"use client";
import { useState } from "react";
import ChatMessage from "./ChatMessage";
import FileUpload from "./FileUpload";

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

export default function Chat() {
  const [messages, setMessages] = useState<Message[]>([]);
  const [input, setInput] = useState("");
  const [isLoading, setIsLoading] = useState(false);
  const [hasUploadedFile, setHasUploadedFile] = useState(false);

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!input.trim() || isLoading) return;

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

    try {
      const response = await fetch(`${process.env.NEXT_PUBLIC_API_URL}/ask`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ text: userMessage }),
      });

      const data = await response.json();
      setMessages((prev) => [
        ...prev,
        { type: "assistant", content: data.answer },
      ]);
    } catch (error) {
      console.error("Error:", error);
      setMessages((prev) => [
        ...prev,
        {
          type: "assistant",
          content: "Sorry, there was an error processing your request.",
        },
      ]);
    } finally {
      setIsLoading(false);
    }
  };

  return (
    <div className="w-full max-w-4xl mx-auto h-[80vh] flex flex-col">
      {!hasUploadedFile ? (
        <FileUpload onUploadSuccess={() => setHasUploadedFile(true)} />
      ) : (
        <>
          <div className="flex-1 overflow-y-auto p-4 space-y-4">
            {messages.map((message, index) => (
              <ChatMessage
                key={index}
                type={message.type}
                content={message.content}
              />
            ))}
            {isLoading && (
              <div className="text-center text-gray-500">Loading...</div>
            )}
          </div>
          <form onSubmit={handleSubmit} className="p-4 border-t">
            <div className="flex gap-2">
              <input
                type="text"
                value={input}
                onChange={(e) => setInput(e.target.value)}
                placeholder="Ask a question about your PDF..."
                className="flex-1 p-2 border rounded-lg dark:bg-gray-800"
                disabled={isLoading}
              />
              <button
                type="submit"
                disabled={isLoading}
                className="px-4 py-2 bg-blue-500 text-white rounded-lg hover:bg-blue-600 disabled:opacity-50"
              >
                Send
              </button>
            </div>
          </form>
        </>
      )}
    </div>
  );
}