// SPDX-License-Identifier: GPL-3.0-only
/*
 * Wayland input handling.
 *
 * Copyright (c) 2024, Richard Acayan. All rights reserved.
 */

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <wayland-client-protocol.h>
#include <xkbcommon/xkbcommon.h>

#include "input.h"
#include "keymap.h"
#include "ufkbd.h"
#include "wayland.h"
#include "wayland/input-method-unstable-v2.h"
#include "wayland/virtual-keyboard-unstable-v1.h"

static void ignore()
{}

static void on_pointer_move(void *data,
			    struct wl_pointer *pointer __attribute__((unused)),
			    uint32_t serial __attribute__((unused)),
			    wl_fixed_t x,
			    wl_fixed_t y)
{
	struct ufkbd_wl_input *ctx = data;
	struct ufkbd_input_wayland *ufkbd_wl = ctx->ufkbd_wl;
	struct ufkbd_ctx *ufkbd = ufkbd_wl->ufkbd;

	ufkbd_input_position(ufkbd, UFKBD_PRESS_MAX - 1, x / 256, y / 256);
}

static void on_pointer_button(void *data,
			      struct wl_pointer *pointer,
			      uint32_t serial,
			      uint32_t time,
			      uint32_t button,
			      uint32_t state)
{
	struct ufkbd_wl_input *ctx = data;
	struct ufkbd_input_wayland *ufkbd_wl = ctx->ufkbd_wl;
	struct ufkbd_ctx *ufkbd = ufkbd_wl->ufkbd;

	if (state == WL_POINTER_BUTTON_STATE_PRESSED)
		ufkbd_input_press(ufkbd, UFKBD_PRESS_MAX - 1);
	else if (state == WL_POINTER_BUTTON_STATE_RELEASED)
		ufkbd_input_release(ufkbd, UFKBD_PRESS_MAX - 1);
}

static const struct wl_pointer_listener pointer_listener = {
	.enter = ignore,
	.leave = ignore,
	.motion = on_pointer_move,
	.button = on_pointer_button,
	.axis = ignore,
	.frame = ignore,
	.axis_source = ignore,
	.axis_stop = ignore,
	.axis_discrete = ignore,
	.axis_value120 = ignore,
	.axis_relative_direction = ignore,
};

void on_touch_down(void *data,
		   struct wl_touch *wl_touch,
		   uint32_t serial,
		   uint32_t time,
		   struct wl_surface *surface,
		   int32_t id,
		   wl_fixed_t x,
		   wl_fixed_t y)
{
	struct ufkbd_wl_input *ctx = data;
	struct ufkbd_input_wayland *ufkbd_wl = ctx->ufkbd_wl;
	struct ufkbd_ctx *ufkbd = ufkbd_wl->ufkbd;

	ufkbd_input_position(ufkbd, id, x / 256, y / 256);
	ufkbd_input_press(ufkbd, id);
}

void on_touch_up(void *data,
		 struct wl_touch *wl_touch,
		 uint32_t serial,
		 uint32_t time,
		 int32_t id)
{
	struct ufkbd_wl_input *ctx = data;
	struct ufkbd_input_wayland *ufkbd_wl = ctx->ufkbd_wl;
	struct ufkbd_ctx *ufkbd = ufkbd_wl->ufkbd;

	ufkbd_input_release(ufkbd, id);
}

void on_touch_motion(void *data,
		     struct wl_touch *wl_touch,
		     uint32_t time,
		     int32_t id,
		     wl_fixed_t x,
		     wl_fixed_t y)
{
	struct ufkbd_wl_input *ctx = data;
	struct ufkbd_input_wayland *ufkbd_wl = ctx->ufkbd_wl;
	struct ufkbd_ctx *ufkbd = ufkbd_wl->ufkbd;

	ufkbd_input_position(ufkbd, id, x / 256, y / 256);
}

static const struct wl_touch_listener touch_listener = {
	.down = on_touch_down,
	.up = on_touch_up,
	.motion = on_touch_motion,
	.frame = ignore,
	.cancel = ignore,
	.shape = ignore,
	.orientation = ignore,
};

static void on_seat_caps(void *data,
			 struct wl_seat *seat,
			 uint32_t capabilities)
{
	struct ufkbd_wl_input *ctx = data;

	if (capabilities & WL_SEAT_CAPABILITY_TOUCH) {
		ctx->touch = wl_seat_get_touch(seat);
		if (ctx->touch == NULL)
			return;

		wl_touch_add_listener(ctx->touch, &touch_listener, ctx);
	} else {
		if (ctx->touch != NULL)
			wl_touch_destroy(ctx->touch);

		ctx->touch = NULL;
	}

	if (capabilities & WL_SEAT_CAPABILITY_POINTER) {
		ctx->pointer = wl_seat_get_pointer(seat);
		if (ctx->pointer == NULL)
			return;

		wl_pointer_add_listener(ctx->pointer, &pointer_listener, ctx);
	} else {
		if (ctx->pointer != NULL)
			wl_pointer_destroy(ctx->pointer);

		ctx->pointer = NULL;
	}
}

static void on_seat_name(void *data,
			 struct wl_seat *seat,
			 const char *name)
{
	printf("wl: found seat %s\n", name);
}

struct wl_seat_listener seat_listener = {
	.name = on_seat_name,
	.capabilities = on_seat_caps,
};

static int try_create_virtual_keyboard(struct ufkbd_wl_input *ctx)
{
	struct ufkbd_keymap *keymap = ctx->ufkbd_wl->ufkbd->keymap;

	if (ctx->manager == NULL)
		return -EINVAL;

	if (ctx->seat == NULL)
		return -EINVAL;

	if (ctx->kb != NULL)
		return -EEXIST;

	ctx->kb = zwp_virtual_keyboard_manager_v1_create_virtual_keyboard(ctx->manager,
									  ctx->seat);
	if (ctx->kb == NULL)
		return -ENOMEM;

	zwp_virtual_keyboard_v1_keymap(ctx->kb, WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1,
				       keymap->fd, keymap->size);

	return 0;
}

static void on_global_vkman(void *data,
			    struct wl_registry *reg,
			    uint32_t name, uint32_t version)
{
	struct ufkbd_wl_input *ctx = data;

	ctx->manager = wl_registry_bind(reg, name,
					&zwp_virtual_keyboard_manager_v1_interface,
					version);
	if (ctx->manager == NULL)
		return;

	try_create_virtual_keyboard(ctx);
}

static void on_global_seat(void *data,
			   struct wl_registry *reg,
			   uint32_t name, uint32_t version)
{
	struct ufkbd_wl_input *ctx = data;

	ctx->seat = wl_registry_bind(reg, name, &wl_seat_interface, version);
	if (ctx->seat == NULL)
		return;

	wl_seat_add_listener(ctx->seat, &seat_listener, ctx);

	try_create_virtual_keyboard(ctx);
}

int ufkbd_wl_input_send_key(struct ufkbd_wl_input *ctx, int key, bool repeat)
{
	if (ctx->kb == NULL)
		return -ENODEV;

	zwp_virtual_keyboard_v1_key(ctx->kb, 0, key, WL_KEYBOARD_KEY_STATE_PRESSED);

	if (!repeat)
		zwp_virtual_keyboard_v1_key(ctx->kb, 0, key, WL_KEYBOARD_KEY_STATE_RELEASED);

	return 0;
}

int ufkbd_wl_input_send_mod(struct ufkbd_wl_input *ctx, enum ufkbd_modifier mod, bool pressed)
{
	int bit;

	if (ctx->kb == NULL)
		return -ENODEV;

	if (mod == UFKBD_MOD_SHIFT)
		bit = 0x1;
	else if (mod == UFKBD_MOD_CTRL)
		bit = 0x4;
	else if (mod == UFKBD_MOD_ALT)
		bit = 0x8;
	else
		bit = 0;

	if (pressed)
		ctx->mod_state |= bit;
	else
		ctx->mod_state &= ~bit;

	zwp_virtual_keyboard_v1_modifiers(ctx->kb, ctx->mod_state, 0, 0, 0);

	return 0;
}

int ufkbd_wl_input_init(struct ufkbd_input_wayland *ufkbd_wl,
			struct ufkbd_wl_input **out)
{
	struct ufkbd_wl_input *ctx;
	int ret;

	ctx = calloc(1, sizeof(*ctx));
	if (ctx == NULL)
		return -errno;

	ctx->ufkbd_wl = ufkbd_wl;

	ctx->listener_seat.iface = &wl_seat_interface;
	ctx->listener_seat.cb = on_global_seat;
	ctx->listener_seat.data = ctx;

	ret = ufkbd_wl_global_listener_add(ufkbd_wl, &ctx->listener_seat);
	if (ret)
		goto err;

	ctx->listener_manager.iface = &zwp_virtual_keyboard_manager_v1_interface;
	ctx->listener_manager.cb = on_global_vkman;
	ctx->listener_manager.data = ctx;

	ret = ufkbd_wl_global_listener_add(ufkbd_wl, &ctx->listener_manager);
	if (ret)
		goto err;

	*out = ctx;

	return 0;

err:
	free(ctx);
	return ret;
}

void ufkbd_wl_input_uninit(struct ufkbd_wl_input *ctx)
{
	if (ctx->touch != NULL)
		wl_touch_destroy(ctx->touch);

	if (ctx->pointer != NULL)
		wl_pointer_destroy(ctx->pointer);

	if (ctx->seat != NULL)
		wl_seat_destroy(ctx->seat);

	if (ctx->kb != NULL)
		zwp_virtual_keyboard_v1_destroy(ctx->kb);

	if (ctx->manager != NULL)
		zwp_virtual_keyboard_manager_v1_destroy(ctx->manager);

	free(ctx);
}