using Femto.Common.Domain;
using Femto.Modules.Auth.Application.Dto;
using Femto.Modules.Auth.Data;
using Femto.Modules.Auth.Models;
using Microsoft.EntityFrameworkCore;

namespace Femto.Modules.Auth.Application.Interface.Register;

internal class RegisterCommandHandler(AuthContext context)
    : ICommandHandler<RegisterCommand, UserInfo>
{
    public async Task<UserInfo> Handle(RegisterCommand request, CancellationToken cancellationToken)
    {
        var now = DateTimeOffset.UtcNow;

        var code = await context
            .SignupCodes.Where(c => c.Code == request.SignupCode)
            .Where(c => c.ExpiresAt == null || c.ExpiresAt > now)
            .Where(c => c.RedeemingUserId == null)
            .SingleOrDefaultAsync(cancellationToken);

        if (code is null)
            throw new DomainError("invalid signup code");

        var usernameTaken = await context.Users.AnyAsync(
            u => u.Username == request.Username,
            cancellationToken
        );

        if (usernameTaken)
            throw new DomainError("username taken");
        
        var user = new UserIdentity(request.Username);

        await context.AddAsync(user, cancellationToken);

        user.SetPassword(request.Password);

        code.Redeem(user.Id);

        return new UserInfo(user);
    }
}