From d60548dfc448d93d4b0f792448ecddba8f7d6eb8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Wed, 23 Aug 2023 17:17:34 +0200
Subject: [PATCH] integrate webserver into cli

---
 pkgs/clan-cli/clan_cli/__init__.py       |  7 ++--
 pkgs/clan-cli/clan_cli/webui/__init__.py | 39 ++++++++++++++++++++++
 pkgs/clan-cli/clan_cli/webui/server.py   | 41 ++++++++++++++++++++++++
 pkgs/clan-cli/default.nix                | 10 ++++--
 4 files changed, 93 insertions(+), 4 deletions(-)
 create mode 100644 pkgs/clan-cli/clan_cli/webui/__init__.py
 create mode 100644 pkgs/clan-cli/clan_cli/webui/server.py

diff --git a/pkgs/clan-cli/clan_cli/__init__.py b/pkgs/clan-cli/clan_cli/__init__.py
index 18022fe5b..52777182a 100644
--- a/pkgs/clan-cli/clan_cli/__init__.py
+++ b/pkgs/clan-cli/clan_cli/__init__.py
@@ -3,9 +3,9 @@ import sys
 from types import ModuleType
 from typing import Optional
 
-from . import admin, secrets, update
+from . import admin, secrets, update, webui
 
-# from . import admin, config, secrets, update
+# from . import admin, config, secrets, update, webui
 from .errors import ClanError
 from .ssh import cli as ssh_cli
 
@@ -39,6 +39,9 @@ def main() -> None:
     )
     update.register_parser(parser_update)
 
+    parser_webui = subparsers.add_parser("webui", help="start webui")
+    webui.register_parser(parser_webui)
+
     if argcomplete:
         argcomplete.autocomplete(parser)
 
diff --git a/pkgs/clan-cli/clan_cli/webui/__init__.py b/pkgs/clan-cli/clan_cli/webui/__init__.py
new file mode 100644
index 000000000..013468bc4
--- /dev/null
+++ b/pkgs/clan-cli/clan_cli/webui/__init__.py
@@ -0,0 +1,39 @@
+import argparse
+from typing import Callable, NoReturn, Optional
+
+start_server: Optional[Callable] = None
+ServerImportError: Optional[ImportError] = None
+try:
+    from .server import start_server
+except ImportError as e:
+    ServerImportError = e
+
+
+def fastapi_is_not_installed(_: argparse.Namespace) -> NoReturn:
+    assert ServerImportError is not None
+    print(
+        f"Dependencies for the webserver is not installed. The webui command has been disabled ({ServerImportError})"
+    )
+    exit(1)
+
+
+def register_parser(parser: argparse.ArgumentParser) -> None:
+    parser.add_argument("--port", type=int, default=2979, help="Port to listen on")
+    parser.add_argument("--host", type=str, default="::1", help="Host to listen on")
+    parser.add_argument(
+        "--no-open", action="store_true", help="Don't open the browser", default=False
+    )
+    parser.add_argument(
+        "--reload", action="store_true", help="Don't reload on changes", default=False
+    )
+    parser.add_argument(
+        "--log-level",
+        type=str,
+        default="info",
+        help="Log level",
+        choices=["critical", "error", "warning", "info", "debug", "trace"],
+    )
+    if start_server is None:
+        parser.set_defaults(func=fastapi_is_not_installed)
+    else:
+        parser.set_defaults(func=start_server)
diff --git a/pkgs/clan-cli/clan_cli/webui/server.py b/pkgs/clan-cli/clan_cli/webui/server.py
new file mode 100644
index 000000000..7205496bc
--- /dev/null
+++ b/pkgs/clan-cli/clan_cli/webui/server.py
@@ -0,0 +1,41 @@
+import argparse
+import time
+import urllib.request
+import webbrowser
+from threading import Thread
+
+from fastapi import FastAPI
+
+# XXX: can we dynamically load this using nix develop?
+from uvicorn import run
+
+app = FastAPI()
+
+
+@app.get("/health")
+async def read_root() -> str:
+    return "OK"
+
+
+def defer_open_browser(base_url: str) -> None:
+    for i in range(5):
+        try:
+            urllib.request.urlopen(base_url + "/health")
+            break
+        except OSError:
+            time.sleep(i)
+    webbrowser.open(base_url)
+
+
+def start_server(args: argparse.Namespace) -> None:
+    if not args.no_open:
+        Thread(
+            target=defer_open_browser, args=(f"http://[{args.host}]:{args.port}",)
+        ).start()
+    run(
+        "clan_cli.webui.server:app",
+        host=args.host,
+        port=args.port,
+        log_level=args.log_level,
+        reload=args.reload,
+    )
diff --git a/pkgs/clan-cli/default.nix b/pkgs/clan-cli/default.nix
index 746775a0c..de9dfb297 100644
--- a/pkgs/clan-cli/default.nix
+++ b/pkgs/clan-cli/default.nix
@@ -1,5 +1,7 @@
 { age
 , argcomplete
+, fastapi
+, uvicorn
 , bubblewrap
 , installShellFiles
 , nix
@@ -22,7 +24,11 @@ let
   # evaluating the flake .#
   CLAN_OPTIONS_FILE = ./clan_cli/config/jsonschema/options.json;
 
-  dependencies = [ argcomplete ];
+  dependencies = [
+    argcomplete # optional dependency: if not enabled, shell completion will not work
+    fastapi
+    uvicorn # optional dependencies: if not enabled, webui subcommand will not work
+  ];
 
   testDependencies = [
     pytest
@@ -73,7 +79,7 @@ python3.pkgs.buildPythonPackage {
     wheel
   ] ++ testDependencies;
 
-  passthru.testDependencies = testDependencies;
+  passthru.testDependencies = dependencies ++ testDependencies;
 
   makeWrapperArgs = [
     "--set CLAN_FLAKE ${self}"