"""Example FastAPI application for the Streamline Gateway."""

from datetime import datetime

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI(title="API Example", description="A simple FastAPI app example")


class Message(BaseModel):
    """Message model."""

    text: str


class MessageResponse(BaseModel):
    """Message response model."""

    message: str
    timestamp: str
    echo: str


@app.get("/")
async def root() -> dict[str, str]:
    """Root endpoint."""
    return {
        "message": "Welcome to the API Example!",
        "docs": "/docs",
        "health": "/health",
    }


@app.get("/health")
async def health() -> dict[str, str]:
    """Health check endpoint."""
    return {"status": "healthy", "timestamp": datetime.now().isoformat()}


@app.post("/echo")
async def echo(message: Message) -> MessageResponse:
    """Echo the received message with a timestamp."""
    return MessageResponse(
        message="Message received",
        timestamp=datetime.now().isoformat(),
        echo=message.text,
    )


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: str | None = None) -> dict[str, int | str | None]:
    """Example endpoint with path and query parameters."""
    return {"item_id": item_id, "q": q}