Initial Codes

app/utils/logger.py

@@ -0,0 +1,180 @@
+"""
+Centralised application logging for DBClient.
+
+Call ``setup_logging()`` once at startup (in main.py).
+Then anywhere in the codebase:
+
+    from app.utils.logger import get_logger
+    log = get_logger(__name__)
+    log.info("Connected to %s", host)
+    log.error("Query failed", exc_info=True)   # includes full traceback
+
+Log files are written to  ~/.dbclient/logs/dbclient.log
+with daily rotation, keeping the last 7 files.
+
+The module also installs:
+  • sys.excepthook  — logs every uncaught exception with full traceback
+  • threading.excepthook — logs uncaught exceptions in background threads
+"""
+from __future__ import annotations
+
+import logging
+import logging.handlers
+import os
+import sys
+import threading
+import traceback
+from pathlib import Path
+
+# ── Constants ─────────────────────────────────────────────────────────────────
+
+APP_DIR  = Path.home() / ".dbclient"
+LOG_DIR  = APP_DIR / "logs"
+LOG_FILE = LOG_DIR / "dbclient.log"
+
+# File: DEBUG and above  |  Console: WARNING and above
+FILE_LEVEL    = logging.DEBUG
+CONSOLE_LEVEL = logging.WARNING
+
+# Rotate at midnight, keep 7 days of log files
+BACKUP_COUNT = 7
+
+LOG_FORMAT = (
+    "[%(asctime)s] [%(levelname)-8s] [%(name)s:%(lineno)d]  %(message)s"
+)
+DATE_FORMAT = "%Y-%m-%d %H:%M:%S"
+
+# ── Public helpers ────────────────────────────────────────────────────────────
+
+def get_logger(name: str) -> logging.Logger:
+    """Return a module-level logger.  Always call as ``get_logger(__name__)``."""
+    return logging.getLogger(name)
+
+
+def get_log_path() -> Path:
+    """Return the absolute path of the current log file."""
+    return LOG_FILE
+
+
+# ── Setup ─────────────────────────────────────────────────────────────────────
+
+def setup_logging(level: int = FILE_LEVEL) -> None:
+    """
+    Initialise the root logger.  Safe to call multiple times (idempotent).
+
+    Parameters
+    ----------
+    level : int
+        Minimum level written to the log file (default: DEBUG).
+        The console handler always uses WARNING regardless of this setting.
+    """
+    LOG_DIR.mkdir(parents=True, exist_ok=True)
+
+    root = logging.getLogger()
+    if root.handlers:
+        # Already configured — nothing to do
+        return
+
+    root.setLevel(logging.DEBUG)
+
+    fmt = logging.Formatter(LOG_FORMAT, datefmt=DATE_FORMAT)
+
+    # ── Rotating file handler (midnight rollover, 7-day retention) ────────────
+    try:
+        fh = logging.handlers.TimedRotatingFileHandler(
+            str(LOG_FILE),
+            when="midnight",
+            backupCount=BACKUP_COUNT,
+            encoding="utf-8",
+            delay=False,
+        )
+        fh.setLevel(level)
+        fh.setFormatter(fmt)
+        root.addHandler(fh)
+    except OSError as exc:
+        # Can't write logs — at least print a warning
+        print(f"[DBClient] WARNING: Could not open log file {LOG_FILE}: {exc}",
+              file=sys.stderr)
+
+    # ── Console handler (WARNING+ only, for developers) ───────────────────────
+    ch = logging.StreamHandler(sys.stderr)
+    ch.setLevel(CONSOLE_LEVEL)
+    ch.setFormatter(fmt)
+    root.addHandler(ch)
+
+    # ── Silence noisy third-party libraries ───────────────────────────────────
+    for noisy in ("pymysql", "psycopg2", "pyodbc", "urllib3", "PIL"):
+        logging.getLogger(noisy).setLevel(logging.WARNING)
+
+    _install_exception_hooks()
+
+    log = get_logger(__name__)
+    log.info("=" * 60)
+    log.info("DBClient started  (Python %s)", sys.version.split()[0])
+    log.info("Log file: %s", LOG_FILE)
+
+
+# ── Unhandled exception hooks ─────────────────────────────────────────────────
+
+def _install_exception_hooks() -> None:
+    """Capture all uncaught exceptions — both in the main thread and workers."""
+    _log = get_logger("dbclient.uncaught")
+
+    # Main thread
+    def _excepthook(exc_type, exc_value, exc_tb):
+        if issubclass(exc_type, KeyboardInterrupt):
+            sys.__excepthook__(exc_type, exc_value, exc_tb)
+            return
+        _log.critical(
+            "Uncaught exception:\n%s",
+            "".join(traceback.format_exception(exc_type, exc_value, exc_tb)),
+        )
+        # Still let Qt/Python print it to stderr so the developer sees it live
+        sys.__excepthook__(exc_type, exc_value, exc_tb)
+
+    sys.excepthook = _excepthook
+
+    # Background threads (Python 3.8+)
+    def _thread_excepthook(args):
+        if args.exc_type is SystemExit:
+            return
+        _log.critical(
+            "Uncaught exception in thread '%s':\n%s",
+            getattr(args.thread, "name", "?"),
+            "".join(traceback.format_exception(
+                args.exc_type, args.exc_value, args.exc_tb
+            )),
+        )
+
+    threading.excepthook = _thread_excepthook
+
+
+# ── Qt message handler ─────────────────────────────────────────────────────────
+
+def install_qt_message_handler() -> None:
+    """
+    Route Qt's own warning/critical messages into the Python log.
+    Call AFTER QApplication is created.
+    """
+    try:
+        from PyQt6.QtCore import qInstallMessageHandler, QtMsgType
+
+        _log = get_logger("Qt")
+        _level_map = {
+            QtMsgType.QtDebugMsg:    logging.DEBUG,
+            QtMsgType.QtInfoMsg:     logging.INFO,
+            QtMsgType.QtWarningMsg:  logging.WARNING,
+            QtMsgType.QtCriticalMsg: logging.ERROR,
+            QtMsgType.QtFatalMsg:    logging.CRITICAL,
+        }
+
+        def _handler(msg_type, context, message):
+            lvl = _level_map.get(msg_type, logging.WARNING)
+            loc = ""
+            if context.file:
+                loc = f" [{context.file}:{context.line}]"
+            _log.log(lvl, "%s%s", message, loc)
+
+        qInstallMessageHandler(_handler)
+    except Exception:
+        pass  # Non-fatal — Qt messages just won't be logged