Add code to link remote and local paths.

setup.py

@@ -50,6 +50,7 @@
         'pyxdg',
         'blinker',
         'natsort',
+        'bidict',
     ],
     extras_require = {
         'setproctitle': ['setproctitle'],

stig/commands/base/config.py

@@ -696,3 +696,51 @@ def completion_candidates_posargs(cls, args):
             return candidates.Candidates(cands, label='Direction', curarg_seps=(',',))
         elif posargs.curarg_index >= 3:
             return candidates.torrent_filter(args.curarg)
+
+class LinkPathCmd(metaclass=CommandMeta):
+    name = 'link'
+    aliases = ()
+    category = 'configuration'
+    provides = set()
+    description = textwrap.dedent(
+        """Links remote and local paths. Call with no arguments to list existing links.
+
+        Example use case: a remote daemon downloads to
+        /var/transmission/downloads/, but this is mounted on the local client
+        as /mnt/nfs/seedbox/. Moving torrents with the move requires the remote
+        path, but tab completion works with the local filesystem. Path links
+        provide a transparent translation layer.
+
+        Links must be bijective; as a consequence the --force flag must be
+        passed to ensure that clobbering is intentional.
+        """)
+    usage = ('link [<OPTIONS>] REMOTE LOCAL',)
+    examples = ('link /var/transmission/downloads/ /mnt/nfs/seedbox/',
+                'link')
+    argspecs = (
+        {'names': ('--force', '-f'),
+         'description': 'Overwrite existing links involving REMOTE or LOCAL.'},
+        {'names': ('REMOTE',),
+         'nargs': '?',
+         'description': 'Remote path to link'},
+        {'names': ('LOCAL',),
+         'nargs': '?',
+         'description': 'Local path to link'}
+    )
+
+    DUMP_WIDTH = 79
+
+    async def run(self, REMOTE, LOCAL, force):
+        log.debug("%s %s %s" % (REMOTE, LOCAL, force))
+        if not (REMOTE or LOCAL):
+            log.debug('Listing links')
+            for link in objects.pathtranslator.links.items():
+                self.info('%s <-> %s' % link)
+            return
+        elif not (REMOTE and LOCAL):
+            self.error("Must specify both REMOTE and LOCAL paths.")
+            return
+        try:
+            objects.pathtranslator.link(REMOTE, LOCAL, force)
+        except Exception as e:
+            raise CmdError(e)

stig/commands/base/torrent.py

@@ -11,6 +11,7 @@
 
 import asyncio
 import os
+from pathlib import Path
 
 from . import _mixin as mixin
 from .. import CmdError, CommandMeta
@@ -48,6 +49,8 @@ class AddTorrentsCmdbase(metaclass=CommandMeta):
     async def run(self, TORRENT, stopped, path):
         success = True
         force_torrentlist_update = False
+        if path:
+            path = objects.pathtranslator.to_remote(path)
         for source in TORRENT:
             source_abs_path = self.make_path_absolute(source)
             response = await self.make_request(objects.srvapi.torrent.add(source_abs_path,
@@ -250,6 +253,7 @@ async def run(self, TORRENT_FILTER, PATH):
         except ValueError as e:
             raise CmdError(e)
         else:
+            PATH = objects.pathtranslator.to_remote(Path(PATH)).as_posix()
             response = await self.make_request(objects.srvapi.torrent.move(tfilter, PATH),
                                                polling_frenzy=True)
             if not response.success:

stig/commands/cli/config.py

@@ -65,3 +65,6 @@ async def _show_limits(self, TORRENT_FILTER, directions):
 
     def _output(self, msg):
         print(msg)
+
+class LinkPathCmd(base.LinkPathCmd):
+    provides = {'cli'}

stig/commands/tui/config.py

@@ -74,3 +74,6 @@ async def _show_limits(self, TORRENT_FILTER, directions):
 
     def _output(self, msg):
         self.info(msg)
+
+class LinkPathCmd(base.LinkPathCmd):
+    provides = {'tui'}

stig/objects.py

@@ -18,6 +18,7 @@
 from .client import API
 from .commands import CommandManager
 from .helpmgr import HelpManager
+from .utils._pathtranslator import PathTranslator
 
 log = logging.make_logger()
 
@@ -26,6 +27,7 @@
 
 localcfg = settings.Settings()
 settings.init_defaults(localcfg)
+pathtranslator = PathTranslator()
 
 srvapi = API(interval=localcfg['tui.poll'])
 

stig/utils/_pathtranslator.py

@@ -0,0 +1,66 @@
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details
+# http://www.gnu.org/licenses/gpl-3.0.txt
+
+from pathlib import Path
+from bidict import bidict, ValueDuplicationError
+
+from ..logging import make_logger  # isort:skip
+
+log = make_logger(__name__)
+
+
+class PathTranslator:
+    def __init__(self):
+        # links: a dict of (remote_root, local_root) pairs
+        self.links = bidict()
+
+    def link(self, remote, local, force=False):
+        remote = Path(remote)
+        local = Path(local)
+        if not local.exists():
+            raise ValueError("Local path %s does not exist." % local)
+        if not local.is_absolute():
+            raise ValueError("Local path %s must be absolute." % local)
+        if not remote.is_absolute():
+            raise ValueError("Remote path %s must be absolute." % remote)
+        if force:
+            self.links.forceput(remote, local)
+        if remote in self.links.keys():
+            raise ValueError(
+                "Remote path %s is already linked to local path %s."
+                % (remote, self.links[remote])
+            )
+        try:
+            self.links[remote] = local
+        except ValueDuplicationError:
+            raise ValueError(
+                "Local path %s is already linked to remote path %s."
+                % (local, self.links[remote])
+            )
+        log.debug("Linked remote path %s to local path %s" % (remote, local))
+
+    def _translate_path(self, path, links):
+        try:
+            path = Path(path)
+        except Exception:
+            raise ValueError("Could not convert %s to Path" % path)
+        for roots in links.items():
+            try:
+                return roots[1] / path.relative_to(roots[0])
+            except ValueError:
+                pass
+        return path
+
+    def to_local(self, p_rem):
+        return self._translate_path(p_rem, self.links)
+
+    def to_remote(self, p_loc):
+        return self._translate_path(p_loc, self.links.inv)