"""Client CRUD API — POST /clients, GET /clients."""
from __future__ import annotations

from pathlib import Path

from fastapi import APIRouter, Form, Request
from fastapi.responses import HTMLResponse
from fastapi.templating import Jinja2Templates
from peewee import IntegrityError

from imptune.db.models import Client

router = APIRouter(prefix="/clients")

templates = Jinja2Templates(
    directory=str(Path(__file__).parent.parent / "templates")
)


def _error_response(message: str, status_code: int = 400) -> HTMLResponse:
    """Return an HTMX-friendly error fragment swapped into #client-list."""
    return HTMLResponse(
        content=f"<div id='client-list' class='error'><p>{message}</p></div>",
        status_code=status_code,
    )


def _render_client_list(request: Request) -> HTMLResponse:
    """Render the client list partial for HTMX swap."""
    clients = list(Client.select().order_by(Client.name))
    return templates.TemplateResponse(
        request=request,
        name="partials/client_list.html",
        context={"clients": clients},
    )


@router.post("", response_class=HTMLResponse)
def create_client(request: Request, name: str = Form(...)) -> HTMLResponse:
    """Create a new client.

    Accepts form-encoded `name`. Validates non-empty. Returns HTMX partial
    with updated client list on success, or error fragment on failure.
    """
    name = name.strip()
    if not name:
        return _error_response("Client name is required.")

    try:
        Client.create(name=name)
    except IntegrityError:
        return _error_response(f"Client '{name}' already exists.", status_code=409)

    return _render_client_list(request)
