# frozen_string_literal: true

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require "azure/core"
require "azure/core/http/retry_policy"

module Azure::Storage::Common::Core::Filter
  class RetryPolicyFilter < Azure::Core::Http::RetryPolicy
    def initialize(retry_count = nil, retry_interval = nil)
      @retry_count = retry_count
      @retry_interval = retry_interval
      @request_options = {}

      super &:should_retry?
    end

    attr_reader :retry_count,
                :retry_interval

    # Overrides the base class implementation of call to determine
    # whether to retry the operation
    #
    # response - HttpResponse. The response from the active request
    # retry_data - Hash. Stores stateful retry data
    def should_retry?(response, retry_data)
      # Fill necessary information
      init_retry_data retry_data

      # Applies the logic when there is subclass overrides it
      apply_retry_policy retry_data

      # Checks the result and count limit
      if retry_data[:retryable].nil?
        retry_data[:retryable] = true
      else
        retry_data[:retryable] &&= retry_data[:count] <= @retry_count
      end
      return false unless retry_data[:retryable]

      # Checks whether there is a local error
      # Cannot retry immediately when it returns true, as it need check other errors
      should_retry_on_local_error? retry_data
      return false unless should_retry_on_error? response, retry_data

      # Determined that it needs to retry.
      adjust_retry_request retry_data

      wait_for_retry

      retry_data[:retryable]
    end

    # Apply the retry policy to determine how the HTTP request should continue retrying
    #
    # retry_data - Hash. Stores stateful retry data
    #
    # The retry_data is a Hash which can be used to store
    # stateful data about the request execution context (such as an
    # incrementing counter, timestamp, etc). The retry_data object
    # will be the same instance throughout the lifetime of the request
    #
    # Alternatively, a subclass could override this method.
    def apply_retry_policy(retry_data)
    end

    # Determines if the HTTP request should continue retrying
    #
    # retry_data - Hash. Stores stateful retry data
    #
    # The retry_data is a Hash which can be used to store
    # stateful data about the request execution context (such as an
    # incrementing counter, timestamp, etc). The retry_data object
    # will be the same instance throughout the lifetime of the request.
    def should_retry_on_local_error?(retry_data)
      unless retry_data[:error]
        retry_data[:retryable] = true;
        return true
      end

      error_message = retry_data[:error].inspect

      if error_message.include?("SocketError: Hostname not known")
        # Retry on local DNS resolving
        # When uses resolv-replace.rb to replace the libc resolver
        # Reference:
        #  https://makandracards.com/ninjaconcept/30815-fixing-socketerror-getaddrinfo-name-or-service-not-known-with-ruby-s-resolv-replace-rb
        #  http://www.subelsky.com/2014/05/fixing-socketerror-getaddrinfo-name-or.html
        retry_data[:retryable] = true;
      elsif error_message.include?("getaddrinfo: Name or service not known")
        # When uses the default resolver
        retry_data[:retryable] = true;
      elsif error_message.downcase.include?("timeout")
        retry_data[:retryable] = true;
      elsif error_message.include?("Errno::ECONNRESET")
        retry_data[:retryable] = true;
      elsif error_message.include?("Errno::EACCES")
        retry_data[:retryable] = false;
      elsif error_message.include?("NOSUPPORT")
        retry_data[:retryable] = false;
      end

      retry_data[:retryable]
    end

    # Determines if the HTTP request should continue retrying
    #
    # response - Azure::Core::Http::HttpResponse. The response from the active request
    # retry_data - Hash. Stores stateful retry data
    #
    # The retry_data is a Hash which can be used to store
    # stateful data about the request execution context (such as an
    # incrementing counter, timestamp, etc). The retry_data object
    # will be the same instance throughout the lifetime of the request.
    def should_retry_on_error?(response, retry_data)
      response = response || retry_data[:error].http_response if retry_data[:error] && retry_data[:error].respond_to?("http_response")
      unless response
        retry_data[:retryable] = false unless retry_data[:error]
        return retry_data[:retryable]
      end

      check_location(response, retry_data)

      check_status_code(retry_data)

      retry_data[:retryable]
    end

    # Adjust the retry parameter and wait for retry
    def wait_for_retry
      sleep @retry_interval if @retry_interval > 0
    end

    # Adjust the retry request
    #
    # retry_data - Hash. Stores stateful retry data
    def adjust_retry_request(retry_data)
      # Adjust the location first
      next_location = @request_options[:target_location].nil? ? get_next_location(retry_data) : @request_options[:target_location]
      retry_data[:current_location] = next_location

      retry_data[:uri] =
        if next_location == Azure::Storage::Common::StorageLocation::PRIMARY
          @request_options[:primary_uri]
        else
          @request_options[:secondary_uri]
        end

      # Now is the time to calculate the exact retry interval. ShouldRetry call above already
      # returned back how long two requests to the same location should be apart from each other.
      # However, for the reasons explained above, the time spent between the last attempt to
      # the target location and current time must be subtracted from the total retry interval
      # that ShouldRetry returned.
      lastAttemptTime =
        if retry_data[:current_location] == Azure::Storage::Common::StorageLocation::PRIMARY
          retry_data[:last_primary_attempt]
        else
          retry_data[:last_secondary_attempt]
        end

      @retry_interval =
        if lastAttemptTime.nil?
          0
        else
          since_last_attempt = Time.now - lastAttemptTime
          remainder = retry_data[:interval] - since_last_attempt
          remainder > 0 ? remainder : 0
        end
    end

    # Initialize the retry data
    #
    # retry_data - Hash. Stores stateful retry data
    def init_retry_data(retry_data)
      @request_options = retry_data[:request_options] unless retry_data[:request_options].nil?

      if retry_data[:current_location].nil?
        retry_data[:current_location] = Azure::Storage::Common::Service::StorageService.get_location(@request_options[:location_mode], @request_options[:request_location_mode])
      end

      if retry_data[:current_location] == Azure::Storage::Common::StorageLocation::PRIMARY
        retry_data[:last_primary_attempt] = Time.now
      else
        retry_data[:last_secondary_attempt] = Time.now
      end
    end

    # Check the location
    #
    # retry_data - Hash. Stores stateful retry data
    def check_location(response, retry_data)
      # If a request sent to the secondary location fails with 404 (Not Found), it is possible
      # that the resource replication is not finished yet. So, in case of 404 only in the secondary
      # location, the failure should still be retryable.
      retry_data[:secondary_not_found] = 
        ((retry_data[:current_location] === Azure::Storage::Common::StorageLocation::SECONDARY) && 
        response.status_code === 404);

      if retry_data[:secondary_not_found]
        retry_data[:status_code] = 500
      else
        if (response.status_code)
          retry_data[:status_code] = response.status_code
        else
          retry_data[:status_code] = nil
        end
      end
    end

    # Check the status code
    #
    # retry_data - Hash. Stores stateful retry data
    def check_status_code(retry_data)
      if (retry_data[:status_code] < 400)
        retry_data[:retryable] = false;
      # Non-timeout Cases
      elsif (retry_data[:status_code] != 408)
        # Always no retry on "not implemented" and "version not supported"
        if (retry_data[:status_code] == 501 || retry_data[:status_code] == 505)
          retry_data[:retryable] = false;
        end

        # When absorb_conditional_errors_on_retry is set (for append blob)
        if (@request_options[:absorb_conditional_errors_on_retry])
          if (retry_data[:status_code] == 412)
            # When appending block with precondition failure and their was a server error before, we ignore the error.
            if (retry_data[:last_server_error])
              retry_data[:error] = nil;
              retry_data[:retryable] = true;
            else
              retry_data[:retryable] = false;
            end
          elsif (retry_data[:retryable] && retry_data[:status_code] >= 500 && retry_data[:status_code] < 600)
            # Retry on the server error
            retry_data[:retryable] = true;
            retry_data[:last_server_error] = true;
          end
        elsif (retry_data[:status_code] < 500)
          # No retry on the client error
          retry_data[:retryable] = false;
        end
      end
    end

    # Get retry request destination
    #
    # retry_data - Hash. Stores stateful retry data
    def get_next_location(retry_data)
      # In case of 404 when trying the secondary location, instead of retrying on the
      # secondary, further requests should be sent only to the primary location, as it most
      # probably has a higher chance of succeeding there.
      if retry_data[:secondary_not_found] && @request_options[:location_mode] != Azure::Storage::Common::LocationMode::SECONDARY_ONLY
        @request_options[:location_mode] = Azure::Storage::Common::LocationMode::PRIMARY_ONLY;
        return Azure::Storage::Common::StorageLocation::PRIMARY
      end

      case @request_options[:location_mode]
      when Azure::Storage::Common::LocationMode::PRIMARY_ONLY
        Azure::Storage::Common::StorageLocation::PRIMARY
      when Azure::Storage::Common::LocationMode::SECONDARY_ONLY
        Azure::Storage::Common::StorageLocation::SECONDARY
      else
        # request_location_mode cannot be SECONDARY_ONLY because it will be blocked at the first time
        if @request_options[:request_location_mode] == Azure::Storage::Common::RequestLocationMode::PRIMARY_ONLY
          Azure::Storage::Common::StorageLocation::PRIMARY
        elsif @request_options[:request_location_mode] == Azure::Storage::Common::RequestLocationMode::SECONDARY_ONLY
          Azure::Storage::Common::StorageLocation::SECONDARY
        else
          if retry_data[:current_location] === Azure::Storage::Common::StorageLocation::PRIMARY
            Azure::Storage::Common::StorageLocation::SECONDARY
          else
            Azure::Storage::Common::StorageLocation::PRIMARY
          end
        end
      end
    end

  end
end