using System.Collections.Generic;
using System.Linq;
using EmployeeManagmentContracts.BindingModels;
using EmployeeManagmentContracts.BusinessLogicContracts;
using EmployeeManagmentContracts.SearchModels;
using EmployeeManagmentContracts.ViewModels;
using EmployeeManagmentDataBaseImplement;
using EmployeeManagmentDataBaseImplement.Models;

namespace EmployeeManagmentBusinessLogic.BusinessLogic
{
    public class EmployeeLogic : IEmployeeLogic
    {
        private readonly EmployeeManagementDbContext _context;

        public EmployeeLogic(EmployeeManagementDbContext context)
        {
            _context = context;
        }

        public void CreateOrUpdate(EmployeeBindingModel model)
        {
            // Проверка на обязательные поля
            if (string.IsNullOrWhiteSpace(model.NameJob))
            {
                throw new ArgumentException("Job name cannot be empty.");
            }

            // Ищем сотрудника по ID, если он уже существует
            var employee = _context.Employees.FirstOrDefault(e => e.Id == model.Id);

            if (employee == null)
            {
                // Создаем нового сотрудника, если не найден
                employee = new Employee
                {
                    NameJob = model.NameJob,
                    StartJob = model.StartJob,
                    EndJob = model.EndJob,
                    PartTimeJob = model.PartTimeJob,
                    Bid = model.Bid,
                    PhisicalPersonsId = model.PhisicalPersonsId
                };

                try
                {
                    _context.Employees.Add(employee);
                    _context.SaveChanges();
                }
                catch (Exception ex)
                {
                    // Логирование ошибки и обработка
                    throw new InvalidOperationException("Error while adding new employee: " + ex.Message);
                }
            }
            else
            {
                // Обновляем данные существующего сотрудника
                employee.NameJob = model.NameJob;
                employee.StartJob = model.StartJob;
                employee.EndJob = model.EndJob;
                employee.PartTimeJob = model.PartTimeJob;
                employee.Bid = model.Bid;
                employee.PhisicalPersonsId = model.PhisicalPersonsId;

                try
                {
                    _context.SaveChanges();
                }
                catch (Exception ex)
                {
                    // Логирование ошибки и обработка
                    throw new InvalidOperationException("Error while updating employee: " + ex.Message);
                }
            }
        }


        public void Delete(int id)
        {
            var employee = _context.Employees.FirstOrDefault(e => e.Id == id);
            if (employee != null)
            {
                // Дополнительная проверка на связи с другими таблицами, если необходимо
                if (employee.Salaries.Any() || employee.Vacations.Any())
                {
                    throw new InvalidOperationException("Employee cannot be deleted because they have related data (e.g., salaries or vacations).");
                }

                _context.Employees.Remove(employee);
                _context.SaveChanges();
            }
            else
            {
                throw new KeyNotFoundException($"Employee with ID {id} not found.");
            }
        }


        public EmployeeViewModel? GetEmployeeById(int id)
        {
            var employee = _context.Employees
                .Where(e => e.Id == id)
                .Select(e => new EmployeeViewModel
                {
                    Id = e.Id,
                    NameJob = e.NameJob,
                    StartJob = e.StartJob,
                    EndJob = e.EndJob,
                    PartTimeJob = e.PartTimeJob,
                    Bid = e.Bid,
                    PhysicalPersonsId = e.PhisicalPersonsId,
                    PhysicalPersonName = e.PhisicalPerson != null ? e.PhisicalPerson.Name : null
                })
                .FirstOrDefault();

            return employee;
        }

        public List<EmployeeViewModel> GetEmployees(EmployeeSearchModel model)
        {
            var query = _context.Employees.AsQueryable();

            if (model.Id.HasValue)
            {
                query = query.Where(e => e.Id == model.Id.Value);
            }

            if (!string.IsNullOrWhiteSpace(model.NameJob))
            {
                query = query.Where(e => e.NameJob.Contains(model.NameJob));
            }

            if (model.StartDateFrom.HasValue)
            {
                query = query.Where(e => e.StartJob >= model.StartDateFrom.Value);
            }

            if (model.StartDateTo.HasValue)
            {
                query = query.Where(e => e.StartJob <= model.StartDateTo.Value);
            }

            if (model.Bid.HasValue)
            {
                query = query.Where(e => e.Bid == model.Bid.Value);
            }

            return query
                .Select(e => new EmployeeViewModel
                {
                    Id = e.Id,
                    NameJob = e.NameJob,
                    StartJob = e.StartJob,
                    EndJob = e.EndJob,
                    PartTimeJob = e.PartTimeJob,
                    Bid = e.Bid,
                    PhysicalPersonsId = e.PhisicalPersonsId,
                    PhysicalPersonName = e.PhisicalPerson != null ? e.PhisicalPerson.Name : null
                })
                .ToList();
        }

    }
}