import { useState, useEffect } from "react";
import { motion } from "motion/react";
import { Bot } from "lucide-react";

function useLoadingMessages() {
  const [messages, setMessages] = useState<string[]>([]);

  useEffect(() => {
    fetch("/loading-messages.yaml")
      .then((r) => r.text())
      .then((text) => {
        const parsed = text
          .split("\n")
          .filter((l) => l.trimStart().startsWith("- "))
          .map((l) => l.replace(/^\s*- /, "").trim())
          .filter(Boolean);
        if (parsed.length > 0) setMessages(parsed);
      })
      .catch(() => {});
  }, []);

  return messages;
}

export default function TypingIndicator() {
  const loadingMessages = useLoadingMessages();
  const [phraseIndex, setPhraseIndex] = useState(0);

  useEffect(() => {
    if (loadingMessages.length === 0) return;
    setPhraseIndex(Math.floor(Math.random() * loadingMessages.length));
    const id = setInterval(() => {
      setPhraseIndex((prev) => {
        let next: number;
        do {
          next = Math.floor(Math.random() * loadingMessages.length);
        } while (loadingMessages.length > 1 && next === prev);
        return next;
      });
    }, 300);
    return () => clearInterval(id);
  }, [loadingMessages]);

  return (
    <motion.div
      className="flex gap-3 px-4 py-2"
      initial={{ opacity: 0, y: 8 }}
      animate={{ opacity: 1, y: 0 }}
      transition={{ duration: 0.25, ease: "easeOut" }}
    >
      <div className="w-7 h-7 rounded-full bg-gradient-to-br from-brand-green-light to-brand-green flex-shrink-0 flex items-center justify-center shadow-sm">
        <Bot className="h-4 w-4 text-white" />
      </div>

      <div className="bg-white border border-neutral-100 rounded-2xl rounded-tl-sm shadow-sm px-4 py-3 min-w-[6rem]">
        {loadingMessages.length > 0 ? (
          <span className="text-sm text-neutral-400 font-medium">
            {loadingMessages[phraseIndex]}…
          </span>
        ) : (
          <div className="flex items-center gap-1.5 animate-pulse">
            <span className="w-2 h-2 rounded-full bg-neutral-300" />
            <span className="w-2 h-2 rounded-full bg-neutral-300" style={{ animationDelay: "150ms" }} />
            <span className="w-2 h-2 rounded-full bg-neutral-300" style={{ animationDelay: "300ms" }} />
          </div>
        )}
      </div>
    </motion.div>
  );
}