Get LearnDash next lesson link or first lesson link if course not started

functions.php

function ld_next_lesson_link() {
	global $post;
	$course_id = learndash_get_course_id( $post );
	$user = _wp_get_current_user();

	if( $course_id && isset( $user->ID ) )  {
		$lessons = learndash_get_lesson_list( $course_id );
		
		if( $lessons ) {
			$first_lesson = reset($lessons);
		}

		$user_course_progress = get_user_meta( $user->ID, '_sfwd-course_progress', true );

		if( isset( $user_course_progress[$course_id] ) ) {
			$course_progress = $user_course_progress[$course_id];

			// get first lesson link
			if( !$course_progress['lessons'] && isset( $first_lesson->ID ) ) {
				$lesson_id = $first_lesson->ID;
			} else {
				end( $course_progress['lessons'] );
				$lesson_id = key( $course_progress['lessons'] );
				
				foreach( $lessons as $key => $lesson ) {
					if( $lesson->ID == $lesson_id ) {
						$lesson_id = $lessons[$key+1]->ID;
						break;
					}
				}
			}
			
		} else {
			// get first lesson link
			if( isset ( $first_lesson->ID ) ) {
				$lesson_id = $first_lesson->ID;
			}
		}

		if( $lesson_id && "sfwd-lessons" == get_post_type( $lesson_id ) ) {
			$link = get_post_permalink( $lesson_id );
			return $link;
		}
	}
}

Hey brother, thanks so much for this! I have created a button on my Courses template page and inserted this - works awesomely!

Now, I would like to hide this button if a user has completed the course.... how can I do that?

Hi adeel-raza,

thanks for sharing. I'm looking at Learndash core files for a way to link lessons to a course. is it what your code "$first_lesson = reset($lessons);" is doing? I also need to link topics to lessons. If you have any idea on what Learndash functions can help achieve that I would greatly appreciate you pointing me in the right direction.
Lauren