#ifndef CKIWI_H_
#define CKIWI_H_

#include <stddef.h>

#ifdef __cplusplus
extern "C" {
#endif

#define KIWI_REF_ISNULL(ref) ((ref).impl_ == NULL)

// LuaJIT start
enum KiwiErrKind {
   KiwiErrNone,
   KiwiErrUnsatisfiableConstraint = 1,
   KiwiErrUnknownConstraint,
   KiwiErrDuplicateConstraint,
   KiwiErrUnknownEditVariable,
   KiwiErrDuplicateEditVariable,
   KiwiErrBadRequiredStrength,
   KiwiErrInternalSolverError,
   KiwiErrAlloc,
   KiwiErrNullObject,
   KiwiErrUnknown,
};

enum KiwiRelOp { KIWI_OP_LE, KIWI_OP_GE, KIWI_OP_EQ };

struct KiwiVarRefType;
struct KiwiConstraintRefType;

typedef struct KiwiVarRefType* KiwiVarRef;
typedef struct KiwiConstraintRefType* KiwiConstraintRef;

struct KiwiTerm {
   KiwiVarRef var;
   double coefficient;
};

typedef struct KiwiExpression {
   double constant;
   int term_count;
   struct KiwiTerm terms[1];  // LuaJIT: struct KiwiTerm terms_[?];
}* KiwiExpressionPtr;

typedef const struct KiwiExpression* KiwiExpressionConstPtr;

typedef struct KiwiErr {
   enum KiwiErrKind kind;
   const char* message;
   bool must_free;
} const* KiwiErrPtr;

struct KiwiSolver;
typedef struct KiwiSolver* KiwiSolverPtr;

KiwiVarRef kiwi_var_new(const char* name);
void kiwi_var_del(KiwiVarRef var);

const char* kiwi_var_name(KiwiVarRef var);

void kiwi_var_set_name(KiwiVarRef var, const char* name);

double kiwi_var_value(KiwiVarRef var);

void kiwi_var_set_value(KiwiVarRef var, double value);

int kiwi_var_eq(KiwiVarRef var, KiwiVarRef other);

KiwiConstraintRef
kiwi_constraint_new(KiwiExpressionConstPtr expression, enum KiwiRelOp op, double strength);
void kiwi_constraint_del(KiwiConstraintRef constraint);

double kiwi_constraint_strength(KiwiConstraintRef constraint);

enum KiwiRelOp kiwi_constraint_op(KiwiConstraintRef constraint);

bool kiwi_constraint_violated(KiwiConstraintRef constraint);
int kiwi_constraint_expression(KiwiConstraintRef constraint, KiwiExpressionPtr out, int out_size);

KiwiErrPtr kiwi_solver_add_constraint(KiwiSolverPtr sp, KiwiConstraintRef constraint);
KiwiErrPtr kiwi_solver_remove_constraint(KiwiSolverPtr sp, KiwiConstraintRef constraint);
bool kiwi_solver_has_constraint(KiwiSolverPtr sp, KiwiConstraintRef constraint);
KiwiErrPtr kiwi_solver_add_edit_var(KiwiSolverPtr sp, KiwiVarRef var, double strength);
KiwiErrPtr kiwi_solver_remove_edit_var(KiwiSolverPtr sp, KiwiVarRef var);
bool kiwi_solver_has_edit_var(KiwiSolverPtr sp, KiwiVarRef var);
KiwiErrPtr kiwi_solver_suggest_value(KiwiSolverPtr sp, KiwiVarRef var, double value);
void kiwi_solver_update_vars(KiwiSolverPtr sp);
void kiwi_solver_reset(KiwiSolverPtr sp);
void kiwi_solver_dump(KiwiSolverPtr sp);
char* kiwi_solver_dumps(KiwiSolverPtr sp);

KiwiSolverPtr kiwi_solver_new();
void kiwi_solver_del(KiwiSolverPtr sp);
// LuaJIT end

#ifdef __cplusplus
}
#endif

// Local Variables:
// mode: c++
// End:
#endif  // CKIWI_H_