
+                base_logger.warning(
+                    "Submodule logger '%s' level %s (%s) is more verbose than base "
+                    "logger level %s (%s). Records below the base level may still be "
+                    "filtered out by handlers depending on their own levels.",
+                    name,
+                    lvl,
+                    sub_level,
+                    logging.getLevelName(base_level_value),
+                    base_level_value,
+                )
+
+            # The logger will *create* records down to the logger's level, but a handler
+            # with a higher level will still drop anything below its own threshold.
+            # Effective emission is gated by both: record.level >= logger.level AND handler.level.
+            logging.getLogger(name).setLevel(lvl)
+
+    # Attach file handlers if requested
+    if files is not None:
+        if isinstance(files, str):
+            # Single file for the entire `agentlightning` hierarchy.
+            _ensure_file_handler(
+                logger=base_logger,
+                filename=files,
+                level=base_level_value,
+                formatter=formatter,
+            )
+        else:
+            # Per-logger files
+            for logger_name, filename in files.items():
+                lg = logging.getLogger(logger_name)
+                # Use the logger's *effective* level at creation time
+                effective_level = lg.getEffectiveLevel()
+                _ensure_file_handler(
+                    logger=lg,
+                    filename=filename,
+                    level=effective_level,
+                    formatter=formatter,
+                )
+
+    # Optionally apply the same handler setup to other loggers outside this module
+    if apply_to:
+        for name in apply_to:
+            lg = logging.getLogger(name)
+            # This removes any existing handlers so we don't duplicate output
+            # and ensures these loggers share exactly the same handlers as base_logger.
+            lg.handlers.clear()
+            for h in base_logger.handlers:
+                lg.addHandler(h)
+            lg.setLevel(base_logger.level)
+            # We've attached handlers directly to these loggers; if propagate
+            # stayed True, records would bubble up to ancestor loggers and could be
+            # emitted twice (here and on the parent/root). Setting False isolates them.
+            lg.propagate = False
+
+    # Optionally capture warnings
+    if capture_warnings:
+        logging.captureWarnings(True)
+
+
+def setup_module(
+    level: int | str = "INFO",
+    *,
+    name: str = "agentlightning",
+    console: bool = True,
+    color: bool | Dict[str, Any] = True,
+    propagate: bool = False,
+    disable_existing_loggers: bool = False,
+) -> logging.Logger:
+    """Initializes and returns the base logger for `agentlightning`.
+
+    This function constructs and applies a `dictConfig` configuration for the
+    logger hierarchy rooted at `name`. It supports either rich console
+    formatting (via `RichHandler`) or plain text formatting, based on the
+    `color` argument.
+
+    Unlike [`setup_logging`][agentlightning.setup_logging], this function configures only a single logger namespace
+    and does not attach extra handlers or submodule levels. It is primarily used
+    internally by [`setup_logging`][agentlightning.setup_logging] but is also suitable for direct integration in
+    custom logging workflows.
+    """
+    root_cfg: Dict[str, Any] = {
+        "version": 1,
+        "disable_existing_loggers": disable_existing_loggers,
+        "loggers": {
+            name: {
+                "handlers": [],
+                "level": level,
+                "propagate": propagate,
+            }
+        },
+        "handlers": {},
+        "formatters": {},
+    }
+
+    # Choose formatter / handler definition
+    if color is not False and console:
+        # Console must be true to display colored outputs
+        if isinstance(color, dict):
+            rich_handler_config = color
+        else:
+            rich_handler_config: Dict[str, Any] = {
+                "rich_tracebacks": False,
+                "markup": False,
+                "show_time": True,
+                "show_path": True,
+            }
+
+            if not _has_width():
+                # e.g., in a CI environment.
+                rich_handler_config["console"] = Console(width=200)
+
+        root_cfg["handlers"]["console"] = {
+            "class": "rich.logging.RichHandler",
+            "level": level,
+            **rich_handler_config,
+        }
+        # RichHandler manages its own style; keep formatter None
+    else:
+        fmt_name = "plain"
+        root_cfg["formatters"][fmt_name] = {
+            "format": DEFAULT_FORMAT,
+            "datefmt": DATE_FORMAT,
+        }
+
+        if console:
+            root_cfg["handlers"]["console"] = {
+                "class": "logging.StreamHandler",
+                "level": level,
+                "formatter": fmt_name,
+            }
+
+    # Attach selected handlers to agentlightning
+    handler_names = list(root_cfg["handlers"].keys())
+    root_cfg["loggers"][name]["handlers"] = handler_names
+
+    # Apply dictConfig (this resets the logger handlers)
+    dictConfig(root_cfg)
+
+    return logging.getLogger(name)
+
+
+def _has_width() -> bool:
+    """Automatically determine whether the terminal has a width."""
+    return sys.stdout.isatty()