refactored naming policy into uri matcher

4 files changed, 10 insertions, 153 deletions

diff --git a/bsie/lib/__init__.py b/bsie/lib/__init__.py
index f44fb74..daa806c 100644
--- a/bsie/lib/__init__.py
+++ b/bsie/lib/__init__.py
@@ -5,7 +5,6 @@ import typing
 # inner-module imports
 from .bsie import BSIE
 from .builder import PipelineBuilder
-from .naming_policy import DefaultNamingPolicy
 
 # exports
 __all__: typing.Sequence[str] = (
diff --git a/bsie/lib/bsie.py b/bsie/lib/bsie.py
index b02e707..9aa0bdb 100644
--- a/bsie/lib/bsie.py
+++ b/bsie/lib/bsie.py
@@ -3,10 +3,10 @@
 import typing
 
 # bsie imports
-from bsie.utils import bsfs, node, ns
+from bsie.utils import bsfs, ns
+from bsie.matcher import Matcher, nodes
 
 # inner-module imports
-from .naming_policy import NamingPolicy
 from .pipeline import Pipeline
 
 # exports
@@ -40,7 +40,7 @@ class BSIE():
             # pipeline.
             pipeline: Pipeline,
             # naming policy
-            naming_policy: NamingPolicy,
+            matcher: Matcher,
             # principals to extract at most. None implies all available w.r.t. extractors.
             collect: typing.Optional[typing.Iterable[bsfs.URI]] = None,
             # principals to discard.
@@ -48,7 +48,7 @@ class BSIE():
             ):
         # store pipeline and naming policy
         self._pipeline = pipeline
-        self._naming_policy = naming_policy
+        self._matcher = matcher
         # start off with available principals
         self._principals = {pred.uri for pred in self._pipeline.principals}
         # limit principals to specified ones by argument.
@@ -79,7 +79,7 @@ class BSIE():
             self,
             path: bsfs.URI,
             principals: typing.Optional[typing.Iterable[bsfs.URI]] = None,
-            ) -> typing.Iterator[typing.Tuple[node.Node, bsfs.URI, typing.Any]]:
+            ) -> typing.Iterator[typing.Tuple[nodes.Node, bsfs.URI, typing.Any]]:
         """Produce triples for a given *path*. Limit to *principals* if given."""
         # get requested principals.
         principals = set(principals) if principals is not None else self._principals
@@ -88,6 +88,6 @@ class BSIE():
         # predicate lookup
         principals = {self.schema.predicate(pred) for pred in principals}
         # invoke pipeline
-        yield from self._naming_policy(self._pipeline(path, principals))
+        yield from self._matcher(self._pipeline(path, principals))
 
 ## EOF ##
diff --git a/bsie/lib/naming_policy.py b/bsie/lib/naming_policy.py
deleted file mode 100644
index fbdbeb0..0000000
--- a/bsie/lib/naming_policy.py
+++ /dev/null
@@ -1,141 +0,0 @@
-
-# standard imports
-import abc
-import os
-import typing
-
-# external imports
-import urllib.parse
-
-# bsie imports
-from bsie.utils import bsfs, errors, ns
-from bsie.utils.node import Node
-
-# exports
-__all__: typing.Sequence[str] = (
-    'DefaultNamingPolicy',
-    )
-
-
-## code ##
-
-class NamingPolicy():
-    """Determine node uri's from node hints."""
-    def __call__(
-            self,
-            iterable: typing.Iterable[typing.Tuple[Node, bsfs.URI, typing.Any]],
-            ):
-        """Apply the policy on a triple iterator."""
-        return NamingPolicyIterator(self, iterable)
-
-    @abc.abstractmethod
-    def handle_node(self, node: Node) -> Node:
-        """Apply the policy on a node."""
-
-
-class NamingPolicyIterator():
-    """Iterates over triples, determines uris according to a *policy* as it goes."""
-
-    # source triple iterator.
-    _iterable: typing.Iterable[typing.Tuple[Node, bsfs.URI, typing.Any]]
-
-    # naming policy
-    _policy: NamingPolicy
-
-    def __init__(
-            self,
-            policy: NamingPolicy,
-            iterable: typing.Iterable[typing.Tuple[Node, bsfs.URI, typing.Any]],
-            ):
-        self._iterable = iterable
-        self._policy = policy
-
-    def __iter__(self):
-        for node, pred, value in self._iterable:
-            # handle subject
-            self._policy.handle_node(node)
-            # handle value
-            if isinstance(value, Node):
-                self._policy.handle_node(value)
-            # yield triple
-            yield node, pred, value
-
-
-class DefaultNamingPolicy(NamingPolicy):
-    """Compose URIs as <host/user/node_type#fragment>
-
-    What information is used as fragment depends on the node type.
-    Typically, the default is to use the "ucid" hint.
-    The fallback in all cases is to generate a random uuid.
-
-    Never changes previously assigned uris. Sets uris in-place.
-
-    """
-
-    def __init__(
-            self,
-            host: bsfs.URI,
-            user: str,
-            ):
-        self._prefix = bsfs.Namespace(os.path.join(host, user))
-        self._uuid = bsfs.uuid.UUID()
-
-    def handle_node(self, node: Node) -> Node:
-        if node.uri is not None:
-            return node
-        if node.node_type == ns.bsn.Entity:
-            return self.name_entity(node)
-        if node.node_type == ns.bsn.Preview:
-            return self.name_preview(node)
-        if node.node_type == ns.bsn.Tag:
-            return self.name_tag(node)
-        if node.node_type == ns.bsn.Face:
-            return self.name_face(node)
-        raise errors.ProgrammingError(f'no naming policy available for {node.node_type}')
-
-    def name_entity(self, node: Node) -> Node:
-        """Set a bsn:Entity node's uri fragment to its ucid."""
-        if 'ucid' in node.hints: # content id
-            fragment = node.hints['ucid']
-        else: # random name
-            fragment = self._uuid()
-        node.uri = getattr(self._prefix.file(), fragment)
-        return node
-
-    def name_preview(self, node: Node) -> Node:
-        """Set a bsn:Preview node's uri fragment to its ucid.
-        Uses its source fragment as fallback. Appends the size if provided.
-        """
-        fragment = None
-        if 'ucid' in node.hints: # content id
-            fragment = node.hints['ucid']
-        if fragment is None and 'source' in node.hints: # source id
-            self.handle_node(node.hints['source'])
-            fragment = node.hints['source'].uri.get('fragment', None)
-        if fragment is None: # random name
-            fragment = self._uuid()
-        if 'size' in node.hints: # append size
-            fragment += '_s' + str(node.hints['size'])
-        node.uri = getattr(self._prefix.preview(), fragment)
-        return node
-
-    def name_tag(self, node: Node) -> Node:
-        # NOTE: Must ensure to produce the same name for that tags with the same label.
-        if 'label' in node.hints: # tag label
-            fragment = urllib.parse.quote(node.hints['label'])
-        else: # random name
-            fragment = self._uuid()
-        # FIXME: match to existing tags in bsfs storage!
-        node.uri = getattr(self._prefix.tag(), fragment)
-        return node
-
-    def name_face(self, node: Node) -> Node:
-        if 'ucid' in node.hints: # content id
-            fragment = node.hints['ucid']
-        else: # random name
-            fragment = self._uuid()
-        node.uri = getattr(self._prefix.face(), fragment)
-        return node
-
-
-## EOF ##
diff --git a/bsie/lib/pipeline.py b/bsie/lib/pipeline.py
index 30fd6fd..98d9cc8 100644
--- a/bsie/lib/pipeline.py
+++ b/bsie/lib/pipeline.py
@@ -6,8 +6,9 @@ import typing
 
 # bsie imports
 from bsie.extractor import Extractor
+from bsie.matcher import nodes
 from bsie.reader import Reader
-from bsie.utils import bsfs, errors, node, ns
+from bsie.utils import bsfs, errors, ns
 
 # exports
 __all__: typing.Sequence[str] = (
@@ -85,7 +86,7 @@ class Pipeline():
             self,
             path: bsfs.URI,
             principals: typing.Optional[typing.Iterable[bsfs.schema.Predicate]] = None,
-            ) -> typing.Iterator[typing.Tuple[node.Node, bsfs.schema.Predicate, typing.Any]]:
+            ) -> typing.Iterator[typing.Tuple[nodes.Node, bsfs.schema.Predicate, typing.Any]]:
         """Extract triples from the file at *path*. Optionally, limit triples to *principals*."""
         # get principals
         principals = set(principals) if principals is not None else set(self.schema.predicates())
@@ -104,9 +105,7 @@ class Pipeline():
             rdr2ext[rdr].add(ext)
 
         # create subject for file
-        subject = node.Node(ns.bsn.Entity,
-            ucid=bsfs.uuid.UCID.from_path(path),
-            )
+        subject = nodes.Entity(ucid=bsfs.uuid.UCID.from_path(path))
 
         # extract information
         for rdr, extrs in rdr2ext.items():