using System;
using System.Runtime.InteropServices;
using System.Text;
using CeresSharp.Exceptions;

namespace CeresSharp.Native;

/// <summary>
/// P/Invoke declarations for Ceres Wrapper C API.
/// This file contains all native function declarations for the Ceres Solver wrapper.
/// </summary>
internal static partial class CeresNative
{
    private const string LibraryName = "libceres_wrapper.so";

    // ============================================================================
    // Error Handling
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_get_error_message(CeresErrorCode errorCode);

    // ============================================================================
    // Library Information and Version
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_get_version_string();

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_get_version_major();

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_get_version_minor();

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_get_version_revision();

    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern CeresErrorCode ceres_wrapper_get_detailed_version_string(
        StringBuilder buffer,
        int bufferSize);

    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern CeresErrorCode ceres_wrapper_get_library_info(
        StringBuilder buffer,
        int bufferSize);

    // ============================================================================
    // Official C API (for Problem creation/destruction)
    // Note: These may need to be imported from libceres.so instead
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_create_problem();

    [LibraryImport(LibraryName)]
    internal static partial void ceres_free_problem(IntPtr problem);

    // ============================================================================
    // Solver Options
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_solver_options();

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_solver_options(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_linear_solver_type(
        IntPtr options, int linearSolverType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_linear_solver_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_minimizer_type(
        IntPtr options, int minimizerType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_minimizer_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_num_iterations(
        IntPtr options, int maxNumIterations);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_max_num_iterations(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_num_threads(
        IntPtr options, int numThreads);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_num_threads(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_function_tolerance(
        IntPtr options, double functionTolerance);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_function_tolerance(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_gradient_tolerance(
        IntPtr options, double gradientTolerance);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_gradient_tolerance(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_parameter_tolerance(
        IntPtr options, double parameterTolerance);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_parameter_tolerance(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_initial_trust_region_radius(
        IntPtr options, double radius);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_initial_trust_region_radius(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_trust_region_radius(
        IntPtr options, double radius);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_max_trust_region_radius(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_min_trust_region_radius(
        IntPtr options, double radius);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_min_trust_region_radius(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_preconditioner_type(
        IntPtr options, int preconditionerType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_preconditioner_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_trust_region_strategy_type(
        IntPtr options, int trustRegionStrategyType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_trust_region_strategy_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_dogleg_type(
        IntPtr options, int doglegType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_dogleg_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_use_nonmonotonic_steps(
        IntPtr options, int useNonmonotonicSteps);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_use_nonmonotonic_steps(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_consecutive_nonmonotonic_steps(
        IntPtr options, int maxSteps);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_max_consecutive_nonmonotonic_steps(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_num_consecutive_invalid_steps(
        IntPtr options, int maxSteps);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_max_num_consecutive_invalid_steps(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_min_relative_decrease(
        IntPtr options, double minRelativeDecrease);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_min_relative_decrease(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_logging_type(
        IntPtr options, int loggingType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_logging_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_minimizer_progress_to_stdout(
        IntPtr options, int minimizerProgressToStdout);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_minimizer_progress_to_stdout(IntPtr options);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern int ceres_wrapper_solver_options_is_valid(
        IntPtr options, StringBuilder errorMessage, int errorMessageSize);

    // Line search options
    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_line_search_type(
        IntPtr options, int lineSearchType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_line_search_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_line_search_direction_type(
        IntPtr options, int lineSearchDirectionType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_line_search_direction_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_nonlinear_conjugate_gradient_type(
        IntPtr options, int ncgType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_nonlinear_conjugate_gradient_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_lbfgs_rank(
        IntPtr options, int maxLbfgsRank);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_max_lbfgs_rank(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_line_search_step_contraction(
        IntPtr options, double maxStepContraction);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_max_line_search_step_contraction(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_min_line_search_step_contraction(
        IntPtr options, double minStepContraction);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_min_line_search_step_contraction(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_num_line_search_step_size_iterations(
        IntPtr options, int maxIterations);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_max_num_line_search_step_size_iterations(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_num_line_search_direction_restarts(
        IntPtr options, int maxRestarts);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_max_num_line_search_direction_restarts(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_line_search_sufficient_function_decrease(
        IntPtr options, double sufficientDecrease);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_line_search_sufficient_function_decrease(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_line_search_sufficient_curvature_decrease(
        IntPtr options, double sufficientCurvatureDecrease);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_line_search_sufficient_curvature_decrease(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_line_search_step_expansion(
        IntPtr options, double maxStepExpansion);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_max_line_search_step_expansion(IntPtr options);

    // Trust region parameters
    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_lm_diagonal(
        IntPtr options, double maxLmDiagonal);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_max_lm_diagonal(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_min_lm_diagonal(
        IntPtr options, double minLmDiagonal);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_min_lm_diagonal(IntPtr options);

    // Linear solver options
    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_sparse_linear_algebra_library_type(
        IntPtr options, int sparseLibraryType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_sparse_linear_algebra_library_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_dense_linear_algebra_library_type(
        IntPtr options, int denseLibraryType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_dense_linear_algebra_library_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_linear_solver_iterations(
        IntPtr options, int maxIterations);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_max_linear_solver_iterations(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_min_linear_solver_iterations(
        IntPtr options, int minIterations);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_min_linear_solver_iterations(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_linear_solver_tolerance(
        IntPtr options, double tolerance);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_linear_solver_tolerance(IntPtr options);

    // Inner iterations
    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_use_inner_iterations(
        IntPtr options, int useInnerIterations);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_use_inner_iterations(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_inner_iteration_tolerance(
        IntPtr options, double tolerance);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_inner_iteration_tolerance(IntPtr options);

    // Timing
    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_max_solver_time_in_seconds(
        IntPtr options, double maxTime);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_options_get_max_solver_time_in_seconds(IntPtr options);

    // Checkpointing
    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_update_state_every_iteration(
        IntPtr options, int updateEveryIteration);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_options_get_update_state_every_iteration(IntPtr options);

    // ============================================================================
    // Solver Summary
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_solver_summary();

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_solver_summary(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_termination_type(IntPtr summary);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern void ceres_wrapper_solver_summary_get_message(
        IntPtr summary, StringBuilder message, int messageSize);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_summary_get_initial_cost(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_summary_get_final_cost(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_iterations(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_num_successful_steps(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_num_unsuccessful_steps(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_num_inner_iteration_steps(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_summary_get_total_time_in_seconds(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_summary_get_preprocessor_time_in_seconds(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_summary_get_minimizer_time_in_seconds(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_summary_get_postprocessor_time_in_seconds(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_summary_get_linear_solver_time_in_seconds(IntPtr summary);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern void ceres_wrapper_solver_summary_get_full_report(
        IntPtr summary, StringBuilder report, int reportSize);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_num_parameter_blocks(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_num_parameters(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_num_effective_parameters(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_num_residual_blocks(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_solver_summary_get_num_residuals(IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_solver_summary_get_cost_change(IntPtr summary);

    // ============================================================================
    // Solve
    // ============================================================================

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern CeresErrorCode ceres_wrapper_solve(
        IntPtr problem,
        IntPtr options,
        IntPtr summary,
        StringBuilder errorMessage,
        int errorMessageSize);

    // ============================================================================
    // Problem Operations
    // ============================================================================

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern CeresErrorCode ceres_wrapper_problem_add_parameter_block(
        IntPtr problem,
        IntPtr parameters,
        int size,
        StringBuilder errorMessage,
        int errorMessageSize);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_set_parameter_block_constant(
        IntPtr problem,
        IntPtr parameters);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_set_parameter_block_variable(
        IntPtr problem,
        IntPtr parameters);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    internal static extern CeresErrorCode ceres_wrapper_problem_remove_parameter_block(
        IntPtr problem,
        IntPtr parameters,
        StringBuilder errorMessage,
        int errorMessageSize);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    internal static extern CeresErrorCode ceres_wrapper_problem_remove_residual_block(
        IntPtr problem,
        IntPtr residualBlockId,
        StringBuilder errorMessage,
        int errorMessageSize);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    internal static extern CeresErrorCode ceres_wrapper_problem_add_residual_block(
        IntPtr problem,
        IntPtr costFunction,
        IntPtr lossFunction,
        IntPtr parameterBlocks,
        int numParameterBlocks,
        out IntPtr residualBlockId,
        StringBuilder errorMessage,
        int errorMessageSize);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_num_parameter_blocks(IntPtr problem);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_num_residual_blocks(IntPtr problem);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_num_parameters(IntPtr problem);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_num_residuals(IntPtr problem);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_has_parameter_block(
        IntPtr problem,
        IntPtr parameters);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_is_parameter_block_constant(
        IntPtr problem,
        IntPtr parameters);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_get_parameter_block_size(
        IntPtr problem,
        IntPtr parameters);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_get_parameter_block_tangent_size(
        IntPtr problem,
        IntPtr parameters);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_has_manifold(
        IntPtr problem,
        IntPtr parameters);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_problem_get_manifold(
        IntPtr problem,
        IntPtr parameters);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_set_manifold(
        IntPtr problem,
        IntPtr parameters,
        IntPtr manifold);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_set_parameter_lower_bound(
        IntPtr problem,
        IntPtr parameters,
        int index,
        double lowerBound);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_set_parameter_upper_bound(
        IntPtr problem,
        IntPtr parameters,
        int index,
        double upperBound);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_problem_get_parameter_lower_bound(
        IntPtr problem,
        IntPtr parameters,
        int index);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_problem_get_parameter_upper_bound(
        IntPtr problem,
        IntPtr parameters,
        int index);

    // ============================================================================
    // Loss Functions
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_huber_loss(double a);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_trivial_loss();

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_cauchy_loss(double a);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_softl1_loss(double a);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_arctan_loss(double a);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_tolerant_loss(double a, double b);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_loss_function(IntPtr loss);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_composed_loss(
        IntPtr f, int ownershipF, IntPtr g, int ownershipG);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_scaled_loss(
        IntPtr rho, double a, int ownership);

    // ============================================================================
    // Manifolds
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_quaternion_manifold();

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_sphere_manifold(int dimension);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_line_manifold(int dimension);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_euclidean_manifold(int dimension);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_subset_manifold(
        IntPtr constantSubset,
        int constantSubsetSize,
        int ambientSize);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_product_manifold(
        IntPtr manifolds,
        int numManifolds);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_manifold(IntPtr manifold);

    // AutoDiff Manifold callbacks
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    internal delegate int CeresAutoDiffManifoldPlus(
        IntPtr userData,
        IntPtr x,
        IntPtr delta,
        IntPtr xPlusDelta);

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    internal delegate int CeresAutoDiffManifoldMinus(
        IntPtr userData,
        IntPtr y,
        IntPtr x,
        IntPtr yMinusX);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_autodiff_manifold(
        int ambientSize,
        int tangentSize,
        CeresAutoDiffManifoldPlus plus,
        CeresAutoDiffManifoldMinus minus,
        IntPtr userData);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_autodiff_manifold(IntPtr manifold);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_manifold_ambient_size(IntPtr manifold);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_manifold_tangent_size(IntPtr manifold);

    // ============================================================================
    // Interpolators
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_bicubic_interpolator(
        IntPtr data,
        int rows,
        int cols);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_bicubic_interpolator(IntPtr interpolator);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_bicubic_interpolator_evaluate(
        IntPtr interpolator,
        double x,
        double y,
        IntPtr value,
        IntPtr gradientX,
        IntPtr gradientY);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_cubic_interpolator(
        IntPtr data,
        int numValues);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_cubic_interpolator(IntPtr interpolator);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_cubic_interpolator_evaluate(
        IntPtr interpolator,
        double x,
        IntPtr value,
        IntPtr gradient);

    // ============================================================================
    // Cost Functions
    // ============================================================================

    // Callback delegate for AutoDiff cost function
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    internal delegate int CeresAutoDiffCostFunctionCallback(
        IntPtr userData,
        IntPtr parameters,
        IntPtr residuals);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_autodiff_cost_function(
        CeresAutoDiffCostFunctionCallback callback,
        IntPtr userData,
        int numResiduals,
        int numParameterBlocks,
        IntPtr parameterBlockSizes);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_dynamic_autodiff_cost_function(
        CeresAutoDiffCostFunctionCallback callback,
        IntPtr userData,
        int numResiduals,
        int numParameterBlocks,
        IntPtr parameterBlockSizes);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_autodiff_cost_function(IntPtr costFunction);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_dynamic_autodiff_cost_function(IntPtr costFunction);

    // Callback delegate for NumericDiff cost function
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    internal delegate int CeresNumericDiffCostFunctionCallback(
        IntPtr parameters,
        IntPtr residuals,
        IntPtr userData);

    // Note: NumericDiff uses a struct, we'll need to marshal it manually
    [StructLayout(LayoutKind.Sequential)]
    internal struct CeresNumericDiffOptions
    {
        public int numResiduals;
        public int numParameterBlocks;
        public IntPtr parameterBlockSizes;
        public CeresNumericDiffCostFunctionCallback callback;
        public IntPtr userData;
    }

    // Note: Using DllImport instead of LibraryImport because CeresNumericDiffOptions contains a delegate
    // which is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern IntPtr ceres_wrapper_create_numeric_diff_cost_function(
        ref CeresNumericDiffOptions options,
        int method);

    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern IntPtr ceres_wrapper_create_dynamic_numeric_diff_cost_function(
        ref CeresNumericDiffOptions options,
        int method);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_numeric_diff_cost_function(IntPtr costFunction);

    // ============================================================================
    // Problem Options
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_problem_options();

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_problem_options(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_options_set_cost_function_ownership(
        IntPtr options, int ownership);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_options_get_cost_function_ownership(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_options_set_loss_function_ownership(
        IntPtr options, int ownership);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_options_get_loss_function_ownership(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_options_set_manifold_ownership(
        IntPtr options, int ownership);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_options_get_manifold_ownership(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_options_set_enable_fast_removal(
        IntPtr options, int enable);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_options_get_enable_fast_removal(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_options_set_disable_all_safety_checks(
        IntPtr options, int disable);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_problem_options_get_disable_all_safety_checks(IntPtr options);

    // Evaluation callback delegate
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    internal delegate void CeresEvaluationCallback(
        IntPtr userData,
        int numResiduals,
        int numParameterBlocks,
        IntPtr parameterBlockSizes);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_options_set_evaluation_callback(
        IntPtr options,
        CeresEvaluationCallback callback,
        IntPtr userData);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_problem_with_options(IntPtr options);

    // ============================================================================
    // Iteration Callback
    // ============================================================================

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    internal delegate int CeresIterationCallback(
        IntPtr userData,
        IntPtr summary);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_solver_options_set_iteration_callback(
        IntPtr options,
        CeresIterationCallback callback,
        IntPtr userData);

    // ============================================================================
    // Covariance
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_covariance_options();

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_covariance_options(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_covariance_options_set_num_threads(
        IntPtr options, int numThreads);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_covariance_options_get_num_threads(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_covariance_options_set_sparse_linear_algebra_library_type(
        IntPtr options, int libraryType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_covariance_options_get_sparse_linear_algebra_library_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_covariance_options_set_algorithm_type(
        IntPtr options, int algorithmType);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_covariance_options_get_algorithm_type(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_covariance_options_set_min_reciprocal_condition_number(
        IntPtr options, double minReciprocalConditionNumber);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_covariance_options_get_min_reciprocal_condition_number(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_covariance_options_set_null_space_rank(
        IntPtr options, int nullSpaceRank);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_covariance_options_get_null_space_rank(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_covariance_options_set_apply_loss_function(
        IntPtr options, int applyLossFunction);

    [LibraryImport(LibraryName)]
    internal static partial int ceres_wrapper_covariance_options_get_apply_loss_function(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_covariance();

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_covariance_with_options(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_covariance(IntPtr covariance);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern CeresErrorCode ceres_wrapper_covariance_compute(
        IntPtr covariance,
        IntPtr problem,
        IntPtr options,
        IntPtr parameterBlocks,
        int numParameterBlocks,
        StringBuilder errorMessage,
        int errorMessageSize);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern CeresErrorCode ceres_wrapper_covariance_get_covariance_block(
        IntPtr covariance,
        IntPtr parameterBlock1,
        IntPtr parameterBlock2,
        IntPtr covarianceBlock,
        StringBuilder errorMessage,
        int errorMessageSize);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern CeresErrorCode ceres_wrapper_covariance_get_covariance_matrix(
        IntPtr covariance,
        IntPtr parameterBlocks,
        int numParameterBlocks,
        IntPtr covarianceMatrix,
        StringBuilder errorMessage,
        int errorMessageSize);

    // ============================================================================
    // Gradient Checker
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_gradient_checker_options();

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_gradient_checker_options(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_gradient_checker_options_set_gradient_check_relative_precision(
        IntPtr options, double precision);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_gradient_checker_options_get_gradient_check_relative_precision(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_gradient_checker_options_set_gradient_check_numeric_derivative_relative_step_size(
        IntPtr options, double stepSize);

    [LibraryImport(LibraryName)]
    internal static partial double ceres_wrapper_gradient_checker_options_get_gradient_check_numeric_derivative_relative_step_size(IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_gradient_checker(
        IntPtr costFunction,
        IntPtr manifolds,
        int numManifolds,
        IntPtr options);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_gradient_checker(IntPtr checker);

    // Note: Using DllImport instead of LibraryImport because StringBuilder is not supported by source-generated P/Invokes
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    internal static extern CeresErrorCode ceres_wrapper_gradient_checker_probe(
        IntPtr checker,
        IntPtr parameters,
        double relativePrecision,
        StringBuilder errorMessage,
        int errorMessageSize);

    // ============================================================================
    // Context
    // ============================================================================

    [LibraryImport(LibraryName)]
    internal static partial IntPtr ceres_wrapper_create_context();

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_free_context(IntPtr context);

    [LibraryImport(LibraryName)]
    internal static partial void ceres_wrapper_problem_options_set_context(
        IntPtr options,
        IntPtr context);

    // ============================================================================
    // Helper Methods
    // ============================================================================

    /// <summary>
    /// Checks error code and throws exception if not successful.
    /// </summary>
    internal static void CheckError(CeresErrorCode errorCode)
    {
        if (errorCode != CeresErrorCode.Success)
        {
            var errorMessagePtr = ceres_wrapper_get_error_message(errorCode);
            var errorMessage = errorMessagePtr != IntPtr.Zero
                ? Marshal.PtrToStringAnsi(errorMessagePtr)
                : $"Unknown error code: {errorCode}";
            throw new CeresException(errorCode, errorMessage);
        }
    }
}