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

/*
 * Request: [flags, modifiers, key byte 0, ..., key byte 3].
 * Flags request preedit and distinguish lifecycle reset from physical Escape.
 * The server identifies the connection as the engine owner; that identity is
 * not sent on the wire.
 * Only Mmask modifier bits are retained.
 * Response: [eaten, commit-length-low, commit-length-high, commit...],
 * followed, when requested, by
 * [preedit-length-low, preedit-length-high, preedit...].
 * Lengths are little-endian byte counts; fields are at most Ipcfieldmax bytes.
 */

enum
{
	Ipcreqwant = 1<<0,
	Ipcreqreset = 1<<1,

	Kspec = 0x110000,
	Kback = Kspec|0x08,
	Ktab = Kspec|0x09,
	Kret = Kspec|0x0d,
	Kesc = Kspec|0x1b,
	Kup = Kspec|0x52,
	Kdown = Kspec|0x54,
	Kmodfirst = Kspec|0xe1,
	Kmodlast = Kspec|0xee,

	Mshift = 1<<0,
	Mctrl = 1<<2,
	Malt = 1<<3,
	Msuper = 1<<6,
	Mmask = Mshift|Mctrl|Malt|Msuper,

	Ipcreqsz = 6,
	Ipclensz = 2,
	Ipcresphdrsz = 1 + Ipclensz,
	Ipcfieldmax = 256,
	Ipcmaxresp = Ipcresphdrsz + Ipcfieldmax + Ipclensz + Ipcfieldmax,
};

typedef struct Ipcresp Ipcresp;
struct Ipcresp
{
	int	eaten;
	size_t	ncommit;
	size_t	npreedit;
};

void	ipcpackreq(unsigned char[Ipcreqsz], int, uint32_t, uint32_t);
void	ipcpackreset(unsigned char[Ipcreqsz], int);
void	ipcunpackreq(const unsigned char[Ipcreqsz], int*, uint32_t*, uint32_t*);
int	ipcreqreset(const unsigned char[Ipcreqsz]);
int	ipcpackresp(unsigned char*, size_t, int, const char*, size_t, const char*, size_t, int);
int	ipcreadn(int, void*, size_t);
int	ipcsend(int, const void*, size_t);
int	ipcreadresp(int, int, char*, size_t, char*, size_t, Ipcresp*);
int	ipcpath(char*, size_t);
int	ipcconnect(void);