class PostImportRunner
  MAX_ROWS = PostImportSourceParser::MAX_ROWS
  ATTRIBUTE_KEYS = %w[title thumbnail_base original_created_from original_created_before duration tags parent_post_ids video_ms].freeze
  def initialize actor:, rows:, existing: 'skip'
    @actor = actor
    @rows = rows
    @existing = existing == 'error' ? 'error' : 'skip'
  end

  def run
    raise ArgumentError, "取込件数は #{ MAX_ROWS } 件までです．" if @rows.length > MAX_ROWS

    results = @rows.map { |row| run_row(row.to_h.deep_transform_keys { _1.to_s.underscore }) }
    { created: results.count { _1[:status] == 'created' }, skipped: results.count { _1[:status] == 'skipped' },
      failed: results.count { _1[:status] == 'failed' }, rows: results }
  end

  private

  def run_row row
    attributes = row.fetch('attributes', { }).to_h.transform_keys { _1.to_s.underscore }
    raise ArgumentError, '取込項目が不正です．' unless (attributes.keys - ATTRIBUTE_KEYS).empty?
    raise ArgumentError, '取込項目が大きすぎます．' if attributes.values.any? { _1.to_s.bytesize > PostImportSourceParser::MAX_CELL_BYTES }
    raise ArgumentError, 'URL が長すぎます．' if row['url'].to_s.bytesize > PostImportSourceParser::MAX_CELL_BYTES
    preview = PostImportPreviewer.new(parsed: { columns: [], rows: [] }, url_column: 0,
                                      mappings: {}, existing: @existing).preview_rows(
                                          rows: [{ source_row: row['source_row'], url: row['url'],
                                                   attributes:, provenance: row['provenance'],
                                                   tag_sources: row['tag_sources'] }],
                                          fetch_metadata: false).first
    return { source_row: row['source_row'], status: 'failed', errors: preview[:errors] } if preview[:errors].present?
    return row.slice('source_row').merge(status: 'skipped') if @existing == 'skip' && preview[:existing]
    attributes['tags'] = preview[:attributes]['tags']
    attributes['url'] = row['url']
    post = PostCreator.new(actor: @actor, attributes:).create!
    { source_row: row['source_row'], status: 'created', post: PostRepr.base(post) }
  rescue ActiveRecord::RecordInvalid => e
    { source_row: row['source_row'], status: 'failed', errors: e.record.errors.to_hash }
  rescue Tag::NicoTagNormalisationError
    { source_row: row['source_row'], status: 'failed', errors: { tags: ['ニコニコ・タグは直接指定できません．'] } }
  rescue Tag::DeprecatedTagNormalisationError
    { source_row: row['source_row'], status: 'failed', errors: { tags: ['廃止済みタグは付与できません．'] } }
  rescue ArgumentError, PostCreator::VideoMsParseError
    { source_row: row['source_row'], status: 'failed', errors: { base: ['入力値が不正です．'] } }
  rescue StandardError => e
    Rails.logger.error("post_import_runner_failure #{ { error: e.class.name, message: e.message }.to_json }")
    { source_row: row['source_row'], status: 'failed', errors: { base: ['登録中にエラーが発生しました．'] } }
  end
end