// frontend/src/shell/NewSessionDialog.tsx
import { useState } from "react";
import { useQuery } from "@tanstack/react-query";
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
} from "../components/ui/dialog";
import { Button } from "../components/ui/button";
import { createSession } from "../api/sessions";
import { listWorkspaces } from "../api/workspaces";
import { listModels } from "../api/models";

interface Props {
  onCreated: (id: string) => void;
}

export function NewSessionDialog({ onCreated }: Props) {
  const [open, setOpen] = useState(false);
  const [question, setQuestion] = useState("");
  const [workspace, setWorkspace] = useState("");
  const [model, setModel] = useState("");
  const [thinking, setThinking] = useState("");
  const [provider, setProvider] = useState("");
  const [error, setError] = useState<string | null>(null);
  const [busy, setBusy] = useState(false);

  const { data: workspaces = [] } = useQuery({
    queryKey: ["workspaces"],
    queryFn: listWorkspaces,
    enabled: open,
  });

  const { data: modelsData } = useQuery({
    queryKey: ["models"],
    queryFn: listModels,
    enabled: open,
  });

  // Model entries may be plain strings or objects ({ id, provider, ... });
  // normalize to { value, label } so the dropdown renders either shape.
  const modelList: { value: string; label: string }[] = Array.isArray(
    modelsData?.models,
  )
    ? modelsData.models.map((m) => {
        if (typeof m === "string") return { value: m, label: m };
        const o = m as { id?: string; provider?: string };
        const value = o.id ?? "";
        const label = o.provider ? `${o.provider}/${value}` : value;
        return { value, label };
      })
    : [];

  // When workspace list loads, pre-select the first one if nothing chosen yet
  const effectiveWorkspace =
    workspace || (workspaces.length > 0 ? workspaces[0].name : "default");

  async function handleSubmit(e: React.FormEvent) {
    e.preventDefault();
    setError(null);
    if (!question.trim()) {
      setError("La domanda non può essere vuota.");
      return;
    }
    setBusy(true);
    try {
      const { id } = await createSession({
        workspace: effectiveWorkspace,
        question: question.trim(),
        ...(model ? { model } : {}),
        ...(thinking ? { thinking } : {}),
        ...(provider ? { provider } : {}),
      });
      setOpen(false);
      setQuestion("");
      setModel("");
      setThinking("");
      setProvider("");
      onCreated(id);
    } catch (err) {
      setError(err instanceof Error ? err.message : "Errore nella creazione della sessione.");
    } finally {
      setBusy(false);
    }
  }

  return (
    <Dialog open={open} onOpenChange={setOpen}>
      <Button
        variant="default"
        size="sm"
        className="w-full"
        onClick={() => setOpen(true)}
      >
        Nuova domanda
      </Button>
      <DialogContent showCloseButton={false}>
        <DialogHeader>
          <DialogTitle>Nuova sessione</DialogTitle>
        </DialogHeader>
        <form onSubmit={handleSubmit} className="flex flex-col gap-3">
          <div>
            <label className="block text-xs font-medium mb-1" htmlFor="nsd-question">
              Domanda
            </label>
            <textarea
              id="nsd-question"
              value={question}
              onChange={(e) => setQuestion(e.target.value)}
              rows={3}
              className="w-full border rounded px-2 py-1 text-sm focus:outline-none focus:ring-1 resize-none"
              placeholder="Inserisci la tua domanda…"
            />
          </div>

          <div>
            <label className="block text-xs font-medium mb-1" htmlFor="nsd-workspace">
              Workspace
            </label>
            <select
              id="nsd-workspace"
              value={workspace}
              onChange={(e) => setWorkspace(e.target.value)}
              className="w-full border rounded px-2 py-1 text-sm"
            >
              {workspaces.length === 0 ? (
                <option value="default">default</option>
              ) : (
                workspaces.map((w) => (
                  <option key={w.name} value={w.name}>
                    {w.name}
                  </option>
                ))
              )}
            </select>
          </div>

          {/* Model field — graceful degradation (§9): free text when models list is empty */}
          <div>
            <label className="block text-xs font-medium mb-1" htmlFor="nsd-model">
              Modello (opzionale)
            </label>
            {modelList.length > 0 ? (
              <select
                id="nsd-model"
                value={model}
                onChange={(e) => setModel(e.target.value)}
                className="w-full border rounded px-2 py-1 text-sm"
              >
                <option value="">— default —</option>
                {modelList.map((m) => (
                  <option key={m.value} value={m.value}>
                    {m.label}
                  </option>
                ))}
              </select>
            ) : (
              <input
                id="nsd-model"
                type="text"
                value={model}
                onChange={(e) => setModel(e.target.value)}
                placeholder="es. claude-sonnet-4-5"
                className="w-full border rounded px-2 py-1 text-sm focus:outline-none focus:ring-1"
                data-testid="model-freetext"
              />
            )}
          </div>

          <div>
            <label className="block text-xs font-medium mb-1" htmlFor="nsd-thinking">
              Thinking (opzionale)
            </label>
            <input
              id="nsd-thinking"
              type="text"
              value={thinking}
              onChange={(e) => setThinking(e.target.value)}
              placeholder="enabled / disabled"
              className="w-full border rounded px-2 py-1 text-sm focus:outline-none focus:ring-1"
            />
          </div>

          <div>
            <label className="block text-xs font-medium mb-1" htmlFor="nsd-provider">
              Provider (opzionale)
            </label>
            <input
              id="nsd-provider"
              type="text"
              value={provider}
              onChange={(e) => setProvider(e.target.value)}
              placeholder="es. anthropic"
              className="w-full border rounded px-2 py-1 text-sm focus:outline-none focus:ring-1"
            />
          </div>

          {error && (
            <p className="text-xs text-destructive" role="alert">
              {error}
            </p>
          )}

          <div className="flex justify-end gap-2 pt-1">
            <Button
              type="button"
              variant="outline"
              size="sm"
              onClick={() => setOpen(false)}
            >
              Annulla
            </Button>
            <Button type="submit" size="sm" disabled={busy}>
              {busy ? "Creazione…" : "Crea"}
            </Button>
          </div>
        </form>
      </DialogContent>
    </Dialog>
  );
}