#ifndef RT_CONFIG_H
#define RT_CONFIG_H

#include "file_tab.h"
#include "runtime.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef enum {
    RT_CVAR_TYPE_INT,
    RT_CVAR_TYPE_FLOAT,
    RT_CVAR_TYPE_STRING,
    RT_CVAR_TYPE_SIZE,
} rt_cvar_type;

typedef struct {
    const char *name;
    const char *description;
    union {
        int i;
        float f;
        const char *s;
        size_t sz;
    };
    rt_cvar_type type;
} rt_cvar;

typedef void(rt_cvar_change_event_handler_fn)(rt_cvar *cvar, void *userdata);

/* n variable name, d description string, v default value*/
#define RT_CVAR_I(n, d, v)                                                                         \
    rt_cvar n = {.name = #n, .description = d, .i = (v), .type = RT_CVAR_TYPE_INT}
#define RT_CVAR_F(n, d, v)                                                                         \
    rt_cvar n = {.name = #n, .description = d, .f = (v), .type = RT_CVAR_TYPE_FLOAT}
#define RT_CVAR_S(n, d, v)                                                                         \
    rt_cvar n = {.name = #n, .description = d, .s = (v), .type = RT_CVAR_TYPE_STRING}
#define RT_CVAR_SZ(n, d, v)                                                                        \
    rt_cvar n = {.name = #n, .description = d, .sz = (v), .type = RT_CVAR_TYPE_SIZE}

RT_DLLEXPORT void rtRegisterCVAR(rt_cvar *cvar);

RT_DLLEXPORT rt_cvar *rtGetCVAR(const char *name);

/* Change event handlers are called when rtNotifyCVARChange is called. 
 * The system gives no guarantees about the order in which these are called.
 *
 * NOTE: A internal mutex is held while the event handlers run, which means that */
RT_DLLEXPORT void rtRegisterCVARChangeEventHandler(rt_cvar *cvar,
                                                   rt_cvar_change_event_handler_fn *event_handler,
                                                   void *userdata);

RT_DLLEXPORT void rtNotifyCVARChange(const rt_cvar *cvar);

/* Load and parse configuration files.
 * They are processed in-order, meaning later files can overwrite earlier files. */
RT_DLLEXPORT rt_result rtProcessConfigFiles(unsigned int count, const rt_file_id *fids);

RT_DLLEXPORT rt_result rtSetCVARFromString(rt_cvar *cvar, const char *value_str);

#ifdef __cplusplus
}
#endif

#endif