【再掲】タグの局所記載 (#351) (#380)

#353 を再開できなかったので．

Reviewed-on: #380
Co-authored-by: miteruzo <miteruzo@naver.com>
Co-committed-by: miteruzo <miteruzo@naver.com>

backend/app/controllers/post_versions_controller.rb

@@ -25,6 +25,7 @@ class PostVersionsController < ApplicationController
         SQL
         .select('post_versions.*', 'prev.title AS prev_title', 'prev.url AS prev_url',
                 'prev.thumbnail_base AS prev_thumbnail_base', 'prev.tags AS prev_tags',
+                'prev.video_ms AS prev_video_ms',
                 'prev.original_created_from AS prev_original_created_from',
                 'prev.original_created_before AS prev_original_created_before')
     q = q.where('post_versions.post_id = ?', post_id) if post_id
@@ -74,6 +75,10 @@ class PostVersionsController < ApplicationController
           current: row.thumbnail_base,
           prev: row.attributes['prev_thumbnail_base']
         },
+        video_ms: {
+          current: row.video_ms,
+          prev: row.attributes['prev_video_ms']
+        },
         tags: build_version_tags(cur_tags, prev_tags),
         original_created_from: {
           current: row.original_created_from&.iso8601,

backend/app/controllers/posts_controller.rb

@@ -1,6 +1,10 @@
 class PostsController < ApplicationController
   Event = Struct.new(:post, :tag, :user, :change_type, :timestamp, keyword_init: true)
 
+  class VideoMsParseError < ArgumentError
+    ;
+  end
+
   def index
     url = params[:url].presence
     title = params[:title].presence
@@ -45,7 +49,9 @@ class PostsController < ApplicationController
         .joins("LEFT JOIN (#{ pt_max_sql }) pt_max ON pt_max.post_id = posts.id")
         .reselect('posts.*', Arel.sql("#{ updated_at_all_sql } AS updated_at_all"))
         .preload(:uploaded_user, :parents, :children,
-                 tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
+                 active_post_tags: [:sections,
+                                    { tag: [:deerjikists, :materials,
+                                            { tag_name: :wiki_page }] }])
         .with_attached_thumbnail
 
     q = q.where('posts.url LIKE ?', "%#{ url }%") if url
@@ -97,7 +103,9 @@ class PostsController < ApplicationController
 
   def random
     post = filtered_posts.preload(:uploaded_user, :parents, :children,
-                                  tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
+                                  active_post_tags: [:sections,
+                                                     { tag: [:deerjikists, :materials,
+                                                             { tag_name: :wiki_page }] }])
                          .with_attached_thumbnail
                          .order('RAND()')
                          .first
@@ -110,7 +118,9 @@ class PostsController < ApplicationController
     post =
         Post
         .includes(:uploaded_user, :parents, :children,
-                  tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
+                  active_post_tags: [:sections,
+                                     { tag: [:deerjikists, :materials,
+                                             { tag_name: :wiki_page }] }])
         .with_attached_thumbnail
         .find_by(id: params[:id])
     return head :not_found unless post
@@ -125,7 +135,7 @@ class PostsController < ApplicationController
                                  child_posts:,
                                  sibling_posts:,
                                  related:)
-                         .merge(tags: build_tag_tree_for(post.tags))
+                         .merge(tags: build_tag_tree_for(post))
   end
 
   def create
@@ -149,11 +159,15 @@ class PostsController < ApplicationController
     ApplicationRecord.transaction do
       post.save!
 
-      tags = Tag.normalise_tags!(tag_names, deny_deprecated: true)
+      Tag.normalise_tags!(tag_names, deny_deprecated: true, with_sections: true) =>
+          { tags:, sections: }
       TagVersioning.record_tag_snapshots!(tags, created_by_user: current_user)
 
       tags = Tag.expand_parent_tags(tags).reject(&:deprecated?)
-      sync_post_tags!(post, tags)
+      post.video_ms = normalise_video_ms(tags)
+      validate_video_sections!(post.video_ms, sections)
+      post.save!
+      sync_post_tags!(post, tags, sections)
 
       sync_parent_posts!(post, parent_post_ids)
 
@@ -166,6 +180,10 @@ class PostsController < ApplicationController
     render_validation_error fields: { tags: 'ニコニコ・タグは直接指定できません．' }
   rescue Tag::DeprecatedTagNormalisationError
     render_unprocessable_entity '廃止済みタグは付与できません．', field: :tags
+  rescue Tag::SectionLiteralParseError
+    render_validation_error fields: { tags: ['タグ区間の記法が不正です．'] }
+  rescue VideoMsParseError
+    render_validation_error fields: { video_ms: ['動画時間の記法が不正です．'] }
   rescue MiniMagick::Error
     render_validation_error fields: { thumbnail: ['サムネイル画像の変換に失敗しました．'] }
   rescue ArgumentError => e
@@ -224,6 +242,8 @@ class PostsController < ApplicationController
                                                  original_created_from:,
                                                  original_created_before:,
                                                  tag_names:,
+                                                 video_ms_param: params[:video_ms],
+                                                 duration_param: params[:duration],
                                                  parent_post_ids:)
 
       snapshot_to_apply =
@@ -254,12 +274,16 @@ class PostsController < ApplicationController
 
     post.reload
     json = PostRepr.base(post, current_user)
-    json['tags'] = build_tag_tree_for(post.tags)
+    json['tags'] = build_tag_tree_for(post)
     render json:, status: :ok
   rescue Tag::NicoTagNormalisationError
     render_validation_error fields: { tags: ['ニコニコ・タグは直接指定できません．'] }
   rescue Tag::DeprecatedTagNormalisationError
     render_unprocessable_entity '廃止済みタグは付与できません．', field: :tags
+  rescue Tag::SectionLiteralParseError
+    render_validation_error fields: { tags: ['タグ区間の記法が不正です．'] }
+  rescue VideoMsParseError
+    render_validation_error fields: { video_ms: ['動画時間の記法が不正です．'] }
   rescue ArgumentError => e
     render_validation_error fields: { parent_post_ids: [e.message] }
   rescue ActiveRecord::RecordInvalid => e
@@ -358,7 +382,7 @@ class PostsController < ApplicationController
   def tagged_post_ids_for(name) =
       Post.joins(tags: :tag_name).where(tag_names: { name: }).select(:id)
 
-  def sync_post_tags! post, desired_tags
+  def sync_post_tags! post, desired_tags, sections
     desired_tags.each do |t|
       t.save! if t.new_record?
     end
@@ -377,13 +401,21 @@ class PostsController < ApplicationController
       end
     end
 
+    PostTagSection.where(post_id: post.id).destroy_all
+    sections.each do |tag_id, ranges|
+      ranges.each do |begin_ms, end_ms|
+        PostTagSection.create!(post_id: post.id, tag_id:, begin_ms:, end_ms:)
+      end
+    end
+
     PostTag.where(post_id: post.id, tag_id: to_remove.to_a).kept.find_each do |pt|
       pt.discard_by!(current_user)
     end
   end
 
-  def build_tag_tree_for tags
-    tags = tags.reject(&:deprecated?).to_a
+  def build_tag_tree_for post
+    post_tags = post.active_post_tags.reject { |post_tag| post_tag.tag.deprecated? }
+    tags = post_tags.map(&:tag)
     tag_ids = tags.map(&:id)
 
     implications = TagImplication.where(parent_tag_id: tag_ids, tag_id: tag_ids)
@@ -398,6 +430,9 @@ class PostsController < ApplicationController
     root_ids = tag_ids - child_ids
 
     tags_by_id = tags.index_by(&:id)
+    sections_by_tag_id = post_tags.to_h { |post_tag|
+      [post_tag.tag_id, post_tag.sections.as_json(only: [:begin_ms, :end_ms])]
+    }
 
     memo = { }
 
@@ -405,8 +440,10 @@ class PostsController < ApplicationController
       tag = tags_by_id[tag_id]
       return nil unless tag
 
+      sections = sections_by_tag_id.fetch(tag_id, [])
+
       if path.include?(tag_id)
-        return TagRepr.inline(tag).merge(children: [])
+        return TagRepr.inline(tag).merge(children: [], sections:)
       end
 
       if memo.key?(tag_id)
@@ -418,7 +455,7 @@ class PostsController < ApplicationController
 
       children = child_ids.filter_map { |cid| build_node.(cid, new_path) }
 
-      memo[tag_id] = TagRepr.inline(tag).merge(children:)
+      memo[tag_id] = TagRepr.inline(tag).merge(children:, sections:)
     end
 
     root_ids.filter_map { |id| build_node.call(id, []) }
@@ -487,6 +524,7 @@ class PostsController < ApplicationController
 
   def post_snapshot_from_version version
     { title: version.title,
+      video_ms: version.respond_to?(:video_ms) ? version.video_ms : nil,
       original_created_from: snapshot_time(version.original_created_from),
       original_created_before: snapshot_time(version.original_created_before),
       tag_names: editable_tag_names_from_version(version),
@@ -499,6 +537,7 @@ class PostsController < ApplicationController
 
   def post_snapshot_from_record post
     { title: post.title,
+      video_ms: post.video_ms,
       original_created_from: snapshot_time(post.original_created_from),
       original_created_before: snapshot_time(post.original_created_before),
       tag_names: editable_tag_names_from_post(post),
@@ -506,16 +545,41 @@ class PostsController < ApplicationController
   end
 
   def editable_tag_names_from_post post
-    post.tags.not_nico.where(deprecated_at: nil)
-        .joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
+    post
+        .post_tags
+        .kept
+        .joins(tag: :tag_name)
+        .merge(Tag.not_nico)
+        .merge(Tag.where(deprecated_at: nil))
+        .includes(:sections, tag: :tag_name)
+        .order('tag_names.name')
+        .map do |post_tag|
+      name = post_tag.tag.tag_name.name
+      sections = post_tag.sections.sort_by(&:begin_ms)
+
+      next name if sections.empty?
+
+      "#{ name }#{ sections.map { Post.section_literal(_1) }.join }"
+    end
   end
 
   def post_incoming_snapshot title:, original_created_from:, original_created_before:,
-                             tag_names:, parent_post_ids:
+                             tag_names:, video_ms_param:, duration_param:, parent_post_ids:
+    Tag.normalise_tags!(tag_names, with_tagme: false, deny_deprecated: true,
+                                        with_sections: true) =>
+        { tags:, sections: }
+
+    tags = Tag.expand_parent_tags(tags).reject(&:deprecated?)
+    video_ms = normalise_video_ms(tags, video_ms_param:, duration_param:)
+    validate_video_sections!(video_ms, sections)
+
     { title:,
+      video_ms:,
       original_created_from: snapshot_time(original_created_from),
       original_created_before: snapshot_time(original_created_before),
-      tag_names: incoming_tag_names_for_snapshot(tag_names),
+      tag_names: tags.uniq(&:id).map { |tag|
+        "#{ tag.name }#{ sections[tag.id].to_a.map { section_literal(_1) }.join }"
+      }.sort,
       parent_post_ids: parent_post_ids.sort }
   end
 
@@ -538,11 +602,8 @@ class PostsController < ApplicationController
     value.to_s
   end
 
-  def incoming_tag_names_for_snapshot raw_tag_names
-    tags = Tag.normalise_tags!(raw_tag_names, with_tagme: false,
-                                              deny_deprecated: true)
-
-    Tag.expand_parent_tags(tags).reject(&:deprecated?).map(&:name).uniq.sort
+  def section_literal section
+    "[#{ Post.ms_to_time(section[0]) }-#{ section[1] ? Post.ms_to_time(section[1]) : '' }]"
   end
 
   def post_conflict_json post:, base_version_no:, base_snapshot:,
@@ -563,6 +624,8 @@ class PostsController < ApplicationController
   def post_snapshot_changes base_snapshot, current_snapshot, incoming_snapshot
     [scalar_snapshot_change(:title, 'タイトル',
                             base_snapshot, current_snapshot, incoming_snapshot),
+     scalar_snapshot_change(:video_ms, '動画時間',
+                            base_snapshot, current_snapshot, incoming_snapshot),
      scalar_snapshot_change(:original_created_from, 'オリジナルの作成日時（以降）',
                             base_snapshot, current_snapshot, incoming_snapshot),
      scalar_snapshot_change(:original_created_before, 'オリジナルの作成日時（より前）',
@@ -626,11 +689,14 @@ class PostsController < ApplicationController
     PostVersionRecorder.ensure_snapshot!(post, created_by_user: current_user)
 
     post.update!(title: snapshot[:title],
+                 video_ms: snapshot[:video_ms],
                  original_created_from: snapshot[:original_created_from],
                  original_created_before: snapshot[:original_created_before])
 
-    editable_tags = Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false,
-                                                               deny_deprecated: true)
+    Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false,
+                                               deny_deprecated: true,
+                                               with_sections: true) =>
+        { tags: editable_tags, sections: }
     TagVersioning.record_tag_snapshots!(editable_tags, created_by_user: current_user)
 
     readonly_tags = post.tags.nico.to_a
@@ -638,14 +704,17 @@ class PostsController < ApplicationController
     tags = readonly_tags + editable_tags
     tags = Tag.expand_parent_tags(tags).reject(&:deprecated?)
 
-    sync_post_tags!(post, tags)
+    post.video_ms = tags.any? { _1.id == Tag.video.id } ? snapshot[:video_ms] : nil
+    validate_video_sections!(post.video_ms, sections)
+    post.save!
+    sync_post_tags!(post, tags, sections)
     sync_parent_posts!(post, snapshot[:parent_post_ids])
 
     PostVersionRecorder.record!(post:, event_type: :update, created_by_user: current_user)
   end
 
   def merge_post_snapshots base_snapshot, current_snapshot, incoming_snapshot
-    [:title, :original_created_from, :original_created_before].map {
+    [:title, :video_ms, :original_created_from, :original_created_before].map {
       [_1, merge_scalar_snapshot_value(base_snapshot[_1],
                                        current_snapshot[_1],
                                        incoming_snapshot[_1])]
@@ -689,4 +758,44 @@ class PostsController < ApplicationController
       render_validation_error record
     end
   end
+
+  def normalise_video_ms tags, video_ms_param: params[:video_ms], duration_param: params[:duration]
+    return nil unless tags.any? { _1.id == Tag.video.id }
+
+    if video_ms_param.present?
+      video_ms = Integer(video_ms_param, exception: false)
+      raise VideoMsParseError unless video_ms&.positive?
+
+      return video_ms
+    end
+
+    return nil if duration_param.blank?
+
+    video_ms = Tag.time_to_ms!(duration_param.to_s, tag_name: '動画時間')
+    raise VideoMsParseError unless video_ms.positive?
+
+    video_ms
+  rescue Tag::SectionLiteralParseError
+    raise VideoMsParseError
+  end
+
+  def validate_video_sections! video_ms, sections
+    return unless video_ms
+
+    sections.each_value do |ranges|
+      ranges.each do |begin_ms, end_ms|
+        if begin_ms >= video_ms
+          post = Post.new
+          post.errors.add :video_ms, 'タグ区間の開始が動画時間以上です．'
+          raise ActiveRecord::RecordInvalid, post
+        end
+
+        if end_ms && end_ms > video_ms
+          post = Post.new
+          post.errors.add :video_ms, 'タグ区間の終端が動画時間を超えてゐます．'
+          raise ActiveRecord::RecordInvalid, post
+        end
+      end
+    end
+  end
 end

backend/app/models/post.rb

@@ -60,6 +60,7 @@ class Post < ApplicationRecord
   before_validation :normalise_url
 
   validates :url, presence: true, uniqueness: true
+  validates :video_ms, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
 
   validate :validate_original_created_range
   validate :url_must_be_http_url
@@ -83,7 +84,42 @@ class Post < ApplicationRecord
     super(options).merge(thumbnail: nil)
   end
 
-  def snapshot_tag_names = tags.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
+  def snapshot_tag_names
+    post_tags
+        .kept
+        .joins(tag: :tag_name)
+        .includes(:sections, tag: :tag_name)
+        .order('tag_names.name')
+        .map do |post_tag|
+      name = post_tag.tag.tag_name.name
+      sections = post_tag.sections.sort_by(&:begin_ms)
+
+      next name if sections.empty?
+
+      "#{ name }#{ sections.map { Post.section_literal(_1) }.join }"
+    end
+  end
+
+  def self.section_literal section
+    "[#{ Post.ms_to_time(section.begin_ms) }-#{ section.end_ms ? Post.ms_to_time(section.end_ms) : '' }]"
+  end
+
+  def self.ms_to_time ms
+    total_s = ms / 1_000
+    s = total_s % 60
+    min = (total_s / 60) % 60
+    h = total_s / 3_600
+    remainder_ms = ms % 1_000
+
+    base =
+        if h.positive?
+          '%d:%02d:%02d' % [h, min, s]
+        else
+          '%d:%02d' % [min, s]
+        end
+
+    remainder_ms.positive? ? "#{ base }.#{ remainder_ms.to_s.rjust(3, '0') }" : base
+  end
 
   def snapshot_parent_post_ids = parents.order(:id).pluck(:id)
 

backend/app/models/post_tag.rb

@@ -10,6 +10,12 @@ class PostTag < ApplicationRecord
   belongs_to :created_user, class_name: 'User', optional: true
   belongs_to :deleted_user, class_name: 'User', optional: true
 
+  has_many :sections, -> { order(:begin_ms) }, class_name: 'PostTagSection',
+                                               foreign_key: [:post_id, :tag_id],
+                                               primary_key: [:post_id, :tag_id],
+                                               dependent: :delete_all,
+                                               inverse_of: :post_tag
+
   validates :post_id, presence: true
   validates :tag_id, presence: true
   validates :post_id, uniqueness: {

backend/app/models/post_tag_section.rb

@@ -0,0 +1,20 @@
+class PostTagSection < ApplicationRecord
+  self.primary_key = :post_id, :tag_id, :begin_ms
+
+  belongs_to :post
+  belongs_to :tag
+
+  belongs_to :post_tag, -> { kept }, foreign_key: [:post_id, :tag_id],
+                                     primary_key: [:post_id, :tag_id],
+                                     inverse_of: :sections,
+                                     optional: true
+
+  validates :post_id, presence: true
+  validates :tag_id, presence: true
+
+  validates :begin_ms, presence: true,
+                       numericality: { only_integer: true, greater_than_or_equal_to: 0 }
+
+  validates :end_ms, numericality: { only_integer: true, greater_than: :begin_ms },
+                     allow_nil: true
+end

backend/app/models/post_version.rb

@@ -5,6 +5,7 @@ class PostVersion < ApplicationRecord
   belongs_to :parent, class_name: 'Post', optional: true
 
   validates :url, presence: true
+  validates :video_ms, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
 
   validate :validate_original_created_range
 

backend/app/models/tag.rb

@@ -17,6 +17,16 @@ class Tag < ApplicationRecord
     end
   end
 
+  class SectionLiteralParseError < ArgumentError
+    attr_reader :tag_name, :literal
+
+    def initialize tag_name, literal
+      @tag_name = tag_name
+      @literal = literal
+      super("invalid section literal for tag #{ tag_name }: #{ literal }")
+    end
+  end
+
   has_many :post_tags, inverse_of: :tag
   has_many :active_post_tags, -> { kept }, class_name: 'PostTag', inverse_of: :tag
   has_many :post_tags_with_discarded, -> { with_discarded }, class_name: 'PostTag'
@@ -105,26 +115,60 @@ class Tag < ApplicationRecord
   def self.normalise_tags! tag_names, with_tagme: true,
                                       with_no_deerjikist: true,
                                       deny_nico: true,
-                                      deny_deprecated: false
+                                      deny_deprecated: false,
+                                      with_sections: false
     if deny_nico && tag_names.any? { |n| n.downcase.start_with?('nico:') }
       raise NicoTagNormalisationError
     end
 
+    sections = { }
     tags = tag_names.map do |name|
+      raw_name = name
       pf, cat = CATEGORY_PREFIXES.find { |p, _| name.downcase.start_with?(p) } || ['', nil]
-      name = TagName.canonicalise(name.sub(/\A#{ pf }/i, '')).first
+
+      name = name.sub(/\A#{ pf }/i, '')
+
+      sections_by_tag = []
+      while (match = name.match(/\A(\S*?)\[([^\[\]\s]*)-([^\[\]\s]*)\](\S*)\z/))
+        name = "#{ match[1] }#{ match[4] }"
+        next if match[2].empty? && match[3].empty?
+
+        sections_by_tag << normalise_section_range!(
+            begin_raw: match[2],
+            end_raw: match[3],
+            tag_name: name)
+      end
+
+      if name.include?('[') || name.include?(']')
+        raise SectionLiteralParseError.new(raw_name, raw_name)
+      end
+
+      name = TagName.canonicalise(name).first
+
       find_or_create_by_tag_name!(name, category: (cat || :general)).tap do |tag|
         if deny_deprecated && tag.deprecated?
           raise DeprecatedTagNormalisationError, [tag.name]
         end
 
         tag.update!(category: cat) if cat && tag.category != cat
+        next if sections_by_tag.empty?
+
+        sections[tag.id] ||= []
+        sections[tag.id].concat(sections_by_tag)
+        sections[tag.id] = merge_section_ranges(sections[tag.id])
+        sections.delete(tag.id) if sections[tag.id] == [[0, nil]]
       end
     end
 
     tags << Tag.tagme if with_tagme && tags.size < 10 && tags.none?(Tag.tagme)
     tags << Tag.no_deerjikist if with_no_deerjikist && tags.all? { |t| !(t.deerjikist?) }
-    tags.uniq(&:id)
+    tags.uniq!(&:id)
+
+    if with_sections
+      { tags:, sections: }
+    else
+      tags
+    end
   end
 
   def self.expand_parent_tags tags
@@ -150,6 +194,45 @@ class Tag < ApplicationRecord
     (result + tags).uniq { |t| t.id }
   end
 
+  def self.normalise_section_range! begin_raw:, end_raw:, tag_name:
+    begin_ms = begin_raw.empty? ? 0 : time_to_ms!(begin_raw, tag_name:)
+    end_ms = end_raw.empty? ? nil : time_to_ms!(end_raw, tag_name:)
+
+    if end_ms
+      begin_ms, end_ms = end_ms, begin_ms if begin_ms > end_ms
+      end_ms = begin_ms + 1 if begin_ms == end_ms
+    end
+
+    [begin_ms, end_ms]
+  end
+
+  def self.merge_section_ranges ranges
+    sorted_ranges = ranges.sort_by { |begin_ms, end_ms| [begin_ms, end_ms || Float::INFINITY] }
+    merged = []
+
+    sorted_ranges.each do |begin_ms, end_ms|
+      if merged.empty?
+        merged << [begin_ms, end_ms]
+        next
+      end
+
+      last_begin_ms, last_end_ms = merged[-1]
+      if last_end_ms.nil? || begin_ms <= last_end_ms
+        merged[-1] = [last_begin_ms, merge_section_end(last_end_ms, end_ms)]
+      else
+        merged << [begin_ms, end_ms]
+      end
+    end
+
+    merged
+  end
+
+  def self.merge_section_end left_end_ms, right_end_ms
+    return nil if left_end_ms.nil? || right_end_ms.nil?
+
+    [left_end_ms, right_end_ms].max
+  end
+
   def self.find_or_create_by_tag_name! name, category:
     tn = TagName.find_undiscard_or_create_by!(name: name.to_s.strip)
     tn = tn.canonical if tn.canonical_id?
@@ -246,6 +329,32 @@ class Tag < ApplicationRecord
     end
   end
 
+  def self.time_to_ms! str, tag_name:
+    match =
+        case str
+        when /\A(?<seconds>\d+)(?:\.(?<ms>\d{1,3}))?\z/
+          { hours: nil, minutes: nil, seconds: Regexp.last_match[:seconds],
+            ms: Regexp.last_match[:ms] }
+        when /\A(?<minutes>\d+):(?<seconds>[0-5]?\d)(?:\.(?<ms>\d{1,3}))?\z/
+          { hours: nil, minutes: Regexp.last_match[:minutes],
+            seconds: Regexp.last_match[:seconds],
+            ms: Regexp.last_match[:ms] }
+        when /\A(?<hours>\d+):(?<minutes>[0-5]?\d):(?<seconds>[0-5]?\d)(?:\.(?<ms>\d{1,3}))?\z/
+          { hours: Regexp.last_match[:hours],
+            minutes: Regexp.last_match[:minutes],
+            seconds: Regexp.last_match[:seconds],
+            ms: Regexp.last_match[:ms] }
+        end
+
+    raise SectionLiteralParseError.new(tag_name, str) unless match
+
+    total_s = match[:seconds].to_i
+    total_s += match[:minutes].to_i * 60 if match[:minutes]
+    total_s += match[:hours].to_i * 3_600 if match[:hours]
+
+    total_s * 1_000 + match[:ms].to_s.ljust(3, '0')[0, 3].to_i
+  end
+
   def nico_tags_cannot_be_deprecated
     if nico? && deprecated_at.present?
       errors.add :deprecated_at, 'ニコタグは廃止できません．'

backend/app/representations/post_repr.rb

@@ -8,6 +8,7 @@ module PostRepr
       :url,
       :title,
       :thumbnail_base,
+      :video_ms,
       :original_created_from,
       :original_created_before,
       :created_at,
@@ -18,7 +19,7 @@ module PostRepr
 
   def base post, current_user = nil
     json = common(post)
-    json['tags'] = tag_json(post.tags)
+    json['tags'] = tag_json(post)
     json['uploaded_user'] = post.uploaded_user && UserRepr.base(post.uploaded_user)
     json['viewed'] = current_user ? current_user.viewed?(post) : false
     json
@@ -52,8 +53,16 @@ module PostRepr
                .merge('thumbnail' => thumbnail_url(post))
   end
 
-  def tag_json tags
-    tags.reject(&:deprecated?).map { |tag| TagRepr.inline(tag) }
+  def tag_json post
+    post
+        .active_post_tags
+        .reject { _1.tag.deprecated? }
+        .sort_by { _1.tag.name }
+        .map { |post_tag|
+      TagRepr.inline(post_tag.tag).merge(
+          'children' => [],
+          'sections' => post_tag.sections.as_json(only: [:begin_ms, :end_ms]))
+    }
   end
 
   def thumbnail_url post

backend/app/services/post_version_recorder.rb

@@ -23,6 +23,7 @@ class PostVersionRecorder < VersionRecorder
     { title: @record.title,
       url: @record.url,
       thumbnail_base: @record.thumbnail_base,
+      video_ms: @record.video_ms,
       tags: @record.snapshot_tag_names.join(' '),
       parent_post_ids: @record.snapshot_parent_post_ids.join(' '),
       original_created_from: @record.original_created_from,