[path] implement conditional 'base-directory'

docs/configuration.rst

@@ -188,12 +188,29 @@ Description
 extractor.*.base-directory
 --------------------------
 Type
-    |Path|_
+    * |Path|_
+    * ``object`` (Condition_ → |Path|_)
 Default
     ``"./gallery-dl/"``
+Example
+    .. code:: json
+
+        "~/Downloads/gallery-dl"
+
+    .. code:: json
+
+        {
+            "score >= 100": "$DL",
+            "duration"    : "$DL/video",
+            ""            : "/tmp/files/"
+        }
 Description
     Directory path used as base for all download destinations.
 
+    If this is an ``object``,
+    it must contain Conditions_ mapping to the |Path|_ to use.
+    Specifying a default |Path|_ with ``""`` is required.
+
 
 extractor.*.parent-directory
 ----------------------------

gallery_dl/path.py

@@ -118,22 +118,32 @@ class PathFormat():
         if WINDOWS:
             self.extended = config("path-extended", True)
 
+        self.basedirectory_conditions = None
         basedir = extractor._parentdir
         if not basedir:
             basedir = config("base-directory")
-            sep = os.sep
             if basedir is None:
-                basedir = f".{sep}gallery-dl{sep}"
+                basedir = self.clean_path(f".{os.sep}gallery-dl{os.sep}")
             elif basedir:
-                basedir = util.expand_path(basedir)
-                altsep = os.altsep
-                if altsep and altsep in basedir:
-                    basedir = basedir.replace(altsep, sep)
-                if basedir[-1] != sep:
-                    basedir += sep
-            basedir = self.clean_path(basedir)
+                if isinstance(basedir, dict):
+                    self.basedirectory_conditions = conds = []
+                    for expr, bdir in basedir.items():
+                        if not expr:
+                            basedir = bdir
+                            continue
+                        conds.append((util.compile_filter(expr),
+                                      self._prepare_basedirectory(bdir)))
+                basedir = self._prepare_basedirectory(basedir)
         self.basedirectory = basedir
 
+    def _prepare_basedirectory(self, basedir):
+        basedir = util.expand_path(basedir)
+        if os.altsep and os.altsep in basedir:
+            basedir = basedir.replace(os.altsep, os.sep)
+        if basedir[-1] != os.sep:
+            basedir += os.sep
+        return self.clean_path(basedir)
+
     def __str__(self):
         return self.realpath
 
@@ -175,11 +185,20 @@ class PathFormat():
         """Build directory path and create it if necessary"""
         self.kwdict = kwdict
 
-        if segments := self.build_directory(kwdict):
-            self.directory = directory = self.basedirectory + self.clean_path(
-                os.sep.join(segments) + os.sep)
+        if self.basedirectory_conditions is None:
+            basedir = self.basedirectory
         else:
-            self.directory = directory = self.basedirectory
+            for condition, basedir in self.basedirectory_conditions:
+                if condition(kwdict):
+                    break
+            else:
+                basedir = self.basedirectory
+
+        if segments := self.build_directory(kwdict):
+            self.directory = directory = \
+                f"{basedir}{self.clean_path(os.sep.join(segments))}{os.sep}"
+        else:
+            self.directory = directory = basedir
 
         if WINDOWS and self.extended:
             directory = self._extended_path(directory)