Fix typing and import in the config file module.

cista/__main__.py

@@ -10,8 +10,24 @@ from cista.util import pwgen
 
 del app, server80.app  # Only import needed, for Sanic multiprocessing
 
-doc = f"""Cista {cista.__version__} - A file storage for the web.
 
+def create_banner():
+    """Create a framed banner with the Cista version."""
+    title = f"Cista {cista.__version__}"
+    subtitle = "A file storage for the web"
+    width = max(len(title), len(subtitle)) + 4
+
+    return f"""\
+╭{"─" * width}╮
+│{title:^{width}}│
+│{subtitle:^{width}}│
+╰{"─" * width}╯
+"""
+
+
+banner = create_banner()
+
+doc = """\
 Usage:
   cista [-c <confdir>] [-l <host>] [--import-droppy] [--dev] [<path>]
   cista [-c <confdir>] --user <name> [--privileged] [--password]
@@ -35,6 +51,14 @@ User management:
   --password        Reset password
 """
 
+first_time_help = """\
+No config file found! Get started with:
+  cista --user yourname --privileged     # If you want user accounts
+  cista -l :8000 /path/to/files          # Run the server on localhost:8000
+
+See cista --help for other options!
+"""
+
 
 def main():
     # Dev mode doesn't catch exceptions
@@ -44,11 +68,19 @@ def main():
     try:
         return _main()
     except Exception as e:
-        print("Error:", e)
+        sys.stderr.write(f"Error: {e}\n")
         return 1
 
 
 def _main():
+    # The banner printing differs by mode, and needs to be done before docopt() printing its messages
+    if any(arg in sys.argv for arg in ("--help", "-h")):
+        sys.stdout.write(banner)
+    elif "--version" in sys.argv:
+        sys.stdout.write(f"cista {cista.__version__}\n")
+        return 0
+    else:
+        sys.stderr.write(banner)
     args = docopt(doc)
     if args["--user"]:
         return _user(args)
@@ -62,18 +94,11 @@ def _main():
         path = None
     _confdir(args)
     exists = config.conffile.exists()
-    print(config.conffile, exists)
     import_droppy = args["--import-droppy"]
     necessary_opts = exists or import_droppy or path
     if not necessary_opts:
         # Maybe run without arguments
-        print(doc)
-        print(
-            "No config file found! Get started with one of:\n"
-            "  cista --user yourname --privileged\n"
-            "  cista --import-droppy\n"
-            "  cista -l :8000 /path/to/files\n"
-        )
+        sys.stderr.write(first_time_help)
         return 1
     settings = {}
     if import_droppy:
@@ -94,7 +119,7 @@ def _main():
         # We have no users, so make it public
         settings["public"] = True
     operation = config.update_config(settings)
-    print(f"Config {operation}: {config.conffile}")
+    sys.stderr.write(f"Config {operation}: {config.conffile}\n")
     # Prepare to serve
     unix = None
     url, _ = serve.parse_listen(config.config.listen)
@@ -104,7 +129,7 @@ def _main():
     dev = args["--dev"]
     if dev:
         extra += " (dev mode)"
-    print(f"Serving {config.config.path} at {url}{extra}")
+    sys.stderr.write(f"Serving {config.config.path} at {url}{extra}\n")
     # Run the server
     serve.run(dev=dev)
     return 0
@@ -137,7 +162,7 @@ def _user(args):
                 "public": False,
             }
         )
-        print(f"Config {operation}: {config.conffile}\n")
+        sys.stderr.write(f"Config {operation}: {config.conffile}\n\n")
 
     name = args["--user"]
     if not name or not name.isidentifier():
@@ -155,12 +180,12 @@ def _user(args):
         changes["password"] = pw = pwgen.generate()
         info += f"\n  Password: {pw}\n"
     res = config.update_user(name, changes)
-    print(info)
+    sys.stderr.write(f"{info}\n")
     if res == "read":
-        print("  No changes")
+        sys.stderr.write("  No changes\n")
 
     if operation == "created":
-        print(
+        sys.stderr.write(
             "Now you can run the server:\n  cista    # defaults set: -l :8000 ~/Downloads\n"
         )
 

cista/config.py

@@ -7,9 +7,11 @@ from contextlib import suppress
 from functools import wraps
 from hashlib import sha256
 from pathlib import Path, PurePath
-from time import time
+from time import sleep, time
+from typing import Callable, Concatenate, Literal, ParamSpec
 
 import msgspec
+import msgspec.toml
 
 
 class Config(msgspec.Struct):
@@ -22,6 +24,13 @@ class Config(msgspec.Struct):
     links: dict[str, Link] = {}
 
 
+# Typing: arguments for config-modifying functions
+P = ParamSpec("P")
+ResultStr = Literal["modified", "created", "read"]
+RawModifyFunc = Callable[Concatenate[Config, P], Config]
+ModifyPublic = Callable[P, ResultStr]
+
+
 class User(msgspec.Struct, omit_defaults=True):
     privileged: bool = False
     hash: str = ""
@@ -34,11 +43,13 @@ class Link(msgspec.Struct, omit_defaults=True):
     expires: int = 0
 
 
-config = None
-conffile = None
+# Global variables - initialized during application startup
+config: Config
+conffile: Path
 
 
-def init_confdir():
+def init_confdir() -> None:
+    global conffile
     if p := os.environ.get("CISTA_HOME"):
         home = Path(p)
     else:
@@ -49,8 +60,6 @@ def init_confdir():
     if not home.is_dir():
         home.mkdir(parents=True, exist_ok=True)
         home.chmod(0o700)
-
-    global conffile
     conffile = home / "db.toml"
 
 
@@ -77,10 +86,10 @@ def dec_hook(typ, obj):
     raise TypeError
 
 
-def config_update(modify):
+def config_update(
+    modify: RawModifyFunc,
+) -> ResultStr | Literal["collision"]:
     global config
-    if conffile is None:
-        init_confdir()
     tmpname = conffile.with_suffix(".tmp")
     try:
         f = tmpname.open("xb")
@@ -95,7 +104,7 @@ def config_update(modify):
             c = msgspec.toml.decode(old, type=Config, dec_hook=dec_hook)
         except FileNotFoundError:
             old = b""
-            c = None
+            c = Config(path=Path(), listen="", secret=secrets.token_hex(12))
         c = modify(c)
         new = msgspec.toml.encode(c, enc_hook=enc_hook)
         if old == new:
@@ -118,17 +127,23 @@ def config_update(modify):
     return "modified" if old else "created"
 
 
-def modifies_config(modify):
-    """Decorator for functions that modify the config file"""
+def modifies_config(
+    modify: Callable[Concatenate[Config, P], Config],
+) -> Callable[P, ResultStr]:
+    """Decorator for functions that modify the config file
+
+    The decorated function takes as first arg Config and returns it modified.
+    The wrapper handles atomic modification and returns a string indicating the result.
+    """
 
     @wraps(modify)
-    def wrapper(*args, **kwargs):
-        def m(c):
+    def wrapper(*args: P.args, **kwargs: P.kwargs) -> ResultStr:
+        def m(c: Config) -> Config:
             return modify(c, *args, **kwargs)
 
         # Retry modification in case of write collision
         while (c := config_update(m)) == "collision":
-            time.sleep(0.01)
+            sleep(0.01)
         return c
 
     return wrapper
@@ -136,8 +151,7 @@ def modifies_config(modify):
 
 def load_config():
     global config
-    if conffile is None:
-        init_confdir()
+    init_confdir()
     config = msgspec.toml.decode(conffile.read_bytes(), type=Config, dec_hook=dec_hook)
 
 
@@ -145,7 +159,7 @@ def load_config():
 def update_config(conf: Config, changes: dict) -> Config:
     """Create/update the config with new values, respecting changes done by others."""
     # Encode into dict, update values with new, convert to Config
-    settings = {} if conf is None else msgspec.to_builtins(conf, enc_hook=enc_hook)
+    settings = msgspec.to_builtins(conf, enc_hook=enc_hook)
     settings.update(changes)
     return msgspec.convert(settings, Config, dec_hook=dec_hook)
 
@@ -155,8 +169,13 @@ def update_user(conf: Config, name: str, changes: dict) -> Config:
     """Create/update a user with new values, respecting changes done by others."""
     # Encode into dict, update values with new, convert to Config
     try:
-        u = conf.users[name].__copy__()
-    except (KeyError, AttributeError):
+        # Copy user by converting to dict and back
+        u = msgspec.convert(
+            msgspec.to_builtins(conf.users[name], enc_hook=enc_hook),
+            User,
+            dec_hook=dec_hook,
+        )
+    except KeyError:
         u = User()
     if "password" in changes:
         from . import auth
@@ -165,7 +184,7 @@ def update_user(conf: Config, name: str, changes: dict) -> Config:
         del changes["password"]
     udict = msgspec.to_builtins(u, enc_hook=enc_hook)
     udict.update(changes)
-    settings = msgspec.to_builtins(conf, enc_hook=enc_hook) if conf else {"users": {}}
+    settings = msgspec.to_builtins(conf, enc_hook=enc_hook)
     settings["users"][name] = msgspec.convert(udict, User, dec_hook=dec_hook)
     return msgspec.convert(settings, Config, dec_hook=dec_hook)
 
@@ -173,6 +192,7 @@ def update_user(conf: Config, name: str, changes: dict) -> Config:
 @modifies_config
 def del_user(conf: Config, name: str) -> Config:
     """Delete named user account."""
-    ret = conf.__copy__()
-    ret.users.pop(name)
-    return ret
+    # Create a copy by converting to dict and back
+    settings = msgspec.to_builtins(conf, enc_hook=enc_hook)
+    settings["users"].pop(name)
+    return msgspec.convert(settings, Config, dec_hook=dec_hook)