Split player backends, add VLC strategy

Extract core player logic and mpg123-bound logic into parent-child
classes so that other player backend strategies can be added. Create a
headless VLC strategy that uses VLC if it's available. Update the pydora
player to prefer VLC if it's available on the system because it supports
a much more broad set of codecs and Pandora is now preferring AAC
formatted files.

1 files changed, 47 insertions, 0 deletions

diff --git a/pandora/py2compat.py b/pandora/py2compat.py
index d83f8c5..fe45462 100644
--- a/pandora/py2compat.py
+++ b/pandora/py2compat.py
@@ -26,3 +26,50 @@ except ImportError:
         from mock import Mock, MagicMock, call, patch  # noqa: F401
     except ImportError:
         pass
+
+
+try:
+    from shutil import which
+except ImportError:
+    import os
+    import sys
+
+    # Copypasta from Python 3.6, exists in 3.3+
+    def which(cmd, mode=os.F_OK | os.X_OK, path=None):
+        def _access_check(fn, mode):
+            return (os.path.exists(fn) and os.access(fn, mode)
+                    and not os.path.isdir(fn))
+
+        if os.path.dirname(cmd):
+            if _access_check(cmd, mode):
+                return cmd
+            return None
+
+        if path is None:
+            path = os.environ.get("PATH", os.defpath)
+        if not path:
+            return None
+        path = path.split(os.pathsep)
+
+        if sys.platform == "win32":
+            if os.curdir not in path:
+                path.insert(0, os.curdir)
+
+            pathext = os.environ.get("PATHEXT", "").split(os.pathsep)
+            if any(cmd.lower().endswith(ext.lower()) for ext in pathext):
+                files = [cmd]
+            else:
+                files = [cmd + ext for ext in pathext]
+        else:
+            files = [cmd]
+
+        seen = set()
+        for dir in path:
+            normdir = os.path.normcase(dir)
+            if normdir not in seen:
+                seen.add(normdir)
+                for thefile in files:
+                    name = os.path.join(dir, thefile)
+                    if _access_check(name, mode):
+                        return name
+        return None