feat: implement QR scanner

ios/PPGMobile/PPGMobile/Models/ServerConnection.swift

@@ -0,0 +1,105 @@
+import Foundation
+
+/// Represents a saved connection to a ppg serve instance.
+struct ServerConnection: Codable, Identifiable, Hashable {
+    let id: UUID
+    var name: String
+    var host: String
+    var port: Int
+    var token: String
+    var ca: String?
+    var isDefault: Bool
+
+    init(name: String = "My Mac", host: String, port: Int = 7700, token: String, ca: String? = nil, isDefault: Bool = false) {
+        self.id = UUID()
+        self.name = name
+        self.host = host
+        self.port = port
+        self.token = token
+        self.ca = ca
+        self.isDefault = isDefault
+    }
+
+    private var usesTLS: Bool {
+        ca != nil
+    }
+
+    var baseURL: URL? {
+        makeURL(scheme: usesTLS ? "https" : "http")
+    }
+
+    var wsURL: URL? {
+        makeURL(
+            scheme: usesTLS ? "wss" : "ws",
+            path: "/ws",
+            queryItems: [URLQueryItem(name: "token", value: token)]
+        )
+    }
+
+    var apiURL: URL? {
+        baseURL?.appendingPathComponent("api")
+    }
+
+    /// Parse a ppg serve QR code payload.
+    /// Format: ppg://connect?host=<host>&port=<port>&token=<token>[&ca=<base64>]
+    static func fromQRCode(_ payload: String) -> ServerConnection? {
+        guard let components = URLComponents(string: payload),
+              components.scheme?.lowercased() == "ppg",
+              components.host?.lowercased() == "connect"
+        else {
+            return nil
+        }
+
+        let params = Dictionary(
+            (components.queryItems ?? []).compactMap { item in
+                item.value.map { (item.name, $0) }
+            },
+            uniquingKeysWith: { _, last in last }
+        )
+
+        guard let host = params["host"], isValidHost(host),
+              let token = params["token"], !token.isEmpty
+        else {
+            return nil
+        }
+
+        let port = params["port"].flatMap(Int.init) ?? 7700
+        guard (1...65_535).contains(port) else { return nil }
+        let ca = params["ca"].flatMap { Data(base64Encoded: $0) != nil ? $0 : nil }
+
+        return ServerConnection(
+            name: host == "0.0.0.0" ? "Local Mac" : host,
+            host: host,
+            port: port,
+            token: token,
+            ca: ca
+        )
+    }
+
+    private func makeURL(
+        scheme: String,
+        path: String = "",
+        queryItems: [URLQueryItem] = []
+    ) -> URL? {
+        var components = URLComponents()
+        components.scheme = scheme
+        components.host = host
+        components.port = port
+        components.path = path
+        components.queryItems = queryItems.isEmpty ? nil : queryItems
+        return components.url
+    }
+
+    private static func isValidHost(_ host: String) -> Bool {
+        guard !host.isEmpty,
+              host.rangeOfCharacter(from: .whitespacesAndNewlines) == nil
+        else {
+            return false
+        }
+
+        var components = URLComponents()
+        components.scheme = "http"
+        components.host = host
+        return components.url != nil
+    }
+}

ios/PPGMobile/PPGMobile/Models/ServerConnectionTests.swift

@@ -0,0 +1,151 @@
+import XCTest
+@testable import PPGMobile
+
+final class ServerConnectionTests: XCTestCase {
+
+    // MARK: - fromQRCode
+
+    func testValidQRCodeParsesCorrectly() {
+        let qr = "ppg://connect?host=192.168.1.10&port=7700&token=abc123"
+        let conn = ServerConnection.fromQRCode(qr)
+
+        XCTAssertNotNil(conn)
+        XCTAssertEqual(conn?.host, "192.168.1.10")
+        XCTAssertEqual(conn?.port, 7700)
+        XCTAssertEqual(conn?.token, "abc123")
+        XCTAssertNil(conn?.ca)
+    }
+
+    func testValidQRCodeWithCAParsesCorrectly() {
+        // "dGVzdA==" is base64 for "test"
+        let qr = "ppg://connect?host=myhost&port=8080&token=secret&ca=dGVzdA=="
+        let conn = ServerConnection.fromQRCode(qr)
+
+        XCTAssertNotNil(conn)
+        XCTAssertEqual(conn?.host, "myhost")
+        XCTAssertEqual(conn?.port, 8080)
+        XCTAssertEqual(conn?.token, "secret")
+        XCTAssertEqual(conn?.ca, "dGVzdA==")
+    }
+
+    func testMissingHostReturnsNil() {
+        let qr = "ppg://connect?port=7700&token=abc123"
+        XCTAssertNil(ServerConnection.fromQRCode(qr))
+    }
+
+    func testEmptyHostReturnsNil() {
+        let qr = "ppg://connect?host=&port=7700&token=abc123"
+        XCTAssertNil(ServerConnection.fromQRCode(qr))
+    }
+
+    func testMissingTokenReturnsNil() {
+        let qr = "ppg://connect?host=myhost&port=7700"
+        XCTAssertNil(ServerConnection.fromQRCode(qr))
+    }
+
+    func testEmptyTokenReturnsNil() {
+        let qr = "ppg://connect?host=myhost&port=7700&token="
+        XCTAssertNil(ServerConnection.fromQRCode(qr))
+    }
+
+    func testMissingPortDefaultsTo7700() {
+        let qr = "ppg://connect?host=myhost&token=abc123"
+        let conn = ServerConnection.fromQRCode(qr)
+
+        XCTAssertNotNil(conn)
+        XCTAssertEqual(conn?.port, 7700)
+    }
+
+    func testInvalidPortReturnsNil() {
+        XCTAssertNil(ServerConnection.fromQRCode("ppg://connect?host=myhost&port=0&token=abc123"))
+        XCTAssertNil(ServerConnection.fromQRCode("ppg://connect?host=myhost&port=70000&token=abc123"))
+    }
+
+    func testInvalidHostReturnsNil() {
+        let qr = "ppg://connect?host=my%20host&port=7700&token=abc123"
+        XCTAssertNil(ServerConnection.fromQRCode(qr))
+    }
+
+    func testWrongSchemeReturnsNil() {
+        let qr = "http://connect?host=myhost&port=7700&token=abc123"
+        XCTAssertNil(ServerConnection.fromQRCode(qr))
+    }
+
+    func testWrongHostReturnsNil() {
+        let qr = "ppg://pair?host=myhost&port=7700&token=abc123"
+        XCTAssertNil(ServerConnection.fromQRCode(qr))
+    }
+
+    func testNonPPGStringReturnsNil() {
+        XCTAssertNil(ServerConnection.fromQRCode("https://example.com"))
+        XCTAssertNil(ServerConnection.fromQRCode("just some text"))
+        XCTAssertNil(ServerConnection.fromQRCode(""))
+    }
+
+    func testDuplicateQueryParamsDoNotCrash() {
+        let qr = "ppg://connect?host=myhost&token=first&token=second&port=7700"
+        let conn = ServerConnection.fromQRCode(qr)
+
+        XCTAssertNotNil(conn)
+        // Last value wins per uniquingKeysWith
+        XCTAssertEqual(conn?.token, "second")
+    }
+
+    func testInvalidBase64CAIsDiscarded() {
+        let qr = "ppg://connect?host=myhost&port=7700&token=abc&ca=not-valid-base64!!!"
+        let conn = ServerConnection.fromQRCode(qr)
+
+        XCTAssertNotNil(conn)
+        XCTAssertNil(conn?.ca)
+    }
+
+    func testLocalhostNameMapping() {
+        let qr = "ppg://connect?host=0.0.0.0&port=7700&token=abc123"
+        let conn = ServerConnection.fromQRCode(qr)
+
+        XCTAssertEqual(conn?.name, "Local Mac")
+    }
+
+    func testNonLocalhostUsesHostAsName() {
+        let qr = "ppg://connect?host=workstation.local&port=7700&token=abc123"
+        let conn = ServerConnection.fromQRCode(qr)
+
+        XCTAssertEqual(conn?.name, "workstation.local")
+    }
+
+    // MARK: - URL construction
+
+    func testBaseURLUsesHTTPWithoutCA() {
+        let conn = ServerConnection(host: "myhost", port: 7700, token: "abc")
+        XCTAssertEqual(conn.baseURL?.absoluteString, "http://myhost:7700")
+    }
+
+    func testBaseURLUsesHTTPSWithCA() {
+        let conn = ServerConnection(host: "myhost", port: 7700, token: "abc", ca: "dGVzdA==")
+        XCTAssertEqual(conn.baseURL?.absoluteString, "https://myhost:7700")
+    }
+
+    func testWsURLUsesWSSWithCA() {
+        let conn = ServerConnection(host: "myhost", port: 7700, token: "abc", ca: "dGVzdA==")
+        XCTAssertEqual(conn.wsURL?.scheme, "wss")
+    }
+
+    func testWsURLPercentEncodesToken() {
+        let conn = ServerConnection(host: "myhost", port: 7700, token: "abc+def&ghi=jkl")
+        guard let url = conn.wsURL else {
+            XCTFail("Expected wsURL to be generated")
+            return
+        }
+
+        let components = URLComponents(url: url, resolvingAgainstBaseURL: false)
+        let tokenValue = components?.queryItems?.first(where: { $0.name == "token" })?.value
+        XCTAssertEqual(tokenValue, "abc+def&ghi=jkl")
+        XCTAssertEqual(components?.queryItems?.count, 1)
+    }
+
+    func testInvalidHostDoesNotCrashURLBuilding() {
+        let conn = ServerConnection(host: "bad host", port: 7700, token: "abc")
+        XCTAssertNil(conn.baseURL)
+        XCTAssertNil(conn.wsURL)
+    }
+}