Python3 Migrate

venv/lib/python3.7/site-packages/mopidy/internal/validation.py

@@ -0,0 +1,133 @@
+import urllib
+from collections.abc import Iterable, Mapping
+
+from mopidy import exceptions
+
+PLAYBACK_STATES = {"paused", "stopped", "playing"}
+
+SEARCH_FIELDS = {
+    "uri",
+    "track_name",
+    "album",
+    "artist",
+    "albumartist",
+    "composer",
+    "performer",
+    "track_no",
+    "genre",
+    "date",
+    "comment",
+    "any",
+}
+
+PLAYLIST_FIELDS = {"uri", "name"}  # TODO: add length and last_modified?
+
+TRACKLIST_FIELDS = {  # TODO: add bitrate, length, disc_no, track_no, modified?
+    "uri",
+    "name",
+    "genre",
+    "date",
+    "comment",
+    "musicbrainz_id",
+}
+
+DISTINCT_FIELDS = {
+    "track",
+    "artist",
+    "albumartist",
+    "album",
+    "composer",
+    "performer",
+    "date",
+    "genre",
+}
+
+
+# TODO: _check_iterable(check, msg, **kwargs) + [check(a) for a in arg]?
+def _check_iterable(arg, msg, **kwargs):
+    """Ensure we have an iterable which is not a string or an iterator"""
+    if isinstance(arg, str):
+        raise exceptions.ValidationError(msg.format(arg=arg, **kwargs))
+    elif not isinstance(arg, Iterable):
+        raise exceptions.ValidationError(msg.format(arg=arg, **kwargs))
+    elif iter(arg) is iter(arg):
+        raise exceptions.ValidationError(msg.format(arg=arg, **kwargs))
+
+
+def check_choice(arg, choices, msg="Expected one of {choices}, not {arg!r}"):
+    if arg not in choices:
+        raise exceptions.ValidationError(
+            msg.format(arg=arg, choices=tuple(choices))
+        )
+
+
+def check_boolean(arg, msg="Expected a boolean, not {arg!r}"):
+    check_instance(arg, bool, msg=msg)
+
+
+def check_instance(arg, cls, msg="Expected a {name} instance, not {arg!r}"):
+    if not isinstance(arg, cls):
+        raise exceptions.ValidationError(msg.format(arg=arg, name=cls.__name__))
+
+
+def check_instances(arg, cls, msg="Expected a list of {name}, not {arg!r}"):
+    _check_iterable(arg, msg, name=cls.__name__)
+    if not all(isinstance(instance, cls) for instance in arg):
+        raise exceptions.ValidationError(msg.format(arg=arg, name=cls.__name__))
+
+
+def check_integer(arg, min=None, max=None):
+    if not isinstance(arg, int):
+        raise exceptions.ValidationError(f"Expected an integer, not {arg!r}")
+    elif min is not None and arg < min:
+        raise exceptions.ValidationError(
+            f"Expected number larger or equal to {min}, not {arg!r}"
+        )
+    elif max is not None and arg > max:
+        raise exceptions.ValidationError(
+            f"Expected number smaller or equal to {max}, not {arg!r}"
+        )
+
+
+def check_query(arg, fields=SEARCH_FIELDS, list_values=True):
+    # TODO: normalize name  -> track_name
+    # TODO: normalize value -> [value]
+    # TODO: normalize blank -> [] or just remove field?
+    # TODO: remove list_values?
+
+    if not isinstance(arg, Mapping):
+        raise exceptions.ValidationError(
+            f"Expected a query dictionary, not {arg!r}"
+        )
+
+    for key, value in arg.items():
+        check_choice(
+            key,
+            fields,
+            msg="Expected query field to be one of " "{choices}, not {arg!r}",
+        )
+        if list_values:
+            msg = 'Expected "{key}" to be list of strings, not {arg!r}'
+            _check_iterable(value, msg, key=key)
+            [_check_query_value(key, v, msg) for v in value]
+        else:
+            _check_query_value(
+                key, value, 'Expected "{key}" to be a string, not {arg!r}'
+            )
+
+
+def _check_query_value(key, arg, msg):
+    if not isinstance(arg, str) or not arg.strip():
+        raise exceptions.ValidationError(msg.format(arg=arg, key=key))
+
+
+def check_uri(arg, msg="Expected a valid URI, not {arg!r}"):
+    if not isinstance(arg, str):
+        raise exceptions.ValidationError(msg.format(arg=arg))
+    elif urllib.parse.urlparse(arg).scheme == "":
+        raise exceptions.ValidationError(msg.format(arg=arg))
+
+
+def check_uris(arg, msg="Expected a list of URIs, not {arg!r}"):
+    _check_iterable(arg, msg)
+    [check_uri(a, msg) for a in arg]