import './AIRoadmap.css';

import { useQuery } from '@tanstack/react-query';
import { useCallback, useRef, useState } from 'react';
import { flushSync } from 'react-dom';
import { useToast } from '../../hooks/use-toast';
import { queryClient } from '../../stores/query-client';
import { AITutorLayout } from '../AITutor/AITutorLayout';
import { UpgradeAccountModal } from '../Billing/UpgradeAccountModal';
import { aiRoadmapOptions, generateAIRoadmap } from '../../queries/ai-roadmap';
import { GenerateAIRoadmap } from './GenerateAIRoadmap';
import { AIRoadmapContent, type RoadmapNodeDetails } from './AIRoadmapContent';
import { AIRoadmapChat } from './AIRoadmapChat';
import { AlertCircleIcon } from 'lucide-react';
import { isLoggedIn } from '../../lib/jwt';
import { showLoginPopup } from '../../lib/popup';
import { aiLimitOptions } from '../../queries/ai-course';
import { billingDetailsOptions } from '../../queries/billing';

export type AIRoadmapChatActions = {
  handleNodeClick: (node: RoadmapNodeDetails) => void;
};

type AIRoadmapProps = {
  roadmapSlug?: string;
};

export function AIRoadmap(props: AIRoadmapProps) {
  const { roadmapSlug: defaultRoadmapSlug } = props;
  const [roadmapSlug, setRoadmapSlug] = useState(defaultRoadmapSlug);

  const toast = useToast();
  const [showUpgradeModal, setShowUpgradeModal] = useState(false);
  const [isRegenerating, setIsRegenerating] = useState(false);
  const [regeneratedSvgHtml, setRegeneratedSvgHtml] = useState<string | null>(
    null,
  );

  const aiChatActionsRef = useRef<AIRoadmapChatActions | null>(null);

  // only fetch the guide if the guideSlug is provided
  // otherwise we are still generating the guide
  const {
    data: aiRoadmap,
    isLoading: isLoadingBySlug,
    error: aiRoadmapError,
  } = useQuery(aiRoadmapOptions(roadmapSlug), queryClient);

  const {
    data: tokenUsage,
    isLoading: isTokenUsageLoading,
    refetch: refetchTokenUsage,
  } = useQuery(aiLimitOptions(), queryClient);

  const { data: userBillingDetails, isLoading: isBillingDetailsLoading } =
    useQuery(billingDetailsOptions(), queryClient);

  const isLimitExceeded = (tokenUsage?.used || 0) >= (tokenUsage?.limit || 0);
  const isPaidUser = userBillingDetails?.status === 'active';

  const handleRegenerate = async (prompt?: string) => {
    if (!isLoggedIn()) {
      showLoginPopup();
      return;
    }

    if (!isPaidUser && isLimitExceeded) {
      setShowUpgradeModal(true);
      return;
    }

    flushSync(() => {
      setIsRegenerating(true);
      setRegeneratedSvgHtml(null);
    });

    queryClient.cancelQueries(aiRoadmapOptions(roadmapSlug));
    queryClient.setQueryData(aiRoadmapOptions(roadmapSlug).queryKey, (old) => {
      if (!old) {
        return old;
      }

      return {
        ...old,
        data: '',
        svgHtml: '',
      };
    });

    setRegeneratedSvgHtml('');
    await generateAIRoadmap({
      roadmapSlug: aiRoadmap?.slug || '',
      term: aiRoadmap?.term || '',
      prompt,
      isForce: true,
      onStreamingChange: setIsRegenerating,
      onRoadmapSvgChange: (svg) => {
        setRegeneratedSvgHtml(svg.outerHTML);
      },
      onError: (error) => {
        toast.error(error);
      },
      onFinish: () => {
        setIsRegenerating(false);
        refetchTokenUsage();
        queryClient.invalidateQueries(aiRoadmapOptions(roadmapSlug));
      },
    });
  };

  const isLoading =
    isLoadingBySlug ||
    isRegenerating ||
    isTokenUsageLoading ||
    isBillingDetailsLoading;

  const handleNodeClick = useCallback(
    (node: RoadmapNodeDetails) => {
      aiChatActionsRef.current?.handleNodeClick(node);
    },
    [aiChatActionsRef],
  );

  return (
    <AITutorLayout
      wrapperClassName="flex-row p-0 lg:p-0 overflow-hidden relative bg-white"
      containerClassName="h-[calc(100vh-49px)] overflow-hidden relative"
    >
      {showUpgradeModal && (
        <UpgradeAccountModal onClose={() => setShowUpgradeModal(false)} />
      )}

      {!isLoading && aiRoadmapError && (
        <div className="absolute inset-0 z-10 flex h-full flex-col items-center justify-center bg-white">
          <div className="flex flex-col items-center justify-center gap-2">
            <AlertCircleIcon className="size-10 text-gray-500" />
            <p className="text-center">
              {aiRoadmapError?.message || 'Something went wrong'}
            </p>
          </div>
        </div>
      )}

      <div className="grow overflow-y-auto p-4 pt-0">
        {roadmapSlug && !aiRoadmapError && (
          <AIRoadmapContent
            svgHtml={regeneratedSvgHtml ?? aiRoadmap?.svgHtml ?? ''}
            isLoading={isLoading}
            onRegenerate={handleRegenerate}
            roadmapSlug={roadmapSlug}
            onNodeClick={handleNodeClick}
          />
        )}
        {!roadmapSlug && !aiRoadmapError && (
          <GenerateAIRoadmap onRoadmapSlugChange={setRoadmapSlug} />
        )}
      </div>

      <AIRoadmapChat
        roadmapSlug={roadmapSlug}
        isRoadmapLoading={!aiRoadmap}
        onUpgrade={() => setShowUpgradeModal(true)}
        aiChatActionsRef={aiChatActionsRef}
      />
    </AITutorLayout>
  );
}