initial commit

2023-05-21 17:59:36 +03:00
commit 97c462ead2
159 changed files with 10987 additions and 0 deletions
@@ -0,0 +1,69 @@
+# frozen_string_literal: true
+
+module Flows
+  module ProcessDocument
+    DPI = 200
+    FORMAT = '.jpg'
+    ATTACHMENT_NAME = 'preview_images'
+
+    PDF_CONTENT_TYPE = 'application/pdf'
+    Q = 35
+    MAX_WIDTH = 1400
+
+    module_function
+
+    def call(attachment)
+      if attachment.content_type == PDF_CONTENT_TYPE
+        generate_pdf_preview_images(attachment)
+      elsif attachment.content_type.starts_with?('image/')
+        generate_preview_image(attachment)
+      end
+
+      attachment
+    end
+
+    def generate_preview_image(attachment)
+      binary = attachment.download
+
+      ActiveStorage::Attachment.where(name: ATTACHMENT_NAME, record: attachment).destroy_all
+
+      image = Vips::Image.new_from_buffer(binary, '')
+      image = image.resize(MAX_WIDTH / image.width.to_f)
+
+      io = StringIO.new(image.write_to_buffer(FORMAT, Q: Q))
+
+      ActiveStorage::Attachment.create!(
+        blob: ActiveStorage::Blob.create_and_upload!(
+          io:, filename: "0#{FORMAT}",
+          metadata: { analyzed: true, identified: true, width: image.width, height: image.height }
+        ),
+        name: ATTACHMENT_NAME,
+        record: attachment
+      )
+    end
+
+    def generate_pdf_preview_images(attachment)
+      binary = attachment.download
+
+      ActiveStorage::Attachment.where(name: ATTACHMENT_NAME, record: attachment).destroy_all
+
+      (0..).each do |page_number|
+        page = Vips::Image.new_from_buffer(binary, '', dpi: DPI, page: page_number)
+        page = page.resize(MAX_WIDTH / page.width.to_f)
+
+        io = StringIO.new(page.write_to_buffer(FORMAT, Q: Q))
+
+        ActiveStorage::Attachment.create!(
+          blob: ActiveStorage::Blob.create_and_upload!(
+            io:, filename: "#{page_number}#{FORMAT}",
+            metadata: { analyzed: true, identified: true, width: page.width, height: page.height }
+          ),
+          name: ATTACHMENT_NAME,
+          record: attachment
+        )
+      rescue Vips::Error
+        break
+      end
+    end
+  end
+end