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2 | 2 | // InterstitialTagBuilder.swift |
3 | 3 | // mamba |
4 | 4 | // |
5 | | -// Created by Migneco, Ray on 11/1/24. |
| 5 | +// Created by Migneco, Ray on 10/22/24. |
6 | 6 | // Copyright © 2024 Comcast Corporation. |
7 | 7 | // Licensed under the Apache License, Version 2.0 (the "License"); |
8 | 8 | // you may not use this file except in compliance with the License. |
|
18 | 18 | // |
19 | 19 |
|
20 | 20 | import Foundation |
| 21 | + |
| 22 | +/// A utility class for configuring and constructing an interstitial tag |
| 23 | +/// The properties in this class are in accordance with the HLS spec |
| 24 | +/// outlined in `draft-pantos-hls-rfc8216bis-15` Appendix D |
| 25 | +/// https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis#appendix-D |
| 26 | +public final class InterstitialTagBuilder { |
| 27 | + |
| 28 | + /// An Interstitial EXT-X-DATERANGE tag MUST have a CLASS attribute whose |
| 29 | + /// value is "com.apple.hls.interstitial". |
| 30 | + static let appleHLSInterstitialClassIdentifier = "com.apple.hls.interstitial" |
| 31 | + |
| 32 | + /// A quoted-string that uniquely identifies a Date Range in the |
| 33 | + /// Playlist. This attribute is REQUIRED |
| 34 | + let id: String |
| 35 | + |
| 36 | + /// required to be "com.apple.hls.interstitial" |
| 37 | + let classId: String |
| 38 | + |
| 39 | + /// date/time at which the Date Range begins. This attribute is REQUIRED. |
| 40 | + let startDate: Date |
| 41 | + |
| 42 | + /// The value of the X-ASSET-URI is a quoted-string absolute URI for a |
| 43 | + /// single interstitial asset. An Interstitial EXT-X-DATERANGE tag |
| 44 | + /// MUST have either the X-ASSET-URI attribute or the X-ASSET-LIST |
| 45 | + /// attribute. It MUST NOT have both. |
| 46 | + let assetUri: String? |
| 47 | + |
| 48 | + /// The value of the X-ASSET-LIST is a quoted-string URI to a JSON |
| 49 | + /// object. |
| 50 | + let assetList: String? |
| 51 | + |
| 52 | + /// the duration of the interstitial content in seconds |
| 53 | + var duration: Double? |
| 54 | + |
| 55 | + /// the expected duration of the interstitial content in seconds which can indicate a value when the actual duration is not yet known |
| 56 | + var plannedDuration: Double? |
| 57 | + |
| 58 | + /// The value of X-RESUME-OFFSET is a decimal-floating-point of seconds that specifies where primary playback is to resume |
| 59 | + /// following the playback of the interstitial. |
| 60 | + var resumeOffset: Double? |
| 61 | + |
| 62 | + /// The value of X-PLAYOUT-LIMIT is a decimal-floating-point of seconds that specifies a limit for the playout time of the entire interstitial. |
| 63 | + var playoutLimit: Double? |
| 64 | + |
| 65 | + /// The value of the X-SNAP attribute is an enumerated-string-list of Snap Identifiers. |
| 66 | + /// The defined Snap Identifiers are: OUT and IN. This attribute is OPTIONAL. |
| 67 | + var alignment: HLSInterstitialAlignment? |
| 68 | + |
| 69 | + /// The value of the X-RESTRICT attribute is an enumerated-string-list of Navigation Restriction Identifiers. The defined Navigation |
| 70 | + /// Restriction Identifiers are: SKIP and JUMP. These restrictions are enforced at the player UI level. |
| 71 | + var restrictions: HLSInterstitialSeekRestrictions? |
| 72 | + |
| 73 | + /// This attribute indicates whether the interstitial is intended to be presented as distinct from the content ("HIGHLIGHT") or not differentiated ("PRIMARY"). |
| 74 | + var timelineStyle: HLSInterstitialTimelineStyle? |
| 75 | + |
| 76 | + /// The attribute indicates whether the interstitial should be presented as a single point on the timeline or as a range. |
| 77 | + var timelineOccupation: HLSInterstitialTimelineOccupation? |
| 78 | + |
| 79 | + /// Provides a hint to the client to know how coordinated playback of the same asset will behave across multiple players |
| 80 | + var contentMayVary: Bool? |
| 81 | + |
| 82 | + /// The "X-" prefix defines a namespace reserved for client-defined attributes. The client-attribute MUST be a legal AttributeName. |
| 83 | + /// Clients SHOULD use a reverse-DNS syntax when defining their own attribute names to avoid collisions. The attribute value MUST be |
| 84 | + /// a quoted-string, a hexadecimal-sequence, or a decimal-floating- point. An example of a client-defined attribute is X-COM-EXAMPLE- |
| 85 | + /// AD-ID="XYZ123". These attributes are OPTIONAL. |
| 86 | + var clientAttributes: [String: LosslessStringConvertible]? |
| 87 | + |
| 88 | + /// Creates a Tag Builder using an asset Uri |
| 89 | + /// |
| 90 | + /// - Parameters: |
| 91 | + /// - id: the identifier for the interstitial |
| 92 | + /// - startDate: `Date` at which the interstitial begins |
| 93 | + /// - assetUri: the URI locating the interstitial |
| 94 | + public init(id: String, startDate: Date, assetUri: String) { |
| 95 | + self.id = id |
| 96 | + self.startDate = startDate |
| 97 | + self.assetUri = assetUri |
| 98 | + self.assetList = nil |
| 99 | + self.classId = Self.appleHLSInterstitialClassIdentifier |
| 100 | + } |
| 101 | + |
| 102 | + /// Creates a Tag Builder using an Asset List Uri |
| 103 | + /// |
| 104 | + /// - Parameters: |
| 105 | + /// - id: the identifier for the interstitial |
| 106 | + /// - startDate: `Date` indicating when the interstitial begins |
| 107 | + /// - assetList: the URI to a JSON object containing the assets |
| 108 | + public init(id: String, startDate: Date, assetList: String) { |
| 109 | + self.id = id |
| 110 | + self.startDate = startDate |
| 111 | + self.assetList = assetList |
| 112 | + self.assetUri = nil |
| 113 | + self.classId = Self.appleHLSInterstitialClassIdentifier |
| 114 | + } |
| 115 | + |
| 116 | + /// Specifies the duration of the interstitial |
| 117 | + /// |
| 118 | + /// - Parameter duration: `Double` indicating duration |
| 119 | + /// |
| 120 | + /// - Returns: an instance of the builder |
| 121 | + @discardableResult |
| 122 | + public func withDuration(_ duration: Double) -> Self { |
| 123 | + self.duration = duration |
| 124 | + |
| 125 | + return self |
| 126 | + } |
| 127 | + |
| 128 | + /// Specifies the planned duration of the interstitial |
| 129 | + /// |
| 130 | + /// - Parameter duration: `Double` indicating duration |
| 131 | + /// |
| 132 | + /// - Returns: an instance of the builder |
| 133 | + @discardableResult |
| 134 | + public func withPlannedDuration(_ plannedDuration: Double) -> Self { |
| 135 | + self.plannedDuration = plannedDuration |
| 136 | + |
| 137 | + return self |
| 138 | + } |
| 139 | + |
| 140 | + /// Configures the interstitial with a resume offset |
| 141 | + /// |
| 142 | + /// - Parameter offset: `Double` indicating the resume offset |
| 143 | + /// |
| 144 | + /// - Returns: an instance of the builder |
| 145 | + @discardableResult |
| 146 | + public func withResumeOffset(_ offset: Double) -> Self { |
| 147 | + self.resumeOffset = offset |
| 148 | + |
| 149 | + return self |
| 150 | + } |
| 151 | + |
| 152 | + /// Configures the interstitial with a playout limit |
| 153 | + /// |
| 154 | + /// - Parameter limit: `Double` indicating playout limit |
| 155 | + /// |
| 156 | + /// - Returns: an instance of the builder |
| 157 | + @discardableResult |
| 158 | + public func withPlayoutLimit(_ limit: Double) -> Self { |
| 159 | + self.playoutLimit = limit |
| 160 | + |
| 161 | + return self |
| 162 | + } |
| 163 | + |
| 164 | + /// Specifies the alignment of the interstitial with respect to content |
| 165 | + /// |
| 166 | + /// - Parameter alignment: `HLSInterstitialAlignment` specifying alignment guides |
| 167 | + /// |
| 168 | + /// - Returns: an instance of the builder |
| 169 | + @discardableResult |
| 170 | + public func withAlignment(_ alignment: HLSInterstitialAlignment) -> Self { |
| 171 | + self.alignment = alignment |
| 172 | + |
| 173 | + return self |
| 174 | + } |
| 175 | + |
| 176 | + /// Specifies seek restrictions applied to the interstitial |
| 177 | + /// |
| 178 | + /// - Parameter restrictions: instance of `HLSInterstitialSeekRestrictions` |
| 179 | + /// |
| 180 | + /// - Returns: an instance of the builder |
| 181 | + public func withRestrictions(_ restrictions: HLSInterstitialSeekRestrictions) -> Self { |
| 182 | + self.restrictions = restrictions |
| 183 | + |
| 184 | + return self |
| 185 | + } |
| 186 | + |
| 187 | + /// Specifies how the interstitial is styled on the timeline |
| 188 | + /// |
| 189 | + /// - Parameter style: `HLSInterstitialTimelineStyle` type |
| 190 | + /// |
| 191 | + /// - Returns: an instance of the builder |
| 192 | + @discardableResult |
| 193 | + public func withTimelineStyle(_ style: HLSInterstitialTimelineStyle) -> Self { |
| 194 | + self.timelineStyle = style |
| 195 | + |
| 196 | + return self |
| 197 | + } |
| 198 | + |
| 199 | + /// Describes how the interstitial occupies the content timeline |
| 200 | + /// |
| 201 | + /// - Parameter occupation: `HLSInterstitialTimelineOccupation` type |
| 202 | + /// |
| 203 | + /// - Returns: an instance of the builder |
| 204 | + @discardableResult |
| 205 | + public func withTimelineOccupation(_ occupation: HLSInterstitialTimelineOccupation) -> Self { |
| 206 | + self.timelineOccupation = occupation |
| 207 | + |
| 208 | + return self |
| 209 | + } |
| 210 | + |
| 211 | + /// Indicates if the interstitial content varies or stays the same during a shared watching activity |
| 212 | + /// |
| 213 | + /// - Parameter variation: `Bool` indicating if there's variation |
| 214 | + /// |
| 215 | + /// - Returns: an instance of the builder |
| 216 | + @discardableResult |
| 217 | + public func withContentVariation(_ variation: Bool) -> Self { |
| 218 | + self.contentMayVary = variation |
| 219 | + |
| 220 | + return self |
| 221 | + } |
| 222 | + |
| 223 | + /// Specifies client attributes describing the interstitial |
| 224 | + /// |
| 225 | + /// - Parameter attributes: a map of `[String: LosslessStringConvertible]` describing the attributes |
| 226 | + /// |
| 227 | + /// - Returns: an instance of the builder |
| 228 | + @discardableResult |
| 229 | + public func withClientAttributes(_ attributes: [String: LosslessStringConvertible]) -> Self { |
| 230 | + self.clientAttributes = attributes |
| 231 | + |
| 232 | + return self |
| 233 | + } |
| 234 | + |
| 235 | + /// Builds the DateRange tag utilizing the configured HLS interstitial properties |
| 236 | + /// |
| 237 | + /// - Returns: `PlaylistTag` |
| 238 | + public func buildTag() -> PlaylistTag { |
| 239 | + |
| 240 | + var tagDictionary = PlaylistTagDictionary() |
| 241 | + |
| 242 | + tagDictionary[PantosValue.id.rawValue] = PlaylistTagValueData(value: id, quoteEscaped: true) |
| 243 | + let startDateString = String.DateFormatter.iso8601MS.string(from: startDate) |
| 244 | + tagDictionary[PantosValue.startDate.rawValue] = PlaylistTagValueData(value: startDateString, |
| 245 | + quoteEscaped: true) |
| 246 | + tagDictionary[PantosValue.classAttribute.rawValue] = PlaylistTagValueData(value: classId, |
| 247 | + quoteEscaped: true) |
| 248 | + |
| 249 | + if let assetUri { |
| 250 | + tagDictionary[PantosValue.assetUri.rawValue] = PlaylistTagValueData(value: assetUri, quoteEscaped: true) |
| 251 | + } |
| 252 | + |
| 253 | + if let assetList { |
| 254 | + tagDictionary[PantosValue.assetList.rawValue] = PlaylistTagValueData(value: assetList, quoteEscaped: true) |
| 255 | + } |
| 256 | + |
| 257 | + if let duration { |
| 258 | + tagDictionary[PantosValue.duration.rawValue] = PlaylistTagValueData(value: String(duration), |
| 259 | + quoteEscaped: false) |
| 260 | + } |
| 261 | + |
| 262 | + if let plannedDuration { |
| 263 | + tagDictionary[PantosValue.plannedDuration.rawValue] = PlaylistTagValueData(value: String(plannedDuration), |
| 264 | + quoteEscaped: false) |
| 265 | + } |
| 266 | + |
| 267 | + if let resumeOffset { |
| 268 | + tagDictionary[PantosValue.resumeOffset.rawValue] = PlaylistTagValueData(value: String(resumeOffset), |
| 269 | + quoteEscaped: false) |
| 270 | + } |
| 271 | + |
| 272 | + if let playoutLimit { |
| 273 | + tagDictionary[PantosValue.playoutLimit.rawValue] = PlaylistTagValueData(value: String(playoutLimit), |
| 274 | + quoteEscaped: false) |
| 275 | + } |
| 276 | + |
| 277 | + if let restrictions { |
| 278 | + let str = restrictions.restrictions.map({ $0.rawValue }).joined(separator: ",") |
| 279 | + tagDictionary[PantosValue.restrict.rawValue] = PlaylistTagValueData(value: str, quoteEscaped: true) |
| 280 | + } |
| 281 | + |
| 282 | + if let alignment { |
| 283 | + let str = alignment.values.map({ $0.rawValue }).joined(separator: ",") |
| 284 | + tagDictionary[PantosValue.snap.rawValue] = PlaylistTagValueData(value: str, quoteEscaped: true) |
| 285 | + } |
| 286 | + |
| 287 | + if let timelineStyle { |
| 288 | + tagDictionary[PantosValue.timelineStyle.rawValue] = PlaylistTagValueData(value: timelineStyle.rawValue, |
| 289 | + quoteEscaped: true) |
| 290 | + } |
| 291 | + |
| 292 | + if let timelineOccupation { |
| 293 | + tagDictionary[PantosValue.timelineOccupies.rawValue] = PlaylistTagValueData(value: timelineOccupation.rawValue, |
| 294 | + quoteEscaped: true) |
| 295 | + } |
| 296 | + |
| 297 | + if let contentMayVary { |
| 298 | + tagDictionary[PantosValue.contentMayVary.rawValue] = PlaylistTagValueData(value: contentMayVary == true ? "YES" : "NO", |
| 299 | + quoteEscaped: true) |
| 300 | + } |
| 301 | + |
| 302 | + if let clientAttributes { |
| 303 | + for (k, v) in clientAttributes { |
| 304 | + tagDictionary[k] = PlaylistTagValueData(value: String(v), quoteEscaped: true) |
| 305 | + } |
| 306 | + } |
| 307 | + |
| 308 | + return PlaylistTag(tagDescriptor: PantosTag.EXT_X_DATERANGE, |
| 309 | + stringTagData: nil, |
| 310 | + parsedValues: tagDictionary) |
| 311 | + } |
| 312 | +} |
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