adding sorting to protocol

Signed-off-by: Matt Bruce <mbrucedogs@gmail.com>

EmployeeDirectory/Classes/RequestBuilder.swift

@@ -0,0 +1,55 @@
+//
+//  RequestBuilder.swift
+//  EmployeeDirectory
+//
+//  Created by Matt Bruce on 1/21/25.
+//
+
+import Foundation
+
+/// Enum representing HTTP methods
+public enum HTTPMethod: String {
+    case get = "GET"
+    case post = "POST"
+    case put = "PUT"
+    case delete = "DELETE"
+    case patch = "PATCH"
+    case head = "HEAD"
+    case options = "OPTIONS"
+}
+
+/// A utility for constructing HTTP requests
+public struct RequestBuilder {
+    private var url: URL
+    private var method: HTTPMethod
+    private var headers: [String: String] = [:]
+    private var body: Data?
+
+    public init(url: URL, method: HTTPMethod = .get) {
+        self.url = url
+        self.method = method
+    }
+
+    /// Add a header to the request
+    @discardableResult
+    public mutating func addHeader(key: String, value: String) -> Self {
+        headers[key] = value
+        return self
+    }
+
+    /// Set the body of the request
+    @discardableResult
+    public mutating func setBody(_ data: Data?) -> Self {
+        body = data
+        return self
+    }
+
+    /// Build the `URLRequest`
+    public func build() -> URLRequest {
+        var request = URLRequest(url: url)
+        request.httpMethod = method.rawValue
+        request.allHTTPHeaderFields = headers
+        request.httpBody = body
+        return request
+    }
+}

EmployeeDirectory/Models/Employees.swift

@@ -11,8 +11,14 @@ public struct Employees: Codable {
         
     /// Array of Employees
     public var employees: [Employee]
-    
+    public let total: Int
+    public let page: Int
+    public let perPage: Int
+
     private enum CodingKeys: String, CodingKey {
         case employees
+        case total
+        case page
+        case perPage = "per_page"
     }
 }

EmployeeDirectory/Protocols/EmployeeServiceProtocol.swift

@@ -5,12 +5,11 @@
 //  Created by Matt Bruce on 1/20/25.
 //
 
-
 /// This will be the interface for the API for Employees
 public protocol EmployeeServiceProtocol {
-    
     /// This will get a list of all employees
     /// - Parameter serviceMode: Mode in which to hit.
     /// - Returns: An Employees struct
     func getEmployees(_ serviceMode: EmployeeServiceMode) async throws -> Employees
+    func getEmployees(_ serviceMode: EmployeeServiceMode, page: Int, perPage: Int, sortField: EmployeeSortField, sortOrder: EmployeeSortOrder) async throws -> Employees
 }

EmployeeDirectory/Services/EmployeeService.swift

@@ -6,6 +6,17 @@
 //
 import Foundation
 
+public enum EmployeeSortField: String {
+    case fullName
+    case team
+    case employeeType
+}
+
+public enum EmployeeSortOrder: String {
+    case ascending = "asc"
+    case descending = "desc"
+}
+
 /// These are the testing URL Endpoints for different states
 public enum EmployeeServiceMode: String, CaseIterable {
     case production
@@ -42,4 +53,34 @@ public class EmployeeService: EmployeeServiceProtocol {
     public func getEmployees(_ serviceMode: EmployeeServiceMode = .production) async throws -> Employees {
         return try await NetworkService.shared.fetchData(from: serviceMode.endpoint, as: Employees.self)
     }
+    
+    /// Fetch employees with pagination support
+    /// - Parameters:
+    ///   - page: The page number to fetch.
+    ///   - perPage: The number of employees per page.
+    /// - Returns: A paginated Employees object.
+    public func getEmployees(_ serviceMode: EmployeeServiceMode = .production,
+                             page: Int, perPage: Int,
+                             sortField: EmployeeSortField = .fullName,
+                             sortOrder: EmployeeSortOrder = .ascending) async throws -> Employees {
+        
+        guard var urlComponents = URLComponents(string: serviceMode.endpoint) else {
+            throw NetworkServiceError.invalidURL
+        }
+        
+        urlComponents.queryItems = [
+            URLQueryItem(name: "page", value: "\(page)"),
+            URLQueryItem(name: "perPage", value: "\(perPage)"),
+            URLQueryItem(name: "sortField", value: "\(sortField.rawValue)"),
+            URLQueryItem(name: "sortOrder", value: "\(sortOrder.rawValue)")
+        ]
+        
+        guard let url = urlComponents.url else {
+            throw NetworkServiceError.invalidURL
+        }
+        
+        let request = RequestBuilder(url: url, method: .get).build()
+        
+        return try await NetworkService.shared.fetchData(with: request, as: Employees.self)
+    }
 }

EmployeeDirectory/Services/MockEmployeeService.swift

@@ -0,0 +1,72 @@
+//
+//  MockEmployeeService.swift
+//  EmployeeDirectory
+//
+//  Created by Matt Bruce on 1/21/25.
+//
+import Foundation
+
+public class MockEmployeeService: EmployeeServiceProtocol {
+    // MARK: - Properties
+    public static let shared = MockEmployeeService() // Default shared instance
+    private var employees: Employees
+
+    // MARK: - Initializer
+
+    public init() {
+        let jsonFileName = "localTest"
+        guard let url = Bundle.main.url(forResource: jsonFileName, withExtension: "json"),
+                let data = try? Data(contentsOf: url),
+              let localData = try? JSONDecoder().decode(Employees.self, from: data) else {
+            employees = .init(employees: [], total: 0, page: 0, perPage: 0)
+            return
+        }
+        employees = localData
+    }
+    
+    public func getEmployees(_ serviceMode: EmployeeServiceMode) async throws -> Employees {
+        return employees
+    }
+    
+    public func getEmployees(_ serviceMode: EmployeeServiceMode = .production,
+                             page: Int, perPage: Int,
+                             sortField: EmployeeSortField = .team,
+                             sortOrder: EmployeeSortOrder = .ascending) async throws -> Employees {
+        
+        employees = .init(employees:  employees.employees.sorted(by: sortField, with: sortOrder),
+                          total: employees.employees.count,
+                          page: page,
+                          perPage: perPage)
+               
+        let totalUsers = employees.employees.count
+        let startIndex = (page - 1) * perPage
+        let endIndex = min(startIndex + perPage, totalUsers)
+
+        guard startIndex < totalUsers else {
+            return .init(employees: [], total: totalUsers, page: page, perPage: perPage) // Return empty if out of bounds
+        }
+        let paginatedUsers = Array(employees.employees[startIndex..<endIndex])
+        return .init(employees: paginatedUsers, total: totalUsers, page: page, perPage: perPage)
+    }
+}
+
+extension Array where Element == Employee {
+    func sorted(by field: EmployeeSortField, with option: EmployeeSortOrder) -> [Employee] {
+        switch field {
+        case .fullName:
+            return option == .ascending
+            ? sorted { $0.fullName < $1.fullName }
+            : sorted { $0.fullName > $1.fullName }
+            
+        case .team:
+            return option == .ascending
+            ? sorted { $0.team < $1.team || ($0.team == $1.team && $0.fullName < $1.fullName) }
+            : sorted { $0.team > $1.team || ($0.team == $1.team && $0.fullName < $1.fullName) }
+            
+        case .employeeType:
+            return option == .ascending
+            ? sorted { $0.employeeType.rawValue < $1.employeeType.rawValue || ($0.employeeType.rawValue == $1.employeeType.rawValue && $0.fullName < $1.fullName) }
+            : sorted { $0.employeeType.rawValue > $1.employeeType.rawValue || ($0.employeeType.rawValue == $1.employeeType.rawValue && $0.fullName < $1.fullName) }
+        }
+    }
+}

EmployeeDirectory/Services/NetworkService.swift

@@ -49,14 +49,24 @@ public class NetworkService {
     /// - Throws: A `ServiceError` for network, decoding, or unexpected errors.
     /// - Returns: The decoded object of the specified type.
     public func fetchData<T: Decodable>(from endpoint: String, as type: T.Type) async throws -> T {
+        //ensure a valid URL
+        guard let url = URL(string: endpoint) else {
+            throw NetworkServiceError.invalidURL
+        }
+        
+        return try await fetchData(with: URLRequest(url: url), as: type)
+    }
+    
+    /// Fetches data using a URLRequest and decodes it into a generic Decodable type.
+    /// - Parameters:
+    ///   - request: The URLRequest to execute.
+    ///   - type: The type to decode the data into.
+    /// - Throws: A `NetworkServiceError` for network, decoding, or unexpected errors.
+    /// - Returns: The decoded object of the specified type.
+    public func fetchData<T: Decodable>(with request: URLRequest, as type: T.Type) async throws -> T {
         do {
-            //ensure a valid URL
-            guard let url = URL(string: endpoint) else {
-                throw NetworkServiceError.invalidURL
-            }
-
             // Perform network request
-            let (data, response) = try await URLSession.shared.data(for: URLRequest(url: url))
+            let (data, response) = try await session.data(for: request)
             
             // Validate HTTP response
             guard let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode == 200 else {

EmployeeDirectory/ViewControllers/EmployeesViewController.swift

@@ -31,6 +31,9 @@ class EmployeesViewController: UIViewController {
     /// Will show specific state of the viewModel
     private var footerView: TableFooterView?
     
+    // Prevents multiple calls during rapid scrolling
+    private var isFetchingNextPage: Bool = false
+
     // MARK: - Public Methods
 
     public override func viewDidLoad() {
@@ -49,6 +52,7 @@ class EmployeesViewController: UIViewController {
         // Configure TableView
         tableView.register(EmployeeTableViewCell.self, forCellReuseIdentifier: EmployeeTableViewCell.identifier)
         tableView.dataSource = self
+        tableView.delegate = self
         view.addSubview(tableView)
         tableView.frame = view.bounds
 
@@ -98,26 +102,55 @@ class EmployeesViewController: UIViewController {
     
     /// Show state in specific use-cases for the EmployeesViewModel
     private func updateFooter() {
-        var message: String? {
-            guard !viewModel.isLoading else { return nil }
-            return viewModel.errorMessage ?? (viewModel.employees.isEmpty ? "No employees found, please try to refresh." : nil)
+        var footerMessage: String?
+        
+        // Check for error messages or empty state first
+        if let message = viewModel.errorMessage ?? (viewModel.employees.isEmpty && !viewModel.isLoading ? "No employees found, please try to refresh." : nil) {
+            footerMessage = message
+            
+        }        
+        // Show loading footer if there are more pages to load
+        else if (viewModel.isLoading || isFetchingNextPage) && viewModel.hasMorePages {
+            footerMessage = "Loading more employees..."
         }
         
-        if let message, !viewModel.isLoading {
+        if let footerMessage {
             // Lazy initialize footerView if needed
             if footerView == nil {
-                footerView = TableFooterView(message: message)
-            } else { // Update the message
-                footerView?.update(message: message)
+                footerView = TableFooterView(message: footerMessage)
+            } else {
+                footerView?.update(message: footerMessage)
             }
             footerView?.frame = CGRect(x: 0, y: 0, width: tableView.frame.width, height: 150)
             tableView.tableFooterView = footerView
+
         } else {
             tableView.tableFooterView = nil
         }
     }
 }
 
+// MARK: - UITableViewDelegate
+extension EmployeesViewController: UITableViewDelegate {
+    func scrollViewDidScroll(_ scrollView: UIScrollView) {
+        let offsetY = scrollView.contentOffset.y
+        let contentHeight = scrollView.contentSize.height
+        let scrollViewHeight = scrollView.frame.size.height
+
+        if offsetY > contentHeight - scrollViewHeight - 100 && !isFetchingNextPage {
+            isFetchingNextPage = true
+            updateFooter()
+            viewModel.loadNextPage()
+
+            // Reset the flag after a short delay to allow new fetches
+            DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { [weak self] in
+                self?.isFetchingNextPage = false
+            }
+        }
+    }
+}
+
+
 // Mark: - Objective-C Methods
 extension EmployeesViewController {
     

EmployeeDirectory/ViewModels/EmployeesViewModel.swift

@@ -16,36 +16,57 @@ public class EmployeesViewModel: ObservableObject {
     @Published public private(set) var employees: [Employee] = []
     @Published public private(set) var errorMessage: String? = nil
     @Published public private(set) var isLoading: Bool = false
-    
+    @Published public private(set) var hasMorePages: Bool = true
+
+    private var currentPage = 1
+    private let perPage = 10
+    private var totalEmployees = 0
+
     public init() {}
-    
-    public func fetchEmployees() {
-        // resetting values out the values before fetching new data
-        errorMessage = nil
+
+    /// Fetch employees for the given page
+    public func fetchEmployees(page: Int = 1) {
+        // Prevent duplicate calls
+        guard !isLoading else { return }
         isLoading = true
 
         Task {
             do {
-                // Fetch employees using the async method
-                let wrapper = try await EmployeeService.shared.getEmployees(serviceMode)
+                // Fetch employees using the paginated API
+                let wrapper = try await MockEmployeeService.shared.getEmployees(.empty ,page: page, perPage: perPage)
                 
                 // Update published properties
-                employees = wrapper.employees
+                if page == 1 {
+                    employees = wrapper.employees // Replace list for the first page
+                } else {
+                    employees.append(contentsOf: wrapper.employees) // Append for subsequent pages
+                }
+                
+                totalEmployees = wrapper.total
+                currentPage = page
+                hasMorePages = employees.count < totalEmployees
                 isLoading = false
 
             } catch {
                 // Handle errors
-                employees = []
                 isLoading = false
-                errorMessage = "An unexpected error occurred, please try to refresh"
+                errorMessage = "An unexpected error occurred, please try to refresh."
             }
         }
-
     }
-    
+
+    /// Load the next page of employees
+    public func loadNextPage() {
+        guard hasMorePages else { return }
+        fetchEmployees(page: currentPage + 1)
+    }
+
+    /// Change the service mode (e.g., production, malformed, empty)
     public func changeMode(to mode: EmployeeServiceMode) {
         serviceMode = mode
-        fetchEmployees()
+        currentPage = 1
+        employees = []
+        hasMorePages = true
+        fetchEmployees(page: 1)
     }
 }
-

EmployeeDirectory/Views/EmployeeTableViewCell.swift

@@ -128,11 +128,10 @@ public class EmployeeTableViewCell: UITableViewCell {
 
         // Bind the image to the photoImageView
         smallPhotoSubscriber = viewModel.$smallPhoto
+            .compactMap { $0 }
             .receive(on: DispatchQueue.main)
             .sink { [weak self] image in
-                if let image {
-                    self?.photoImageView.image = image
-                }
+                self?.photoImageView.image = image
             }
 
         // Bind data to UI components