Create POSSystemStatusService to load WC plugin and POS feature switch value from one system status API request.

Author: jaclync

Modules/Sources/Networking/Mapper/SingleItemMapper.swift

@@ -2,16 +2,20 @@ import Foundation
 
 /// SingleItemMapper: Maps generic REST API requests for a single item
 ///
-struct SingleItemMapper<Output: Decodable>: Mapper {
+public struct SingleItemMapper<Output: Decodable>: Mapper {
     /// Site Identifier associated to the items that will be parsed.
     ///
     /// We're injecting this field via `JSONDecoder.userInfo` because SiteID is not returned by our endpoints.
     ///
     let siteID: Int64
 
+    public init(siteID: Int64) {
+        self.siteID = siteID
+    }
+
     /// (Attempts) to convert a dictionary into Output.
     ///
-    func map(response: Data) throws -> Output {
+    public func map(response: Data) throws -> Output {
         let decoder = JSONDecoder()
         decoder.dateDecodingStrategy = .formatted(DateFormatter.Defaults.dateTimeFormatter)
         decoder.userInfo = [

Modules/Sources/Yosemite/PointOfSale/Eligibility/POSSystemStatusService.swift

@@ -0,0 +1,81 @@
+import Foundation
+import Networking
+
+public protocol POSSystemStatusServiceProtocol {
+    /// Loads WooCommerce plugin and POS feature switch value remotely for eligibility checks.
+    /// - Parameter siteID: The site ID to fetch information for.
+    /// - Returns: POSPluginAndFeatureInfo containing plugin and feature data.
+    /// - Throws: Network or parsing errors.
+    func loadWooCommercePluginAndPOSFeatureSwitch(siteID: Int64) async throws -> POSPluginAndFeatureInfo
+}
+
+/// Contains WooCommerce plugin information and POS feature switch value.
+public struct POSPluginAndFeatureInfo {
+    public let wcPlugin: SystemPlugin?
+    public let featureValue: Bool?
+
+    public init(wcPlugin: SystemPlugin?, featureValue: Bool?) {
+        self.wcPlugin = wcPlugin
+        self.featureValue = featureValue
+    }
+}
+
+/// Service for fetching POS-related system status information.
+public final class POSSystemStatusService: POSSystemStatusServiceProtocol {
+    private let remote: SystemStatusRemote
+
+    public init(credentials: Credentials?) {
+        let network = AlamofireNetwork(credentials: credentials)
+        remote = SystemStatusRemote(network: network)
+    }
+
+    public func loadWooCommercePluginAndPOSFeatureSwitch(siteID: Int64) async throws -> POSPluginAndFeatureInfo {
+        let mapper = SingleItemMapper<POSPluginEligibilitySystemStatus>(siteID: siteID)
+        let systemStatus: POSPluginEligibilitySystemStatus = try await remote.loadSystemStatus(
+            for: siteID,
+            fields: [.activePlugins, .settings],
+            mapper: mapper
+        )
+
+        // Finds WooCommerce plugin from active plugins response.
+        guard let wcPlugin = systemStatus.activePlugins.first(where: { $0.plugin == Constants.wcPluginPath }) else {
+            return POSPluginAndFeatureInfo(wcPlugin: nil, featureValue: nil)
+        }
+
+        // Extracts POS feature value from settings response.
+        let featureValue = systemStatus.settings.enabledFeatures.contains(SiteSettingsFeature.pointOfSale.rawValue) ? true : nil
+        return POSPluginAndFeatureInfo(wcPlugin: wcPlugin, featureValue: featureValue)
+    }
+}
+
+private extension POSSystemStatusService {
+    enum Constants {
+        static let wcPluginPath = "woocommerce/woocommerce.php"
+    }
+}
+
+// MARK: - Errors
+
+public enum POSSystemStatusServiceError: Error {
+    case wooCommercePluginNotFound
+}
+
+// MARK: - Network Response Structs
+
+private struct POSPluginEligibilitySystemStatus: Decodable {
+    let activePlugins: [SystemPlugin]
+    let settings: POSEligibilitySystemStatusSettings
+
+    enum CodingKeys: String, CodingKey {
+        case activePlugins = "active_plugins"
+        case settings
+    }
+}
+
+private struct POSEligibilitySystemStatusSettings: Decodable {
+    let enabledFeatures: [String]
+
+    enum CodingKeys: String, CodingKey {
+        case enabledFeatures = "enabled_features"
+    }
+}