Amend NIP-52 to support calendars and RSVPs

Sources/NostrSDK/EventCreating.swift

@@ -338,11 +338,11 @@ public extension EventCreating {
     /// Creates a ``DateBasedCalendarEvent`` (kind 31922) which starts on a date and ends before a different date in the future.
     /// Its use is appropriate for all-day or multi-day events where time and time zone hold no significance. e.g., anniversary, public holidays, vacation days.
     /// - Parameters:
-    ///   - name: The name of the calendar event.
+    ///   - title: The title of the calendar event.
     ///   - description: A detailed description of the calendar event.
     ///   - startDate: An inclusive start date. Must be less than end, if it exists. If there are any components other than year, month,
     ///   - endDate: An exclusive end date. If omitted, the calendar event ends on the same date as start.
-    ///   - location: The location of the calendar event. e.g. address, GPS coordinates, meeting room name, link to video call.
+    ///   - locations: The locations of the calendar event. e.g. address, GPS coordinates, meeting room name, link to video call.
     ///   - geohash: The [geohash](https://en.wikipedia.org/wiki/Geohash) to associate calendar event with a searchable physical location.
     ///   - participants: The participants of the calendar event.
     ///   - hashtags: Hashtags to categorize the calendar event.
@@ -351,7 +351,7 @@ public extension EventCreating {
     /// - Returns: The signed ``DateBasedCalendarEvent``.
     ///
     /// See [NIP-52](https://github.com/nostr-protocol/nips/blob/master/52.md).
-    func dateBasedCalendarEvent(withName name: String, description: String = "", startDate: TimeOmittedDate, endDate: TimeOmittedDate? = nil, location: String? = nil, geohash: String? = nil, participants: [CalendarEventParticipant]? = nil, hashtags: [String]? = nil, references: [URL]? = nil, signedBy keypair: Keypair) throws -> DateBasedCalendarEvent {
+    func dateBasedCalendarEvent(withTitle title: String, description: String = "", startDate: TimeOmittedDate, endDate: TimeOmittedDate? = nil, locations: [String]? = nil, geohash: String? = nil, participants: [CalendarEventParticipant]? = nil, hashtags: [String]? = nil, references: [URL]? = nil, signedBy keypair: Keypair) throws -> DateBasedCalendarEvent {
 
         var tags: [Tag] = []
 
@@ -369,12 +369,12 @@ public extension EventCreating {
         // and the end date being placed next to the start date.
         tags = [
             Tag(name: .identifier, value: UUID().uuidString),
-            Tag(name: "name", value: name),
+            Tag(name: .title, value: title),
             Tag(name: "start", value: startDate.dateString)
         ] + tags
 
-        if let location {
-            tags.append(Tag(name: "location", value: location))
+        if let locations, !locations.isEmpty {
+            tags += locations.map { Tag(name: "location", value: $0) }
         }
 
         if let geohash {
@@ -398,13 +398,13 @@ public extension EventCreating {
 
     /// Creates a ``TimeBasedCalendarEvent`` (kind 31923) which spans between a start time and end time.
     /// - Parameters:
-    ///   - name: The name of the calendar event.
+    ///   - title: The title of the calendar event.
     ///   - description: A detailed description of the calendar event.
     ///   - startTimestamp: An inclusive start timestamp.
     ///   - endTimestamp: An exclusive end timestamp. If omitted, the calendar event ends instantaneously.
     ///   - startTimeZone: The time zone of the start timestamp.
     ///   - endTimeZone: The time zone of the end timestamp. If omitted and startTimeZone is provided, the time zone of the end timestamp is the same as the start timestamp.
-    ///   - location: The location of the calendar event. e.g. address, GPS coordinates, meeting room name, link to video call.
+    ///   - locations: The locations of the calendar event. e.g. address, GPS coordinates, meeting room name, link to video call.
     ///   - geohash: The [geohash](https://en.wikipedia.org/wiki/Geohash) to associate calendar event with a searchable physical location.
     ///   - participants: The participants of the calendar event.
     ///   - hashtags: Hashtags to categorize the calendar event.
@@ -413,7 +413,7 @@ public extension EventCreating {
     /// - Returns: The signed ``TimeBasedCalendarEvent``.
     ///
     /// See [NIP-52](https://github.com/nostr-protocol/nips/blob/master/52.md).
-    func timeBasedCalendarEvent(withName name: String, description: String = "", startTimestamp: Date, endTimestamp: Date? = nil, startTimeZone: TimeZone? = nil, endTimeZone: TimeZone? = nil, location: String? = nil, geohash: String? = nil, participants: [CalendarEventParticipant]? = nil, hashtags: [String]? = nil, references: [URL]? = nil, signedBy keypair: Keypair) throws -> TimeBasedCalendarEvent {
+    func timeBasedCalendarEvent(withTitle title: String, description: String = "", startTimestamp: Date, endTimestamp: Date? = nil, startTimeZone: TimeZone? = nil, endTimeZone: TimeZone? = nil, locations: [String]? = nil, geohash: String? = nil, participants: [CalendarEventParticipant]? = nil, hashtags: [String]? = nil, references: [URL]? = nil, signedBy keypair: Keypair) throws -> TimeBasedCalendarEvent {
 
         // If the end timestamp is omitted, the calendar event ends instantaneously.
         if let endTimestamp {
@@ -425,7 +425,7 @@ public extension EventCreating {
 
         var tags: [Tag] = [
             Tag(name: .identifier, value: UUID().uuidString),
-            Tag(name: "name", value: name),
+            Tag(name: .title, value: title),
             Tag(name: "start", value: String(Int64(startTimestamp.timeIntervalSince1970)))
         ]
 
@@ -442,8 +442,8 @@ public extension EventCreating {
             tags.append(Tag(name: "end_tzid", value: endTimeZone.identifier))
         }
 
-        if let location {
-            tags.append(Tag(name: "location", value: location))
+        if let locations, !locations.isEmpty {
+            tags += locations.map { Tag(name: "location", value: $0) }
         }
 
         if let geohash {

Sources/NostrSDK/Events/Calendars/CalendarEventInterpreting.swift

@@ -7,21 +7,17 @@
 
 import Foundation
 
-public protocol CalendarEventInterpreting: NostrEvent, CalendarEventParticipantInterpreting, HashtagInterpreting, ReferenceTagInterpreting {}
+public protocol CalendarEventInterpreting: NostrEvent, CalendarEventParticipantInterpreting, HashtagInterpreting, ReferenceTagInterpreting, IdentifierTagInterpreting, TitleTagInterpreting {}
 public extension CalendarEventInterpreting {
-    /// Universally unique identifier (UUID).
-    var uuid: String? {
-        tags.first { $0.name == TagName.identifier.rawValue }?.value
-    }
-
     /// The name of the calendar event.
+    @available(*, deprecated, message: "This method of naming a calendar event is out of spec, not preferred, and will be removed in the future. Please use only the title field when it is available.")
     var name: String? {
         tags.first { $0.name == "name" }?.value
     }
 
-    /// The location of the calendar event. e.g. address, GPS coordinates, meeting room name, link to video call.
-    var location: String? {
-        tags.first { $0.name == "location" }?.value
+    /// The locations of the calendar event. e.g. address, GPS coordinates, meeting room name, link to video call.
+    var locations: [String] {
+        tags.filter { $0.name == "location" }.map { $0.value }
     }
 
     /// The [geohash](https://en.wikipedia.org/wiki/Geohash) to associate calendar event with a searchable physical location.

Sources/NostrSDK/Events/Calendars/CalendarEventRSVP.swift

@@ -0,0 +1,31 @@
+//
+//  CalendarEventRSVP.swift
+//  
+//
+//  Created by Terry Yiu on 12/1/23.
+//
+
+import Foundation
+
+public final class CalendarEventRSVP: NostrEvent, IdentifierTagInterpreting {
+    public var calendarEventIdentifier: String? {
+        // TODO
+        return nil
+    }
+
+    public var status: CalendarEventRSVPStatus? {
+        guard let statusTag = tags.first(where: { $0.name == "l" && $0.otherParameters.first == "status" }) else {
+            return nil
+        }
+
+        return CalendarEventRSVPStatus(rawValue: statusTag.value)
+    }
+
+    public var freebusy: CalendarEventRSVPFreebusy? {
+        guard let freebusyTag = tags.first(where: { $0.name == "l" && $0.otherParameters.first == "freebusy" }) else {
+            return nil
+        }
+
+        return CalendarEventRSVPFreebusy(rawValue: freebusyTag.value)
+    }
+}

Sources/NostrSDK/Events/Calendars/CalendarEventRSVPFreebusy.swift

@@ -0,0 +1,35 @@
+//
+//  CalendarEventRSVPFreebusy.swift
+//
+//
+//  Created by Terry Yiu on 12/17/23.
+//
+
+import Foundation
+
+public enum CalendarEventRSVPFreebusy: RawRepresentable, CaseIterable, Codable, Equatable {
+
+    public typealias RawValue = String
+
+    case free
+    case busy
+    case unknown(RawValue)
+
+    static public let allCases: AllCases = [
+        .free,
+        .busy
+    ]
+
+    public init?(rawValue: String) {
+        self = Self.allCases.first { $0.rawValue == rawValue }
+               ?? .unknown(rawValue)
+    }
+
+    public var rawValue: String {
+        switch self {
+        case .free: return "free"
+        case .busy: return "busy"
+        case let .unknown(value): return value
+        }
+    }
+}

Sources/NostrSDK/Events/Calendars/CalendarEventRSVPStatus.swift

@@ -0,0 +1,38 @@
+//
+//  File.swift
+//  
+//
+//  Created by Terry Yiu on 12/17/23.
+//
+
+import Foundation
+
+public enum CalendarEventRSVPStatus: RawRepresentable, CaseIterable, Codable, Equatable {
+
+    public typealias RawValue = String
+
+    case accepted
+    case declined
+    case tentative
+    case unknown(RawValue)
+
+    static public let allCases: AllCases = [
+        .accepted,
+        .declined,
+        .tentative
+    ]
+
+    public init?(rawValue: String) {
+        self = Self.allCases.first { $0.rawValue == rawValue }
+               ?? .unknown(rawValue)
+    }
+
+    public var rawValue: String {
+        switch self {
+        case .accepted: return "accepted"
+        case .declined: return "declined"
+        case .tentative: return "tentative"
+        case let .unknown(value): return value
+        }
+    }
+}

Sources/NostrSDK/Events/Calendars/CalendarNostrEvent.swift

@@ -0,0 +1,11 @@
+//
+//  CalendarNostrEvent.swift
+//
+//
+//  Created by Terry Yiu on 12/1/23.
+//
+
+import Foundation
+
+public final class CalendarNostrEvent: NostrEvent, IdentifierTagInterpreting, TitleTagInterpreting {
+}

Sources/NostrSDK/Events/Tags/IdentifierTagInterpreting.swift

@@ -0,0 +1,17 @@
+//
+//  IdentifierTagInterpreting.swift
+//
+//
+//  Created by Terry Yiu on 12/8/23.
+//
+
+import Foundation
+
+public protocol IdentifierTagInterpreting: NostrEvent {}
+public extension IdentifierTagInterpreting {
+    /// The identifier of the event. For parameterized replaceable events, this identifier remains stable across replacements.
+    /// This identifier is represented by the ``d`` tag, which is distinctly different from the ``id`` field on ``NostrEvent``.
+    var identifier: String? {
+        firstValueForTagName(.identifier)
+    }
+}

Sources/NostrSDK/Events/Tags/TitleTagInterpreting.swift

@@ -0,0 +1,16 @@
+//
+//  TitleTagInterpreting.swift
+//
+//
+//  Created by Terry Yiu on 12/8/23.
+//
+
+import Foundation
+
+public protocol TitleTagInterpreting: NostrEvent {}
+public extension TitleTagInterpreting {
+    /// The title of the event.
+    var title: String? {
+        firstValueForTagName(.title)
+    }
+}

Sources/NostrSDK/Tag.swift

@@ -36,7 +36,7 @@ public enum TagName: String {
 
     case summary
 
-    /// a title for a long-form content event
+    /// a title for an event
     case title
 
     /// a web URL the event is referring to in some way. See [NIP-24 - Extra metadata fields and tags](https://github.com/nostr-protocol/nips/blob/master/24.md#tags).