wip

logger.py

@@ -0,0 +1,109 @@
+"""Central logging configuration for the Seed project.
+
+Usage anywhere in the codebase:
+    from logger import get_logger
+    log = get_logger(__name__)
+    log.info("message")
+    log.warning("watch out")
+    log.error("something broke")
+
+Environment variables:
+    LOG_LEVEL   — DEBUG | INFO | WARNING | ERROR | CRITICAL  (default: INFO)
+    LOG_FILE    — path to write a rotating log file (optional)
+"""
+from __future__ import annotations
+
+import logging
+import logging.handlers
+import os
+import sys
+from typing import Final
+
+_LEVEL_MAP: Final = {
+    "DEBUG": logging.DEBUG,
+    "INFO": logging.INFO,
+    "WARNING": logging.WARNING,
+    "ERROR": logging.ERROR,
+    "CRITICAL": logging.CRITICAL,
+}
+
+_LOG_LEVEL: int = _LEVEL_MAP.get(os.getenv("LOG_LEVEL", "INFO").upper(), logging.INFO)
+_LOG_FILE: str | None = os.getenv("LOG_FILE")
+
+# ── ANSI colour codes (console only) ─────────────────────────────────────────
+_RESET  = "\033[0m"
+_BOLD   = "\033[1m"
+_GREY   = "\033[90m"
+_CYAN   = "\033[96m"
+_YELLOW = "\033[93m"
+_RED    = "\033[91m"
+_BRED   = "\033[1;91m"
+
+_LEVEL_COLOURS: Final[dict[int, str]] = {
+    logging.DEBUG:    _GREY,
+    logging.INFO:     _CYAN,
+    logging.WARNING:  _YELLOW,
+    logging.ERROR:    _RED,
+    logging.CRITICAL: _BRED,
+}
+
+
+class _ColourFormatter(logging.Formatter):
+    _FMT = "{colour}{level:<8}{reset} {grey}{asctime}  {name}{reset}  {msg}"
+
+    def format(self, record: logging.LogRecord) -> str:
+        colour = _LEVEL_COLOURS.get(record.levelno, "")
+        level  = record.levelname
+        grey   = _GREY if sys.stderr.isatty() else ""
+        reset  = _RESET if sys.stderr.isatty() else ""
+        col    = colour if sys.stderr.isatty() else ""
+
+        self.datefmt = "%H:%M:%S"
+        base = super().format(record)
+        return self._FMT.format(
+            colour=col, level=level, reset=reset,
+            grey=grey, asctime=self.formatTime(record, self.datefmt),
+            name=record.name, msg=record.getMessage(),
+        ) + (f"\n{record.exc_text}" if record.exc_info and self.formatException(record.exc_info) else "")
+
+
+_FILE_FMT = logging.Formatter(
+    fmt="%(asctime)s  %(levelname)-8s  %(name)s  %(message)s",
+    datefmt="%Y-%m-%dT%H:%M:%S",
+)
+
+
+def _build_root_logger() -> logging.Logger:
+    root = logging.getLogger("seed")
+    root.setLevel(_LOG_LEVEL)
+
+    if root.handlers:
+        return root  # already configured (e.g. imported twice)
+
+    # Console handler
+    console = logging.StreamHandler(sys.stderr)
+    console.setLevel(_LOG_LEVEL)
+    console.setFormatter(_ColourFormatter())
+    root.addHandler(console)
+
+    # Optional rotating file handler
+    if _LOG_FILE:
+        fh = logging.handlers.RotatingFileHandler(
+            _LOG_FILE, maxBytes=10 * 1024 * 1024, backupCount=5, encoding="utf-8"
+        )
+        fh.setLevel(_LOG_LEVEL)
+        fh.setFormatter(_FILE_FMT)
+        root.addHandler(fh)
+
+    root.propagate = False
+    return root
+
+
+_root = _build_root_logger()
+
+
+def get_logger(name: str) -> logging.Logger:
+    """Return a child logger namespaced under 'seed'."""
+    if name.startswith("seed.") or name == "seed":
+        return logging.getLogger(name)
+    return logging.getLogger(f"seed.{name}")