#include <errno.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <unistd.h>

#include "../srv.c"
#include "../cutest/cutest.h"

void	testengineinit(int);
void	testenginehandle(Keyreq*);
void*	testengineowner(void);
void	testenginepreedit(Str*);

#undef recv

typedef struct Enginegate Enginegate;
typedef struct Testclient Testclient;

struct Enginegate
{
	Channel	*seen;
	Channel	*go;
	Channel	*stop;
	Channel	*done;
};

struct Testclient
{
	int	fd;
	int	peer;
	dev_t	dev;
	ino_t	ino;
	Channel	*done;
};

static void
enginegate(void *arg)
{
	Enginegate *g;
	Keyreq req;
	uchar token;
	Alt alts[] = {
		{keyc, &req, CHANRCV, nil},
		{nil, &token, CHANRCV, nil},
		{nil, nil, CHANEND, nil},
	};

	g = arg;
	alts[1].c = g->stop;
	for(;;)
		switch(alt(alts)){
		case 0:
			chansend(g->seen, &req);
			chanrecv(g->go, &token);
			testenginehandle(&req);
			break;
		case 1:
			chansend(g->done, &token);
			return;
		}
}

static void
clientproc(void *arg)
{
	Testclient *client;
	uchar token;

	client = arg;
	clientthread((void*)(uintptr)client->fd);
	token = 0;
	chansend(client->done, &token);
}

static int
startclient(struct ct *t, Testclient *client)
{
	struct stat st;
	int fd[2];
	uchar token;

	memset(client, 0, sizeof *client);
	client->fd = -1;
	client->peer = -1;
	if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd) < 0)
		return CT_ERRORF(t, "socketpair failed: %s", strerror(errno));
	client->fd = fd[0];
	client->peer = fd[1];
	if(fstat(client->fd, &st) < 0){
		close(client->fd);
		close(client->peer);
		client->fd = -1;
		client->peer = -1;
		return CT_ERRORF(t, "socket stat failed: %s", strerror(errno));
	}
	client->dev = st.st_dev;
	client->ino = st.st_ino;
	client->done = chancreate(sizeof token, 0);
	token = 0;
	if(channbsend(clientc, &token) <= 0){
		close(client->fd);
		close(client->peer);
		chanfree(client->done);
		client->fd = -1;
		client->peer = -1;
		client->done = nil;
		return CT_ERRORF(t, "client slot unavailable");
	}
	if(proccreate(clientproc, client, 8192) < 0){
		chanrecv(clientc, &token);
		close(client->fd);
		close(client->peer);
		chanfree(client->done);
		client->fd = -1;
		client->peer = -1;
		client->done = nil;
		return CT_ERRORF(t, "client worker creation failed");
	}
	return 1;
}

static int
sendkey(struct ct *t, Testclient *client, int want, u32int mod, u32int key)
{
	uchar req[Ipcreqsz];

	ipcpackreq(req, want, mod, key);
	if(ipcsend(client->peer, req, sizeof req) == 0)
		return 1;
	return CT_ERRORF(t, "request send failed: %s", strerror(errno));
}

static int
sendreset(struct ct *t, Testclient *client, int want)
{
	uchar req[Ipcreqsz];

	ipcpackreset(req, want);
	if(ipcsend(client->peer, req, sizeof req) == 0)
		return 1;
	return CT_ERRORF(t, "reset send failed: %s", strerror(errno));
}

static Keyreq
nextrequest(struct ct *t, Enginegate *g, int op)
{
	Keyreq req;

	memset(&req, 0, sizeof req);
	chanrecv(g->seen, &req);
	CT_EQ_INT(t, op, req.op);
	return req;
}

static void
allowrequest(Enginegate *g)
{
	uchar token;

	token = 0;
	chansend(g->go, &token);
}

static int
readreply(struct ct *t, Testclient *client, int want, char *preedit, int npreedit)
{
	char commit[Maxutf];
	Ipcresp resp;

	if(ipcreadresp(client->peer, want, commit, sizeof commit,
	   preedit, npreedit, &resp) < 0)
		return CT_ERRORF(t, "response read failed: %s", strerror(errno));
	CT_EQ_STR(t, "", commit);
	return resp.eaten;
}

static void
waitclient(struct ct *t, Testclient *client)
{
	struct stat st;
	uchar token;

	chanrecv(client->done, &token);
	errno = 0;
	if(fstat(client->fd, &st) == 0)
		CT_CHECK(t, st.st_dev != client->dev || st.st_ino != client->ino);
	else
		CT_EQ_INT(t, EBADF, errno);
	chanfree(client->done);
	client->done = nil;
}

static void
disconnectclient(struct ct *t, Enginegate *g, Testclient *client, void *owner)
{
	Keyreq req;
	uchar token;

	close(client->peer);
	client->peer = -1;
	req = nextrequest(t, g, Keyrelease);
	if(owner != nil)
		CT_EQ_PTR(t, owner, req.owner);
	CT_CHECK(t, channbrecv(client->done, &token) <= 0);
	allowrequest(g);
	waitclient(t, client);
}

void
server_connection_ownership(struct ct *t)
{
	Channel *oldclientc;
	Enginegate gate;
	Testclient a, b, c;
	Keyreq req;
	Drawcmd dc;
	Str shown;
	char preedit[Maxutf];
	void *aowner, *bowner, *cowner;
	uchar byte, token;
	ssize_t n;
	int gateactive;

	memset(&gate, 0, sizeof gate);
	memset(&a, 0, sizeof a);
	memset(&b, 0, sizeof b);
	memset(&c, 0, sizeof c);
	a.fd = a.peer = b.fd = b.peer = c.fd = c.peer = -1;
	aowner = bowner = cowner = nil;
	oldclientc = clientc;
	while(channbrecv(drawc, &dc) > 0)
		;
	clientc = chancreate(sizeof token, 3);
	gate.seen = chancreate(sizeof(Keyreq), 0);
	gate.go = chancreate(sizeof token, 0);
	gate.stop = chancreate(sizeof token, 0);
	gate.done = chancreate(sizeof token, 0);
	testengineinit(LangJP);
	gateactive = proccreate(enginegate, &gate, 8192) >= 0;
	if(!CT_CHECK(t, gateactive))
		goto cleanup;
	if(!startclient(t, &a) || !startclient(t, &b))
		goto cleanup;

	if(!sendkey(t, &a, 1, 0, 'k'))
		goto cleanup;
	req = nextrequest(t, &gate, Keypress);
	aowner = req.owner;
	allowrequest(&gate);
	CT_CHECK(t, readreply(t, &a, 1, preedit, sizeof preedit));
	CT_EQ_STR(t, "k", preedit);
	if(!sendkey(t, &a, 1, 0, 'a'))
		goto cleanup;
	req = nextrequest(t, &gate, Keypress);
	CT_EQ_PTR(t, aowner, req.owner);
	allowrequest(&gate);
	CT_CHECK(t, readreply(t, &a, 1, preedit, sizeof preedit));
	CT_EQ_STR(t, "か", preedit);
	CT_EQ_PTR(t, aowner, testengineowner());

	if(!sendkey(t, &b, 1, 0, 'n'))
		goto cleanup;
	req = nextrequest(t, &gate, Keypress);
	bowner = req.owner;
	CT_CHECK(t, bowner != aowner);
	allowrequest(&gate);
	CT_CHECK(t, readreply(t, &b, 1, preedit, sizeof preedit));
	CT_EQ_STR(t, "ん", preedit);
	CT_EQ_PTR(t, bowner, testengineowner());

	if(!sendreset(t, &a, 1))
		goto cleanup;
	req = nextrequest(t, &gate, Keyreset);
	CT_EQ_PTR(t, aowner, req.owner);
	allowrequest(&gate);
	CT_CHECK(t, readreply(t, &a, 1, preedit, sizeof preedit));
	CT_EQ_STR(t, "", preedit);
	CT_EQ_PTR(t, bowner, testengineowner());
	if(!sendkey(t, &b, 1, 0, Kmodfirst))
		goto cleanup;
	req = nextrequest(t, &gate, Keypress);
	allowrequest(&gate);
	CT_CHECK(t, !readreply(t, &b, 1, preedit, sizeof preedit));
	CT_EQ_STR(t, "ん", preedit);

	disconnectclient(t, &gate, &a, aowner);
	CT_EQ_PTR(t, bowner, testengineowner());
	if(!sendkey(t, &b, 1, 0, 'y'))
		goto cleanup;
	req = nextrequest(t, &gate, Keypress);
	allowrequest(&gate);
	CT_CHECK(t, readreply(t, &b, 1, preedit, sizeof preedit));
	if(!sendkey(t, &b, 1, 0, 'a'))
		goto cleanup;
	req = nextrequest(t, &gate, Keypress);
	allowrequest(&gate);
	CT_CHECK(t, readreply(t, &b, 1, preedit, sizeof preedit));
	CT_EQ_STR(t, "にゃ", preedit);

	if(!sendreset(t, &b, 1))
		goto cleanup;
	req = nextrequest(t, &gate, Keyreset);
	CT_EQ_PTR(t, bowner, req.owner);
	allowrequest(&gate);
	CT_CHECK(t, readreply(t, &b, 1, preedit, sizeof preedit));
	CT_EQ_STR(t, "", preedit);
	CT_EQ_PTR(t, bowner, testengineowner());

	if(!sendkey(t, &b, 0, 0, 'k'))
		goto cleanup;
	req = nextrequest(t, &gate, Keypress);
	CT_EQ_PTR(t, bowner, req.owner);
	allowrequest(&gate);
	CT_CHECK(t, readreply(t, &b, 0, nil, 0));
	errno = 0;
	n = recv(b.peer, &byte, 1, MSG_PEEK|MSG_DONTWAIT);
	CT_EQ_INT(t, -1, n);
	CT_CHECK(t, errno == EAGAIN || errno == EWOULDBLOCK);
	CT_EQ_PTR(t, bowner, testengineowner());
	if(!sendkey(t, &b, 1, 0, 'a'))
		goto cleanup;
	req = nextrequest(t, &gate, Keypress);
	allowrequest(&gate);
	CT_CHECK(t, readreply(t, &b, 1, preedit, sizeof preedit));
	CT_EQ_STR(t, "か", preedit);

	disconnectclient(t, &gate, &b, bowner);
	CT_EQ_PTR(t, nil, testengineowner());
	testenginepreedit(&shown);
	CT_EQ_INT(t, 0, shown.n);

	if(!startclient(t, &c))
		goto cleanup;
	if(!sendkey(t, &c, 1, 0, 'k'))
		goto cleanup;
	req = nextrequest(t, &gate, Keypress);
	cowner = req.owner;
	close(c.peer);
	c.peer = -1;
	allowrequest(&gate);
	req = nextrequest(t, &gate, Keyrelease);
	CT_EQ_PTR(t, cowner, req.owner);
	CT_EQ_PTR(t, cowner, testengineowner());
	CT_CHECK(t, channbrecv(c.done, &token) <= 0);
	allowrequest(&gate);
	waitclient(t, &c);
	CT_EQ_PTR(t, nil, testengineowner());
	CT_CHECK(t, channbrecv(clientc, &token) <= 0);

cleanup:
	if(a.peer >= 0)
		disconnectclient(t, &gate, &a, aowner);
	if(b.peer >= 0)
		disconnectclient(t, &gate, &b, bowner);
	if(c.peer >= 0)
		disconnectclient(t, &gate, &c, cowner);
	if(gateactive){
		token = 0;
		chansend(gate.stop, &token);
		chanrecv(gate.done, &token);
	}
	chanfree(gate.seen);
	chanfree(gate.go);
	chanfree(gate.stop);
	chanfree(gate.done);
	chanfree(clientc);
	clientc = oldclientc;
	while(channbrecv(drawc, &dc) > 0)
		;
}