Update many files.

Add some description about this project, and now it has a simple UI (made with Qt)

If you don't specify the mode of (interface?) the UI. Launcher will show a crude window that lets you
 select a mode to start the (real) launcher.

Test version data fetching functions. Looks great.

core_lib/__init__.py

@@ -0,0 +1 @@
+__version__ = '0.1.0'

core_lib/core_init.py

@@ -0,0 +1,3 @@
+import logging
+
+logger = logging.getLogger("Launcher.CoreLib")

core_lib/log/default.py

@@ -0,0 +1,23 @@
+import logging
+import sys
+
+from colorlog import ColoredFormatter
+
+DEFAULT_FORMAT = '%(asctime)s:%(name)s:%(levelname)s: %(message)s'
+DEFAULT_DATE_FORMAT = '%H:%M:%S'
+
+def get_colorful_handler():
+    handler = logging.StreamHandler(sys.stdout)
+    formatter = ColoredFormatter(
+        '%(light_white)s%(asctime)s:%(light_green)s%(name)s:%(log_color)s%(levelname)s%(reset)s: %(message)s',
+        log_colors={
+            'DEBUG': 'cyan',
+            'INFO': 'green',
+            'WARNING': 'yellow',
+            'ERROR': 'light_red',
+            'CRITICAL': 'red',
+        },
+        datefmt=DEFAULT_DATE_FORMAT
+    )
+    handler.setFormatter(formatter)
+    return handler

core_lib/qt/hack.py

@@ -0,0 +1,10 @@
+from PySide6.QtGui import QScreen
+from PySide6.QtWidgets import QMainWindow, QApplication
+
+
+def move_window_to_center(window: QMainWindow):
+    main_screen = QApplication.primaryScreen()
+    center = QScreen.availableGeometry(main_screen).center()
+    geometry = window.frameGeometry()
+    geometry.moveCenter(center)
+    window.move(geometry.topLeft())

core_lib/unclassified.py

@@ -1,10 +1,121 @@
-from PySide6.QtGui import QScreen
-from PySide6.QtWidgets import QMainWindow, QApplication
+import json
+
+import requests
+from .core_init import logger
+
+MOJANG_VERSION_MANIFEST_V2 = "https://piston-meta.mojang.com/mc/game/version_manifest_v2.json"
+
+def get_version_manifest(manifest_url=MOJANG_VERSION_MANIFEST_V2, timeout=10) -> dict | None:
+    logger.debug("Getting version manifest from {}".format(manifest_url))
+
+    try:
+        r = requests.get(manifest_url, timeout=timeout)
+    except requests.exceptions.RequestException as e:
+        logger.error("Error getting version manifest from {}".format(manifest_url))
+        logger.error("Exception: {}".format(e))
+        return None
+
+    try:
+        data = r.json()
+        logger.debug("VersionManifest: {}".format(json.dumps(data, indent=4)))
+        return data
+    except ValueError as e:
+        logger.error("Unable to deserialize response data into dictionary.")
+        logger.error("URL: {}".format(manifest_url))
+        logger.error("Exception: {}".format(e))
+        return None
+
+def get_latest_version(version_manifest: dict, is_snapshot=False) -> None | str:
+    latest = version_manifest.get("latest", {})
+
+    if len(latest) == 0:
+        logger.debug("No latest version section available in version manifest.")
+        logger.debug("Data: {}".format(json.dumps(version_manifest, indent=4)))
+        return None
+
+    latest_ver = latest.get("release" if not is_snapshot else "snapshot", None)
+
+    if latest_ver is None:
+        logger.debug("No latest version available.")
+    else:
+        logger.debug("Latest version: {}".format(latest_ver))
+
+    return latest_ver
+
+def get_specific_version_manifest_url(version_manifest: dict,
+                                      version_id: str, is_snapshot=False) -> str | None:
+    versions = version_manifest.get("versions", [])
+
+    if len(versions) == 0:
+        logger.debug("No version section available in version manifest.")
+        return None
+
+    ver_type = "release" if not is_snapshot else "snapshot"
+    versions = [version for version in versions if version.get("type") ==  ver_type]
+
+    for version in versions:
+        if version.get("id") == version_id:
+            specific_ver_manifest_url = version.get("url", None)
+
+            if specific_ver_manifest_url is None:
+                logger.debug("Specific version manifest URL not available in version manifest.")
+                return None
+
+            return specific_ver_manifest_url
+
+    logger.debug("No version section available in version manifest.")
+
+    return None
+
+def fetch_specific_version_manifest(version_manifest: dict, spec_version: str) -> dict | None:
+    ver_url = get_specific_version_manifest_url(version_manifest, spec_version)
+
+    if ver_url is None:
+        logger.debug("Unable to get specific version manifest url from version manifest.\n"
+                     "Version: {}".format(spec_version))
+        return None
+
+    try:
+        r = requests.get(ver_url, timeout=10)
+    except requests.exceptions.RequestException as e:
+        logger.error("Error getting version manifest from {}".format(ver_url))
+        logger.error("Exception: {}".format(e))
+        return None
+
+    try:
+        data = r.json()
+        logger.debug("SpecificVersionManifest: {}".format(json.dumps(data, indent=4)))
+        return data
+    except ValueError as e:
+        logger.error("Unable to deserialize response data into dictionary.")
 
 
-def move_window_to_center(window: QMainWindow):
-    main_screen = QApplication.primaryScreen()
-    center = QScreen.availableGeometry(main_screen).center()
-    geometry = window.frameGeometry()
-    geometry.moveCenter(center)
-    window.move(geometry.topLeft())
+def find_useful_part_in_specific_version_manifest(spec_version_manifest: dict)\
+        -> tuple[dict | None, dict | None, dict | None, dict | None, list | None, str | None]:
+    arguments = spec_version_manifest.get("arguments", {})
+    asset_index = spec_version_manifest.get("assetIndex", {})
+    downloads = spec_version_manifest.get("downloads", {})
+    java_version = spec_version_manifest.get("java_version", {})
+    libraries = spec_version_manifest.get("libraries", [])
+    main_class = spec_version_manifest.get("mainClass", None)
+
+    if len(arguments) == 0:
+        logger.debug("No arguments section available in version manifest.")
+
+    if len(asset_index) == 0:
+        logger.debug("No asset index section available in version manifest.")
+
+    if len(downloads) == 0:
+        logger.debug("No downloads section available in version manifest.")
+
+    if len(java_version) == 0:
+        logger.debug("No java version section available in version manifest.")
+
+    if len(libraries) == 0:
+        logger.debug("No libraries section available in version manifest.")
+
+    if main_class is None:
+        logger.debug("No main class section available in version manifest.")
+
+    return arguments, asset_index, downloads, java_version, libraries, main_class
+