using Microsoft.EntityFrameworkCore;
using PnvPanel.Application.Auth;
using PnvPanel.Application.Common.Interfaces;
using LiteCqrs;
using PnvPanel.Application.Common.Models;
using PnvPanel.Domain.Audit;
using PnvPanel.Domain.Support;

namespace PnvPanel.Application.Admin.Maintenance;

public sealed class DeleteClosedTicketsCommandHandler(
    IAppDbContext dbContext,
    IFileStorage fileStorage,
    ICurrentUser currentUser
) : ICommandHandler<DeleteClosedTicketsCommand, Result<int>>
{
    public async Task<Result<int>> Handle(
        DeleteClosedTicketsCommand command,
        CancellationToken cancellationToken
    )
    {
        if (currentUser.UserId is not { } adminId)
            return Result.Failure<int>(AuthErrors.Unauthorized);

        var ticketIds = await dbContext
            .SupportTickets.AsNoTracking()
            .Where(t => t.Status == TicketStatus.Closed)
            .Select(t => t.Id)
            .ToListAsync(cancellationToken);

        if (ticketIds.Count == 0)
            return Result.Success(0);

        // Тикет/комментарий/вложение — плоские сущности без FK-каскада (см. SupportTicket), поэтому
        // порядок удаления важен: вложения (+ файлы на диске) -> комментарии -> тикеты.
        var comments = await dbContext
            .TicketComments.Where(c => ticketIds.Contains(c.TicketId))
            .ToListAsync(cancellationToken);
        var commentIds = comments.Select(c => c.Id).ToList();

        var attachments = await dbContext
            .TicketAttachments.Where(a => commentIds.Contains(a.CommentId))
            .ToListAsync(cancellationToken);

        foreach (var attachment in attachments)
            await fileStorage.DeleteAsync(attachment.StoredFileName, cancellationToken);

        dbContext.TicketAttachments.RemoveRange(attachments);
        dbContext.TicketComments.RemoveRange(comments);

        var tickets = await dbContext
            .SupportTickets.Where(t => ticketIds.Contains(t.Id))
            .ToListAsync(cancellationToken);
        dbContext.SupportTickets.RemoveRange(tickets);

        dbContext.AuditLogs.Add(
            AuditLog.Create(
                adminId,
                "ClosedTicketsCleanedUp",
                "SupportTicket",
                "bulk",
                metadata: $"{{\"count\":{ticketIds.Count}}}",
                AuditSource.Web
            )
        );

        return Result.Success(ticketIds.Count);
    }
}