using Dapper;
using Npgsql;

namespace KArtSell.Modules.IdentityAccess.ManageIdentityAndRoles.Features.RequestMfaSetup;

public interface IRequestMfaSetupSql
{
    Task<(Guid Id, string State, int Revision)> GetIdentityAsync(Guid identityId, CancellationToken ct);
    Task UpdateIdentityStateAsync(Guid identityId, string newState, int expectedRevision, CancellationToken ct);
}

public sealed class RequestMfaSetupSql : IRequestMfaSetupSql
{
    private readonly Func<Task<NpgsqlConnection>> _connectionFactory;

    public RequestMfaSetupSql(Func<Task<NpgsqlConnection>> connectionFactory)
    {
        _connectionFactory = connectionFactory;
    }

    public async Task<(Guid Id, string State, int Revision)> GetIdentityAsync(Guid identityId, CancellationToken ct)
    {
        using var conn = await _connectionFactory();
        const string sql = """
            SELECT id, state, revision_version
            FROM identity.identity
            WHERE id = @identityId
            """;

        var row = await conn.QuerySingleOrDefaultAsync<dynamic>(sql, new { identityId }, commandTimeout: 5);
        if (row is null)
            throw new InvalidOperationException($"Identity {identityId} not found");

        return ((Guid)row.id, (string)row.state, (int)row.revision_version);
    }

    public async Task UpdateIdentityStateAsync(Guid identityId, string newState, int expectedRevision, CancellationToken ct)
    {
        using var conn = await _connectionFactory();
        const string sql = """
            UPDATE identity.identity
            SET state = @newState,
                revision_version = revision_version + 1,
                updated_at = NOW(),
                published_at = NOW()
            WHERE id = @identityId AND revision_version = @expectedRevision
            """;

        var rowsAffected = await conn.ExecuteAsync(sql, new
        {
            identityId,
            newState,
            expectedRevision
        }, commandTimeout: 5);

        if (rowsAffected == 0)
            throw new InvalidOperationException("Optimistic concurrency violation: state changed");
    }
}