From 6ee0c7600be3d87ba2cec419586250efae971f4b Mon Sep 17 00:00:00 2001
From: Kangwook Lee <pbzweihander@gmail.com>
Date: Mon, 2 Aug 2021 03:19:43 +0900
Subject: [PATCH] Add HookableInMemoryHandler logging handler

---
 .gitignore               |  2 +-
 qt_ui/logging_config.py  | 19 +++++++++++++++----
 qt_ui/logging_handler.py | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 5 deletions(-)
 create mode 100644 qt_ui/logging_handler.py

diff --git a/.gitignore b/.gitignore
index b9205033..7d556efc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,7 +18,7 @@ env/
 /liberation_preferences.json
 /state.json
 
-logs/
+/logs/
 
 qt_ui/logs/liberation.log
 
diff --git a/qt_ui/logging_config.py b/qt_ui/logging_config.py
index ea08efe3..8d7a26af 100644
--- a/qt_ui/logging_config.py
+++ b/qt_ui/logging_config.py
@@ -3,6 +3,8 @@ import logging
 import os
 from logging.handlers import RotatingFileHandler
 
+from qt_ui.logging_handler import HookableInMemoryHandler
+
 
 def init_logging(version: str) -> None:
     """Initializes the logging configuration."""
@@ -10,13 +12,22 @@ def init_logging(version: str) -> None:
         os.mkdir("logs")
 
     fmt = "%(asctime)s :: %(levelname)s :: %(message)s"
+    formatter = logging.Formatter(fmt)
+
     logging.basicConfig(level=logging.DEBUG, format=fmt)
     logger = logging.getLogger()
 
-    handler = RotatingFileHandler("./logs/liberation.log", "a", 5000000, 1)
-    handler.setLevel(logging.DEBUG)
-    handler.setFormatter(logging.Formatter(fmt))
+    rotating_file_handler = RotatingFileHandler(
+        "./logs/liberation.log", "a", 5000000, 1
+    )
+    rotating_file_handler.setLevel(logging.DEBUG)
+    rotating_file_handler.setFormatter(formatter)
 
-    logger.addHandler(handler)
+    hookable_in_memory_handler = HookableInMemoryHandler()
+    hookable_in_memory_handler.setLevel(logging.DEBUG)
+    hookable_in_memory_handler.setFormatter(formatter)
+
+    logger.addHandler(rotating_file_handler)
+    logger.addHandler(hookable_in_memory_handler)
 
     logger.info(f"DCS Liberation {version}")
diff --git a/qt_ui/logging_handler.py b/qt_ui/logging_handler.py
new file mode 100644
index 00000000..465e4cb1
--- /dev/null
+++ b/qt_ui/logging_handler.py
@@ -0,0 +1,38 @@
+import logging
+import typing
+
+LogHook = typing.Callable[[str], None]
+
+
+class HookableInMemoryHandler(logging.Handler):
+    """Hookable in-memory logging handler for logs window"""
+
+    _log: str
+    _hook: typing.Optional[typing.Callable[[str], None]]
+
+    def __init__(self, *args, **kwargs):
+        super(HookableInMemoryHandler, self).__init__(*args, **kwargs)
+        self._log = ""
+        self._hook = None
+
+    @property
+    def log(self) -> str:
+        return self._log
+
+    def emit(self, record):
+        msg = self.format(record)
+        self._log += msg + "\n"
+        if self._hook is not None:
+            self._hook(msg)
+
+    def write(self, m):
+        pass
+
+    def clearLog(self) -> None:
+        self._log = ""
+
+    def setHook(self, hook: typing.Callable[[str], None]) -> None:
+        self._hook = hook
+
+    def clearHook(self) -> None:
+        self._hook = None