/* radare - LGPL - Copyright 2015-2026 - pancake */

#include <r_io.h>

typedef struct {
	RBuffer *buf;
	ut64 offset;
} RIOSparse;

#define RIOSPARSE_BUF(x) (((RIOSparse*)(x)->data)->buf)
#define RIOSPARSE_OFF(x) (((RIOSparse*)(x)->data)->offset)

static int __write(RIO *io, RIODesc *fd, const ut8 *buf, int count) {
	R_RETURN_VAL_IF_FAIL (io && fd && fd->data && buf, -1);
	RBuffer *b = RIOSPARSE_BUF (fd);
	int r = r_buf_write_at (b, RIOSPARSE_OFF (fd), buf, count);
	if (r >= 0) {
		r_buf_seek (b, r, R_BUF_CUR);
	}
	return r;
}

static int __read(RIO *io, RIODesc *fd, ut8 *buf, int count) {
	R_RETURN_VAL_IF_FAIL (io && fd && fd->data && buf, -1);
	RBuffer *b = RIOSPARSE_BUF (fd);
	int r = r_buf_read_at (b, RIOSPARSE_OFF (fd), buf, count);
	if (r >= 0) {
		r_buf_seek (b, r, R_BUF_CUR);
	}
	return r;
}

static bool __close(RIODesc *fd) {
	R_RETURN_VAL_IF_FAIL (fd && fd->data, false);
	RIOSparse *riom = fd->data;
	r_unref (riom->buf);
	R_FREE (fd->data);
	return true;
}

static ut64 __lseek(RIO *io, RIODesc *fd, ut64 offset, int whence) {
	if (!fd->data) {
		return offset;
	}
	ut64 r_offset = r_buf_seek (RIOSPARSE_BUF (fd), offset, whence);
	RIOSPARSE_OFF (fd) = r_offset;
	return r_offset;
}

static bool __plugin_open(RIO *io, const char *pathname, bool many) {
	return r_str_startswith (pathname, "sparse://");
}

static RIODesc *__open(RIO *io, const char *pathname, int rw, int mode) {
	if (!__plugin_open (io, pathname, 0)) {
		return NULL;
	}
	int size = (int)r_num_math (NULL, pathname + 9);
	if (size < 1) {
		R_LOG_ERROR ("Invalid size. Use sparse://<number>");
		return NULL;
	}
	RIOSparse *mal = R_NEW0 (RIOSparse);
	mal->buf = r_buf_new_sparse (io->Oxff);
	if (!mal->buf) {
		free (mal);
		return NULL;
	}
	ut8 *data = calloc (1, size);
	if (data) {
		r_buf_write_at (mal->buf, 0, data, size);
		free (data);
	} else {
		R_LOG_ERROR ("Cannot allocate %d bytes", size);
	}
	return r_io_desc_new (io, &r_io_plugin_sparse, pathname, rw, mode, mal);
}

RIOPlugin r_io_plugin_sparse = {
	.meta = {
		.name = "sparse",
		.author = "pancake",
		.desc = "Sparse buffer allocation plugin",
		.license = "LGPL-3.0-only",
	},
	.uris = "sparse://",
	.open = __open,
	.close = __close,
	.read = __read,
	.check = __plugin_open,
	.seek = __lseek,
	.write = __write,
	.resize = NULL,
};

#ifndef R2_PLUGIN_INCORE
R_API RLibStruct radare_plugin = {
	.type = R_LIB_TYPE_IO,
	.data = &r_io_plugin_sparse,
	.version = R2_VERSION
};
#endif