/*
 * gc - A simple mark and sweep garbage collector for C.
 */

#ifndef __GC_H__
#define __GC_H__

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>

#define LOGLEVEL LOGLEVEL_DEBUG

enum {
	LOGLEVEL_CRITICAL,
	LOGLEVEL_WARNING,
	LOGLEVEL_INFO,
	LOGLEVEL_DEBUG,
	LOGLEVEL_NONE
};

extern const char *log_level_strings[];

#define log(level, fmt, ...)                                                   \
	do {                                                                   \
		if (level <= LOGLEVEL)                                         \
			fprintf(stderr, "[%s] %s:%s:%d: " fmt "\n",            \
				log_level_strings[level], __func__, __FILE__,  \
				__LINE__, __VA_ARGS__);                        \
	} while (0)

#define LOG_CRITICAL(fmt, ...) log(LOGLEVEL_CRITICAL, fmt, __VA_ARGS__)
#define LOG_WARNING(fmt, ...) log(LOGLEVEL_WARNING, fmt, __VA_ARGS__)
#define LOG_INFO(fmt, ...) log(LOGLEVEL_INFO, fmt, __VA_ARGS__)
#define LOG_DEBUG(fmt, ...) log(LOGLEVEL_DEBUG, fmt, __VA_ARGS__)

struct AllocationMap;

typedef struct GarbageCollector {
	struct AllocationMap *allocs; // allocation map
	bool paused; // (temporarily) switch gc on/off
	void *bos; // bottom of stack
	size_t min_size;
} GarbageCollector;

extern GarbageCollector gc; // Global garbage collector for all
	// single-threaded applications

/*
 * Starting, stopping, pausing, resuming and running the GC.
 */
void gc_start(GarbageCollector *gc, void *bos);
void gc_start_ext(GarbageCollector *gc, void *bos, size_t initial_size,
		  size_t min_size, double downsize_load_factor,
		  double upsize_load_factor, double sweep_factor);
size_t gc_stop(GarbageCollector *gc);
void gc_pause(GarbageCollector *gc);
void gc_resume(GarbageCollector *gc);
size_t gc_run(GarbageCollector *gc);

/*
 * Allocating and deallocating memory.
 */
void *gc_malloc(GarbageCollector *gc, size_t size);
void *gc_malloc_static(GarbageCollector *gc, size_t size, void (*dtor)(void *));
void *gc_malloc_ext(GarbageCollector *gc, size_t size, void (*dtor)(void *));
void *gc_calloc(GarbageCollector *gc, size_t count, size_t size);
void *gc_calloc_ext(GarbageCollector *gc, size_t count, size_t size,
		    void (*dtor)(void *));
void *gc_realloc(GarbageCollector *gc, void *ptr, size_t size);
void gc_free(GarbageCollector *gc, void *ptr);

/*
 * Lifecycle management
 */
void *gc_make_static(GarbageCollector *gc, void *ptr);

/*
 * Helper functions and stdlib replacements.
 */
char *gc_strdup(GarbageCollector *gc, const char *s);

#endif /* !__GC_H__ */