"use client";

import { useEffect, useState } from "react";
import { useRouter } from "next/navigation";
import { api, ApiError } from "@/lib/api";
import { useAuth } from "@/lib/auth";

export default function CreatePage() {
  const { user, loading } = useAuth();
  const router = useRouter();

  const [title, setTitle] = useState("");
  const [prompt, setPrompt] = useState("");
  const [mode, setMode] = useState<"instrumental" | "vocals">("instrumental");
  const [lyrics, setLyrics] = useState("");
  const [isPublic, setIsPublic] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [busy, setBusy] = useState(false);

  useEffect(() => {
    if (!loading && !user) router.push("/login");
  }, [loading, user, router]);

  const onSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setError(null);
    setBusy(true);
    try {
      await api.createSong({
        title: title || prompt.slice(0, 60) || "Untitled",
        prompt,
        mode,
        lyrics: mode === "vocals" ? lyrics : null,
        is_public: isPublic,
      });
      router.push("/library");
    } catch (err) {
      setError(err instanceof ApiError ? err.message : "Something went wrong");
    } finally {
      setBusy(false);
    }
  };

  if (loading || !user) return null;

  return (
    <div className="mx-auto max-w-2xl px-6 py-16">
      <h1 className="text-3xl font-bold">Create a song</h1>
      <p className="mt-2 text-white/50">
        Describe the vibe — genre, mood, instruments, story. Generation happens in the background;
        you&apos;ll see it appear in your library once it&apos;s ready.
      </p>

      <form onSubmit={onSubmit} className="mt-8 flex flex-col gap-5">
        <label className="flex flex-col gap-1.5 text-sm text-white/70">
          Title
          <input
            value={title}
            onChange={(e) => setTitle(e.target.value)}
            className="input"
            placeholder="Midnight Drive"
          />
        </label>

        <label className="flex flex-col gap-1.5 text-sm text-white/70">
          Prompt
          <textarea
            required
            value={prompt}
            onChange={(e) => setPrompt(e.target.value)}
            rows={4}
            className="textarea"
            placeholder="Dreamy synthwave with driving bass, nostalgic and hopeful"
          />
        </label>

        <div className="flex gap-2 text-sm">
          {(["instrumental", "vocals"] as const).map((m) => (
            <button
              type="button"
              key={m}
              onClick={() => setMode(m)}
              className={`rounded-full px-4 py-1.5 font-medium capitalize transition-colors ${
                mode === m ? "bg-white text-black" : "border border-white/15 text-white/70 hover:bg-white/10"
              }`}
            >
              {m}
            </button>
          ))}
        </div>

        {mode === "vocals" && (
          <label className="flex flex-col gap-1.5 text-sm text-white/70">
            Lyrics
            <textarea
              required
              value={lyrics}
              onChange={(e) => setLyrics(e.target.value)}
              rows={6}
              className="textarea"
              placeholder={"[Verse 1]\nWrite your lyrics here…"}
            />
          </label>
        )}

        <label className="flex items-center gap-2 text-sm text-white/70">
          <input
            type="checkbox"
            checked={isPublic}
            onChange={(e) => setIsPublic(e.target.checked)}
            className="h-4 w-4 rounded border-white/30 bg-transparent"
          />
          Share to public feed
        </label>

        {error && <p className="text-sm text-red-400">{error}</p>}

        <button
          type="submit"
          disabled={busy}
          className="mt-2 rounded-full bg-gradient-to-r from-fuchsia-500 to-cyan-400 px-6 py-3 text-sm font-semibold text-black hover:opacity-90 disabled:opacity-50"
        >
          {busy ? "Queuing generation…" : "Generate song"}
        </button>
      </form>
    </div>
  );
}