fix(datastore): store time zone info in Temporal.DateTime (#3393)

* fix(datastore): store time zone info in Temporal.DateTime

* change to use private enum

* add support for hh:mm:ss timezone format

* resolve comments

* refactor implementation with enums

Author: 5d

Amplify/Categories/DataStore/Model/Internal/Model+DateFormatting.swift

@@ -27,7 +27,7 @@ public struct ModelDateFormatting {
     public static let encodingStrategy: JSONEncoder.DateEncodingStrategy = {
         let strategy = JSONEncoder.DateEncodingStrategy.custom { date, encoder in
             var container = encoder.singleValueContainer()
-            try container.encode(Temporal.DateTime(date).iso8601String)
+            try container.encode(Temporal.DateTime(date, timeZone: .utc).iso8601String)
         }
         return strategy
     }()

Amplify/Categories/DataStore/Model/Temporal/Date.swift

@@ -18,16 +18,20 @@ extension Temporal {
     ///
     ///  - Note: `.medium`, `.long`, and `.full` are the same date format.
     public struct Date: TemporalSpec {
+
         // Inherits documentation from `TemporalSpec`
         public let foundationDate: Foundation.Date
 
+        // Inherits documentation from `TemporalSpec`
+        public let timeZone: TimeZone? = .utc
+
         // Inherits documentation from `TemporalSpec`
         public static func now() -> Self {
-            Temporal.Date(Foundation.Date())
+            Temporal.Date(Foundation.Date(), timeZone: .utc)
         }
 
         // Inherits documentation from `TemporalSpec`
-        public init(_ date: Foundation.Date) {
+        public init(_ date: Foundation.Date, timeZone: TimeZone?) {
             self.foundationDate = Temporal
                 .iso8601Calendar
                 .startOfDay(for: date)

Amplify/Categories/DataStore/Model/Temporal/DateTime.swift

@@ -15,27 +15,33 @@ extension Temporal {
     ///  * `.long` => `yyyy-MM-dd'T'HH:mm:ssZZZZZ`
     ///  * `.full` => `yyyy-MM-dd'T'HH:mm:ss.SSSZZZZZ`
     public struct DateTime: TemporalSpec {
+
         // Inherits documentation from `TemporalSpec`
         public let foundationDate: Foundation.Date
 
+        // Inherits documentation from `TemporalSpec`
+        public let timeZone: TimeZone?
+
         // Inherits documentation from `TemporalSpec`
         public static func now() -> Self {
-            Temporal.DateTime(Foundation.Date())
+            Temporal.DateTime(Foundation.Date(), timeZone: .utc)
         }
 
         /// `Temporal.Time` of this `Temporal.DateTime`.
         public var time: Time {
-            Time(foundationDate)
+            Time(foundationDate, timeZone: timeZone)
         }
 
         // Inherits documentation from `TemporalSpec`
-        public init(_ date: Foundation.Date) {
+        public init(_ date: Foundation.Date, timeZone: TimeZone? = .utc) {
             let calendar = Temporal.iso8601Calendar
             let components = calendar.dateComponents(
                 DateTime.iso8601DateComponents,
                 from: date
             )
 
+            self.timeZone = timeZone
+
             foundationDate = calendar
                 .date(from: components) ?? date
         }
@@ -57,3 +63,5 @@ extension Temporal {
 
 // Allow date unit and time unit operations on `Temporal.DateTime`
 extension Temporal.DateTime: DateUnitOperable, TimeUnitOperable {}
+
+extension Temporal.DateTime: Sendable { }

Amplify/Categories/DataStore/Model/Temporal/SpecBasedDateConverting.swift

@@ -12,7 +12,7 @@ import Foundation
 @usableFromInline
 internal struct SpecBasedDateConverting<Spec: TemporalSpec> {
     @usableFromInline
-    internal typealias DateConverter = (_ string: String, _ format: TemporalFormat?) throws -> Date
+    internal typealias DateConverter = (_ string: String, _ format: TemporalFormat?) throws -> (Date, TimeZone)
 
     @usableFromInline
     internal let convert: DateConverter
@@ -28,19 +28,21 @@ internal struct SpecBasedDateConverting<Spec: TemporalSpec> {
     internal static func `default`(
         iso8601String: String,
         format: TemporalFormat? = nil
-    ) throws -> Date {
+    ) throws -> (Date, TimeZone) {
         let date: Foundation.Date
+        let tz: TimeZone = TimeZone(iso8601DateString: iso8601String) ?? .utc
         if let format = format {
             date = try Temporal.date(
                 from: iso8601String,
                 with: [format(for: Spec.self)]
             )
+
         } else {
             date = try Temporal.date(
                 from: iso8601String,
                 with: TemporalFormat.sortedFormats(for: Spec.self)
             )
         }
-        return date
+        return (date, tz)
     }
 }

Amplify/Categories/DataStore/Model/Temporal/Temporal+Comparable.swift

@@ -15,11 +15,13 @@ import Foundation
 extension TemporalSpec where Self: Comparable {
 
     public static func == (lhs: Self, rhs: Self) -> Bool {
-        return lhs.iso8601String == rhs.iso8601String
+        return lhs.iso8601FormattedString(format: .full, timeZone: .utc)
+            == rhs.iso8601FormattedString(format: .full, timeZone: .utc)
     }
 
     public static func < (lhs: Self, rhs: Self) -> Bool {
-        return lhs.iso8601String < rhs.iso8601String
+        return lhs.iso8601FormattedString(format: .full, timeZone: .utc)
+             < rhs.iso8601FormattedString(format: .full, timeZone: .utc)
     }
 }
 

Amplify/Categories/DataStore/Model/Temporal/Temporal.swift

@@ -27,6 +27,10 @@ public protocol TemporalSpec {
     /// by a Foundation `Date` instance.
     var foundationDate: Foundation.Date { get }
 
+    /// The timezone field is an optional field used to specify the timezone associated
+    /// with a particular date.
+    var timeZone: TimeZone? { get }
+
     /// The ISO-8601 formatted string in the UTC `TimeZone`.
     /// - SeeAlso: `iso8601FormattedString(TemporalFormat, TimeZone) -> String`
     var iso8601String: String { get }
@@ -57,7 +61,7 @@ public protocol TemporalSpec {
     /// Constructs a `TemporalSpec` from a `Date` object.
     /// - Parameter date: The `Date` instance that will be used as the reference of the
     /// `TemporalSpec` instance.
-    init(_ date: Foundation.Date)
+    init(_ date: Foundation.Date, timeZone: TimeZone?)
 
     /// A string representation of the underlying date formatted using ISO8601 rules.
     ///
@@ -90,25 +94,25 @@ extension TemporalSpec {
     /// The ISO8601 representation of the scalar using `.full` as the format and `.utc` as `TimeZone`.
     /// - SeeAlso: `iso8601FormattedString(format:timeZone:)`
     public var iso8601String: String {
-        iso8601FormattedString(format: .full)
+        iso8601FormattedString(format: .full, timeZone: timeZone ?? .utc)
     }
 
     @inlinable
     public init(iso8601String: String, format: TemporalFormat) throws {
-        let date = try SpecBasedDateConverting<Self>()
+        let (date, tz) = try SpecBasedDateConverting<Self>()
             .convert(iso8601String, format)
 
-        self.init(date)
+        self.init(date, timeZone: tz)
     }
 
     @inlinable
     public init(
         iso8601String: String
     ) throws {
-        let date = try SpecBasedDateConverting<Self>()
+        let (date, tz) = try SpecBasedDateConverting<Self>()
             .convert(iso8601String, nil)
 
-        self.init(date)
+        self.init(date, timeZone: tz)
     }
 }
 

Amplify/Categories/DataStore/Model/Temporal/TemporalOperation.swift

@@ -33,6 +33,6 @@ extension TemporalSpec {
                 """
             )
         }
-        return Self.init(date)
+        return Self.init(date, timeZone: timeZone)
     }
 }

Amplify/Categories/DataStore/Model/Temporal/Time.swift

@@ -18,13 +18,16 @@ extension Temporal {
         // Inherits documentation from `TemporalSpec`
         public let foundationDate: Foundation.Date
 
+        // Inherits documentation from `TemporalSpec`
+        public let timeZone: TimeZone? = .utc
+
         // Inherits documentation from `TemporalSpec`
         public static func now() -> Self {
-            Temporal.Time(Foundation.Date())
+            Temporal.Time(Foundation.Date(), timeZone: .utc)
         }
 
         // Inherits documentation from `TemporalSpec`
-        public init(_ date: Foundation.Date) {
+        public init(_ date: Foundation.Date, timeZone: TimeZone?) {
             // Sets the date to a fixed instant so time-only operations are safe
             let calendar = Temporal.iso8601Calendar
             var components = calendar.dateComponents(
@@ -45,7 +48,6 @@ extension Temporal {
             components.year = 2_000
             components.month = 1
             components.day = 1
-
             self.foundationDate = calendar
                 .date(from: components) ?? date
         }

Amplify/Categories/DataStore/Model/Temporal/TimeZone+Extension.swift

@@ -0,0 +1,150 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+
+import Foundation
+
+extension TimeZone {
+
+    @usableFromInline
+    internal init?(iso8601DateString: String) {
+        switch ISO8601TimeZonePart.from(iso8601DateString: iso8601DateString) {
+        case .some(.utc):
+            self.init(abbreviation: "UTC")
+        case let .some(.hh(hours: hours)):
+            self.init(secondsFromGMT: hours * 60 * 60)
+        case let .some(.hhmm(hours: hours, minutes: minutes)),
+             let .some(.hh_mm(hours: hours, minuts: minutes)):
+            self.init(secondsFromGMT: hours * 60 * 60 +
+                      (hours > 0 ? 1 : -1) * minutes * 60)
+        case let .some(.hh_mm_ss(hours: hours, minutes: minutes, seconds: seconds)):
+            self.init(secondsFromGMT: hours * 60 * 60 +
+                      (hours > 0 ? 1 : -1) * minutes * 60 +
+                      (hours > 0 ? 1 : -1) * seconds)
+        case .none:
+            return nil
+        }
+    }
+}
+
+
+/// ISO8601 Time Zone formats
+/// - Note:
+///   `±hh:mm:ss` is not a standard of ISO8601 date formate. It's supported by `AWSDateTime` exclusively.
+///
+/// references:
+///   https://en.wikipedia.org/wiki/ISO_8601#Time_zone_designators
+///   https://docs.aws.amazon.com/appsync/latest/devguide/scalars.html#graph-ql-aws-appsync-scalars
+fileprivate enum ISO8601TimeZoneFormat {
+    case utc, hh, hhmm, hh_mm, hh_mm_ss
+
+    var format: String {
+        switch self {
+        case .utc:
+            return "Z"
+        case .hh:
+            return "±hh"
+        case .hhmm:
+            return "±hhmm"
+        case .hh_mm:
+            return "±hh:mm"
+        case .hh_mm_ss:
+            return "±hh:mm:ss"
+        }
+    }
+
+    var regex: NSRegularExpression? {
+        switch self {
+        case .utc:
+            return try? NSRegularExpression(pattern: "^Z$")
+        case .hh:
+            return try? NSRegularExpression(pattern: "^[+-]\\d{2}$")
+        case .hhmm:
+            return try? NSRegularExpression(pattern: "^[+-]\\d{2}\\d{2}$")
+        case .hh_mm:
+            return try? NSRegularExpression(pattern: "^[+-]\\d{2}:\\d{2}$")
+        case .hh_mm_ss:
+            return try? NSRegularExpression(pattern: "^[+-]\\d{2}:\\d{2}:\\d{2}$")
+        }
+    }
+
+    var parts: [NSRange] {
+        switch self {
+        case .utc:
+            return []
+        case .hh:
+            return [NSRange(location: 0, length: 3)]
+        case .hhmm:
+            return [
+                NSRange(location: 0, length: 3),
+                NSRange(location: 3, length: 2)
+            ]
+        case .hh_mm:
+            return [
+                NSRange(location: 0, length: 3),
+                NSRange(location: 4, length: 2)
+            ]
+        case .hh_mm_ss:
+            return [
+                NSRange(location: 0, length: 3),
+                NSRange(location: 4, length: 2),
+                NSRange(location: 7, length: 2)
+            ]
+        }
+    }
+}
+
+fileprivate enum ISO8601TimeZonePart {
+    case utc
+    case hh(hours: Int)
+    case hhmm(hours: Int, minutes: Int)
+    case hh_mm(hours: Int, minuts: Int)
+    case hh_mm_ss(hours: Int, minutes: Int, seconds: Int)
+
+
+    static func from(iso8601DateString: String) -> ISO8601TimeZonePart? {
+        return tryExtract(from: iso8601DateString, with: .utc)
+        ?? tryExtract(from: iso8601DateString, with: .hh)
+        ?? tryExtract(from: iso8601DateString, with: .hhmm)
+        ?? tryExtract(from: iso8601DateString, with: .hh_mm)
+        ?? tryExtract(from: iso8601DateString, with: .hh_mm_ss)
+        ?? nil
+    }
+}
+
+fileprivate func tryExtract(
+    from dateString: String,
+    with format: ISO8601TimeZoneFormat
+) -> ISO8601TimeZonePart? {
+    guard dateString.count > format.format.count else {
+        return nil
+    }
+
+    let tz = String(dateString.dropFirst(dateString.count - format.format.count))
+
+    guard format.regex.flatMap({
+        $0.firstMatch(in: tz, range: NSRange(location: 0, length: tz.count))
+    }) != nil else {
+        return nil
+    }
+
+    let parts = format.parts.compactMap { range in
+        Range(range, in: tz).flatMap { Int(tz[$0]) }
+    }
+
+    guard parts.count == format.parts.count else {
+        return nil
+    }
+
+    switch format {
+    case .utc: return .utc
+    case .hh: return .hh(hours: parts[0])
+    case .hhmm: return .hhmm(hours: parts[0], minutes: parts[1])
+    case .hh_mm: return .hh_mm(hours: parts[0], minuts: parts[1])
+    case .hh_mm_ss: return .hh_mm_ss(hours: parts[0], minutes: parts[1], seconds: parts[2])
+    }
+}