//
//  EmployeeService.swift
//  EmployeeDirectory
//
//  Created by Matt Bruce on 1/20/25.
//
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
internal enum EmployeeServiceMode: String, CaseIterable {
    case production
    case malformed
    case empty
    
    public var service: EmployeeServiceProtocol {
        switch self {
        case .production:
            return MockEmployeeService.shared
            //return EmployeeService.shared
        case .malformed:
            return EmployeeMalformedService.shared
        case .empty:
            return EmployeeEmptyService.shared
        }
    }
    
    /// 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() async throws -> Employees {
        return try await NetworkService.shared.fetchData(from: EmployeeServiceMode.production.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(page: Int, perPage: Int,
                             sortField: EmployeeSortField = .fullName,
                             sortOrder: EmployeeSortOrder = .ascending) async throws -> Employees {
        
        guard var urlComponents = URLComponents(string: EmployeeServiceMode.production.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)
    }
}

/// Service Layer for Employees
public class EmployeeMalformedService: EmployeeServiceProtocol {
    // MARK: - Properties
    public static let shared = EmployeeMalformedService() // 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() async throws -> Employees {
        return try await NetworkService.shared.fetchData(from: EmployeeServiceMode.malformed.endpoint, as: Employees.self)
    }
    
    public func getEmployees(page: Int, perPage: Int, sortField: EmployeeSortField, sortOrder: EmployeeSortOrder) async throws -> Employees {
        return try await NetworkService.shared.fetchData(from: EmployeeServiceMode.malformed.endpoint, as: Employees.self)
    }
}

/// Service Layer for Employees
public class EmployeeEmptyService: EmployeeServiceProtocol {
    // MARK: - Properties
    public static let shared = EmployeeEmptyService() // 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() async throws -> Employees {
        return try await NetworkService.shared.fetchData(from: EmployeeServiceMode.empty.endpoint, as: Employees.self)
    }
    
    public func getEmployees(page: Int, perPage: Int, sortField: EmployeeSortField, sortOrder: EmployeeSortOrder) async throws -> Employees {
        return try await NetworkService.shared.fetchData(from: EmployeeServiceMode.empty.endpoint, as: Employees.self)
    }
}