class PostImportRunner
  def initialize actor:, rows:
    @actor = actor
    @rows = rows
  end

  def run
    normalised_rows = PostImportRowNormaliser.normalise!(@rows)
    previews = PostImportPreviewer.new.preview_rows(rows: normalised_rows,
                                                    fetch_metadata: false)
    preview_map = previews.index_by { _1[:source_row] }

    results = normalised_rows.map do |row|
      run_row(row, preview_map.fetch(row['source_row']))
    end

    { 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, preview
    attributes = row.fetch('attributes', { }).transform_keys { _1.to_s.underscore }
    return { source_row: row['source_row'],
             status: 'failed',
             errors: preview[:validation_errors] } if preview[:validation_errors].present?
    return row.slice('source_row').merge(status: 'skipped') if preview[:skip_reason] == '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
    { 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