using ROLAC.API.DTOs.Invitations;
using ROLAC.API.Entities;

namespace ROLAC.API.Services;

public interface IInvitationService
{
    /// <summary>
    /// Generates a single-use, 7-day invitation link for a member. Auto-creates the member's
    /// login account (no password) when none exists, and revokes any prior unused invitation for
    /// that account. Returns the raw token (shown once) and its expiry.
    /// Throws <see cref="InvalidOperationException"/> when the member is missing or has no email.
    /// </summary>
    Task<CreateInvitationResult> CreateAsync(CreateInvitationRequest request);

    /// <summary>Checks whether a raw token is still usable, without mutating it.</summary>
    Task<ValidateInvitationResult> ValidateAsync(string rawToken);

    /// <summary>
    /// Consumes an invitation: validates the token, sets the account password (enforcing the
    /// Identity policy), and marks the invitation used. Returns the account on success, or an
    /// error message describing why it failed (invalid/expired/used token or a policy violation).
    /// </summary>
    Task<(AppUser? User, string? Error)> AcceptAsync(string rawToken, string newPassword);

    /// <summary>E-mails an already-generated invitation link to the member via IEmailService.</summary>
    Task SendEmailAsync(int memberId, string link);
}