using CMSMicroservice.Application.Common.Interfaces;
using CMSMicroservice.Application.Common.Models;
using MediatR;
using Microsoft.EntityFrameworkCore;

namespace CMSMicroservice.Application.UserCQ.Queries.GetMyInvitees;

public class GetMyInviteesQueryHandler : IRequestHandler<GetMyInviteesQuery, GetMyInviteesResult>
{
    private readonly IApplicationDbContext _context;
    private readonly ICurrentUserService _currentUser;

    public GetMyInviteesQueryHandler(IApplicationDbContext context, ICurrentUserService currentUser)
    {
        _context = context;
        _currentUser = currentUser;
    }

    public async Task<GetMyInviteesResult> Handle(GetMyInviteesQuery request, CancellationToken cancellationToken)
    {
        var userId = request.UserId == 0
            ? (long.TryParse(_currentUser.UserId, out var id) ? id : 0)
            : request.UserId;

        if (userId == 0)
            throw new UnauthorizedAccessException("User ID not found in JWT token");

        var baseQuery = _context.UserInvitations
            .AsNoTracking()
            .Where(x => x.InviterUserId == userId)
            .Select(x => new
            {
                x.InviteeUserId,
                InviteeFirstName = x.Invitee.FirstName,
                InviteeLastName = x.Invitee.LastName,
                InviteeMobile = x.Invitee.Mobile,
                RegisteredAt = x.Invitee.Created,
                IsClubActive = x.Invitee.ClubMembership != null && x.Invitee.ClubMembership.IsActive,
                InvitedAt = x.Created
            });

        var all = await baseQuery.ToListAsync(cancellationToken);
        var total = all.Count;
        var clubActive = all.Count(x => x.IsClubActive);
        var clubInactive = total - clubActive;

        var filtered = all.AsEnumerable();
        var status = request.ClubStatusFilter?.Trim().ToUpperInvariant();
        if (status == "ACTIVE")
            filtered = filtered.Where(x => x.IsClubActive);
        else if (status == "INACTIVE")
            filtered = filtered.Where(x => !x.IsClubActive);

        var ordered = filtered.OrderByDescending(x => x.InvitedAt).ToList();

        var paginationState = request.PaginationState ?? new PaginationState { PageNumber = 1, PageSize = 10 };
        if (paginationState.PageNumber < 1) paginationState.PageNumber = 1;
        if (paginationState.PageSize < 1) paginationState.PageSize = 10;

        var totalCount = ordered.Count;
        var pageItems = ordered
            .Skip((paginationState.PageNumber - 1) * paginationState.PageSize)
            .Take(paginationState.PageSize)
            .ToList();

        var totalPage = totalCount == 0
            ? 0
            : (int)Math.Ceiling((double)totalCount / paginationState.PageSize);

        return new GetMyInviteesResult
        {
            MetaData = new MetaData
            {
                TotalCount = totalCount,
                CurrentPage = paginationState.PageNumber,
                PageSize = paginationState.PageSize,
                TotalPage = totalPage,
                HasPrevious = paginationState.PageNumber > 1,
                HasNext = paginationState.PageNumber < totalPage
            },
            Stats = new InviteeStatsDto
            {
                TotalInvitees = total,
                ClubActiveCount = clubActive,
                ClubInactiveCount = clubInactive
            },
            Invitees = pageItems.Select(x => new InviteeDto
            {
                UserId = x.InviteeUserId,
                FirstName = x.InviteeFirstName,
                LastName = x.InviteeLastName,
                Mobile = x.InviteeMobile,
                RegisteredAt = x.RegisteredAt,
                IsClubActive = x.IsClubActive
            }).ToList()
        };
    }
}