Change JournalLock.obtain_lock() return to an Enum.

This way we can tell the difference between:

1. This process obtained the lock.
2. Another process has the lock.
3. We couldn't get the lock due to not being able to open the lock file
   read-write.

Case 3 is currently also returned if the configured journal directory
doesn't exist.  This will be the case on any MacOS system that never had
the game running.  Likely given the OS hasn't been supported for the
game in years now.

# Conflicts:
#	EDMarketConnector.py

EDMarketConnector.py

@@ -39,7 +39,7 @@ from config import appversion, appversion_nobuild, config, copyright
 # isort: on
 
 from EDMCLogging import edmclogger, logger, logging
-from journal_lock import JournalLock
+from journal_lock import JournalLock, JournalLockResult
 
 if __name__ == '__main__':  # noqa: C901
     # Command-line arguments
@@ -84,18 +84,15 @@ if __name__ == '__main__':  # noqa: C901
     if args.force_localserver_for_auth:
         config.set_auth_force_localserver()
 
-    def no_other_instance_running() -> bool:  # noqa: CCR001
-        """
-        Ensure only one copy of the app is running for the configured journal directory.
-
-        :returns: True if we are the single instance, else False.
-        """
+    def handle_edmc_callback_or_foregrounding():  # noqa: CCR001
+        """Handle any edmc:// auth callback, else foreground existing window."""
         logger.trace('Begin...')
 
         if platform == 'win32':
 
-            if not locked:
-                # Need to do the check for this being an edmc:// auth callback
+            # If *this* instance hasn't locked, then another already has and we
+            # now need to do the edmc:// checks for auth callback
+            if locked != JournalLockResult.LOCKED:
                 import ctypes
                 from ctypes.wintypes import BOOL, HWND, INT, LPARAM, LPCWSTR, LPWSTR
 

journal_lock.py

@@ -2,6 +2,7 @@
 
 import pathlib
 import tkinter as tk
+from enum import Enum
 from os import getpid as os_getpid
 from sys import platform
 from tkinter import ttk
@@ -17,6 +18,15 @@ if TYPE_CHECKING:
         return x
 
 
+class JournalLockResult(Enum):
+    """Enumeration of possible outcomes of trying to lock the Journal Directory."""
+
+    LOCKED = 1
+    JOURNALDIR_NOTEXIST = 2
+    JOURNALDIR_READONLY = 3
+    ALREADY_LOCKED = 4
+
+
 class JournalLock:
     """Handle locking of journal directory."""
 
@@ -28,11 +38,11 @@ class JournalLock:
         # We never test truthiness of this, so let it be defined when first assigned.  Avoids type hint issues.
         # self.journal_dir_lockfile: Optional[IO] = None
 
-    def obtain_lock(self) -> bool:
+    def obtain_lock(self) -> JournalLockResult:
         """
         Attempt to obtain a lock on the journal directory.
 
-        :return: bool - True if we successfully obtained the lock
+        :return: LockResult - See the class Enum definition
         """
         self.journal_dir_lockfile_name = self.journal_dir_path / 'edmc-journal-lock.txt'
         logger.trace(f'journal_dir_lockfile_name = {self.journal_dir_lockfile_name!r}')
@@ -44,7 +54,7 @@ class JournalLock:
         except Exception as e:  # For remote FS this could be any of a wide range of exceptions
             logger.warning(f"Couldn't open \"{self.journal_dir_lockfile_name}\" for \"w+\""
                            f" Aborting duplicate process checks: {e!r}")
-            return False
+            return JournalLockResult.JOURNALDIR_READONLY
 
         if platform == 'win32':
             logger.trace('win32, using msvcrt')
@@ -57,7 +67,7 @@ class JournalLock:
             except Exception as e:
                 logger.info(f"Exception: Couldn't lock journal directory \"{self.journal_dir}\""
                             f", assuming another process running: {e!r}")
-                return False
+                return JournalLockResult.ALREADY_LOCKED
 
         else:
             logger.trace('NOT win32, using fcntl')
@@ -67,7 +77,7 @@ class JournalLock:
             except ImportError:
                 logger.warning("Not on win32 and we have no fcntl, can't use a file lock!"
                                "Allowing multiple instances!")
-                return True  # Lie about being locked
+                return JournalLockResult.LOCKED
 
             try:
                 fcntl.flock(self.journal_dir_lockfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
@@ -75,13 +85,13 @@ class JournalLock:
             except Exception as e:
                 logger.info(f"Exception: Couldn't lock journal directory \"{self.journal_dir}\", "
                             f"assuming another process running: {e!r}")
-                return False
+                return JournalLockResult.ALREADY_LOCKED
 
         self.journal_dir_lockfile.write(f"Path: {self.journal_dir}\nPID: {os_getpid()}\n")
         self.journal_dir_lockfile.flush()
 
         logger.trace('Done')
-        return True
+        return JournalLockResult.LOCKED
 
     def release_lock(self) -> bool:
         """