//
//  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) }
        }
    }
}