'use client'
import { ChevronLeft, ChevronRight } from 'lucide-react'
import { getUriWithOrg } from '@services/config/config'
import { useRouter } from 'next/navigation'
import React, { useEffect, useState, useRef } from 'react'
import ActivityIndicators from '@components/Pages/Courses/ActivityIndicators'
import ActivityChapterDropdown from './ActivityChapterDropdown'
import { getCourseThumbnailMediaDirectory } from '@services/media/media'
import { useOrg } from '@components/Contexts/OrgContext'

interface FixedActivitySecondaryBarProps {
  course: any
  currentActivityId: string
  orgslug: string
  activity: any
}

export default function FixedActivitySecondaryBar(props: FixedActivitySecondaryBarProps): React.ReactNode {
  const router = useRouter();
  const [isScrolled, setIsScrolled] = useState(false);
  const [shouldShow, setShouldShow] = useState(false);
  const mainActivityInfoRef = useRef<HTMLDivElement | null>(null);
  const org = useOrg() as any;

  // Function to find the current activity's position in the course
  const findActivityPosition = () => {
    let allActivities: any[] = [];
    let currentIndex = -1;
    
    // Flatten all activities from all chapters
    props.course.chapters.forEach((chapter: any) => {
      chapter.activities.forEach((activity: any) => {
        const cleanActivityUuid = activity.activity_uuid?.replace('activity_', '');
        allActivities.push({
          ...activity,
          cleanUuid: cleanActivityUuid,
          chapterName: chapter.name
        });
        
        // Check if this is the current activity
        if (cleanActivityUuid === props.currentActivityId.replace('activity_', '')) {
          currentIndex = allActivities.length - 1;
        }
      });
    });
    
    return { allActivities, currentIndex };
  };
  
  const { allActivities, currentIndex } = findActivityPosition();
  
  // Get previous and next activities
  const prevActivity = currentIndex > 0 ? allActivities[currentIndex - 1] : null;
  const nextActivity = currentIndex < allActivities.length - 1 ? allActivities[currentIndex + 1] : null;
  
  // Navigate to an activity
  const navigateToActivity = (activity: any) => {
    if (!activity) return;
    
    const cleanCourseUuid = props.course.course_uuid?.replace('course_', '');
    router.push(getUriWithOrg(props.orgslug, '') + `/course/${cleanCourseUuid}/activity/${activity.cleanUuid}`);
  };

  // Handle scroll and intersection observer
  useEffect(() => {
    const handleScroll = () => {
      setIsScrolled(window.scrollY > 0);
    };

    // Set up intersection observer for the main activity info
    const observer = new IntersectionObserver(
      ([entry]) => {
        // Show the fixed bar when the main info is not visible
        setShouldShow(!entry.isIntersecting);
      },
      {
        threshold: [0, 0.1, 1],
        rootMargin: '-80px 0px 0px 0px' // Increased margin to account for the header
      }
    );

    // Start observing the main activity info section with a slight delay to ensure DOM is ready
    setTimeout(() => {
      const mainActivityInfo = document.querySelector('.activity-info-section');
      if (mainActivityInfo) {
        mainActivityInfoRef.current = mainActivityInfo as HTMLDivElement;
        observer.observe(mainActivityInfo);
      }
    }, 100);

    window.addEventListener('scroll', handleScroll);
    
    return () => {
      window.removeEventListener('scroll', handleScroll);
      if (mainActivityInfoRef.current) {
        observer.unobserve(mainActivityInfoRef.current);
      }
    };
  }, []);

  return (
    <>
      {shouldShow && (
        <div 
          className={`fixed top-[60px] left-0 right-0 z-40 bg-white/90 backdrop-blur-xl transition-all duration-300 animate-in fade-in slide-in-from-top ${
            isScrolled ? 'nice-shadow' : ''
          }`}
        >
          <div className="container mx-auto px-4">
            <div className="flex items-center justify-between h-16 py-2">
              {/* Left Section - Course Info and Navigation */}
              <div className="flex items-center space-x-2 sm:space-x-4 min-w-0 flex-shrink">
                <img
                  className="w-[35px] sm:w-[45px] h-[20px] sm:h-[26px] rounded-md object-cover flex-shrink-0"
                  src={`${getCourseThumbnailMediaDirectory(
                    org?.org_uuid,
                    props.course.course_uuid,
                    props.course.thumbnail_image
                  )}`}
                  alt=""
                />
                <ActivityChapterDropdown
                  course={props.course}
                  currentActivityId={props.currentActivityId}
                  orgslug={props.orgslug}
                />
                <div className="flex flex-col -space-y-0.5 min-w-0 hidden sm:block">
                  <p className="text-sm font-medium text-gray-500">Course</p>
                  <h1 className="font-semibold text-gray-900 text-base truncate">
                    {props.course.name}
                  </h1>
                </div>
              </div>

              {/* Right Section - Navigation Controls */}
              <div className="flex items-center flex-shrink-0">
                <div className="flex items-center space-x-2 sm:space-x-3">
                  <button
                    onClick={() => navigateToActivity(prevActivity)}
                    className={`flex items-center space-x-1 sm:space-x-2 py-1.5 px-1.5 sm:px-2 rounded-md transition-all duration-200 ${
                      prevActivity 
                        ? 'text-gray-700 hover:bg-gray-100' 
                        : 'text-gray-300 cursor-not-allowed'
                    }`}
                    disabled={!prevActivity}
                    title={prevActivity ? `Previous: ${prevActivity.name}` : 'No previous activity'}
                  >
                    <ChevronLeft size={16} className="shrink-0 sm:w-5 sm:h-5" />
                    <div className="flex flex-col items-start hidden sm:flex">
                      <span className="text-xs text-gray-500">Previous</span>
                      <span className="text-sm font-medium text-left truncate max-w-[100px] sm:max-w-[150px]">
                        {prevActivity ? prevActivity.name : 'No previous activity'}
                      </span>
                    </div>
                  </button>

                  <span className="text-sm font-medium text-gray-500 px-1 sm:px-2">
                    {currentIndex + 1} of {allActivities.length}
                  </span>

                  <button
                    onClick={() => navigateToActivity(nextActivity)}
                    className={`flex items-center space-x-1 sm:space-x-2 py-1.5 px-1.5 sm:px-2 rounded-md transition-all duration-200`}
                    disabled={!nextActivity}
                    title={nextActivity ? `Next: ${nextActivity.name}` : 'No next activity'}
                  >
                    <div className="flex flex-col items-end hidden sm:flex">
                      <span className={`text-xs ${nextActivity ? 'text-gray-500' : 'text-gray-500'}`}>Next</span>
                      <span className="text-sm font-medium text-right truncate max-w-[100px] sm:max-w-[150px]">
                        {nextActivity ? nextActivity.name : 'No next activity'}
                      </span>
                    </div>
                    <ChevronRight size={16} className="shrink-0 sm:w-5 sm:h-5" />
                  </button>
                </div>
              </div>
            </div>
          </div>
        </div>
      )}
    </>
  );
}