"use client";

import Image from "next/image";

import { useState, useRef, useEffect } from "react";

interface Message {
  role: "user" | "assistant";
  content: string;
}

const RAG_API_URL = "https://ai.apply4jobs.de/api/v1/chat/completions";

export default function ChatWidget() {
  const [isOpen, setIsOpen] = useState(false);
  const [messages, setMessages] = useState<Message[]>([
    {
      role: "assistant",
      content:
        "Hallo! Ich bin Sebastians KI-Assistent. Stellen Sie mir gerne Fragen zu seiner Berufserfahrung, seinen Fähigkeiten oder Projekten. 👋\n\nHello! I'm Sebastian's AI assistant. Feel free to ask me about his professional experience, skills or projects.",
    },
  ]);
  const [input, setInput] = useState("");
  const [isLoading, setIsLoading] = useState(false);
  const messagesEndRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    messagesEndRef.current?.scrollIntoView({ behavior: "smooth" });
  }, [messages, isLoading]);

  const sendMessage = async () => {
    if (!input.trim() || isLoading) return;

    const userMessage: Message = { role: "user", content: input.trim() };
    setMessages((prev) => [...prev, userMessage]);
    setInput("");
    setIsLoading(true);

    try {
      const response = await fetch(RAG_API_URL, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          model: "sebastian-rag",
          messages: [...messages, userMessage],
          stream: false,
        }),
      });

      const data = await response.json();
      const assistantContent =
        data?.choices?.[0]?.message?.content ?? "Entschuldigung, ich konnte keine Antwort generieren.";

      setMessages((prev) => [
        ...prev,
        { role: "assistant", content: assistantContent },
      ]);
    } catch {
      setMessages((prev) => [
        ...prev,
        {
          role: "assistant",
          content: "Es ist ein Fehler aufgetreten. Bitte versuchen Sie es erneut.",
        },
      ]);
    } finally {
      setIsLoading(false);
    }
  };

  const handleKeyDown = (e: React.KeyboardEvent) => {
    if (e.key === "Enter" && !e.shiftKey) {
      e.preventDefault();
      sendMessage();
    }
  };

  return (
    <>
      {/* Chat Window */}
      {isOpen && (
        <div className="fixed bottom-24 right-6 z-50 w-96 max-w-[calc(100vw-2rem)] bg-white rounded-2xl shadow-2xl flex flex-col overflow-hidden border border-gray-200"
          style={{ height: "520px" }}>
          {/* Header */}
          <div className="bg-gradient-to-r from-blue-600 to-blue-700 px-4 py-3 flex items-center justify-between">
            <div className="flex items-center gap-3">
              <div className="w-9 h-9 rounded-full overflow-hidden bg-white/20 flex-shrink-0">
                <Image src="/img/Bewerbungsfoto_2025.jpg" alt="Sebastian Fröhlich" width={36} height={36} className="w-full h-full object-cover object-center" />
              </div>
              <div>
                <p className="text-white font-semibold text-sm">Sebastian Fröhlich</p>
                <p className="text-blue-200 text-xs">KI-Assistent · AI Assistant</p>
              </div>
            </div>
            <button
              onClick={() => setIsOpen(false)}
              className="text-white/80 hover:text-white transition-colors text-xl leading-none"
            >
              ×
            </button>
          </div>

          {/* Messages */}
          <div className="flex-1 overflow-y-auto px-4 py-3 space-y-3 bg-gray-50">
            {messages.map((msg, i) => (
              <div key={i} className={`flex ${msg.role === "user" ? "justify-end" : "justify-start"}`}>
                <div
                  className={`max-w-[80%] rounded-2xl px-4 py-2 text-sm whitespace-pre-wrap ${
                    msg.role === "user"
                      ? "bg-blue-600 text-white rounded-br-sm"
                      : "bg-white text-gray-800 shadow-sm border border-gray-100 rounded-bl-sm"
                  }`}
                >
                  {msg.content}
                </div>
              </div>
            ))}
            {isLoading && (
              <div className="flex justify-start">
                <div className="bg-white text-gray-500 rounded-2xl rounded-bl-sm px-4 py-3 text-sm shadow-sm border border-gray-100 flex items-center gap-2">
                  <span className="flex gap-1">
                    <span className="w-1.5 h-1.5 bg-blue-400 rounded-full animate-bounce" style={{ animationDelay: "0ms" }} />
                    <span className="w-1.5 h-1.5 bg-blue-400 rounded-full animate-bounce" style={{ animationDelay: "150ms" }} />
                    <span className="w-1.5 h-1.5 bg-blue-400 rounded-full animate-bounce" style={{ animationDelay: "300ms" }} />
                  </span>
                  <span className="text-xs text-gray-400">Antwort wird generiert…</span>
                </div>
              </div>
            )}
            <div ref={messagesEndRef} />
          </div>

          {/* Input */}
          <div className="px-3 py-3 bg-white border-t border-gray-100 flex gap-2 items-end">
            <textarea
              value={input}
              onChange={(e) => setInput(e.target.value)}
              onKeyDown={handleKeyDown}
              placeholder="Ihre Frage / Your question…"
              rows={1}
              disabled={isLoading}
              className="flex-1 resize-none rounded-xl border border-gray-200 px-3 py-2 text-sm focus:outline-none focus:border-blue-400 disabled:opacity-50 max-h-24"
            />
            <button
              onClick={sendMessage}
              disabled={isLoading || !input.trim()}
              className="bg-blue-600 hover:bg-blue-700 disabled:opacity-40 disabled:cursor-not-allowed text-white rounded-xl px-4 py-2 text-sm font-medium transition-colors"
            >
              ↑
            </button>
          </div>
        </div>
      )}

      {/* Floating Button */}
      <button
        onClick={() => setIsOpen(!isOpen)}
        className="fixed bottom-6 right-6 z-50 w-14 h-14 bg-blue-600 hover:bg-blue-700 text-white rounded-full shadow-lg hover:shadow-xl transition-all flex items-center justify-center"
        aria-label="Chat öffnen"
      >
        {isOpen ? (
          <span className="text-2xl leading-none">×</span>
        ) : (
          <svg xmlns="http://www.w3.org/2000/svg" className="w-6 h-6" fill="none" viewBox="0 0 24 24" stroke="currentColor">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M8 10h.01M12 10h.01M16 10h.01M9 16H5a2 2 0 01-2-2V6a2 2 0 012-2h14a2 2 0 012 2v8a2 2 0 01-2 2h-5l-5 5v-5z" />
          </svg>
        )}
      </button>
    </>
  );
}