#include "dat.h"
#include "fn.h"

static Im im;
static int popup = 0;
static int visible = 0;
static void dictqmap(Im*);

typedef struct Search Search;
struct Search
{
	int	on;
	Str	raw;
	Str	text;
};
static Search search;

static void
backmap(Im *im)
{
	spopr(&im->pre);
}

Lang langs[] = {
	{LangEN,    "english", nil,      transmap, backmap, dictqmap, nil, nil},
	{LangJP,    "hira",    "kanji",  transmap, backmap, dictqmap, nil, nil},
	{LangJPK,   "kata",    "kanji",  transmap, backmap, dictqmap, nil, nil},
	{LangKO,    "hangul",  nil,      transko,  backko,  dictqmap, nil, nil},
	{LangEMOJI, nil,       "emoji",  nil,      nil,     nil,      nil, nil},
	{LangVI,    "telex",   nil,      transvi,  backvi,  dictqmap, nil, nil},
};
int nlang = nelem(langs);

static void
clearkouho(void)
{
	im.nkouho = 0;
	im.sel = -1;
}

static void
setkouho(Dictres *res)
{
	int i;

	clearkouho();
	for(i = 0; i < res->nkouho; i++){
		im.kouho[i] = res->kouho[i];
		im.nkouho++;
	}
}

static void
show(void)
{
	static Drawcmd old;
	Drawcmd dc;
	Str *pre;
	int i, first, n;

	sclear(&dc.pre);
	pre = search.on ? &search.text : &im.pre;
	if(popup){
		if(search.on || im.l->map == nil || !mapget(im.l->map, pre, &dc.pre))
			dc.pre = *pre;
	}
	first = im.sel >= Maxdisp ? im.sel - Maxdisp + 1 : 0;
	n = im.nkouho - first;
	if(n > Maxdisp) n = Maxdisp;
	dc.nkouho = n;
	dc.sel = im.sel >= 0 ? im.sel - first : -1;
	for(i = 0; i < n; i++)
		dc.kouho[i] = im.kouho[first + i];
	if(dc.pre.n == 0 && n == 0 && !visible)
		return;
	visible = dc.pre.n != 0 || n != 0;
	/* imthread is the sole producer; keep only the newest pending draw. */
	while(channbrecv(drawc, &old) > 0)
		;
	channbsend(drawc, &dc);
}

static void
reset(void)
{
	sclear(&im.pre);
	sclear(&im.raw);
	clearkouho();
	show();
}

void
dictsend(Im *im, Str *key)
{
	Dictreq req;

	req.key = *key;
	req.lang = im->l->lang;
	req.pre = im->pre;
	channbsend(dictreqc, &req);
}

static void
dictqmap(Im *im)
{
	Str dict;

	clearkouho();
	show();
	if(!mapget(im->l->map, &im->pre, &dict))
		return;
	dictsend(im, &dict);
}

static int
setlang(int c)
{
	Lang *l;

	l = getlang(c);
	if(l == nil)
		return 0;
	im.l = l;
	return 1;
}

static void
commit(Str *com)
{
	Str val;

	if(im.l->map != nil && mapget(im.l->map, &im.pre, &val))
		sappend(com, &val);
	else
		sappend(com, &im.pre);
	sclear(&im.pre);
	sclear(&im.raw);
}

static int
dotrans(Rune c, Str *com)
{
	Emit e;
	Dictreq req;
	Str mapped;

	e = im.l->trans(&im, c);
	if(im.l->lang == LangVI){
		if(e.s.n > 0 || !e.eat)
			sclear(&im.raw);
		if(e.eat && e.next.n > 0){
			if(im.raw.n >= Maxrunes){
				if(!mapget(im.l->map, &e.next, &mapped))
					mapped = e.next;
				sappend(com, &mapped);
				reset();
				return e.eat;
			}
			sputr(&im.raw, c);
		}
	}
	clearkouho();
	if(e.s.n > 0)
		sappend(com, &e.s);
	sclear(&im.pre);
	sappend(&im.pre, &e.next);
	if(e.eat && e.dict.n > 0){
		req.key = e.dict;
		req.lang = im.l->lang;
		req.pre = im.pre;
		channbsend(dictreqc, &req);
	}
	return e.eat;
}

Lang*
getlang(int lang)
{
	int i;

	for(i = 0; i < nelem(langs); i++)
		if(langs[i].lang == lang)
			return &langs[i];
	return nil;
}

static int
maplookup(Trie *t, Str *key, Str *out)
{
	char buf[Maxutf], *v;
	int klen, vlen;

	if(key->n == 0)
		return 0;
	v = nil;
	vlen = 0;
	klen = stoutf(key, buf, sizeof(buf));
	if(!trielookup(t, buf, klen, &v, &vlen))
		return 0;
	if(out != nil && v != nil)
		sinit(out, v, vlen);
	return 1;
}

Emit
transmap(Im *im, Rune c)
{
	Emit e = {0};
	Str key;
	Trie *t;

	t = im->l->map;
	key = im->pre;
	sputr(&key, c);
	if(maplookup(t, &key, &e.dict)){
		e.eat = 1;
		e.next = key;
		return e;
	}
	if(!mapget(t, &im->pre, &e.s))
		e.s = im->pre;
	sclear(&key);
	sputr(&key, c);
	if(!maplookup(t, &key, &e.dict))
		return e;
	e.eat = 1;
	sputr(&e.next, c);
	return e;
}

static Rune
ctrlkey(Rune c)
{
	if(c >= 'A' && c <= 'Z')
		c += 'a' - 'A';
	if(c >= 'a' && c <= 'z')
		return c - 'a' + 1;
	return c;
}

static int
ismodkey(u32int ks)
{
	return ks >= Kmodfirst && ks <= Kmodlast;
}

static void
foldascii(Str *s)
{
	int i;

	for(i = 0; i < s->n; i++)
		if(s->r[i] >= 'A' && s->r[i] <= 'Z')
			s->r[i] += 'a' - 'A';
}

static void
transstr(Lang *l, Str *raw, Str *out)
{
	static Im q;
	Emit e;
	Str mapped;
	int i;

	sclear(out);
	if(l == nil || l->trans == nil || (l->trans == transmap && l->map == nil)){
		*out = *raw;
		return;
	}
	memset(&q, 0, sizeof q);
	q.l = l;
	for(i = 0; i < raw->n; i++){
		e = l->trans(&q, raw->r[i]);
		sappend(out, &e.s);
		q.pre = e.next;
		if(!e.eat && out->n < Maxrunes)
			sputr(out, raw->r[i]);
	}
	if(q.pre.n == 0)
		return;
	if(l->map != nil && mapget(l->map, &q.pre, &mapped))
		sappend(out, &mapped);
	else
		sappend(out, &q.pre);
}

static void
addkouho(Str *s)
{
	int i;

	for(i = 0; i < im.nkouho; i++)
		if(scmp(&im.kouho[i], s) == 0)
			return;
	if(im.nkouho < Maxkouho)
		im.kouho[im.nkouho++] = *s;
}

static void
emojilookup(Str *key, Dictres *res)
{
	Dictreq req;

	req.key = *key;
	req.pre = req.key;
	req.lang = LangEMOJI;
	dictlookup(&req, res);
}

static void
emojiquery(void)
{
	static Dictres res;
	Str raw, local;
	int i, rawhit, localhit;

	raw = search.raw;
	foldascii(&raw);
	transstr(im.l, &search.raw, &local);
	foldascii(&local);
	clearkouho();
	emojilookup(&raw, &res);
	rawhit = res.nkouho != 0;
	for(i = 0; i < res.nkouho; i++)
		addkouho(&res.kouho[i]);
	localhit = 0;
	if(scmp(&raw, &local) != 0){
		emojilookup(&local, &res);
		localhit = res.nkouho != 0;
		for(i = 0; i < res.nkouho; i++)
			addkouho(&res.kouho[i]);
	}
	search.text = rawhit || !localhit ? raw : local;
	show();
}

static void
endsearch(void)
{
	search.on = 0;
	sclear(&search.raw);
	sclear(&search.text);
	clearkouho();
	show();
}

static void
startsearch(Str *com)
{
	if(im.pre.n > 0)
		commit(com);
	sclear(&im.pre);
	sclear(&im.raw);
	clearkouho();
	search.on = 1;
	sclear(&search.raw);
	sclear(&search.text);
	show();
}

static void
commitsearch(Str *com)
{
	sappend(com, &search.text);
	endsearch();
}

static int
pickemoji(int n, Str *com)
{
	if(n < 0 || n >= im.nkouho)
		return 0;
	sappend(com, &im.kouho[n]);
	endsearch();
	return 1;
}

static int
searchkey(u32int ks, u32int mod, Str *com)
{
	int n, off;
	Rune c;

	if(ismodkey(ks))
		return 0;
	if(ks == Kdown || ks == Kup){
		if(im.nkouho == 0)
			return 1;
		if(ks == Kdown && im.sel < im.nkouho - 1)
			im.sel++;
		if(ks == Kup && im.sel > 0)
			im.sel--;
		show();
		return 1;
	}
	n = ks - '1';
	off = im.sel >= Maxdisp ? im.sel - Maxdisp + 1 : 0;
	if(n >= 0 && n < Maxdisp && off + n < im.nkouho && mod == 0){
		pickemoji(off + n, com);
		return 1;
	}
	if(ks == Ktab){
		if(im.nkouho == 0)
			return 1;
		if(mod & Mshift){
			if(im.sel <= 0)
				im.sel = im.nkouho - 1;
			else
				im.sel--;
		}else if(im.sel >= im.nkouho - 1)
			im.sel = 0;
		else
			im.sel++;
		show();
		return 1;
	}
	if(ks == Kret){
		if(im.nkouho > 0)
			return pickemoji(im.sel >= 0 ? im.sel : 0, com);
		commitsearch(com);
		return 1;
	}
	if(ks == Kback){
		if(search.raw.n == 0)
			return 1;
		spopr(&search.raw);
		emojiquery();
		return 1;
	}
	if(ks == Kesc){
		endsearch();
		return 1;
	}
	if(mod & Mctrl){
		c = ctrlkey(ks);
		if(c == LangEMOJI){
			endsearch();
			return 1;
		}
		if(c == 0x10){
			popup = !popup;
			show();
			return 1;
		}
		endsearch();
		if(setlang(c))
			return 1;
		return 0;
	}
	if(ks >= Kspec || ks < ' ' || (mod & (Malt|Msuper))){
		commitsearch(com);
		return 0;
	}
	if(search.raw.n >= Maxrunes){
		commitsearch(com);
		return 0;
	}
	sputr(&search.raw, ks);
	emojiquery();
	return 1;
}

static int
keystroke(u32int ks, u32int mod, Str *com)
{
	int n, off;
	Rune c;

	if(ismodkey(ks))
		return 0;
	if(search.on)
		return searchkey(ks, mod, com);
	if(ks == Kdown || ks == Kup){
		if(im.nkouho == 0)
			return 0;
		if(ks == Kdown && im.sel < im.nkouho - 1)
			im.sel++;
		if(ks == Kup && im.sel >= 0)
			im.sel--;
		show();
		return 1;
	}
	n = ks - '1';
	off = 0;
	if(im.sel >= Maxdisp)
		off = im.sel - Maxdisp + 1;
	if(n >= 0 && n < Maxdisp && off + n < im.nkouho){
		sappend(com, &im.kouho[off + n]);
		reset();
		return 1;
	}
	if(ks == Ktab || ks == Kret){
		if(im.sel >= 0 && im.sel < im.nkouho){
			sappend(com, &im.kouho[im.sel]);
			reset();
			return 1;
		}
		if(im.pre.n > 0){
			commit(com);
			reset();
			return 1;
		}
		return 0;
	}
	if(ks == Kback){
		if(im.pre.n == 0)
			return 0;
		im.l->back(&im);
		if(im.pre.n == 0){
			reset();
			return 1;
		}
		im.l->dictq(&im);
		return 1;
	}
	if(ks == Kesc){
		if(im.pre.n == 0)
			return 0;
		reset();
		return 1;
	}
	if(ks >= Kspec || (mod & (Malt|Msuper))){
		commit(com);
		reset();
		return 0;
	}
	if(mod & Mctrl){
		c = ctrlkey(ks);
		if(c == LangEMOJI){
			startsearch(com);
			return 1;
		}
		if(c == 0x10){
			popup = !popup;
			show();
			return 1;
		}
		reset();
		if(setlang(c))
			return 1;
		return 0;
	}
	if(ks == '0' && im.nkouho > 0){
		commit(com);
		reset();
		return 1;
	}
	if(ks > 0x7f || ks == ' '){
		if(im.pre.n == 0)
			return 0;
		commit(com);
		sputr(com, ks);
		reset();
		return 1;
	}
	n = dotrans(ks, com);
	show();
	return n;
}

static void
init(void)
{
	memset(&im, 0, sizeof(im));
	im.l = getlang(LangEN);
	memset(&search, 0, sizeof search);
	visible = 0;
}

static void
imhandlekey(Keyreq *kr)
{
	Keyres res;

	sclear(&res.commit);
	sclear(&res.preedit);
	res.eaten = keystroke(kr->ks, kr->mod, &res.commit);
	if(kr->want)
		res.preedit = search.on ? search.text : im.pre;
	chansend(kr->reply, &res);
}

static void
dictresult(Dictres *res)
{
	if(search.on || res->lang != im.l->lang ||
	   scmp(&res->key, &im.pre) != 0)
		return;
	setkouho(res);
	show();
}

void
imthread(void*)
{
	static Dictres res;
	Keyreq kr;
	Alt alts[] = {
		{keyc, &kr, CHANRCV, nil},
		{dictresc, &res, CHANRCV, nil},
		{nil, nil, CHANEND, nil},
	};

	threadsetname("im");
	init();
	for(;;){
		switch(alt(alts)){
		case 0:
			imhandlekey(&kr);
			break;
		case 1:
			dictresult(&res);
			break;
		}
	}
}

int
mapget(Trie *t, Str *key, Str *out)
{
	char buf[Maxutf], *v;
	int klen, vlen;

	if(key->n == 0)
		return 0;
	klen = stoutf(key, buf, sizeof(buf));
	v = trieget(t, buf, klen, &vlen);
	if(v == nil)
		return 0;
	sinit(out, v, vlen);
	return 1;
}

void
mapinit(char *dir)
{
	char path[1024];
	int i;

	for(i = 0; i < nelem(langs); i++){
		if(langs[i].mapname == nil)
			continue;
		snprint(path, sizeof(path), "%s/%s.map", dir, langs[i].mapname);
		langs[i].map = trieopen(path);
	}
}