#399

backend/app/services/post_import_previewer.rb

@@ -9,30 +9,55 @@ class PostImportPreviewer
   end
 
   def preview
+    preview_rows(rows: @parsed[:rows])
+  end
+
+  def preview_rows rows:, fetch_metadata: true, metadata_cache: { }
     urls = { }
-    @parsed[:rows].map do |row|
-      values = row[:values]
-      attributes = FIELDS.to_h { |field| [field, mapped_value(field, values)] }
-      url = values[@url_column].to_s.strip
-      metadata, warnings = fetch_metadata(url)
-      attributes = metadata.merge(attributes) { |_key, automatic, input| input.presence || automatic }
+    rows.map do |row|
+      row = row.symbolize_keys
+      values = row[:values] || []
+      attributes = row[:attributes]&.stringify_keys || FIELDS.to_h { |field| [field, mapped_value(field, values)] }
+      provenance = row[:provenance]&.stringify_keys || mapped_provenance(attributes)
+      url = row[:url].presence || values[@url_column].to_s.strip
+      provenance['url'] ||= row[:url].present? ? 'manual' : 'mapped'
+      attributes['url'] = url
+      fetch_warnings = Array(row[:fetch_warnings]).dup
+      should_fetch = fetch_metadata == true || fetch_metadata.to_i == row[:source_row].to_i
+      metadata, fetch_warnings = metadata_for(url, should_fetch, metadata_cache, fetch_warnings)
+      metadata.each do |field, value|
+        next unless provenance[field] == 'automatic' || attributes[field].blank?
+
+        attributes[field] = value
+        provenance[field] = 'automatic'
+      end
       post = Post.new(url:)
       post.valid?
       normal_url = post.url
       errors = post.errors.to_hash.transform_values(&:dup)
+      validation_warnings = []
       errors[:url] = ['URL が重複しています．'] if normal_url.present? && urls.key?(normal_url)
       urls[normal_url] = true if normal_url.present?
       if normal_url.present? && Post.exists?(url: normal_url)
-        @existing == 'error' ? errors[:url] = ['既存投稿です．'] : warnings << '既存投稿のためスキップします．'
+        @existing == 'error' ? errors[:url] = ['既存投稿です．'] : validation_warnings << '既存投稿のためスキップします．'
       end
-      validate_preview_tags(attributes['tags'], errors)
+      validate_basic_data(attributes, errors)
+      validate_preview_tags(attributes['tags'], errors, validation_warnings)
       validate_parents(attributes['parent_post_ids'], errors)
-      { source_row: row[:source_row], url: normal_url || url, attributes:, warnings:, errors:,
-        status: errors.present? ? 'error' : (warnings.present? ? 'warning' : 'ready'),
+      attributes.delete('url')
+      { source_row: row[:source_row], url: normal_url || url, attributes:, provenance:,
+        fetch_warnings:, validation_warnings:, warnings: fetch_warnings + validation_warnings, errors:,
+        status: errors.present? ? 'error' : ((fetch_warnings + validation_warnings).present? ? 'warning' : 'ready'),
         existing: normal_url.present? && Post.exists?(url: normal_url) }
     end
   end
 
+  def metadata_for url, fetch_metadata, cache, previous_warnings
+    return [{ }, previous_warnings] unless fetch_metadata
+
+    cache[url] ||= fetch_metadata(url)
+  end
+
   private
 
   def mapped_value field, values
@@ -43,33 +68,71 @@ class PostImportPreviewer
     Array(mapping['columns']).filter_map { |index| values[index.to_i].to_s.presence }.join(field == 'tags' ? ' ' : '')
   end
 
+  def mapped_provenance attributes
+    attributes.to_h.to_h { |field, value|
+      mapping = @mappings[field.to_s]
+      origin =
+          if value.present? && mapping&.[]('kind') == 'fixed'
+            'fixed'
+          elsif value.present?
+            'mapped'
+          else
+            'automatic'
+          end
+      [field.to_s, origin]
+    }
+  end
+
   def fetch_metadata url
     return [{ }, ['URL が空です．']] if url.blank?
 
-    data = PostMetadataFetcher.fetch(url)
+    data = PostMetadataFetcher.fetch(url).stringify_keys
     warnings = []
-    warnings << 'タイトルを取得できませんでした．' if data[:title].blank?
-    warnings << 'サムネールを取得できませんでした．' if data[:thumbnail_base].blank?
+    warnings << 'タイトルを取得できませんでした．' if data['title'].blank?
+    warnings << 'サムネールを取得できませんでした．' if data['thumbnail_base'].blank?
     [data.compact, warnings]
   rescue Preview::UrlSafety::UnsafeUrl, Preview::HttpFetcher::FetchFailed, Preview::HttpFetcher::ResponseTooLarge => e
     [{ }, ["メタデータを取得できませんでした: #{ e.message }"]]
   end
 
-  def validate_preview_tags raw, errors
+  def validate_preview_tags raw, errors, warnings
     names = raw.to_s.split
     return if names.empty?
     if names.any? { _1.downcase.start_with?('nico:') }
       errors[:tags] = ['ニコニコ・タグは直接指定できません．']
       return
     end
-    canonical = names.map { TagName.canonicalise(_1.sub(/\[.*\]\z/, '')).first }
-    if Tag.joins(:tag_name).where(tag_names: { name: canonical }, deprecated_at: nil).count < canonical.uniq.length
-      errors[:tags] = ['存在しないタグ又は廃止済みタグがあります．']
-    end
+    parsed = names.map { |name| TagName.canonicalise(name.sub(/\[.*\]\z/, '')).first }
+    existing = Tag.joins(:tag_name).where(tag_names: { name: parsed }).includes(:tag_name).to_a
+    deprecated = existing.select(&:deprecated?).map(&:name)
+    errors[:tags] = ["廃止済みタグがあります: #{ deprecated.join(' ') }"] if deprecated.present?
+    known = existing.reject(&:deprecated?).map(&:name)
+    new_tags = parsed.uniq - known
+    warnings << "新規タグを作成します: #{ new_tags.join(' ') }" if new_tags.present?
   rescue Tag::SectionLiteralParseError
     errors[:tags] = ['タグ区間の記法が不正です．']
   end
 
+  def validate_basic_data attributes, errors
+    post = Post.new(title: attributes['title'].presence,
+                    url: attributes['url'],
+                    thumbnail_base: attributes['thumbnail_base'].presence,
+                    original_created_from: attributes['original_created_from'].presence,
+                    original_created_before: attributes['original_created_before'].presence,
+                    video_ms: parse_duration(attributes['duration'], errors))
+    post.valid?
+    post.errors.each { |error| (errors[error.attribute] ||= []) << error.message }
+  end
+
+  def parse_duration value, errors
+    return nil if value.blank?
+
+    value.is_a?(Numeric) ? value.to_i : Tag.time_to_ms!(value.to_s, tag_name: '動画時間')
+  rescue Tag::SectionLiteralParseError
+    errors[:video_ms] = ['動画時間の記法が不正です．']
+    nil
+  end
+
   def validate_parents raw, errors
     ids = raw.to_s.split.map { Integer(_1, exception: false) }
     return if ids.compact.empty? && raw.to_s.blank?