import { useState } from "react";
import { Loader, Lock, User } from "lucide-react";
import { api, ApiError } from "../../api/client.js";

interface Props {
  onSuccess: (username: string) => void;
}

export function LoginScreen({ onSuccess }: Props) {
  const [username, setUsername] = useState("");
  const [password, setPassword] = useState("");
  const [error, setError] = useState<string | null>(null);
  const [busy, setBusy] = useState(false);

  async function submit(e: React.SubmitEvent) {
    e.preventDefault();
    if (busy) return;
    setBusy(true);
    setError(null);
    try {
      const res = await api.login(username, password);
      onSuccess(res.username);
    } catch (err) {
      if (err instanceof ApiError && err.status === 401) {
        setError("Invalid username or password.");
      } else if (err instanceof ApiError && err.status === 429) {
        setError(
          "Too many failed attempts. Please wait a moment and try again.",
        );
      } else {
        setError(err instanceof Error ? err.message : "Login failed.");
      }
    } finally {
      setBusy(false);
    }
  }

  return (
    <div className="min-h-screen bg-zinc-950 text-zinc-100 flex items-center justify-center p-4">
      <div className="w-full max-w-sm">
        <div className="flex flex-col items-center mb-8">
          <img src="/logo.svg" alt="NVCurve" className="w-12 h-12 mb-3" />
          <h1 className="text-2xl font-bold text-transparent bg-clip-text bg-gradient-to-r from-violet-400 to-fuchsia-400 tracking-tight">
            NVCurve
          </h1>
          <p className="text-sm text-zinc-500 mt-1">Sign in to continue</p>
        </div>

        <form
          onSubmit={submit}
          className="bg-zinc-900 border border-zinc-800 rounded-xl p-6 shadow-[0_8px_30px_rgb(0,0,0,0.6)] flex flex-col gap-4"
        >
          <div className="flex flex-col gap-1.5">
            <label
              htmlFor="username"
              className="text-xs font-medium text-zinc-400"
            >
              Username
            </label>
            <div className="relative">
              <User
                size={15}
                className="absolute left-3 top-1/2 -translate-y-1/2 text-zinc-500"
              />
              <input
                id="username"
                type="text"
                autoComplete="username"
                autoFocus
                value={username}
                onChange={(e) => setUsername(e.target.value)}
                className="w-full bg-zinc-950 border border-zinc-700 rounded-lg pl-9 pr-3 py-2 text-sm text-zinc-100 placeholder-zinc-600 focus:outline-none focus:border-violet-500 focus:ring-1 focus:ring-violet-500/40"
                placeholder="username"
              />
            </div>
          </div>

          <div className="flex flex-col gap-1.5">
            <label
              htmlFor="password"
              className="text-xs font-medium text-zinc-400"
            >
              Password
            </label>
            <div className="relative">
              <Lock
                size={15}
                className="absolute left-3 top-1/2 -translate-y-1/2 text-zinc-500"
              />
              <input
                id="password"
                type="password"
                autoComplete="current-password"
                value={password}
                onChange={(e) => setPassword(e.target.value)}
                className="w-full bg-zinc-950 border border-zinc-700 rounded-lg pl-9 pr-3 py-2 text-sm text-zinc-100 placeholder-zinc-600 focus:outline-none focus:border-violet-500 focus:ring-1 focus:ring-violet-500/40"
                placeholder="••••••••"
              />
            </div>
          </div>

          {error && (
            <div className="text-sm text-red-400 bg-red-500/10 border border-red-500/20 rounded-lg px-3 py-2">
              {error}
            </div>
          )}

          <button
            type="submit"
            disabled={busy || !username || !password}
            className="mt-1 flex items-center justify-center gap-2 bg-violet-600 hover:bg-violet-500 disabled:opacity-50 disabled:cursor-not-allowed text-white text-sm font-medium rounded-lg py-2.5 transition-colors"
          >
            {busy && <Loader size={15} className="animate-spin" />}
            {busy ? "Signing in…" : "Sign in"}
          </button>
        </form>

        <p className="text-center text-xs text-zinc-600 mt-4">
          Sessions last 24 hours, then you will be asked to sign in again.
        </p>
      </div>
    </div>
  );
}