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

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <wayland-client.h>
#include <xkbcommon/xkbcommon.h>
#include "input-method-unstable-v2-client-protocol.h"
#include "virtual-keyboard-unstable-v1-client-protocol.h"

static struct wl_display *dpy;
static struct wl_seat *seat;
static struct zwp_input_method_manager_v2 *immgr;
static struct zwp_virtual_keyboard_manager_v1 *vkmgr;
static struct zwp_input_method_v2 *im;
static struct zwp_input_method_keyboard_grab_v2 *grab;
static struct zwp_virtual_keyboard_v1 *vk;
static struct xkb_context *xkb;
static struct xkb_keymap *keymap;
static struct xkb_state *xkbst;
static int active;
static int pending;
static u32int imserial;

static void
sendkey(u32int ks, u32int mod, char *com, int csz, char *pre, int psz,
	int *eaten)
{
	Keyreq kr;
	int p[2];
	uchar hdr[2];
	uchar pl;
	int n;

	*eaten = 0;
	com[0] = '\0';
	pre[0] = '\0';
	if(pipe(p) < 0)
		return;
	kr.fd = p[1];
	kr.ks = ks;
	kr.mod = mod;
	kr.want = 1;
	chansend(keyc, &kr);
	if(read(p[0], hdr, 2) != 2)
		goto out;
	*eaten = hdr[0];
	n = hdr[1];
	if(n > 0 && n < csz){
		if(read(p[0], com, n) != n)
			goto out;
		com[n] = '\0';
	}
	if(read(p[0], &pl, 1) != 1)
		goto out;
	if(pl > 0 && pl < psz){
		if(read(p[0], pre, pl) != pl)
			goto out;
		pre[pl] = '\0';
	}
out:
	close(p[0]);
	close(p[1]);
}

static void
sendreset(void)
{
	char com[64], pre[256];
	int eaten;

	sendkey(Kesc, 0, com, sizeof(com), pre, sizeof(pre), &eaten);
}

static u32int
mget(void)
{
	u32int m;

	m = 0;
	if(xkbst == nil)
		return 0;
	if(xkb_state_mod_name_is_active(xkbst,
		XKB_MOD_NAME_SHIFT, XKB_STATE_MODS_EFFECTIVE) > 0)
		m |= Mshift;
	if(xkb_state_mod_name_is_active(xkbst,
		XKB_MOD_NAME_CTRL, XKB_STATE_MODS_EFFECTIVE) > 0)
		m |= Mctrl;
	if(xkb_state_mod_name_is_active(xkbst,
		XKB_MOD_NAME_ALT, XKB_STATE_MODS_EFFECTIVE) > 0)
		m |= Malt;
	if(xkb_state_mod_name_is_active(xkbst,
		XKB_MOD_NAME_LOGO, XKB_STATE_MODS_EFFECTIVE) > 0)
		m |= Msuper;
	return m;
}

static void
kpress(uint32_t time, uint32_t keycode, uint32_t state)
{
	xkb_keysym_t ks;
	u32int k, mod;
	char com[64], pre[256];
	int eaten, plen;

	if(state != WL_KEYBOARD_KEY_STATE_PRESSED || xkbst == nil){
		zwp_virtual_keyboard_v1_key(vk, time, keycode, state);
		return;
	}
	ks = xkb_state_key_get_one_sym(xkbst, keycode + 8);
	k = ks >= 0xff00 ? Kspec + (ks - 0xff00) : xkb_keysym_to_utf32(ks);
	if(k == 0){
		zwp_virtual_keyboard_v1_key(vk, time, keycode, state);
		return;
	}
	mod = mget();
	sendkey(k, mod, com, sizeof(com), pre, sizeof(pre), &eaten);
	if(com[0] != '\0')
		zwp_input_method_v2_commit_string(im, com);
	plen = strlen(pre);
	zwp_input_method_v2_set_preedit_string(im, pre, plen, plen);
	zwp_input_method_v2_commit(im, imserial);
	if(!eaten)
		zwp_virtual_keyboard_v1_key(vk, time, keycode, state);
}

static void
kg_keymap(void *data, struct zwp_input_method_keyboard_grab_v2 *g,
	uint32_t format, int32_t fd, uint32_t size)
{
	char *s;

	(void)data;
	(void)g;
	if(format != WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1){
		close(fd);
		return;
	}
	s = mmap(nil, size, PROT_READ, MAP_PRIVATE, fd, 0);
	if(s != MAP_FAILED){
		if(xkbst != nil){
			xkb_state_unref(xkbst);
			xkbst = nil;
		}
		if(keymap != nil)
			xkb_keymap_unref(keymap);
		keymap = xkb_keymap_new_from_string(xkb, s,
			XKB_KEYMAP_FORMAT_TEXT_V1,
			XKB_KEYMAP_COMPILE_NO_FLAGS);
		if(keymap != nil)
			xkbst = xkb_state_new(keymap);
		munmap(s, size);
	}
	zwp_virtual_keyboard_v1_keymap(vk, format, fd, size);
}

static void
kg_key(void *data, struct zwp_input_method_keyboard_grab_v2 *g,
	uint32_t serial, uint32_t time, uint32_t key, uint32_t state)
{
	(void)data;
	(void)g;
	(void)serial;
	kpress(time, key, state);
}

static void
kg_mods(void *data, struct zwp_input_method_keyboard_grab_v2 *g,
	uint32_t serial, uint32_t dep, uint32_t lat, uint32_t lck,
	uint32_t group)
{
	(void)data;
	(void)g;
	(void)serial;
	if(xkbst != nil)
		xkb_state_update_mask(xkbst, dep, lat, lck, 0, 0, group);
	zwp_virtual_keyboard_v1_modifiers(vk, dep, lat, lck, group);
}

static void
kg_repeat(void *data, struct zwp_input_method_keyboard_grab_v2 *g,
	int32_t rate, int32_t delay)
{
	(void)data;
	(void)g;
	(void)rate;
	(void)delay;
}

static const struct zwp_input_method_keyboard_grab_v2_listener
grab_listener = {
	.keymap = kg_keymap,
	.key = kg_key,
	.modifiers = kg_mods,
	.repeat_info = kg_repeat,
};

static void
im_activate(void *data, struct zwp_input_method_v2 *m)
{
	(void)data;
	(void)m;
	pending = 1;
}

static void
im_deactivate(void *data, struct zwp_input_method_v2 *m)
{
	(void)data;
	(void)m;
	pending = 0;
	if(active){
		active = 0;
		sendreset();
		if(grab != nil){
			zwp_input_method_keyboard_grab_v2_release(grab);
			grab = nil;
		}
	}
}

static void
im_surrounding(void *data, struct zwp_input_method_v2 *m,
	const char *text, uint32_t cursor, uint32_t anchor)
{
	(void)data;
	(void)m;
	(void)text;
	(void)cursor;
	(void)anchor;
}

static void
im_textchange(void *data, struct zwp_input_method_v2 *m, uint32_t cause)
{
	(void)data;
	(void)m;
	(void)cause;
}

static void
im_content(void *data, struct zwp_input_method_v2 *m,
	uint32_t hint, uint32_t purpose)
{
	(void)data;
	(void)m;
	(void)hint;
	(void)purpose;
}

static void
im_done(void *data, struct zwp_input_method_v2 *m)
{
	(void)data;
	(void)m;
	imserial++;
	if(pending && !active){
		active = 1;
		grab = zwp_input_method_v2_grab_keyboard(im);
		if(grab != nil)
			zwp_input_method_keyboard_grab_v2_add_listener(grab,
				&grab_listener, nil);
	}
}

static void
im_unavail(void *data, struct zwp_input_method_v2 *m)
{
	(void)data;
	(void)m;
	fprint(2, "strans: wayland: input-method unavailable\n");
}

static const struct zwp_input_method_v2_listener im_listener = {
	.activate = im_activate,
	.deactivate = im_deactivate,
	.surrounding_text = im_surrounding,
	.text_change_cause = im_textchange,
	.content_type = im_content,
	.done = im_done,
	.unavailable = im_unavail,
};

static void
reg_global(void *data, struct wl_registry *r, uint32_t name,
	const char *iface, uint32_t version)
{
	(void)data;
	(void)version;
	if(strcmp(iface, wl_seat_interface.name) == 0)
		seat = wl_registry_bind(r, name, &wl_seat_interface, 5);
	else if(strcmp(iface, zwp_input_method_manager_v2_interface.name) == 0)
		immgr = wl_registry_bind(r, name,
			&zwp_input_method_manager_v2_interface, 1);
	else if(strcmp(iface,
		zwp_virtual_keyboard_manager_v1_interface.name) == 0)
		vkmgr = wl_registry_bind(r, name,
			&zwp_virtual_keyboard_manager_v1_interface, 1);
}

static void
reg_remove(void *data, struct wl_registry *r, uint32_t name)
{
	(void)data;
	(void)r;
	(void)name;
}

static const struct wl_registry_listener reg_listener = {
	.global = reg_global,
	.global_remove = reg_remove,
};

void
waylandthread(void *_)
{
	struct wl_registry *reg;

	(void)_;
	threadsetname("wayland");
	dpy = wl_display_connect(nil);
	if(dpy == nil){
		fprint(2, "strans: wayland: cannot connect to display\n");
		return;
	}
	xkb = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
	if(xkb == nil){
		wl_display_disconnect(dpy);
		dpy = nil;
		return;
	}
	reg = wl_display_get_registry(dpy);
	wl_registry_add_listener(reg, &reg_listener, nil);
	wl_display_roundtrip(dpy);
	if(seat == nil || immgr == nil || vkmgr == nil){
		fprint(2,
			"strans: wayland: compositor missing input-method-v2\n");
		wl_display_disconnect(dpy);
		dpy = nil;
		return;
	}
	im = zwp_input_method_manager_v2_get_input_method(immgr, seat);
	zwp_input_method_v2_add_listener(im, &im_listener, nil);
	vk = zwp_virtual_keyboard_manager_v1_create_virtual_keyboard(vkmgr, seat);
	while(wl_display_dispatch(dpy) != -1)
		;
}