Download pyluxcore only if needed

__init__.py

@@ -5,6 +5,8 @@
 import subprocess
 from shutil import which
 import pathlib
+import json
+import requests
 
 import bpy
 import addon_utils
@@ -25,35 +27,92 @@
     os.environ["SSL_CERT_FILE"] = certifi.where()
     os.environ["REQUESTS_CA_BUNDLE"] = certifi.where()
 
+def get_wheel_filename(package_name, target_folder):
+    # Get the current Python version and architecture
+    python_version = sys.version_info
+    python_version_str = f'cp{python_version.major}{python_version.minor}'
+    architecture = None
+    machine = None
+    if platform.system() == "Darwin":
+        architecture = 'macosx_'
+        machine = platform.machine()
+    elif platform.system() == "Linux":
+        architecture = 'manylinux_'
+        machine = 'x86_64'
+    elif platform.system() == "Windows":
+        architecture = 'win_' # including the underscore just to be safe this never pops up elsewhere in the future, 'win' is a pretty short string and common term
+        machine = 'amd64'
+
+    if architecture is None or machine is None:
+        print('Warning: Platform could not be resolved in function get_wheel_filename(). Check is considered failed.')
+        return None
+
+    # Fetch package metadata from PyPI
+    url = f'https://pypi.org/pypi/{package_name}/json'
+    response = requests.get(url)
+    if response.status_code != 200:
+        raise ValueError(f"Failed to fetch metadata for package '{package_name}'")
+
+    # Extract latest version of the package
+    metadata = response.json()
+    versions = metadata['releases']
+    latest = list(versions.keys())[-1]
+
+    # Iterate through all versions and look for appropriate wheel files
+    for file in versions[latest]:
+        fname = file['filename']
+        if fname.endswith('.whl'):
+            wheel_filename = fname
+            if python_version_str in file['python_version'] and architecture in fname and machine in fname:
+                return wheel_filename
+
+    return None
+
+def is_latest_wheel_present(package_name, target_folder):
+    wheel_filename = get_wheel_filename(package_name, target_folder)
+    if wheel_filename:
+        wheel_path = os.path.join(target_folder, wheel_filename)
+        if os.path.exists(wheel_path):
+            return True
+    # Finally, if wheel_filename is None or os.path.exists() returned False
+    return False
 
 def install_pyluxcore():
     # We cannot 'pip install' directly, as it would install pyluxcore system-wide
     # instead of in Blender environment
     # Blender has got its own logic for wheel installation, we'll rely on it
 
-    # Download wheel
     root_folder = pathlib.Path(__file__).parent.resolve()
     wheel_folder =  root_folder / "wheels"
-    command = [
-        sys.executable,
-        '-m',
-        'pip',
-        'download',
-        'pyluxcore',
-        '-d',
-        wheel_folder
-    ]
-    process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-    stdout, stderr = process.communicate()
-    output = stdout.decode()
-    error_output = stderr.decode()
-    if output:
-        print("Output:\n", output)
-    if error_output:
-        print("Errors:\n", error_output)
-
-    if process.returncode != 0:
-        raise RuntimeError(f'Failed to download LuxCore with return code {result.returncode}.') from None
+
+    # check if latest pyluxcore version has already been downloaded.
+    # If yes, skip the download to save time
+    pyluxcore_downloaded = is_latest_wheel_present('pyluxcore', wheel_folder)
+    if pyluxcore_downloaded:
+        print('Download of pyluxcore skipped, latest version was found on system')
+    else:
+        print('Downloading pyluxcore')
+        # Download wheel
+        command = [
+            sys.executable,
+            '-m',
+            'pip',
+            'download',
+            'pyluxcore',
+            '-d',
+            wheel_folder
+        ]
+        process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        stdout, stderr = process.communicate()
+        output = stdout.decode()
+        error_output = stderr.decode()
+        if output:
+            print("Output:\n", output)
+        if error_output:
+            print("Errors:\n", error_output)
+
+        if process.returncode != 0:
+            raise RuntimeError(f'Failed to download LuxCore with return code {result.returncode}.') from None
 
     # Setup manifest with wheel list
     manifest_path = root_folder / "blender_manifest.toml"