Add NIP-01 compliant client code

lib/nostr/subscription.rb

@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require 'securerandom'
+
+module Nostr
+  # A subscription the result of a request to receive events from a relay
+  class Subscription
+    # A random string that should be used to represent a subscription
+    #
+    # @api public
+    #
+    # @example
+    #   subscription.id # => 'c24881c305c5cfb7c1168be7e9b0e150'
+    #
+    # @return [String]
+    #
+    attr_reader :id
+
+    # An object that determines what events will be sent in the subscription
+    #
+    # @api public
+    #
+    # @example
+    #   subscription.filter # => #<Nostr::Subscription:0x0000000110eea460 @filter=#<Nostr::Filter:0x0000000110c24de8>,
+    #   @id="0dd7f3fa06cd5f797438dd0b7477f3c7">
+    #
+    # @return [Filter]
+    #
+    attr_reader :filter
+
+    # Initializes a subscription
+    #
+    # @api public
+    #
+    # @example Creating a subscription with no id and no filters
+    #   subscription = Nostr::Subscription.new
+    #
+    # @example Creating a subscription with an ID
+    #   subscription = Nostr::Subscription.new(id: 'c24881c305c5cfb7c1168be7e9b0e150')
+    #
+    # @example Subscribing to all events created after a certain time
+    #   subscription = Nostr::Subscription.new(filter: Nostr::Filter.new(since: 1230981305))
+    #
+    # @param id [String] A random string that should be used to represent a subscription
+    # @param filter [Filter] An object that determines what events will be sent in that subscription
+    #
+    def initialize(filter:, id: SecureRandom.hex)
+      @id = id
+      @filter = filter
+    end
+
+    # Compares two subscriptions. Returns true if all attributes are equal and false otherwise
+    #
+    # @api public
+    #
+    # @example
+    #  subscription1 == subscription1 # => true
+    #
+    # @return [Boolean] True if all attributes are equal and false otherwise
+    #
+    def ==(other)
+      id == other.id && filter == other.filter
+    end
+  end
+end