#ifndef NATIVE_KERNELS_H
#define NATIVE_KERNELS_H
#include <stddef.h>
#include <stdint.h>
typedef struct { double p, T, rho, u, h; } NativeGas;
typedef struct {
    int velocity_index;
    double lower, upper;
    double lower_restitution, upper_restitution, lower_threshold, upper_threshold;
} NativeStop;
/* Discrete slip direction is stored with the sampled state, never in a global
 * RHS cache. Trial/Jacobian evaluations cannot change sticking/sliding mode. */
typedef struct {
    int velocity_index, mode_index;
    double velocity_threshold, breakaway_force;
} NativeFriction;
double native_dry_friction(double velocity, double static_share, double coulomb,
                           double stiction, double stribeck_velocity, int stribeck,
                           double mode);
/* Constants are emitted per medium instance by the model compiler. */
typedef struct { int real_helium; double R, cp, Tref, slope, mu, muT, S; } NativeMedium;
/* Caller-owned scratch for ONE model_eval. Keys use exact values and a copy of
 * every medium constant. No process/thread global cache or approximate reuse. */
enum {
    NATIVE_PROPERTY_PT=1, NATIVE_PROPERTY_H=2, NATIVE_PROPERTY_RHO=4,
    NATIVE_PROPERTY_MU=8, NATIVE_PROPERTY_ISENTROPIC=16
};
/* Optional observer for one evaluation, independent of cache capacity.
 * Slots: EOS, ideal caloric data, dynamic viscosity; each has min/max T. */
#define NATIVE_PROPERTY_DOMAINS 3
typedef struct NativeJacobianScalars NativeJacobianScalars;
typedef struct {
    unsigned seen;
    double minimum[NATIVE_PROPERTY_DOMAINS], maximum[NATIVE_PROPERTY_DOMAINS];
} NativePropertyTemperatures;
typedef struct {
    NativeMedium medium;
    double p, T, h, rho, mu, isentropic_factor, isentropic_exponent;
    unsigned valid;
    NativePropertyTemperatures *temperatures;
    NativeJacobianScalars *jacobian;
} NativePropertyState;
typedef struct {
    NativePropertyState *states;
    size_t count, capacity;
    NativePropertyTemperatures *temperatures;
    NativeJacobianScalars *jacobian;
} NativePropertyCache;
void native_properties_init(NativePropertyCache *, NativePropertyState *, size_t capacity);
int native_gas_context(NativePropertyCache *, double m, double U, double V, NativeGas *);
int native_medium_gas_context(NativePropertyCache *, const NativeMedium *, double m, double U, double V, NativeGas *);
int native_polytropic_gas_context(NativePropertyCache *, const NativeMedium *, double mass, double T, double V, NativeGas *);
/* Immutable baseline entries owned by ONE Jacobian construction. These
 * reviewed kernels are deterministic with a NULL property cache: no cache
 * seeds or temperature observations may be suppressed by a hit. */
typedef int (*NativeCanonicalGas)(NativePropertyCache *,const NativeMedium *,double,double,double,NativeGas *);
typedef struct {
    NativeCanonicalGas kernel;
    double inputs[10]; /* mass, thermal state, volume, and every medium double */
    NativeGas value;
    int medium_kind, valid;
} NativeJacobianGasMemo;
typedef struct { unsigned long evaluations, reuses; } NativeJacobianGasStats;
int native_jacobian_gas(NativeJacobianGasMemo *,NativeCanonicalGas,const NativeMedium *,
                        double mass,double thermal,double volume,NativeGas *,NativeJacobianGasStats *);
enum { NATIVE_JACOBIAN_PH, NATIVE_JACOBIAN_DENSITY, NATIVE_JACOBIAN_PIPE, NATIVE_JACOBIAN_SCALAR_KINDS };
#define NATIVE_JACOBIAN_SCALAR_KEYS 10
typedef struct {
    uint64_t hash;
    double inputs[NATIVE_JACOBIAN_SCALAR_KEYS], value;
    int kind, medium_kind;
    size_t input_count;
} NativeJacobianScalarEntry;
struct NativeJacobianScalars {
    NativeJacobianScalarEntry *entries;
    size_t capacity; /* power of two; zero disables the optional cache */
    int recording;
    unsigned long evaluations[NATIVE_JACOBIAN_SCALAR_KINDS], reuses[NATIVE_JACOBIAN_SCALAR_KINDS];
};
int native_jacobian_scalar_get(NativeJacobianScalars *,int kind,int medium_kind,
                               const double *inputs,size_t count,double *value);
void native_jacobian_scalar_put(NativeJacobianScalars *,int kind,int medium_kind,
                                const double *inputs,size_t count,double value);
double native_temperature_ph_context(NativePropertyCache *, const NativeMedium *, double p, double h);
double native_density_context(NativePropertyCache *, const NativeMedium *, double p, double T);
int native_orifice_context(NativePropertyCache *, double p1, double p2, double h1, double h2,
                           double area, double opening, double *q, double *cm, double *v);
int native_medium_orifice_context(NativePropertyCache *, const NativeMedium *, double p1, double p2, double h1, double h2,
                                  double area, double opening, double *q, double *cm, double *v);
/* One entry per pipe branch, zero-initialized for each model_eval. Never shared
 * across solver trials. Exact inputs, including medium constants, form the key. */
typedef struct {
    NativeMedium medium;
    double p1, p2, T, diameter, length, roughness, flow;
    int kind, valid;
} NativePipeCache;
typedef struct { int converged, iterations, bisections; double relative_residual; } NativePipeSolve;
/* Solve Re^2*f(Re)=K for the shared pipe resistance law. On failure returns
 * NAN, with converged=0; flow_per_re converts the local stopping test to kg/s. */
double native_pipe_resistance(double K, double roughness, double flow_per_re, NativePipeSolve *status);
double native_pipe_flow_context(NativePropertyCache *, const NativeMedium *, double p1, double p2, double T,
                                double diameter, double length, double roughness, int kind);
double native_pipe_flow_cached_context(NativePropertyCache *, NativePipeCache *, const NativeMedium *,
                                       double p1, double p2, double T, double diameter, double length, double roughness, int kind);
void native_pipe_diagnostics_context(NativePropertyCache *, const NativeMedium *, double q, double p, double T,
                                     double diameter, double length, double roughness, int diagnostic, double *result);
int native_medium_init(const NativeMedium *, double p, double T, double V, int legacy_ideal_initial, double *mU);
double native_density(const NativeMedium *, double p, double T);
double native_temperature_ph(const NativeMedium *, double p, double h);
double native_viscosity(const NativeMedium *, double T, int diagnostic);
int native_medium_gas(const NativeMedium *, double m, double U, double V, NativeGas *);
int native_medium_orifice(const NativeMedium *, double p1, double p2, double h1, double h2,
                          double cq_area, double opening, double *q, double *cm, double *v);
double native_pipe_flow(const NativeMedium *, double p1, double p2, double T,
                        double diameter, double length, double roughness, int kind);
double native_pipe_flow_cached(NativePipeCache *, const NativeMedium *,
                               double p1, double p2, double T, double diameter,
                               double length, double roughness, int kind);
void native_pipe_diagnostics(const NativeMedium *, double q, double p, double T,
                             double diameter, double length, double roughness,
                             int diagnostic, double *result);
double native_limit_force(double penetration, double velocity, double stiffness,
                          double damping, double depth, int signed_force);
int native_gas_init(double p, double T, double volume, double *mU);
int native_gas(double m, double U, double volume, NativeGas *gas);
int native_orifice(double p1, double p2, double h1, double h2,
                   double cq_area, double opening, double *flow,
                   double *cm, double *velocity);
double native_contact(double penetration, double velocity, double stiffness,
                      double damping, double pdis, int signed_force);
void native_stop_motion(double x, double v, double lower, double upper,
                        double *acceleration, double *velocity);
double native_signal(double t, double start, int stages, int cyclic, const double *data);
double native_signal_break(double t, double end, double start, int stages,
                           int cyclic, const double *data);
#endif