add rose print albums command

README.md

@@ -115,11 +115,9 @@ Options:
 Commands:
   cache  Manage the read cache.
   fs     Manage the virtual library.
+  print  Print cached library data (JSON-encoded).
 ```
 
-The virtual filesystem is mounted and unmounted by `rose fs mount` and
-`rose fs unmount` respectively.
-
 ## Configuration
 
 Rosé must be configured prior to use. Rosé is configured via a TOML file
@@ -162,6 +160,24 @@ Rosé also supports JPEG and PNG cover art. The supported cover art file stems
 are `cover`, `folder`, and `art`. The supported cover art file extensions are
 `.jpg`, `.jpeg`, and `.png`.
 
+## Virtual Filesystem
+
+The virtual filesystem is mounted and unmounted by `rose fs mount` and
+`rose fs unmount` respectively.
+
+TODO
+
+## Metadata Management
+
+TODO
+
+## Data Querying
+
+The `rose print` family of commands (e.g. `rose print albums`) prints out data
+in the read cache in a JSON-encoded format. The output of this command can be
+piped into tools like `jq`, `fx`, and others in order to further process the
+output.
+
 ## Tagging Conventions
 
 Rosé is lenient in the tags it ingests, but has opinionated conventions for the
@@ -187,10 +203,6 @@ remixer    ::= ' remixed by ' name
 name       ::= string ';' name | string
 ```
 
-## Metadata Management
-
-TODO
-
 ## New Releases
 
 TODO
@@ -225,7 +237,7 @@ TODO; example unit files to schedule Rosé with systemd.
 
 ## Logging
 
-Logs are written to stdout and to `${XDG_STATE_HOME:-$HOME/.local/state}/rose/rose.log`.
+Logs are written to stderr and to `${XDG_STATE_HOME:-$HOME/.local/state}/rose/rose.log`.
 
 # Architecture
 

rose/__init__.py

@@ -17,7 +17,7 @@
         "[%(asctime)s] %(levelname)s: %(message)s",
         datefmt="%H:%M:%S",
     )
-    stream_handler = logging.StreamHandler(sys.stdout)
+    stream_handler = logging.StreamHandler(sys.stderr)
     stream_handler.setFormatter(stream_formatter)
     logger.addHandler(stream_handler)
 

rose/__main__.py

@@ -7,6 +7,7 @@
 
 from rose.cache import migrate_database, update_cache_for_all_releases
 from rose.config import Config
+from rose.print import print_releases
 from rose.virtualfs import mount_virtualfs, unmount_virtualfs
 
 
@@ -75,5 +76,17 @@ def unmount(ctx: Context) -> None:
     unmount_virtualfs(ctx.config)
 
 
+@cli.group()
+def print() -> None:
+    """Print cached library data (JSON-encoded)."""
+
+
+@print.command()
+@click.pass_obj
+def albums(ctx: Context) -> None:
+    """Print albums."""
+    print_releases(ctx.config)
+
+
 if __name__ == "__main__":
     cli()

rose/cache.py

@@ -865,6 +865,7 @@ def list_releases(
                 )
             """
             args.append(sanitized_label_filter)
+        query += " ORDER BY r.source_path"
 
         cursor = conn.execute(query, args)
         for row in cursor:

rose/print.py

@@ -0,0 +1,19 @@
+import json
+from dataclasses import asdict
+from pathlib import Path
+from typing import Any
+
+from rose.cache import list_releases
+from rose.config import Config
+
+
+class CustomJSONEncoder(json.JSONEncoder):
+    def default(self, obj: Any) -> Any:
+        if isinstance(obj, Path):
+            return str(obj)
+        return super().default(obj)
+
+
+def print_releases(c: Config) -> None:
+    releases = [asdict(r) for r in list_releases(c)]
+    print(json.dumps(releases, cls=CustomJSONEncoder))