using LCU.API.Internal.Operations.IncentiveApi.Exceptions;
using LCU.API.Internal.Operations.IncentiveApi.Models;
using LCU.API.Internal.Operations.IncentiveApiLib.Repositories;
using LCU.Library.Internal.IncentiveApiModels.Entities;
using LCU.Library.Internal.IncentiveApiModels.Enums;
using LCU.Library.Internal.IncentiveApiModels.Common;

namespace LCU.API.Internal.Operations.IncentiveApi.Services;

public class DepartmentService : IDepartmentService
{
    private readonly IDepartmentRepository _departmentRepository;
    private readonly IUnitOfWork _unitOfWork;
    private readonly IUserAssignmentService _userAssignmentService;

    public DepartmentService(IDepartmentRepository departmentRepository,
        IUserAssignmentService userAssignmentService, IUnitOfWork unitOfWork)
    {
        _departmentRepository = departmentRepository;
        _userAssignmentService = userAssignmentService;
        _unitOfWork = unitOfWork;
    }

    public async Task<IReadOnlyCollection<Department>> GetAllDepartmentsAsync()
    {
        try
        {
            return await _departmentRepository.GetAllDepartmentsAsync();
        }
        catch (Exception ex)
        {
            Log.Error(ex, "Failed to Retrieve All Departments");
            throw new ServerErrorException();
        }
    }

    public async Task<Department> GetDepartmentByIdAsync(int id)
    {
        try
        {
            var department = await _departmentRepository.FindDepartmentByIdAsync(id);
            if (department == null)
            {
                throw new NotFoundException($"Could Not Find Department With Id {id}");
            }

            return department;
        }
        catch (NotFoundException)
        {
            throw;
        }
        catch (Exception ex)
        {
            Log.Error(ex, $"Failed to Retrieve Department with Id {id}");
            throw new ServerErrorException();
        }
    }

    public async Task<IReadOnlyCollection<Department>> GetDepartmentsByRegionAsync(Region region)
    {
        try
        {
            var departments = await _departmentRepository.FindDepartmentsByRegionAsync(region);
            if (departments == null)
            {
                throw new NotFoundException($"Could Not Find Departments for {region.Name}");
            }

            return departments;
        }
        catch (NotFoundException)
        {
            throw;
        }
        catch (Exception ex)
        {
            Log.Error(ex, $"Could Not Find Departments for {region.Name}");
            throw new ServerErrorException();
        }
    }

    public async Task<IReadOnlyCollection<Department>> GetDepartmentsByBusinessLineAsync(BusinessLine businessLine)
    {
        var departments = await _departmentRepository.FindDepartmentsByBusinessLineAsync(businessLine);
        if (departments == null)
        {
            throw new NotFoundException($"Could Not Find Departments for {businessLine.Name}");
        }
        return departments;
    }

    public async Task<IReadOnlyCollection<UserDepartment>> FindDepartmentAssignmentsForRange(int departmentId,
        MonthRange monthRange)
    {
        return await _departmentRepository.FindDepartmentAssignmentsForRange(departmentId, monthRange);
    }

    public async Task<Department> GetDepartmentsByDayforceGlCodeAsync(int glCode)
    {
        var department = await _departmentRepository.GetDepartmentByDayforceGlCode(glCode);
        if (department == null)
        {
            throw new NotFoundException($"Could Not Find Department for {glCode}");
        }

        return department;
    }

    public async Task<IReadOnlyCollection<Department>> GetHierarchicalDepartmentsForEmployeeAsync(AppUser employee, bool includeManagers)
    {
        try
        {
            if (employee.Departments.Any(x => x.Role == Role.Admin))
            {
                return await GetAllDepartmentsAsync();
            }

            var userDept = employee.Departments.FirstOrDefault(x => x.Role == Role.RegionalManager);
            if (userDept != null && userDept.Department != null && !string.IsNullOrWhiteSpace(userDept.Department.RegionCode))
            {
                var region = Region.FindByCode(userDept.Department.RegionCode);
                if (region != null)
                {
                    return await _departmentRepository.FindDepartmentsByRegionAsync(region);
                }
            }

            var includedRoles = Role.LeadershipRoles;
            if (includeManagers)
            {
                includedRoles = Role.DepartmentManagerRoles;
            }

            return employee.Departments
                .Where(x => includedRoles.Contains(x.Role))
                .Select(x => x.Department).ToList();
        }
        catch (Exception ex)
        {
            Log.Error(ex, "Failed to Retrieve departments user can manage");
            throw new ServerErrorException();
        }
    }

    public async Task<Department> UpdateDepartmentAsync(Department department, int id)
    {
        try
        {
            if (!await IsDepartmentNameUnique(department.DepartmentName, id))
            {
                Log.Debug("Attempted to add department with name that already exists.");
                throw new DuplicateDataException("DepartmentName");
            }

            var existingDepartment = await _departmentRepository.FindDepartmentByIdAsync(id);
            if (existingDepartment == null)
            {
                throw new NotFoundException($"Could Not Find Department With Id {id}");
            }

            existingDepartment.DepartmentName = department.DepartmentName;
            existingDepartment.State = department.State;
            existingDepartment.BusinessLineCode = department.BusinessLineCode;
            existingDepartment.RegionCode = department.RegionCode;

            await _unitOfWork.CompleteAsync();
            return existingDepartment;
        }
        catch (DuplicateDataException)
        {
            throw;
        }
        catch (Exception ex)
        {
            Log.Error(ex, $"Failed to Update Department with Id {id}");
            throw new ServerErrorException();
        }
    }

    public async Task<Department> SaveDepartmentAsync(Department newDepartment)
    {
        try
        {
            if (!await IsDepartmentNameUnique(newDepartment.DepartmentName))
            {
                Log.Debug("Attempted to add department with name that already exists.");
                throw new DuplicateDataException("DepartmentName");
            }

            var department = await _departmentRepository.SaveDepartmentAsync(newDepartment);
            await _unitOfWork.CompleteAsync();
            return department;
        }
        catch (DuplicateDataException)
        {
            throw;
        }
        catch (Exception ex)
        {
            Log.Error(ex, $"Failed to save new Department with Name {newDepartment.DepartmentName}.");
            throw new ServerErrorException();
        }
    }

    public async Task<bool> IsDepartmentNameUnique(string departmentName, int? id = null)
    {
        var existingDepartments = await _departmentRepository.GetAllDepartmentsAsync();
        if (!existingDepartments.Any())
        {
            return true;
        }

        return !existingDepartments.Where(x => x.Id != id).Any(dept =>
            string.Equals(dept.DepartmentName, departmentName, StringComparison.InvariantCultureIgnoreCase));
    }

    public async Task<DepartmentDetails> GetDepartmentDetailsAsync(int id)
    {
        var department = await _departmentRepository.FindDepartmentByIdAsync(id);
        if (department == null)
        {
            throw new NotFoundException($"Could Not Find Department With ID {id}");
        }

        var assignments = await _departmentRepository.FindCurrentDepartmentAssignments(id);

        var departmentDetails = new DepartmentDetails
        {
            Department = department,
            Assignments = assignments,
        };

        if (department.RegionCode != null)
        {
            var regionalManagerAssignment =
                await _userAssignmentService.GetUserAssignment(AssignmentType.RegionalManager,
                    department.RegionCode);
            departmentDetails.RegionalManager = regionalManagerAssignment?.AppUser;
        }

        return departmentDetails;
    }
}