Move logic to extension: Move model files to Shared

Signed-off-by: Roopesh Chander <roop@roopc.net>

WireGuard/Shared/Model/Endpoint.swift

@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018 WireGuard LLC. All Rights Reserved.
+
+import Foundation
+import Network
+
+@available(OSX 10.14, iOS 12.0, *)
+struct Endpoint {
+    let host: NWEndpoint.Host
+    let port: NWEndpoint.Port
+}
+
+// MARK: Converting to and from String
+// For use in the UI
+
+extension Endpoint {
+    init?(from string: String) {
+        // Separation of host and port is based on 'parse_endpoint' function in
+        // https://git.zx2c4.com/WireGuard/tree/src/tools/config.c
+        guard (!string.isEmpty) else { return nil }
+        let startOfPort: String.Index
+        let hostString: String
+        if (string.first! == "[") {
+            // Look for IPv6-style endpoint, like [::1]:80
+            let startOfHost = string.index(after: string.startIndex)
+            guard let endOfHost = string.dropFirst().firstIndex(of: "]") else { return nil }
+            let afterEndOfHost = string.index(after: endOfHost)
+            guard (string[afterEndOfHost] == ":") else { return nil }
+            startOfPort = string.index(after: afterEndOfHost)
+            hostString = String(string[startOfHost ..< endOfHost])
+        } else {
+            // Look for an IPv4-style endpoint, like 127.0.0.1:80
+            guard let endOfHost = string.firstIndex(of: ":") else { return nil }
+            startOfPort = string.index(after: endOfHost)
+            hostString = String(string[string.startIndex ..< endOfHost])
+        }
+        guard let endpointPort = NWEndpoint.Port(String(string[startOfPort ..< string.endIndex])) else { return nil }
+        let invalidCharacterIndex = hostString.unicodeScalars.firstIndex { (c) -> Bool in
+            return !CharacterSet.urlHostAllowed.contains(c)
+        }
+        guard (invalidCharacterIndex == nil) else { return nil }
+        host = NWEndpoint.Host(hostString)
+        port = endpointPort
+    }
+    func stringRepresentation() -> String {
+        switch (host) {
+        case .name(let hostname, _):
+            return "\(hostname):\(port)"
+        case .ipv4(let address):
+            return "\(address):\(port)"
+        case .ipv6(let address):
+            return "[\(address)]:\(port)"
+        }
+    }
+}
+
+// MARK: Codable
+// For serializing to disk
+
+@available(OSX 10.14, iOS 12.0, *)
+extension Endpoint: Codable {
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(self.stringRepresentation())
+    }
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        let endpointString = try container.decode(String.self)
+        guard let endpoint = Endpoint(from: endpointString) else {
+            throw DecodingError.invalidData
+        }
+        self = endpoint
+    }
+    enum DecodingError: Error {
+        case invalidData
+    }
+}
+
+extension Endpoint {
+    func hasHostAsIPAddress() -> Bool {
+        switch (host) {
+        case .name(_, _):
+            return false
+        case .ipv4(_):
+            return true
+        case .ipv6(_):
+            return true
+        }
+    }
+}