using System;
using CeresSharp.Enums;
using CeresSharp.Native;
using CeresSharp.Native.SafeHandles;

namespace CeresSharp.Advanced;

/// <summary>
/// Options for covariance estimation.
/// </summary>
public sealed class CovarianceOptions : IDisposable
{
    private readonly CovarianceOptionsHandle _handle;
    private bool _disposed;

    /// <summary>
    /// Creates a new CovarianceOptions instance with default settings.
    /// </summary>
    public CovarianceOptions()
    {
        _handle = CovarianceOptionsHandle.Create();
    }

    /// <summary>
    /// Gets the native handle.
    /// </summary>
    internal CovarianceOptionsHandle Handle => _handle;

    /// <summary>
    /// Gets or sets the number of threads to use.
    /// </summary>
    public int NumThreads
    {
        get => CeresNative.ceres_wrapper_covariance_options_get_num_threads(_handle.DangerousGetHandle());
        set => CeresNative.ceres_wrapper_covariance_options_set_num_threads(_handle.DangerousGetHandle(), value);
    }

    /// <summary>
    /// Gets or sets the sparse linear algebra library type.
    /// </summary>
    public SparseLinearAlgebraLibraryType SparseLinearAlgebraLibraryType
    {
        get => (SparseLinearAlgebraLibraryType)CeresNative.ceres_wrapper_covariance_options_get_sparse_linear_algebra_library_type(_handle.DangerousGetHandle());
        set => CeresNative.ceres_wrapper_covariance_options_set_sparse_linear_algebra_library_type(_handle.DangerousGetHandle(), (int)value);
    }

    /// <summary>
    /// Gets or sets the algorithm type.
    /// </summary>
    public CovarianceAlgorithmType AlgorithmType
    {
        get => (CovarianceAlgorithmType)CeresNative.ceres_wrapper_covariance_options_get_algorithm_type(_handle.DangerousGetHandle());
        set => CeresNative.ceres_wrapper_covariance_options_set_algorithm_type(_handle.DangerousGetHandle(), (int)value);
    }

    /// <summary>
    /// Gets or sets the minimum reciprocal condition number.
    /// </summary>
    public double MinReciprocalConditionNumber
    {
        get => CeresNative.ceres_wrapper_covariance_options_get_min_reciprocal_condition_number(_handle.DangerousGetHandle());
        set => CeresNative.ceres_wrapper_covariance_options_set_min_reciprocal_condition_number(_handle.DangerousGetHandle(), value);
    }

    /// <summary>
    /// Gets or sets the null space rank.
    /// </summary>
    public int NullSpaceRank
    {
        get => CeresNative.ceres_wrapper_covariance_options_get_null_space_rank(_handle.DangerousGetHandle());
        set => CeresNative.ceres_wrapper_covariance_options_set_null_space_rank(_handle.DangerousGetHandle(), value);
    }

    /// <summary>
    /// Gets or sets whether to apply loss function.
    /// </summary>
    public bool ApplyLossFunction
    {
        get => CeresNative.ceres_wrapper_covariance_options_get_apply_loss_function(_handle.DangerousGetHandle()) != 0;
        set => CeresNative.ceres_wrapper_covariance_options_set_apply_loss_function(_handle.DangerousGetHandle(), value ? 1 : 0);
    }

    public void Dispose()
    {
        if (!_disposed)
        {
            _handle?.Dispose();
            _disposed = true;
        }
    }
}