//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift open source project
//
// Copyright (c) 2018-2023 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

/// A platform supported by Swift Package Manager.
public struct Platform: Equatable, Sendable {

    /// The name of the platform.
    let name: String

    private init(name: String) {
        self.name = name
    }

    /// Creates a custom platform.
    ///
    /// Use this function if none of the predefined platform names match the platform you are targeting.
    /// - Parameter platformName: The name of the platform.
    /// - Returns: A `Platform` instance.
    @available(_PackageDescription, introduced: 5.6)
    public static func custom(_ platformName: String) -> Platform {
        return Platform(name: platformName)
    }

    /// The macOS platform.
    public static let macOS: Platform = Platform(name: "macos")

    /// The Mac Catalyst platform.
    public static let macCatalyst: Platform = Platform(name: "maccatalyst")

    /// The iOS platform.
    public static let iOS: Platform = Platform(name: "ios")

    /// The tvOS platform.
    public static let tvOS: Platform = Platform(name: "tvos")

    /// The watchOS platform.
    public static let watchOS: Platform = Platform(name: "watchos")

    /// The visionOS platform.
    public static let visionOS: Platform = Platform(name: "visionos")

    /// The DriverKit platform
    public static let driverKit: Platform = Platform(name: "driverkit")

    /// The Linux platform.
    public static let linux: Platform = Platform(name: "linux")

    /// The Windows platform.
    @available(_PackageDescription, introduced: 5.2)
    public static let windows: Platform = Platform(name: "windows")

    /// The Android platform.
    @available(_PackageDescription, introduced: 5.2)
    public static let android: Platform = Platform(name: "android")

    /// The WebAssembly System Interface platform.
    @available(_PackageDescription, introduced: 5.3)
    public static let wasi: Platform = Platform(name: "wasi")

    /// The OpenBSD platform.
    @available(_PackageDescription, introduced: 5.8)
    public static let openbsd: Platform = Platform(name: "openbsd")
}

/// A platform that the Swift package supports.
///
/// By default, Swift Package Manager assigns a predefined minimum deployment version for each
/// supported platforms unless you configure supported platforms using the
/// `platforms` API. This predefined deployment version is the oldest deployment
/// target version that the installed SDK supports for a given platform. One
/// exception to this rule is macOS, for which the minimum deployment target
/// version starts from 10.10. Packages can choose to configure the minimum
/// deployment target version for a platform by using the APIs defined in this
/// struct. Swift Package Manager emits appropriate errors when an invalid value is provided for
/// supported platforms, such as an empty array, multiple declarations for the
/// same platform, or an invalid version specification.
///
/// Swift Package Manager emits an error if a dependency isn't compatible with the top-level
/// package's deployment version. The deployment target of a package's
/// dependencies must be lower than or equal to the top-level package's
/// deployment target version for a particular platform.
public struct SupportedPlatform: Equatable, Sendable {

    /// The platform.
    let platform: Platform

    /// The platform version.
    let version: String?

    /// Creates supported platform instance.
    init(platform: Platform, version: String? = nil) {
        self.platform = platform
        self.version = version
    }

    /// Configures the minimum deployment target version for the macOS platform.
    ///
    /// - Since: First available in PackageDescription 5.0
    ///
    /// - Parameter version: The minimum deployment target that the package supports.
    public static func macOS(_ version: SupportedPlatform.MacOSVersion) -> SupportedPlatform {
        return SupportedPlatform(platform: .macOS, version: version.version)
    }

    /// Configures the minimum deployment target version for the macOS platform
    /// using a version string.
    ///
    /// The version string must be a series of two or three dot-separated
    /// integers, such as `10.10` or `10.10.1`.
    ///
    /// - Since: First available in PackageDescription 5.0.
    ///
    /// - Parameter versionString: The minimum deployment target as a string
    ///     representation of two or three dot-separated integers, such as
    ///     `10.10.1`.
    /// - Returns: A `SupportedPlatform` instance.
    public static func macOS(_ versionString: String) -> SupportedPlatform {
        return SupportedPlatform(platform: .macOS, version: SupportedPlatform.MacOSVersion(string: versionString).version)
    }

    /// Configures the minimum deployment target version for the Mac Catalyst platform.
    ///
    /// - Since: First available in PackageDescription 5.5
    ///
    /// - Parameter version: The minimum deployment target that the package supports.
    /// - Returns: A `SupportedPlatform` instance.
    @available(_PackageDescription, introduced: 5.5)
    public static func macCatalyst(_ version: SupportedPlatform.MacCatalystVersion) -> SupportedPlatform {
        return SupportedPlatform(platform: .macCatalyst, version: version.version)
    }

    /// Configures the minimum deployment target version for the Mac Catalyst platform
    /// using a version string.
    ///
    /// The version string must be a series of two or three dot-separated integers, such as `13.0` or `13.0.1`.
    ///
    /// - Since: First available in PackageDescription 5.5
    ///
    /// - Parameter versionString: The minimum deployment target as a string representation of two or three dot-separated integers, such as `13.0.1`.
    /// - Returns: A `SupportedPlatform` instance.
    @available(_PackageDescription, introduced: 5.5)
    public static func macCatalyst(_ versionString: String) -> SupportedPlatform {
        return SupportedPlatform(platform: .macCatalyst, version: SupportedPlatform.MacCatalystVersion(string: versionString).version)
    }

    /// Configures the minimum deployment target version for the iOS platform.
    ///
    /// - Since: First available in PackageDescription 5.0.
    ///
    /// - Parameter version: The minimum deployment target that the package supports.
    /// - Returns: A `SupportedPlatform` instance.
    public static func iOS(_ version: SupportedPlatform.IOSVersion) -> SupportedPlatform {
        return SupportedPlatform(platform: .iOS, version: version.version)
    }

    /// Configures the minimum deployment target version for the iOS platform
    /// using a custom version string.
    ///
    /// The version string must be a series of two or three dot-separated
    /// integers, such as `8.0` or `8.0.1`.
    ///
    /// - Since: First available in PackageDescription 5.0
    ///
    /// - Parameter versionString: The minimum deployment target as a string
    ///     representation of two or three dot-separated integers, such as `8.0.1`.
    /// - Returns: A `SupportedPlatform` instance.
    public static func iOS(_ versionString: String) -> SupportedPlatform {
        return SupportedPlatform(platform: .iOS, version: SupportedPlatform.IOSVersion(string: versionString).version)
    }

    /// Configures the minimum deployment target version for the tvOS platform.
    ///
    /// - Since: First available in PackageDescription 5.0
    ///
    /// - Parameter version: The minimum deployment target that the package supports.
    /// - Returns: A `SupportedPlatform` instance.
    public static func tvOS(_ version: SupportedPlatform.TVOSVersion) -> SupportedPlatform {
        return SupportedPlatform(platform: .tvOS, version: version.version)
    }

    /// Configures the minimum deployment target version for the tvOS platform
    /// using a custom version string.
    ///
    /// The version string must be a series of two or three dot-separated
    /// integers,such as `9.0` or `9.0.1`.
    ///
    /// - Since: First available in PackageDescription 5.0
    ///
    /// - Parameter versionString: The minimum deployment target as a string
    ///     representation of two or three dot-separated integers, such as `9.0.1`.
    /// - Returns: A `SupportedPlatform` instance.
    public static func tvOS(_ versionString: String) -> SupportedPlatform {
        return SupportedPlatform(platform: .tvOS, version: SupportedPlatform.TVOSVersion(string: versionString).version)
    }

    /// Configure the minimum deployment target version for the watchOS
    /// platform.
    ///
    /// - Since: First available in PackageDescription 5.0
    ///
    /// - Parameter version: The minimum deployment target that the package supports.
    /// - Returns: A `SupportedPlatform` instance.
    public static func watchOS(_ version: SupportedPlatform.WatchOSVersion) -> SupportedPlatform {
        return SupportedPlatform(platform: .watchOS, version: version.version)
    }

    /// Configure the minimum deployment target version for the watchOS
    /// platform using a custom version string.
    ///
    /// The version string must be a series of two or three dot-separated integers, such as `2.0` or `2.0.1`.
    ///
    /// - Since: First available in PackageDescription 5.0
    ///
    /// - Parameter versionString: The minimum deployment target as a string
    ///     representation of two or three dot-separated integers, such as `2.0.1`.
    /// - Returns: A `SupportedPlatform` instance.
    public static func watchOS(_ versionString: String) -> SupportedPlatform {
        return SupportedPlatform(platform: .watchOS, version: SupportedPlatform.WatchOSVersion(string: versionString).version)
    }

    /// Configure the minimum deployment target version for the visionOS
    /// platform.
    ///
    /// - Since: First available in PackageDescription 5.9
    ///
    /// - Parameter version: The minimum deployment target that the package supports.
    /// - Returns: A `SupportedPlatform` instance.
    @available(_PackageDescription, introduced: 5.9)
    public static func visionOS(_ version: SupportedPlatform.VisionOSVersion) -> SupportedPlatform {
        return SupportedPlatform(platform: .visionOS, version: version.version)
    }

    /// Configure the minimum deployment target version for the visionOS
    /// platform using a custom version string.
    ///
    /// The version string must be a series of two or three dot-separated integers, such as `1.0` or `1.0.0`.
    ///
    /// - Since: First available in PackageDescription 5.9
    ///
    /// - Parameter versionString: The minimum deployment target as a string
    ///     representation of two or three dot-separated integers, such as `1.0.0`.
    /// - Returns: A `SupportedPlatform` instance.
    @available(_PackageDescription, introduced: 5.9)
    public static func visionOS(_ versionString: String) -> SupportedPlatform {
        return SupportedPlatform(platform: .visionOS, version: SupportedPlatform.VisionOSVersion(string: versionString).version)
    }

    /// Configures the minimum deployment target version for the DriverKit platform.
    ///
    /// - Parameter version: The minimum deployment target that the package supports.
    @available(_PackageDescription, introduced: 5.5)
    public static func driverKit(_ version: SupportedPlatform.DriverKitVersion) -> SupportedPlatform {
        return SupportedPlatform(platform: .driverKit, version: version.version)
    }

    /// Configures the minimum deployment target version for the DriverKit platform
    /// using a custom version string.
    ///
    /// - Parameter versionString: The minimum deployment target as a string representation of two or three dot-separated integers, such as `19.0.1`.
    /// - Returns: A `SupportedPlatform` instance.
    @available(_PackageDescription, introduced: 5.5)
    public static func driverKit(_ versionString: String) -> SupportedPlatform {
        return SupportedPlatform(platform: .driverKit, version: SupportedPlatform.DriverKitVersion(string: versionString).version)
    }

    /// Configures the minimum deployment target version for custom platforms.
    ///
    /// - Since: First available in PackageDescription 5.6
    ///
    /// - Parameters:
    ///   - platformName: The name of the platform.
    ///   - versionString: The minimum deployment target as a string representation of two or three dot-separated integers, such as `19.0.1`.
    /// - Returns: A `SupportedPlatform` instance.
    @available(_PackageDescription, introduced: 5.6)
    public static func custom(_ platformName: String,  versionString: String) -> SupportedPlatform {
        do {
            try CustomPlatformVersion.validateVersion(versionString)
        } catch {
            errors.append("\(error)")
        }
        return SupportedPlatform(platform: .custom(platformName), version: versionString)
    }
}

/// An extension to the SupportedPlatform struct that defines major platform versions.
extension SupportedPlatform {

    /// The supported macOS version.
    public struct MacOSVersion: AppleOSVersion {
        fileprivate static let name = "macOS"
        fileprivate static let minimumMajorVersion = 10

        /// The underlying version representation.
        let version: String

        fileprivate init(uncheckedVersion version: String) {
            self.version = version
        }

        /// The value that represents macOS 10.10.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "macOS 10.13 is the oldest supported version")
        public static let v10_10: MacOSVersion = .init(string: "10.10")

        /// The value that represents macOS 10.11.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "macOS 10.13 is the oldest supported version")
        public static let v10_11: MacOSVersion = .init(string: "10.11")

        /// The value that represents macOS 10.12.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "macOS 10.13 is the oldest supported version")
        public static let v10_12: MacOSVersion = .init(string: "10.12")

        /// The value that represents macOS 10.13.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0)
        public static let v10_13: MacOSVersion = .init(string: "10.13")

        /// The value that represents macOS 10.14.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0)
        public static let v10_14: MacOSVersion = .init(string: "10.14")

        /// The value that represents macOS 10.15.
        ///
        /// - Since: First available in PackageDescription 5.1.
        @available(_PackageDescription, introduced: 5.1)
        public static let v10_15: MacOSVersion = .init(string: "10.15")

        /// The value that represents macOS 10.16, which has been
        /// replaced by the value for macOS 11.0.
        ///
        /// - Since: First available in PackageDescription 5.3.
        @available(*, unavailable, renamed: "v11")
        @available(_PackageDescription, introduced: 5.3)
        public static let v10_16: MacOSVersion = .init(string: "11.0")

        /// The value that represents macOS 11.0.
        /// - Since: First available in PackageDescription 5.3.
        @available(_PackageDescription, introduced: 5.3)
        public static let v11: MacOSVersion = .init(string: "11.0")

        /// The value that represents macOS 12.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v12: MacOSVersion = .init(string: "12.0")

        /// The value that represents macOS 13.0.
        ///
        /// - Since: First available in PackageDescription 5.7.
        @available(_PackageDescription, introduced: 5.7)
        public static let v13: MacOSVersion = .init(string: "13.0")

        /// The value that represents macOS 14.0.
        ///
        /// - Since: First available in PackageDescription 5.9.
        @available(_PackageDescription, introduced: 5.9)
        public static let v14: MacOSVersion = .init(string: "14.0")

        /// The value that represents macOS 15.0.
        ///
        /// - Since: First available in PackageDescription 6.0.
        @available(_PackageDescription, introduced: 6.0)
        public static let v15: MacOSVersion = .init(string: "15.0")
    }

    /// The supported tvOS version.
    public struct TVOSVersion: AppleOSVersion {
        fileprivate static let name = "tvOS"
        fileprivate static let minimumMajorVersion = 9

        /// The underlying version representation.
        let version: String

        fileprivate init(uncheckedVersion version: String) {
            self.version = version
        }

        /// The value that represents tvOS 9.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "tvOS 11.0 is the oldest supported version")
        public static let v9: TVOSVersion = .init(string: "9.0")

        /// The value that represents tvOS 10.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "tvOS 11.0 is the oldest supported version")
        public static let v10: TVOSVersion = .init(string: "10.0")

        /// The value that represents tvOS 11.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0)
        public static let v11: TVOSVersion = .init(string: "11.0")

        /// The value that represents tvOS 12.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0)
        public static let v12: TVOSVersion = .init(string: "12.0")

        /// The value that represents tvOS 13.0.
        ///
        /// - Since: First available in PackageDescription 5.1.
        @available(_PackageDescription, introduced: 5.1)
        public static let v13: TVOSVersion = .init(string: "13.0")

        /// The value that represents tvOS 14.0.
        ///
        /// - Since: First available in PackageDescription 5.3.
        @available(_PackageDescription, introduced: 5.3)
        public static let v14: TVOSVersion = .init(string: "14.0")

        /// The value that represents tvOS 15.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v15: TVOSVersion = .init(string: "15.0")

        /// The value that represents tvOS 16.0.
        ///
        /// - Since: First available in PackageDescription 5.7.
        @available(_PackageDescription, introduced: 5.7)
        public static let v16: TVOSVersion = .init(string: "16.0")

        /// The value that represents tvOS 17.0.
        ///
        /// - Since: First available in PackageDescription 5.9.
        @available(_PackageDescription, introduced: 5.9)
        public static let v17: TVOSVersion = .init(string: "17.0")

        /// The value that represents tvOS 18.0.
        ///
        /// - Since: First available in PackageDescription 6.0.
        @available(_PackageDescription, introduced: 6.0)
        public static let v18: TVOSVersion = .init(string: "18.0")
    }

    /// The supported Mac Catalyst version.
    public struct MacCatalystVersion: AppleOSVersion {
        fileprivate static let name = "macCatalyst"
        fileprivate static let minimumMajorVersion = 13

        /// The underlying version representation.
        let version: String

        fileprivate init(uncheckedVersion version: String) {
            self.version = version
        }

        /// The value that represents Mac Catalyst 13.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v13: MacCatalystVersion = .init(string: "13.0")

        /// The value that represents Mac Catalyst 14.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v14: MacCatalystVersion = .init(string: "14.0")

        /// The value that represents Mac Catalyst 15.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v15: MacCatalystVersion = .init(string: "15.0")

        /// The value that represents Mac Catalyst 16.0.
        ///
        /// - Since: First available in PackageDescription 5.7.
        @available(_PackageDescription, introduced: 5.7)
        public static let v16: MacCatalystVersion = .init(string: "16.0")

        /// The value that represents Mac Catalyst 17.0.
        ///
        /// - Since: First available in PackageDescription 5.9.
        @available(_PackageDescription, introduced: 5.9)
        public static let v17: MacCatalystVersion = .init(string: "17.0")

        /// The value that represents Mac Catalyst 18.0.
        ///
        /// - Since: First available in PackageDescription 6.0.
        @available(_PackageDescription, introduced: 6.0)
        public static let v18: MacCatalystVersion = .init(string: "18.0")
    }

    /// The supported iOS version.
    public struct IOSVersion: AppleOSVersion {
        fileprivate static let name = "iOS"
        fileprivate static let minimumMajorVersion = 2

        /// The underlying version representation.
        let version: String

        fileprivate init(uncheckedVersion version: String) {
            self.version = version
        }

        /// The value that represents iOS 8.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "iOS 11.0 is the oldest supported version")
        public static let v8: IOSVersion = .init(string: "8.0")

        /// The value that represents iOS 9.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "iOS 11.0 is the oldest supported version")
        public static let v9: IOSVersion = .init(string: "9.0")

        /// The value that represents iOS 10.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "iOS 11.0 is the oldest supported version")
        public static let v10: IOSVersion = .init(string: "10.0")

        /// The value that represents iOS 11.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0)
        public static let v11: IOSVersion = .init(string: "11.0")

        /// The value that represents iOS 12.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0)
        public static let v12: IOSVersion = .init(string: "12.0")

        /// The value that represents iOS 13.0.
        ///
        /// - Since: First available in PackageDescription 5.1.
        @available(_PackageDescription, introduced: 5.1)
        public static let v13: IOSVersion = .init(string: "13.0")

        /// The value that represents iOS 14.0.
        ///
        /// - Since: First available in PackageDescription 5.3.
        @available(_PackageDescription, introduced: 5.3)
        public static let v14: IOSVersion = .init(string: "14.0")

        /// The value that represents iOS 15.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v15: IOSVersion = .init(string: "15.0")

        /// The value that represents iOS 16.0.
        ///
        /// - Since: First available in PackageDescription 5.7.
        @available(_PackageDescription, introduced: 5.7)
        public static let v16: IOSVersion = .init(string: "16.0")

        /// The value that represents iOS 17.0.
        ///
        /// - Since: First available in PackageDescription 5.9.
        @available(_PackageDescription, introduced: 5.9)
        public static let v17: IOSVersion = .init(string: "17.0")

        /// The value that represents iOS 18.0.
        ///
        /// - Since: First available in PackageDescription 6.0.
        @available(_PackageDescription, introduced: 6.0)
        public static let v18: IOSVersion = .init(string: "18.0")
    }

    /// The supported watchOS version.
    public struct WatchOSVersion: AppleOSVersion {
        fileprivate static let name = "watchOS"
        fileprivate static let minimumMajorVersion = 2

        /// The underlying version representation.
        let version: String

        fileprivate init(uncheckedVersion version: String) {
            self.version = version
        }

        /// The value that represents watchOS 2.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "watchOS 4.0 is the oldest supported version")
        public static let v2: WatchOSVersion = .init(string: "2.0")

        /// The value that represents watchOS 3.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0, deprecated: 5.7, message: "watchOS 4.0 is the oldest supported version")
        public static let v3: WatchOSVersion = .init(string: "3.0")

        /// The value that represents watchOS 4.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0)
        public static let v4: WatchOSVersion = .init(string: "4.0")

        /// The value that represents watchOS 5.0.
        ///
        /// - Since: First available in PackageDescription 5.0.
        @available(_PackageDescription, introduced: 5.0)
        public static let v5: WatchOSVersion = .init(string: "5.0")

        /// The value that represents watchOS 6.0.
        ///
        /// - Since: First available in PackageDescription 5.1.
        @available(_PackageDescription, introduced: 5.1)
        public static let v6: WatchOSVersion = .init(string: "6.0")

        /// The value that represents watchOS 7.0.
        ///
        /// - Since: First available in PackageDescription 5.3.
        @available(_PackageDescription, introduced: 5.3)
        public static let v7: WatchOSVersion = .init(string: "7.0")

        /// The value that represents watchOS 8.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v8: WatchOSVersion = .init(string: "8.0")

        /// The value that represents watchOS 9.0.
        ///
        /// - Since: First available in PackageDescription 5.7.
        @available(_PackageDescription, introduced: 5.7)
        public static let v9: WatchOSVersion = .init(string: "9.0")

        /// The value that represents watchOS 10.0.
        ///
        /// - Since: First available in PackageDescription 5.9.
        @available(_PackageDescription, introduced: 5.9)
        public static let v10: WatchOSVersion = .init(string: "10.0")

        /// The value that represents watchOS 11.0.
        ///
        /// - Since: First available in PackageDescription 6.0.
        @available(_PackageDescription, introduced: 6.0)
        public static let v11: WatchOSVersion = .init(string: "11.0")
    }

    /// The supported visionOS version.
    public struct VisionOSVersion: AppleOSVersion {
        fileprivate static let name = "visionOS"
        fileprivate static let minimumMajorVersion = 1

        /// The underlying version representation.
        let version: String

        fileprivate init(uncheckedVersion version: String) {
            self.version = version
        }

        /// The value that represents visionOS 1.0.
        ///
        /// - Since: First available in PackageDescription 5.9.
        @available(_PackageDescription, introduced: 5.9)
        public static let v1: VisionOSVersion = .init(string: "1.0")

        /// The value that represents visionOS 2.0.
        ///
        /// - Since: First available in PackageDescription 6.0.
        @available(_PackageDescription, introduced: 6.0)
        public static let v2: VisionOSVersion = .init(string: "2.0")
    }

    /// The supported DriverKit version.
    public struct DriverKitVersion: AppleOSVersion {
        fileprivate static let name = "DriverKit"
        fileprivate static let minimumMajorVersion = 19

        /// The underlying version representation.
        let version: String

        fileprivate init(uncheckedVersion version: String) {
            self.version = version
        }

        /// The value that represents DriverKit 19.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v19: DriverKitVersion = .init(string: "19.0")

        /// The value that represents DriverKit 20.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v20: DriverKitVersion = .init(string: "20.0")

        /// The value that represents DriverKit 21.0.
        ///
        /// - Since: First available in PackageDescription 5.5.
        @available(_PackageDescription, introduced: 5.5)
        public static let v21: DriverKitVersion = .init(string: "21.0")

        /// The value that represents DriverKit 22.0.
        ///
        /// - Since: First available in PackageDescription 5.7.
        @available(_PackageDescription, introduced: 5.7)
        public static let v22: DriverKitVersion = .init(string: "22.0")

        /// The value that represents DriverKit 23.0.
        ///
        /// - Since: First available in PackageDescription 5.9.
        @available(_PackageDescription, introduced: 5.9)
        public static let v23: DriverKitVersion = .init(string: "23.0")

        /// The value that represents DriverKit 24.0.
        ///
        /// - Since: First available in PackageDescription 6.0.
        @available(_PackageDescription, introduced: 6.0)
        public static let v24: DriverKitVersion = .init(string: "24.0")
    }

    /// A supported custom platform version.
    public struct CustomPlatformVersion: AppleOSVersion {
        /// The name of the custom platform.
        static var name: String = "custom platform"
        /// The minimum valid major version number.
        static var minimumMajorVersion = 0

        fileprivate init(uncheckedVersion version: String) {
        }
    }
}

fileprivate protocol AppleOSVersion: Sendable {
    static var name: String { get }
    static var minimumMajorVersion: Int { get }
    init(uncheckedVersion: String)
}

struct StringError: Error, CustomStringConvertible {
    var error: String

    init(_ error: String) {
        self.error = error
    }

    var description: String { error }
}

fileprivate extension AppleOSVersion {

    static func validateVersion(_ string: String) throws {
        let components = string.split(separator: ".", omittingEmptySubsequences: false)

        func error(_ error: String) throws {
            throw StringError("invalid \(Self.name) version \(string); \(error)")
        }

        for (idx, component) in components.enumerated() {
            if component.isEmpty {
                try error("found an empty component")
            }

            if idx < 2 {
                if UInt(component) == nil {
                    try error("\(component) should be a positive integer")
                }
            }
        }

        if (UInt(components[0]) ?? 0) < Self.minimumMajorVersion {
            try error("the minimum major version should be \(Self.minimumMajorVersion)")
        }
    }

    init(string: String) {
        do {
            try Self.validateVersion(string)
        } catch {
            errors.append("\(error)")
        }

        self.init(uncheckedVersion: string)
    }
}