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// C-ABI surface of the Nim library. Hand-maintained; ffigen parses this.
#ifndef NIMFLUTTER_H
#define NIMFLUTTER_H

#include <stddef.h>

#ifdef __cplusplus
extern "C" {
#endif

#if defined(_WIN32)
  #define NF_API __declspec(dllexport)
#else
  #define NF_API __attribute__((visibility("default")))
#endif

// Runs NimMain. Idempotent. Shared builds run it from a library constructor,
// but static archives (iOS) have no such hook, so call this first.
NF_API void nf_init(void);

NF_API int nf_add(int a, int b);

// Returns a NUL-terminated string allocated by Nim on the SHARED heap.
// Caller MUST release it with nf_free. Never free it with Dart's calloc.
NF_API char *nf_greet(const char *name);

NF_API void nf_free(void *p);

// Fills rows [y0, y1) of a w x h Mandelbrot image as RGBA8888, packed from
// the start of `buf`. The buffer is owned by the CALLER: Nim allocates
// nothing here and there is nothing to nf_free. Bands are independent, so
// separate calls may run concurrently on different threads/isolates.
//
// `buf_len` is how many bytes `buf` holds; it must be at least
// (y1 - y0) * w * 4. Every rejection is all-or-nothing — a buffer one byte
// short writes nothing at all, rather than filling what fits, since partial
// output is indistinguishable from a rendered frame. The size is computed in
// 64-bit, because that product overflows int32 for plausible geometry.
NF_API void nf_mandelbrot(unsigned char *buf, size_t buf_len, int w, int h,
                          double cx, double cy, double scale, int max_iter,
                          int y0, int y1);

#ifdef __cplusplus
}
#endif
#endif // NIMFLUTTER_H