Added service to download the Snap app if needed

Author: ymollard

pypot/creatures/services_launcher.py

@@ -185,15 +185,20 @@ def main():
         snap_static_port = 8888
         snap_static_server = HTTPServer(("0.0.0.0", snap_static_port), SimpleHTTPRequestHandler)
 
-        os.chdir(os.path.join(os.path.dirname(__file__), "..", "snap"))
-        snap_static_server_process = Process(target=snap_static_server.serve_forever, args=())
-        static_server_started = True
-        snap_static_server_process.start()
-
-        snap_url = 'http://127.0.0.1:{}/snap.html'.format(snap_static_port)
-        block_url = 'http://{}:{}/snap-blocks.xml'.format(
-            find_local_ip(), args.snap_port)
-        url = '{}#open:{}'.format(snap_url, block_url)
+        from pypot.vpl.snap import download_snap_interactively
+        static_app = download_snap_interactively()
+        if static_app is None:
+            print("The static server was not started because the VPL app has not been downloaded")
+        else:
+            os.chdir(static_app)
+            snap_static_server_process = Process(target=snap_static_server.serve_forever, args=())
+            static_server_started = True
+            snap_static_server_process.start()
+
+            snap_url = 'http://127.0.0.1:{}/snap.html'.format(snap_static_port)
+            block_url = 'http://{}:{}/snap-blocks.xml'.format(
+                find_local_ip(), args.snap_port)
+            url = '{}#open:{}'.format(snap_url, block_url)
 
     with closing(start_poppy_with_services(args)):
 

pypot/vpl/__init__.py

@@ -0,0 +1,67 @@
+import sys
+import tempfile
+from wget import download
+from urllib.error import URLError
+from zipfile import ZipFile
+from pathlib import Path
+
+def get_pypot_datadir(app_name="pypot"):
+    """
+    Returns pypot's directory for peristent data.
+    Attempt creation if create==True.
+
+    # linux: ~/.local/share
+    # macOS: ~/Library/Application Support
+    # windows: C:/Users/<USER>/AppData/Roaming
+    """
+    home = Path.home()
+
+    if sys.platform == "win32":
+        data_dir = home / "AppData/Roaming"
+    elif sys.platform == "linux":
+        data_dir = home / ".local/share"
+    elif sys.platform == "darwin":
+        data_dir = home / "Library/Application Support"
+    else:
+        raise ValueError("Can't find the user data directory of your platform '{}'".format(sys.platform))
+
+    #app_name = app_name if version is None else app_name + "-" + str(version)
+    pypot_dir = data_dir / app_name
+    return pypot_dir
+
+
+def download_vpl_interactively(vpl_app_name, vpl_app_url, extract=False):
+    """
+    Download the specified Visual Programming langage web app and returns its path.
+    If it couldn't be downloaded, return None
+    """
+    pypot_datadir = get_pypot_datadir()
+    vpl_dir = pypot_datadir / vpl_app_name
+    actual_vpl_dir = vpl_dir / vpl_app_name if extract else vpl_dir
+    
+    if vpl_dir.is_dir():
+        return actual_vpl_dir
+    else:
+        while True:
+            response = input("This is the first time you are launching {}, it needs to be downloaded first. Proceed? [Y/n] ".format(vpl_app_name))
+            if response.lower() in ["y", ""]:
+                try:
+                    vpl_dir.mkdir(parents=True)
+                except FileExistsError:
+                    pass
+                print("Downloading...")
+                try:
+                    downloaded_app = download(vpl_app_url, tempfile.gettempdir())
+                except URLError as e:
+                    print("Cannot download the {] app from {}: {}".format(vpl_app_name, vpl_app_url, str(e)), file=sys.stderr)
+                else:
+                    try:
+                        with ZipFile(downloaded_app, 'r') as archive:
+                            archive.extractall(vpl_dir)
+                    except FileNotFoundError:
+                        print("Couldn't extract {} from zipfile".format(vpl_app_name))
+                    else:
+                        return actual_vpl_dir
+            else:
+                print("Download aborted by user", file=sys.stderr)
+                return None

pypot/vpl/download.py

@@ -0,0 +1,13 @@
+from .download import download_vpl_interactively
+
+# Snap 5.4.5 application download to local data directory in userspace
+VPL_APP_URL = "https://codeload.github.com/jmoenig/Snap/zip/v5.4.5"
+VPL_APP_NAME = "Snap-5.4.5"
+VPL_EXTRACT_ZIP_ROOT = True 
+
+def download_snap_interactively():
+    """
+    Download the Snap 5.4.5 Programming langage web app and returns its path.
+    If it couldn't be downloaded, return None
+    """
+    return download_vpl_interactively(VPL_APP_NAME, VPL_APP_URL, VPL_EXTRACT_ZIP_ROOT)

pypot/vpl/snap.py

@@ -20,6 +20,7 @@ def version():
                     'bottle',
                     'requests',
                     'opencv-contrib-python',
+                    'wget',
                     ]
 
 if sys.version_info < (3, 5):