//
//  EmployeeService.swift
//  EmployeeDirectory
//
//  Created by Matt Bruce on 1/20/25.
//
import Foundation

/// These are the testing URL Endpoints for different states
public enum EmployeeServiceMode: String, CaseIterable {
    case production
    case malformed
    case empty
    
    /// Enpoint in which to grabe employees from.
    public var endpoint: String {
        switch self {
        case .production:
            return "https://s3.amazonaws.com/sq-mobile-interview/employees.json"
        case .malformed:
            return "https://s3.amazonaws.com/sq-mobile-interview/employees_malformed.json"
        case .empty:
            return "https://s3.amazonaws.com/sq-mobile-interview/employees_empty.json"
        }
    }
}

/// Service Layer for Employees
public class EmployeeService: EmployeeServiceProtocol {
    // MARK: - Properties
    public static let shared = EmployeeService() // Default shared instance

    // MARK: - Initializer

    public init() {}
    
    // MARK: - Public Methods

    /// This will get a list of all employees
    /// - Parameter serviceMode: Mode in which to hit.
    /// - Returns: An Employees struct
    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) 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)")
        ]
        
        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)
    }
}