# frozen_string_literal: true

module BackupRestore
  class S3BackupStore < BackupStore
    UPLOAD_URL_EXPIRES_AFTER_SECONDS ||= 6.hours.to_i

    delegate :abort_multipart,
             :presign_multipart_part,
             :list_multipart_parts,
             :complete_multipart,
             to: :s3_helper

    def initialize(opts = {})
      @s3_options = S3Helper.s3_options(SiteSetting)
      @s3_options.merge!(opts[:s3_options]) if opts[:s3_options]
    end

    def s3_helper
      @s3_helper ||= S3Helper.new(s3_bucket_name_with_prefix, "", @s3_options.clone)
    end

    def remote?
      true
    end

    def file(filename, include_download_source: false)
      obj = s3_helper.object(filename)
      create_file_from_object(obj, include_download_source) if obj.exists?
    end

    def delete_file(filename)
      obj = s3_helper.object(filename)

      if obj.exists?
        obj.delete
        reset_cache
      end
    end

    def download_file(filename, destination_path, failure_message = nil)
      s3_helper.download_file(filename, destination_path, failure_message)
    end

    def upload_file(filename, source_path, content_type)
      obj = s3_helper.object(filename)
      raise BackupFileExists.new if obj.exists?

      obj.upload_file(source_path, content_type: content_type)
      reset_cache
    end

    def generate_upload_url(filename)
      obj = s3_helper.object(filename)
      raise BackupFileExists.new if obj.exists?

      # TODO (martin) We can remove this at a later date when we move this
      # ensure CORS for backups and direct uploads to a post-site-setting
      # change event, so the rake task doesn't have to be run manually.
      @s3_helper.ensure_cors!([S3CorsRulesets::BACKUP_DIRECT_UPLOAD])

      presigned_url(obj, :put, UPLOAD_URL_EXPIRES_AFTER_SECONDS)
    rescue Aws::Errors::ServiceError => e
      Rails.logger.warn(
        "Failed to generate upload URL for S3: #{e.message.presence || e.class.name}",
      )
      raise StorageError.new(e.message.presence || e.class.name)
    end

    def signed_url_for_temporary_upload(
      file_name,
      expires_in: S3Helper::UPLOAD_URL_EXPIRES_AFTER_SECONDS,
      metadata: {}
    )
      obj = object_from_path(file_name)
      raise BackupFileExists.new if obj.exists?
      key = temporary_upload_path(file_name)
      s3_helper.presigned_url(
        key,
        method: :put_object,
        expires_in: expires_in,
        opts: {
          metadata: metadata,
          acl: SiteSetting.s3_use_acls ? "private" : nil,
        },
      )
    end

    def temporary_upload_path(file_name)
      FileStore::BaseStore.temporary_upload_path(file_name, folder_prefix: temporary_folder_prefix)
    end

    def temporary_folder_prefix
      folder_prefix = s3_helper.s3_bucket_folder_path.nil? ? "" : s3_helper.s3_bucket_folder_path

      if Rails.env.test?
        folder_prefix = File.join(folder_prefix, "test_#{ENV["TEST_ENV_NUMBER"].presence || "0"}")
      end

      folder_prefix
    end

    def create_multipart(file_name, content_type, metadata: {})
      obj = object_from_path(file_name)
      raise BackupFileExists.new if obj.exists?
      key = temporary_upload_path(file_name)
      s3_helper.create_multipart(key, content_type, metadata: metadata)
    end

    def move_existing_stored_upload(
      existing_external_upload_key:,
      original_filename: nil,
      content_type: nil
    )
      s3_helper.copy(
        existing_external_upload_key,
        File.join(s3_helper.s3_bucket_folder_path, original_filename),
        options: {
          acl: SiteSetting.s3_use_acls ? "private" : nil,
          apply_metadata_to_destination: true,
        },
      )
      s3_helper.delete_object(existing_external_upload_key)
    end

    def object_from_path(path)
      s3_helper.object(path)
    end

    private

    def unsorted_files
      objects = []

      s3_helper.list.each do |obj|
        objects << create_file_from_object(obj) if obj.key.match?(file_regex)
      end

      objects
    rescue Aws::Errors::ServiceError => e
      Rails.logger.warn("Failed to list backups from S3: #{e.message.presence || e.class.name}")
      raise StorageError.new(e.message.presence || e.class.name)
    end

    def create_file_from_object(obj, include_download_source = false)
      expires = SiteSetting.s3_presigned_get_url_expires_after_seconds
      BackupFile.new(
        filename: File.basename(obj.key),
        size: obj.size,
        last_modified: obj.last_modified,
        source: include_download_source ? presigned_url(obj, :get, expires) : nil,
      )
    end

    def presigned_url(obj, method, expires_in_seconds)
      obj.presigned_url(method, expires_in: expires_in_seconds)
    end

    def cleanup_allowed?
      !SiteSetting.s3_disable_cleanup
    end

    def s3_bucket_name_with_prefix
      File.join(SiteSetting.s3_backup_bucket, RailsMultisite::ConnectionManagement.current_db)
    end

    def file_regex
      @file_regex ||=
        begin
          path = s3_helper.s3_bucket_folder_path || ""

          if path.present?
            path = "#{path}/" unless path.end_with?("/")
            path = Regexp.quote(path)
          end

          %r{\A#{path}[^/]*\.t?gz\z}i
        end
    end

    def free_bytes
      nil
    end
  end
end