import { useState, useEffect } from "react";
import { useChatStore } from "@/stores/chatStore";
import { getTranscripts } from "@/lib/api";
import { useScrollToBottom } from "@/hooks/useScrollToBottom";
import { CHAT_UPDATED_EVENT, chatEventEmitter } from "@/lib/chatEventEmitter";
import type { Transcript } from "@/lib/types";

export function useChatPage() {
  const [selectedTranscripts, setSelectedTranscripts] = useState<Transcript[]>(
    []
  );
  const [selectedTranscript, setSelectedTranscript] =
    useState<Transcript | null>(null);
  const [isLoading, setIsLoading] = useState<boolean>(false);
  const [evaluatingMessageIndex, setEvaluatingMessageIndex] = useState<
    number | null
  >(null);
  const [hasScrolledToBottom, setHasScrolledToBottom] = useState(false);
  const [isTranscriptsOpen, setIsTranscriptsOpen] = useState<boolean>(false);

  const { selectedChat, selectedChatId } = useChatStore();
  const { scrollRef, scrollToBottom } = useScrollToBottom();

  const handleTranscriptClick = async (transcript: Transcript) => {
    if (!transcript) return;
    setSelectedTranscript(transcript);

    if (transcript.filename !== selectedTranscript?.filename) {
      try {
        const data = await getTranscripts(transcript.filename);
        setSelectedTranscripts(data);
        setIsTranscriptsOpen(true);
      } catch (error) {
        console.error("Error loading transcripts:", error);
      }
    }
  };

  const handleEvaluate = (messageIndex: number) => {
    setEvaluatingMessageIndex(messageIndex);
  };

  useEffect(() => {
    if (!hasScrolledToBottom) {
      scrollToBottom();
      setHasScrolledToBottom(true);
    }

    const handleChatUpdate = () => {
      if (!hasScrolledToBottom) {
        scrollToBottom();
        setHasScrolledToBottom(true);
      }
    };

    chatEventEmitter.on(CHAT_UPDATED_EVENT, handleChatUpdate);
    return () => {
      chatEventEmitter.off(CHAT_UPDATED_EVENT, handleChatUpdate);
    };
  }, [scrollToBottom, hasScrolledToBottom]);

  return {
    selectedTranscripts,
    selectedTranscript,
    isLoading,
    evaluatingMessageIndex,
    setEvaluatingMessageIndex,
    selectedChat,
    selectedChatId,
    scrollRef,
    scrollToBottom,
    handleTranscriptClick,
    handleEvaluate,
    isTranscriptsOpen,
    setIsTranscriptsOpen,
  };
}