using DigitalData.Core.Abstraction.Application.Repository;
using DigitalData.Core.Exceptions;
using EnvelopeGenerator.Application.Common.Interfaces.Services.Notification;
using EnvelopeGenerator.Application.Common.Query;
using EnvelopeGenerator.Domain.Constants;
using EnvelopeGenerator.Domain.Entities;
using EnvelopeGenerator.Domain.Interfaces;
using MediatR;
using Microsoft.EntityFrameworkCore;

namespace EnvelopeGenerator.Application.PdfSigning;

/// <summary>
/// 
/// </summary>
public record FinalizeEnvelopeCommand : EnvelopeQueryBase, IRequest
{
    internal int? UserId { get; private set; } = null;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="userId"></param>
    /// <returns></returns>
    public FinalizeEnvelopeCommand Authorized(int userId)
    {
        UserId = userId;
        return this;
    }

    /// <summary>
    /// 
    /// </summary>
    public bool BurnedAllowed { get; init; } = false;

    /// <summary>
    /// 
    /// </summary>
    public bool SaveDocResult { get; init; } = true;
}

/// <summary>
/// 
/// </summary>
/// <param name="Repo"></param>
/// <param name="Sender"></param>
/// <param name="NtfServer"></param>
public class FinalizeEnvelopeCommandHandler(IRepository<Envelope> Repo, ISender Sender, IEnvelopeNotificationService NtfServer) : IRequestHandler<FinalizeEnvelopeCommand>
{
    /// <summary>
    /// 
    /// </summary>
    /// <param name="request"></param>
    /// <param name="cancel"></param>
    /// <returns></returns>
    /// <exception cref="NotFoundException"></exception>
    public async Task Handle(FinalizeEnvelopeCommand request, CancellationToken cancel)
    {
        var envelopeQuery = Repo.Query;

        if (request.Id is int id)
            envelopeQuery = envelopeQuery.Where(e => e.Id == id);
        else if (request.Uuid is string uuid)
            envelopeQuery = envelopeQuery.Where(e => e.Uuid == uuid);
        
        var envelope = await envelopeQuery
            .Include(e => e.EnvelopeReceivers).ThenInclude(er => er.Receiver)
            .Include(e => e.Documents)
            .SingleOrDefaultAsync(cancel)
                ?? throw new NotFoundException($"Envelope is not found ID: {request.Id} UUID: {request.Uuid}");

        if(request.UserId is int userId && userId != envelope.UserId)
            throw new InvalidOperationException($"Envelope is not owned by user ID: {request.Id} UUID: {request.Uuid}");

        // already burned
        if (!request.BurnedAllowed && envelope.IsBurned())
            throw new InvalidOperationException($"Envelope is already burned ID: {request.Id} UUID: {request.Uuid}");

        // envelope is not completely signed
        if (envelope.Status!= EnvelopeStatus.EnvelopeCompletelySigned)
            throw new InvalidOperationException($"Envelope status is not completely signed ID: {request.Id} UUID: {request.Uuid}");

        using var docStream = await Sender.Send(new SignPdfByEnvelopeCommand()
        {
            Envelope = envelope
        }, cancel);

        if (docStream.CanSeek) 
            docStream.Position = 0;

        using var ms = new MemoryStream();
        docStream.CopyTo(ms);
        byte[] doc = ms.ToArray();

        foreach (var er in envelope.EnvelopeReceivers)
        {
            await NtfServer.Notify(er.Receiver.EmailAddress, new DocumentSignedNotification()
            {
                DocumentTitle = envelope.Title,
                NameReceiver = er.Name,
                Attachments = [
                    ($"unterzeichnetes-dokument.pdf", doc)
                    ]
            }, cancel);
        }

        if (request.SaveDocResult)
            await Repo.UpdateAsync(e => e.DocResult = doc, e => e.Id == envelope.Id, cancel);
    }
}