Add internal KVM switch dashboard and service

app/main.py

@@ -0,0 +1,71 @@
+from __future__ import annotations
+
+from contextlib import asynccontextmanager
+from pathlib import Path
+from typing import Any
+
+from fastapi import FastAPI, HTTPException
+from fastapi.responses import FileResponse, HTMLResponse
+from fastapi.staticfiles import StaticFiles
+from pydantic import BaseModel
+
+from app.service import KvmSwitcherService
+
+
+PROJECT_ROOT = Path(__file__).resolve().parent.parent
+STATIC_DIR = PROJECT_ROOT / "static"
+INDEX_PATH = STATIC_DIR / "index.html"
+
+
+class SettingsPayload(BaseModel):
+    device_role: str
+    device_port: str
+
+
+def create_app(
+    service: KvmSwitcherService | None = None,
+    manage_lifecycle: bool = True,
+) -> FastAPI:
+    active_service = service or KvmSwitcherService()
+
+    lifespan = None
+    if manage_lifecycle:
+        @asynccontextmanager
+        async def lifespan(app_instance: FastAPI):
+            del app_instance
+            active_service.start()
+            try:
+                yield
+            finally:
+                active_service.stop()
+
+    app = FastAPI(title="Internal KVM Switch", version="0.1.0", lifespan=lifespan)
+    app.state.kvm_service = active_service
+
+    if STATIC_DIR.exists():
+        app.mount("/static", StaticFiles(directory=STATIC_DIR), name="static")
+
+    @app.get("/")
+    async def root() -> Any:
+        if INDEX_PATH.exists():
+            return FileResponse(INDEX_PATH)
+        return HTMLResponse("<h1>Internal KVM Switch</h1><p>Dashboard file not found.</p>")
+
+    @app.get("/api/status")
+    async def get_status() -> dict[str, Any]:
+        return active_service.get_status()
+
+    @app.post("/api/settings")
+    async def post_settings(payload: SettingsPayload) -> dict[str, Any]:
+        try:
+            return active_service.save_settings(
+                device_role=payload.device_role,
+                device_port=payload.device_port,
+            )
+        except ValueError as exc:
+            raise HTTPException(status_code=400, detail=str(exc)) from exc
+
+    return app
+
+
+app = create_app()