Add a test method to download client and libraries.

Add a simple File object to simplify certain file operations.

INFO: Libraries are unfiltered. Some of the library that for other platform will be downloaded too.

app.py

@@ -1,12 +1,15 @@
 import logging
 import textwrap
+from pathlib import Path
 
 from PySide6.QtCore import Qt
-from PySide6.QtWidgets import QApplication, QMainWindow, QPushButton, QVBoxLayout, QWidget, QDialog, QPlainTextEdit, \
+from PySide6.QtWidgets import QApplication, QMainWindow, QPushButton, QVBoxLayout, QDialog, QPlainTextEdit, \
     QHBoxLayout
+
+from core_lib.common.common import download_file, FileObject, download_multiple_files
 from core_lib.qt.hack import move_window_to_center
-from core_lib.game.version_info import get_version_manifest, get_latest_version, get_specific_version_manifest_url, \
-    fetch_specific_version_manifest, find_useful_part_in_specific_version_manifest
+from core_lib.game.version_info import get_version_manifest, get_latest_version, \
+    fetch_specific_version_manifest, find_useful_part_in_specific_version_manifest, get_core_file_download_url_and_hash
 
 
 class Launcher(QApplication):
@@ -27,13 +30,21 @@ class Launcher(QApplication):
         def __init__(self, parent):
             super().__init__(parent)
             self.parent = parent
-            self.resize(300, 200)
-            self.setWindowFlags(self.windowFlags() | Qt.WindowMaximizeButtonHint)
+            self.resize(800, 600)
+            self.setWindowFlags(self.windowFlags() | Qt.WindowType.WindowMaximizeButtonHint)
 
             self.button = QPushButton("Fetch Version Data")
             self.button.setObjectName("ActionButton")
             self.button.clicked.connect(self.run_test)
 
+            self.button_2 = QPushButton("Download client")
+            self.button_2.setObjectName("ActionButton")
+            self.button_2.clicked.connect(self.run_download_client)
+
+            self.button_3 = QPushButton("Download libraries")
+            self.button_3.setObjectName("ActionButton")
+            self.button_3.clicked.connect(self.run_download_libraries)
+
             self.output = QPlainTextEdit()
             self.output.setReadOnly(True)
 
@@ -44,6 +55,8 @@ class Launcher(QApplication):
             self.right_layout.setObjectName("RightLayout")
             self.right_layout.setAlignment(Qt.AlignmentFlag.AlignRight)
             self.right_layout.addWidget(self.button)
+            self.right_layout.addWidget(self.button_2)
+            self.right_layout.addWidget(self.button_3)
             self.right_layout.addStretch()
             self.right_layout.setContentsMargins(0, 10, 0, 0)
 
@@ -63,6 +76,7 @@ class Launcher(QApplication):
             return self.parent.parent
 
         def run_test(self):
+            self.output.clear()
             data = get_version_manifest()
             ver = get_latest_version(data)
             ver_data = fetch_specific_version_manifest(data, ver)
@@ -85,6 +99,57 @@ class Launcher(QApplication):
 
             self.output.setPlainText(content)
 
+        def run_download_client(self):
+            self.output.clear()
+
+            data = get_version_manifest()
+            ver = get_latest_version(data)
+            ver_data = fetch_specific_version_manifest(data, ver)
+            url, sha1 = get_core_file_download_url_and_hash(ver_data)
+
+            dest = Path(Path(__file__).parent, "temp", f"client-{ver}.jar")
+
+            if url:
+                file = FileObject(dest, url=url)
+                download_file(file)
+            else:
+                self.output.setPlainText("Download URL not found.")
+                return
+
+            self.output.setPlainText("Client downloaded." if dest.exists() else "Client not found.")
+
+        def run_download_libraries(self):
+            self.output.clear()
+
+            def log_file_downloaded(filepath):
+                self.output.appendPlainText(f"Downloaded {filepath}.")
+
+            data = get_version_manifest()
+            ver = get_latest_version(data)
+            ver_data = fetch_specific_version_manifest(data, ver)
+            _, _, _, _, libraries, _ = find_useful_part_in_specific_version_manifest(ver_data)
+
+            output_dir = Path(Path(__file__).parent, "tmp", f"libraries-{ver}")
+
+            output_dir.mkdir(parents=True, exist_ok=True)
+
+            items = []
+
+            for library in libraries:
+                url = library.get("downloads", {}).get("artifact", {}).get("url")
+                sha1 = library.get("downloads", {}).get("artifact", {}).get("sha1")
+                relative_path = library.get("downloads", {}).get("artifact", {}).get("path")
+                full_path = output_dir / relative_path
+
+                if not url:
+                    continue
+
+                file = FileObject(full_path, url=url, sha1=sha1)
+                items.append(file)
+
+            download_multiple_files(items, download_callback=log_file_downloaded)
+
+
     def exec(self):
         self.main_window.show()
         self.exec_()