using LCU.API.Internal.Operations.IncentiveApi.Extensions;
using LCU.API.Internal.Operations.IncentiveApi.Services.DispersalStrategy;
using LCU.API.Internal.Operations.IncentiveApi.Models;
using LCU.API.Internal.Operations.IncentiveApi.Models.GoalDispersal;
using LCU.API.Internal.Operations.IncentiveApiLib.Services;
using LCU.API.Internal.Operations.IncentiveApiLib.Repositories;
using LCU.Library.Internal.IncentiveApiModels.Entities;
using LCU.Library.Internal.IncentiveApiModels.Common;
using LCU.API.Internal.Operations.IncentiveApiLib.Persistence;
using LCU.Library.Internal.IncentiveApiModels.Requests;

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

public class GoalService : IGoalService
{
    private readonly IGoalRepository _goalRepository;
    private readonly IGoalChangeRepository _goalChangeRepository;
    private readonly ICurrentUserService _currentUserService;
    private readonly IDispersalStrategyService _dispersalStrategyService;
    private readonly IDepartmentRepository _departmentRepository;
    private readonly IUserService _userService;
    private readonly IUnitOfWork _unitOfWork;

    public GoalService(
        IGoalRepository goalRepository,
        IGoalChangeRepository goalChangeRepository,
        ICurrentUserService currentUserService,
        IDispersalStrategyService dispersalStrategyService,
        IUnitOfWork unitOfWork,
        IUserService userService,
        IDepartmentRepository departmentRepository
    )
    {
        _goalRepository = goalRepository;
        _goalChangeRepository = goalChangeRepository;
        _currentUserService = currentUserService;
        _unitOfWork = unitOfWork;
        _userService = userService;
        _departmentRepository = departmentRepository;
        _dispersalStrategyService = dispersalStrategyService;
    }

    public async Task<List<Goal>> SaveGoalAsync(GoalChange goalChange)
    {
        return await SaveGoalRangeAsync(new List<GoalChange>() { goalChange });
    }

    private async Task<GoalChange> ConfirmAppUserIdAndSaveGoalChange(GoalChange goalChange)
    {
        if (!goalChange.IsDepartmentGoalChange())
        {
            var appUser = await _userService.GetUserByEmployeeIdAsync(goalChange.PersonId);
            goalChange.AppUserId = appUser.Id;
        }

        await _goalChangeRepository.SaveGoalChangeAsync(goalChange);
        return goalChange;
    }

    public async Task<List<Goal>> SaveGoalRangeAsync(List<GoalChange> goalChanges)
    {
        var goalsToSave = new List<Goal>();
        foreach (var goalChange in goalChanges)
        {
            await ConfirmAppUserIdAndSaveGoalChange(goalChange);

            var goal = await _goalRepository.FindExistingGoal(goalChange);
            if (goal != null)
            {
                var originalGoalValue = goal.Value;
                goal.Value = goalChange.Value;

                if (goal.IsDepartmentGoal() && originalGoalValue != goal.Value)
                {
                    goalsToSave.AddRange(await CreatePersonnelGoalChangesFromDepartmentGoalChange(goalChange, originalGoalValue));
                }
            }
            else
            {
                goal = new Goal()
                {
                    AppUserId = goalChange.AppUserId,
                    Product = goalChange.Product,
                    EmployeeId = goalChange.PersonId,
                    DepartmentId = goalChange.DepartmentId,
                    StartDate = goalChange.StartDate.StartOfMonth(),
                    EndDate = goalChange.EndDate.EndOfMonth(),
                    Value = goalChange.Value
                };
                await _goalRepository.SaveGoalAsync(goal);
            }

            goalsToSave.Add(goal);
        }

        await _unitOfWork.CompleteAsync();
        return goalsToSave;
    }

    private async Task<List<Goal>> CreatePersonnelGoalChangesFromDepartmentGoalChange(GoalChange goalChange, int originalGoalValue)
    {
        if (!goalChange.IsDepartmentGoalChange()) return new List<Goal>();
        var personnelGoals = new List<Goal>();
        var departmentPersonnelGoals = await GetMonthlyPersonnelGoalsAsync(
            new DepartmentPersonnelSearchRequest()
            {
                DepartmentId = goalChange.DepartmentId,
                IncludeAllPersonnel = true,
                Year = goalChange.StartDate.Year,
                Month = goalChange.StartDate.Month,
            });
        var receipt = _dispersalStrategyService.ExtrapolateSingleDepartmentProduct(
            new DepartmentGoalExtrapolationRequest()
            {
                DepartmentGoalEndDate = goalChange.EndDate.EndOfMonth(),
                DepartmentGoalStartDate = goalChange.StartDate.StartOfMonth(),
                DepartmentId = goalChange.DepartmentId,
                NewDepartmentGoal = goalChange.Value,
                OriginalDepartmentGoal = originalGoalValue,
                Product = goalChange.Product
            }, departmentPersonnelGoals);

        foreach (var reDispersedGoalChange in receipt.GoalChanges)
        {
            await ConfirmAppUserIdAndSaveGoalChange(reDispersedGoalChange);
            var reDispersedGoal = await CreateOrUpdateGoalFromGoalChange(reDispersedGoalChange);
            personnelGoals.Add(reDispersedGoal);
        }

        return personnelGoals;
    }

    private async Task<Goal> CreateOrUpdateGoalFromGoalChange(GoalChange goalChange)
    {
        var goal = await _goalRepository.FindExistingGoal(goalChange);
        if (goal != null)
        {
            goal.Value = goalChange.Value;
        }
        else
        {
            goal = new Goal()
            {
                Product = goalChange.Product,
                AppUserId = goalChange.AppUserId,
                EmployeeId = goalChange.PersonId,
                DepartmentId = goalChange.DepartmentId,
                StartDate = goalChange.StartDate.StartOfMonth(),
                EndDate = goalChange.EndDate.EndOfMonth(),
                Value = goalChange.Value
            };
            await _goalRepository.SaveGoalAsync(goal);
        }

        return goal;
    }

    public async Task<DepartmentGoals> GetAnnualDepartmentGoalsAsync(int departmentId, int year)
    {
        var goals = new DepartmentGoals(departmentId, year);

        goals.ApplyAll(await _goalRepository.FindAnnualDepartmentGoals(departmentId, year));
        return goals;
    }

    public async Task<IReadOnlyCollection<DepartmentGoals>> GetAllAnnualDepartmentGoalsAsync(int year)
    {
        var departments = await _departmentRepository.GetAllDepartmentsAsync();
        var departmentGoals = new List<DepartmentGoals>();
        foreach (var department in departments)
        {
            if (department.Id != null)
            {
                departmentGoals.Add(await GetAnnualDepartmentGoalsAsync(department.Id.Value, year));
            }
        }

        return departmentGoals;
    }

    public async Task<PersonnelGoals> GetMonthlyPersonnelGoalsAsync(DepartmentPersonnelSearchRequest searchRequest)
    {
        var users = await _userService.FindDepartmentAssignments(searchRequest);
        var goals = new PersonnelGoals(searchRequest.DepartmentId, searchRequest.Year, searchRequest.Month, users);

        goals.ApplyAll(await _goalRepository.FindMonthlyPersonnelGoals(searchRequest.DepartmentId, users,
            searchRequest.Year, searchRequest.Month));
        return goals;
    }

    public async Task<IReadOnlyCollection<Goal>> GetGoalsAsync(GoalSearchRequest goalSearchRequest)
    {
        return await _goalRepository.GetGoalsAsync(goalSearchRequest);
    }

    public async Task<IReadOnlyCollection<GoalChange>> GetGoalChangesAsync()
    {
        return await _goalChangeRepository.GetGoalChangesAsync();
    }

    public async Task<EmployeeGoals> GetEmployeeGoalsForMonthRangeAsync(AppUser employee, MonthRange monthRange)
    {
        var users = new List<AppUser>()
        {
            employee
        };
        var goals = new EmployeeGoals(employee, monthRange);


        foreach (var dept in goals.Departments)
        {
            goals.ApplyAll(
                await _goalRepository.FindPersonnelGoalsByMonthRange(dept.DepartmentId, users, monthRange));
        }

        return goals;
    }

    public async Task<IReadOnlyCollection<DepartmentGoalsForRange>> GetEmployeeDepartmentsGoalsForMonthRangeAsync(AppUser employee, MonthRange monthRange)
    {
        var allGoals = new List<DepartmentGoalsForRange>();

        foreach (var dept in employee.Departments)
        {
            var isAssignedInMonthRange = dept.StartDate.Date < monthRange.EndTime.Date &&
                                         (dept.EndDate == null ||
                                          monthRange.StartTime.Date < dept.EndDate.Value.Date);
            if (isAssignedInMonthRange)
            {
                var StartDate = dept.StartDate.Date < monthRange.StartTime.Date
                    ? monthRange.StartTime.Date
                    : dept.StartDate.Date;
                var EndDate = dept.EndDate == null ? monthRange.EndTime.Date
                    : dept.EndDate.Value.Date > monthRange.EndTime.Date ? monthRange.EndTime.Date
                    : dept.EndDate.Value.Date;
                var monthRangeOfAssignment = new MonthRange
                (
                    StartDate.Year,
                    StartDate.Month,
                    EndDate.Year,
                    EndDate.Month
                );

                var goals = new DepartmentGoalsForRange(dept.DepartmentId, monthRangeOfAssignment);
                var deptGoals =
                    await _goalRepository.FindDepartmentGoalsByMonthRange(goals.DepartmentId, goals.MonthRange);
                goals.ApplyAll(deptGoals);
                allGoals.Add(goals);
            }
        }

        return allGoals;
    }
}