module Miniatura

# File lib/miniatura.rb, line 8
def generate_thumb(options = {})
  @exit_code, @error = nil
  raise Errno::ENOENT unless File.exist?(current_path)
  options[:file_extension] ||= 'jpeg'
  options[:rotate] = 0
  options[:size] = determine_thumb_dimension_ratio_from_uploaded_video(options[:size])
  tmp_path = generate_temp_file(options[:file_extension])
  cmd = generate_command_for_thumbnail(options, tmp_path)
  show_logs(cmd)
  execute_command(cmd)
  handle_exit_code(@exit_code, @error)
  File.rename tmp_path, current_path
end

# File lib/miniatura.rb, line 24
def determine_thumb_dimension_ratio_from_uploaded_video(size)
  video = MiniExiftool.new(current_path)
  orientation = video.rotation
  image_width, image_height = video_dimension(orientation, video.imagewidth, video.imageheight, size)
  return "#{image_width.to_i}" + 'x' + "#{image_height.to_i}"
end

# File lib/miniatura.rb, line 69
def execute_command(command)
  Open3.popen3(command) do |stdin, stdout, stderr, wait_thr|
    @error = stderr.read
    @exit_code = wait_thr.value
  end
end

# File lib/miniatura.rb, line 48
def find_width_and_height_of_landscape_video(video_width, video_height, size)
  ratio = size.to_f/video_width
  image_width = size
  image_height = video_height * ratio
  return image_width, image_height
end

# File lib/miniatura.rb, line 41
def find_width_and_height_of_portrait_video(video_width, video_height, size)
  ratio = size.to_f/video_height
  image_width = size
  image_height = video_width * ratio
  return image_width, image_height
end

# File lib/miniatura.rb, line 59
def generate_command_for_thumbnail(options, temp_file_path)
  thumbnail = GenerateCommand.new(current_path, temp_file_path)
  return thumbnail.generate_command(options)
end

# File lib/miniatura.rb, line 55
def generate_temp_file(file_extension)
  File.join(File.dirname(current_path), "tmpfile.#{file_extension}")
end

# File lib/miniatura.rb, line 76
def handle_exit_code(exit_code, error)
  logger = Miniatura::Logger.new.logger
  if exit_code == 0
    logger.info 'Success!'
  else
    logger.error "Failure due to following error:  #{error}"
  end
end

# File lib/miniatura.rb, line 64
def show_logs(command)
  logger = Miniatura::Logger.new.logger
  logger.info("Running command: #{command}")
end

# File lib/miniatura.rb, line 31
def video_dimension(orientation, video_width, video_height, size)
  case orientation
    when 0, 180
      image_width, image_height = find_width_and_height_of_landscape_video(video_width, video_height, size)
    else
      image_width, image_height = find_width_and_height_of_portrait_video(video_width, video_height, size)
  end
  return image_width, image_height
end