# frozen_string_literal: true

# Copyright (C) 2014-2020 MongoDB Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

module Mongo
  class Error
    # Exception raised if there are write errors upon executing a bulk
    # operation.
    #
    # Unlike OperationFailure, BulkWriteError does not currently expose
    # individual error components (such as the error code). The result document
    # (which can be obtained using the +result+ attribute) provides detailed
    # error information and can be examined by the application if desired.
    #
    # @note A bulk operation that resulted in a BulkWriteError may have
    #   written some of the documents to the database. If the bulk write
    #   was unordered, writes may have also continued past the write that
    #   produced a BulkWriteError.
    #
    # @since 2.0.0
    class BulkWriteError < Error
      # @return [ BSON::Document ] result The error result.
      attr_reader :result

      # @return [ Array<String> ] Deduplicated list of "host:port" addresses of
      #   the servers that produced this bulk write error. Empty when no
      #   addresses were supplied.
      attr_reader :server_addresses

      # Instantiate the new exception.
      #
      # @example Instantiate the exception.
      #   Mongo::Error::BulkWriteError.new(response)
      #
      # @param [ Hash ] result A processed response from the server
      #   reporting results of the operation.
      # @param [ Array<String | Mongo::Address | Mongo::Server::Description> ]
      #   server_addresses Addresses of the servers that produced this error.
      #   Entries are normalized to "host:port" strings.
      #
      # @since 2.0.0
      def initialize(result, server_addresses: nil)
        @result = result
        @server_addresses = normalize_server_addresses(server_addresses)

        # Exception constructor behaves differently for a nil argument and
        # for no argument. Avoid passing nil explicitly.
        message = build_message
        message ? super(message) : super()
      end

      private

      # Generates an error message when there are multiple write errors.
      #
      # @example Multiple documents fail validation
      #
      # col has validation { 'validator' => { 'x' => { '$type' => 'string' } } }
      # col.insert_many([{_id: 1}, {_id: 2}], ordered: false)
      #
      # Multiple errors:
      #   [121]: Document failed validation --
      #     {"failingDocumentId":1,"details":{"operatorName":"$type",
      #     "specifiedAs":{"x":{"$type":"string"}},"reason":"field was
      #     missing"}};
      #   [121]: Document failed validation --
      #     {"failingDocumentId":2, "details":{"operatorName":"$type",
      #     "specifiedAs":{"x":{"$type":"string"}}, "reason":"field was
      #     missing"}}
      #
      # @return [ String ] The error message
      def build_message
        errors = @result['writeErrors']
        return nil unless errors

        fragment = ''
        cut_short = false
        errors.first(10).each_with_index do |error, i|
          fragment += '; ' if fragment.length > 0
          fragment += "[#{error['code']}]: #{error['errmsg']}"
          fragment += " -- #{error['errInfo'].to_json}" if error['errInfo']

          if fragment.length > 3000
            cut_short = i < [ 9, errors.length ].min
            break
          end
        end

        fragment += '...' if errors.length > 10 || cut_short

        fragment = "Multiple errors: #{fragment}" if errors.length > 1

        if Mongo.include_server_address_in_errors && @server_addresses.any?
          fragment = "#{fragment} (on #{@server_addresses.join(', ')})"
        end

        fragment
      end

      def normalize_server_addresses(value)
        return [] if value.nil?

        Array(value).filter_map do |entry|
          case entry
          when String then entry
          when Mongo::Address then entry.seed
          when Mongo::Server::Description then entry.address&.seed
          else
            raise ArgumentError,
                  "server_addresses entries must be String, Mongo::Address, or Mongo::Server::Description; got #{entry.class}"
          end
        end.uniq
      end
    end
  end
end
