#399

backend/app/services/post_create_preflight.rb

@@ -0,0 +1,104 @@
+class PostCreatePreflight
+  class ValidationFailed < StandardError
+    attr_reader :fields, :base_errors
+
+    def initialize fields: { }, base_errors: []
+      super('入力内容を確認してください．')
+      @fields = fields
+      @base_errors = base_errors
+    end
+  end
+
+  def initialize attributes:, thumbnail: nil
+    @attributes = attributes.symbolize_keys
+    @thumbnail = thumbnail
+  end
+
+  def run
+    preview = PostImportPreviewer.new.preview_rows(
+        rows: [preview_row],
+        fetch_metadata: false).first
+
+    validate_thumbnail_upload!
+
+    if preview[:validation_errors].present?
+      raise ValidationFailed.new(fields: preview[:validation_errors])
+    end
+
+    {
+        url: preview[:url],
+        title: preview[:attributes]['title'],
+        thumbnail_base: preview[:attributes]['thumbnail_base'],
+        tags: preview[:attributes]['tags'],
+        parent_post_ids: preview[:attributes]['parent_post_ids'],
+        original_created_from: preview[:attributes]['original_created_from'],
+        original_created_before: preview[:attributes]['original_created_before'],
+        duration: preview[:attributes]['duration'],
+        video_ms: preview[:attributes]['video_ms'],
+        field_warnings: preview[:field_warnings],
+        base_warnings: preview[:base_warnings],
+        existing_post: existing_post_compact(preview[:existing_post_id]) }
+  end
+
+  private
+
+  def preview_row
+    {
+        source_row: 1,
+        url: @attributes[:url].to_s,
+        attributes: {
+            'title' => @attributes[:title].to_s,
+            'thumbnail_base' => @attributes[:thumbnail_base].to_s,
+            'original_created_from' => @attributes[:original_created_from].to_s,
+            'original_created_before' => @attributes[:original_created_before].to_s,
+            'duration' => @attributes[:duration].to_s,
+            'video_ms' => @attributes[:video_ms],
+            'tags' => @attributes[:tags].to_s,
+            'parent_post_ids' => parent_post_ids_text },
+        provenance: {
+            'url' => 'manual',
+            'title' => 'manual',
+            'thumbnail_base' => 'manual',
+            'original_created_from' => 'manual',
+            'original_created_before' => 'manual',
+            'duration' => 'manual',
+            'video_ms' => 'manual',
+            'tags' => 'manual',
+            'parent_post_ids' => 'manual' },
+        tag_sources: {
+            'automatic' => '',
+            'manual' => @attributes[:tags].to_s } }
+  end
+
+  def parent_post_ids_text
+    Array(@attributes[:parent_post_ids]).flat_map { _1.to_s.split }.join(' ')
+  end
+
+  def validate_thumbnail_upload!
+    return if @attributes[:thumbnail_base].present?
+    return if @thumbnail.blank?
+
+    attachment = Post.resized_thumbnail_attachment(@thumbnail)
+    attachment[:io].close if attachment[:io].respond_to?(:close)
+  rescue MiniMagick::Error
+    raise ValidationFailed.new(fields: { thumbnail: ['サムネイル画像の変換に失敗しました．'] })
+  end
+
+  def existing_post_compact post_id
+    return nil if post_id.blank?
+
+    post = Post.with_attached_thumbnail.find_by(id: post_id)
+    return nil if post.nil?
+
+    {
+        id: post.id,
+        title: post.title,
+        url: post.url,
+        thumbnail_url:
+            if post.thumbnail.attached?
+              Rails.application.routes.url_helpers.rails_storage_proxy_url(
+                  post.thumbnail,
+                  only_path: false)
+            end }
+  end
+end