default value = false

• PS Module wrappers for ffmpeg, yt-dlp, etc?
• add error handling and logging

default value = "All"

• split PascalCase course names into separate words
• make functions for file path parsing
• eliminate duplicate code
• eliminate dummy delimiters

• remove non-numeric characters from $courseNumber, $sectionNumber, $lessonNumber variables
• remove non-alphabetic and non-punctuation characters from $courseName, $sectionName, $lessonName variables
• trim and eliminate redundant spaces from all variables

Since the downloader is not a PowerShell cmdlet, its errors won't trigger in a try/catch block. Therefore, it'll need something like this to pass its error messages back to PowerShell:

$downloaderStatus = ffmpeg -i ..... 2>&1

Then the contents of $downloaderStatus can be run through a regex match to determine if it failed, and if so, how.

default value = 3

• case 3:
  • create a folder for each AppName, CourseName, and SectionName
  • name files "LessonNumber - LessonName"
• case 2:
  • create a folder for each AppName and CourseName
  • name files "SectionNumber - SectionName - LessonNumber - LessonName"
• case 1:
  • create a folder for each AppName
  • name files "CourseNumber - CourseName - SectionNumber - SectionName - LessonNumber - LessonName"
• case 0:
  • name files "AppName - CourseNumber - CourseName - SectionNumber - SectionName - LessonNumber - LessonName"

• create a new PSCustomObject variable to contain all course data
• on each loop iteration, add a new record to the object with the current values
• pass the completed PSCustomObject to a ForEach-Object loop
• add optional parallelism parameter; default value = 1

• all variable values
• subtitles
• other metadata from response JSON