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

/// 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 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 {
    public enum EmployeeServiceError: Error {
        case error
        //case LoadError
        //case other(Error)
    }
    // 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 {
        var employees: Employees
        let cache = EmployeeCacheService.shared
        do {
            employees = try cache.load()
            return employees
        } catch {
            if let networkFound = try? await fetchNetworkEmployees() {
                employees = networkFound
                return employees
            }
        }
        throw EmployeeServiceError.error
    }
    
    public func fetchNetworkEmployees() async throws -> Employees {
        var employees: Employees
        if let networkFound = try? await NetworkService.shared.fetchData(from: EmployeeServiceMode.production.endpoint, as: Employees.self) {
            employees = networkFound
            try? EmployeeCacheService.shared.save(from: employees)
            return employees
        } else {
            throw EmployeeServiceError.error
        }
    }
}

/// 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)
    }
}

/// 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)
    }
}