using AutoMapper;
using MediatR;
using Mws.Application.Auth;
using Mws.Application.Common;
using Mws.Application.Permissions;
using Mws.Domain.Users;

namespace Mws.Application.Accounts;

public record CreateAccountCommand(Guid ActorUserId, CreateAccountRequest Request) : IRequest<AccountDto>;

public class CreateAccountHandler(IUnitOfWork uow, IPasswordHasher passwordHasher, IPermissionService permissions, IMapper mapper)
    : IRequestHandler<CreateAccountCommand, AccountDto>
{
    private const string Screen = "accounts";

    public async Task<AccountDto> Handle(CreateAccountCommand command, CancellationToken ct)
    {
        await permissions.EnsureAsync(command.ActorUserId, Screen, PermissionAction.Create, ct);

        var request = command.Request;
        var username = request.Username.Trim();
        if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(request.Password))
        {
            throw new BadRequestException("Username and password are required");
        }

        if (await uow.Users.ExistsByUsernameAsync(username, ct))
        {
            throw new BadRequestException("Username already exists");
        }

        var role = await uow.Roles.GetByIdAsync(request.RoleId, ct)
            ?? throw new BadRequestException("Role not found");

        var now = DateTime.UtcNow;
        var user = new User
        {
            Id = Guid.NewGuid(),
            Username = username,
            PasswordHash = passwordHasher.Hash(request.Password),
            DisplayName = request.DisplayName.Trim(),
            RoleId = role.Id,
            IsActive = true,
            CreatedAt = now,
            UpdatedAt = now,
        };

        uow.Users.Add(user);
        await uow.SaveChangesAsync(ct);
        user.Role = role;
        return mapper.Map<AccountDto>(user);
    }
}