#pragma once

#ifdef Plan9
#include <u.h>
#include <libc.h>
typedef vlong int64_t;
typedef uvlong uint64_t;
typedef int int32_t;
typedef uint uint32_t;
typedef short int16_t;
typedef ushort uint16_t;
typedef schar int8_t;
typedef uchar uint8_t;
#define NULL nil
#define stderr 2
#define fprintf fprint
#define vfprintf vfprint
#define PRIu64 "ull"
#define PRId64 "ll"
#endif

#ifdef __GNUC__
#define PB_GNUC_ATTR(a) __attribute__((a))
#else
#define PB_GNUC_ATTR(a)
#endif

/* callback return codes */
enum {
	PB_CALLBACK_ERROR = -1, /* parsing should fail */
	PB_CALLBACK_THROW_AWAY, /* throw away the value */
	PB_CALLBACK_OK,
};

enum {
	PB_FLAG_MASK_TYPE = 3, /* PB_TYPE_* */
	PB_FLAG_POINTER = 1<<2,
	PB_FLAG_TRUNCATE = 1<<3,
	PB_FLAG_CONST_SIZE = 1<<4,
	PB_FLAG_REQUIRED = 1<<5,
	PB_FLAG_SIGNED = 1<<6,
	PB_FLAG_NO_PRINT = 1<<7,
	PB_FLAG_IS_CONST = 1<<8,
	PB_FLAG_TYPE_UNSIGNED = 1<<9,
};

enum {
	PB_TYPE_STRING,
	PB_TYPE_BYTES,
	PB_TYPE_INTEGER,
	PB_TYPE_MSG,
};

struct pb_default { /* default value */
	uint64_t integer;
	void *pointer;
	uint16_t size;
};

struct pb_field {
#ifdef PB_PRINTERS
	const char *name;
	char *(*seprint)(const void *in, char *s, char *e, int left, int indent, const struct pb_field *field);
#endif
	uint16_t offset; /* offset in the parent data struct, bytes */
	int16_t num_at; /* offset in the parent data struct of the "int num" related to this field, bytes */
	uint16_t num; /* number of entries in the array */
	uint16_t size; /* sizeof() of the field if not array, sizeof(a[0]) if array */
	uint16_t flags;
	uint8_t index; /* [1,255], 0 is used for non-protobuf fields */
	uint8_t dfltidx; /* points to the array of default values, [1,255] */
	uint8_t msgidx; /* points to the array of message types, [1,255] */
	uint8_t cbidx; /* points to the array of callbacks, [1,255] */
};

struct pb_msg {
	const struct pb_field *fields;
#ifdef PB_PRINTERS
	const char *name;
	const int *indices;
#endif

	/* buffer to store strings by pointers */
	int16_t buffer_at;
	uint16_t buffer_size;

	/* stuff that is not used goes into the "rest" buffer */
	int16_t rest_at;
	uint16_t rest_size;

	uint8_t num_fields;
};

struct pb_data {
	const struct pb_msg *msgs;
	const struct pb_default *dflts;
	const void **cbs;
};

void pb_reset(void *out, const struct pb_msg *msg, const struct pb_data *pb);
const uint8_t *pb_decode(void *out, const uint8_t *s, const uint8_t *e, const struct pb_msg *msg, const struct pb_data *pb);
uint8_t *pb_encode(const void *in, uint8_t *s, uint8_t *e, const struct pb_msg *msg, const struct pb_data *pb);
char *pb_seprint(const void *in, char *s, char *e, const struct pb_msg *msg, const struct pb_data *pb, int left, int indent);

#ifdef PB_PRINTERS
char *seprintf(char *s, char *e, char *fmt, ...) PB_GNUC_ATTR(format(printf, 3, 4));
#endif