Various improvements

README.md

@@ -81,6 +81,31 @@ Put your OpenAI API key in the platform configuration directory for chap, e.g.,
 
  * `chap grep needle`
 
+## `@FILE` arguments
+
+It's useful to set a bunch of related arguments together, for instance to fully
+configure a back-end. This functionality is implemented via `@FILE` arguments.
+
+Before any other command-line argument parsing is performed, `@FILE` arguments are expanded:
+
+ * An `@FILE` argument is searched relative to the current directory
+ * An `@:FILE` argument is searched relative to the configuration directory (e.g., $HOME/.config/chap)
+ * If an argument starts with a literal `@`, double it: `@@`
+ * `@.` stops processing any further `@FILE` arguments and leaves them unchanged.
+The contents of an `@FILE` are parsed according to `shlex.split(comments=True)`.
+Comments are not supported.
+A typical content might look like this:
+```
+# gpt-3.5.txt: Use cheaper gpt 3.5 and custom prompt
+--backend openai-chatgpt
+-B model:gpt-3.5-turbo
+-s my-custom-system-message.txt
+```
+and you might use it with
+```
+chap @:gpt-3.5.txt ask what version of gpt is this
+```
+
 ## Interactive terminal usage
 The interactive terminal mode is accessed via `chap tui`.
 

src/chap/backends/openai_chatgpt.py

@@ -72,6 +72,9 @@ class Parameters:
         max_request_tokens: int = 1024
         """The approximate greatest number of tokens to send in a request. When the session is long, the system prompt and 1 or more of the most recent interaction steps are sent."""
 
+        url: str = "https://api.openai.com/v1/chat/completions"
+        """The URL of a chatgpt-pcompatible server's completion endpoint."""
+
     def __init__(self) -> None:
         self.parameters = self.Parameters()
 
@@ -97,7 +100,7 @@ def make_full_prompt(self, all_history: Session) -> Session:
     def ask(self, session: Session, query: str, *, timeout: float = 60) -> str:
         full_prompt = self.make_full_prompt(session + [User(query)])
         response = httpx.post(
-            "https://api.openai.com/v1/chat/completions",
+            self.parameters.url,
             json={
                 "model": self.parameters.model,
                 "messages": session_to_list(full_prompt),
@@ -128,7 +131,7 @@ async def aask(
             async with httpx.AsyncClient(timeout=timeout) as client:
                 async with client.stream(
                     "POST",
-                    "https://api.openai.com/v1/chat/completions",
+                    self.parameters.url,
                     headers={"authorization": f"Bearer {self.get_key()}"},
                     json={
                         "model": self.parameters.model,

src/chap/core.py

@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: MIT
 
 
+from collections.abc import Sequence
 import asyncio
 import datetime
 import io
@@ -11,6 +12,7 @@
 import pathlib
 import pkgutil
 import subprocess
+import shlex
 from dataclasses import MISSING, Field, dataclass, fields
 from typing import (
     Any,
@@ -40,6 +42,7 @@
 
 conversations_path = platformdirs.user_state_path("chap") / "conversations"
 conversations_path.mkdir(parents=True, exist_ok=True)
+configuration_path = platformdirs.user_config_path("chap")
 
 
 class ABackend(Protocol):
@@ -333,7 +336,34 @@ class Obj:
     session_filename: Optional[pathlib.Path] = None
 
 
-class MyCLI(click.MultiCommand):
+def expand_splats(args: list[str]) -> list[str]:
+    result = []
+    saw_at_dot = False
+    for a in args:
+        if a == "@.":
+            saw_at_dot = True
+            continue
+        if saw_at_dot:
+            result.append(a)
+            continue
+        if a.startswith("@@"):  ## double @ to escape an argument that starts with @
+            result.append(a[1:])
+            continue
+        if not a.startswith("@"):
+            result.append(a)
+            continue
+        if a.startswith("@:"):
+            fn: pathlib.Path | str = configuration_path / a[2:]
+        else:
+            fn = a[1:]
+        with open(fn, "r", encoding="utf-8") as f:
+            content = f.read()
+        parts = shlex.split(content)
+        result.extend(expand_splats(parts))
+    return result
+
+
+class MyCLI(click.Group):
     def make_context(
         self,
         info_name: Optional[str],
@@ -370,6 +400,42 @@ def format_options(
         if hasattr(api, "parameters"):
             format_backend_help(api, formatter)
 
+    def main(
+        self,
+        args: Sequence[str] | None = None,
+        prog_name: str | None = None,
+        complete_var: str | None = None,
+        standalone_mode: bool = True,
+        windows_expand_args: bool = True,
+        **extra: Any,
+    ) -> Any:
+        if args is None:
+            args = sys.argv[1:]
+            if os.name == "nt" and windows_expand_args:
+                args = click.utils._expand_args(args)
+        else:
+            args = list(args)
+
+        args = expand_splats(args)
+
+        return super().main(
+            args,
+            prog_name=prog_name,
+            complete_var=complete_var,
+            standalone_mode=standalone_mode,
+            windows_expand_args=windows_expand_args,
+            **extra,
+        )
+
+
+class ConfigRelativeFile(click.File):
+    def convert(
+        self, value: Any, param: click.Parameter | None, ctx: click.Context | None
+    ) -> Any:
+        if isinstance(value, str) and value.startswith(":"):
+            value = configuration_path / value[1:]
+        return super().convert(value, param, ctx)
+
 
 main = MyCLI(
     help="Commandline interface to ChatGPT",
@@ -382,11 +448,12 @@ def format_options(
             callback=version_callback,
         ),
         click.Option(
-            ("--system-message-file", "-@"),
-            type=click.File("r"),
+            ("--system-message-file", "-s"),
+            type=ConfigRelativeFile("r"),
             default=None,
             callback=set_system_message_from_file,
             expose_value=False,
+            help=f"Set the system message from a file. If the filename starts with `:` it is relative to the configuration path {configuration_path}.",
         ),
         click.Option(
             ("--system-message", "-S"),