class PdfProcessorService
DEFAULT_OPTIONS = {
quality: 40,
resize_percentage: 50,
format: 'jpg'
}.freeze
def initialize(resource, options = {})
@resource = resource
@options = DEFAULT_OPTIONS.merge(options)
end
def process_pdfs
@resource.pdfs.each do |pdf|
pdf_path = get_blob_path(pdf)
process_single_pdf(pdf_path)
end
end
private
def get_blob_path(pdf)
ActiveStorage::Blob.service.send(:path_for, pdf.key)
end
def process_single_pdf(pdf_path)
page_count = get_page_count(pdf_path)
(0...page_count).each do |index|
Rails.logger.info "Processing page #{index + 1} of #{page_count} from #{pdf_path}"
process_page(pdf_path, index)
rescue StandardError => e
Rails.logger.error "Failed to process page #{index + 1}: #{e.message}"
raise
end
end
def get_page_count(pdf_path)
Rails.logger.debug "Checking PDF: #{pdf_path}"
Rails.logger.debug "File exists: #{File.exist?(pdf_path)}"
Rails.logger.debug "File size: #{File.size(pdf_path)}"
Rails.logger.debug "File type: #{`file -b #{pdf_path}`}"
# Try multiple methods to get page count
identify_output = `identify -format %n "#{pdf_path}" 2>&1`
gs_output = `gs -q -dNODISPLAY -c "#{pdf_path} (r) file runpdfbegin pdfpagecount = quit" 2>&1`
Rails.logger.debug "Identify output: #{identify_output}"
Rails.logger.debug "Ghostscript output: #{gs_output}"
count = identify_output.to_i
if count <= 0
count = gs_output.to_i
end
Rails.logger.debug "Final page count: #{count}"
raise "Invalid page count: #{count}" unless count.positive?
count
rescue StandardError => e
Rails.logger.error "Failed to get page count: #{e.message}"
raise
end
def process_page(pdf_path, page_index)
temp_files = create_page_images(pdf_path, page_index)
attach_processed_image(temp_files[:reduced], page_index)
ensure
cleanup_temp_files(temp_files)
end
def create_page_images(pdf_path, index)
original_path = "page-#{index + 1}.#{@options[:format]}"
reduced_path = "reduced-page-#{index + 1}.#{@options[:format]}"
create_original_image(pdf_path, index, original_path)
create_reduced_image(original_path, reduced_path)
{ original: original_path, reduced: reduced_path }
end
def create_original_image(pdf_path, index, output_path)
MiniMagick::Tool::Convert.new do |convert|
convert << "#{pdf_path}[#{index}]"
convert << output_path
end
rescue StandardError => e
Rails.logger.error "Failed to create original image for page #{index + 1} from #{pdf_path}: #{e.message}"
raise
end
def create_reduced_image(input_path, output_path)
MiniMagick::Tool::Convert.new do |convert|
convert << input_path
convert << "-quality"
convert << @options[:quality].to_s
convert.strip
convert << "-resize"
convert << "#{@options[:resize_percentage]}%"
convert << output_path
end
rescue StandardError => e
Rails.logger.error "Failed to create reduced image from #{input_path}: #{e.message}"
raise
end
def attach_processed_image(image_path, index)
return unless File.exist?(image_path)
filename = generate_filename(index)
image_blob = create_blob(image_path, filename)
@resource.pdf_snapshots.attach(image_blob)
end
def generate_filename(index)
base_name = @resource.name.strip.downcase.gsub(/\s/, "_")
"#{base_name}_page-#{index + 1}.#{@options[:format]}"
end
def create_blob(path, filename)
ActiveStorage::Blob.create_and_upload!(
io: File.open(path),
filename: filename,
content_type: "image/#{@options[:format]}"
)
end
def cleanup_temp_files(temp_files)
temp_files.values.each do |path|
File.delete(path) if File.exist?(path)
end
end
end
