#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 <tkeyboard.h>
#include <config.h>

static void keyboard_keymap(void *data, struct wl_keyboard *keyboard, uint32_t format, int32_t fd, uint32_t size)
{
	struct keyboard_data *kbd = data;

	if (format != WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1)
	{
		close(fd);
		return;
	}

	char *map_str = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
	if (map_str == MAP_FAILED)
	{
		close(fd);
		return;
	}

	kbd->xkb_context = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
	kbd->xkb_keymap = xkb_keymap_new_from_string(
		kbd->xkb_context, map_str,
		XKB_KEYMAP_FORMAT_TEXT_V1,
		XKB_KEYMAP_COMPILE_NO_FLAGS);
	kbd->xkb_state = xkb_state_new(kbd->xkb_keymap);

	munmap(map_str, size);
	close(fd);
}

static void keyboard_enter(void *data, struct wl_keyboard *keyboard, uint32_t serial, struct wl_surface *surface, struct wl_array *keys)
{
	printf("keyboard_enter\n");
}

static void keyboard_leave(void *data, struct wl_keyboard *keyboard, uint32_t serial, struct wl_surface *surface)
{
	printf("keyboard_leave\n");
}

static void keyboard_key(void *data, struct wl_keyboard *keyboard, uint32_t serial, uint32_t time, uint32_t key, uint32_t state)
{
	struct keyboard_data *kbd = data;
	xkb_keysym_t sym = XKB_KEY_NoSymbol;

	if (kbd->xkb_state != NULL)
	{
		// Wayland keycodes are Linux evdev scancodes;
		// xkbcommon expects keycodes offset by 8.
		sym = xkb_state_key_get_one_sym(kbd->xkb_state, key + 8);
	}

	printf("keyboard_key: scancode=%d state=%d keysym=%u\n", key, state, sym);

	uint32_t mods = 0;
	if (kbd->xkb_state != NULL && kbd->xkb_keymap != NULL)
	{
		xkb_mod_index_t ci = xkb_keymap_mod_get_index(kbd->xkb_keymap, "Control");
		if (ci != XKB_MOD_INVALID && xkb_state_mod_index_is_active(kbd->xkb_state, ci, XKB_STATE_MODS_EFFECTIVE))
			mods |= MOD_CTRL;
		xkb_mod_index_t si = xkb_keymap_mod_get_index(kbd->xkb_keymap, "Shift");
		if (si != XKB_MOD_INVALID && xkb_state_mod_index_is_active(kbd->xkb_state, si, XKB_STATE_MODS_EFFECTIVE))
			mods |= MOD_SHIFT;
		xkb_mod_index_t ai = xkb_keymap_mod_get_index(kbd->xkb_keymap, "Mod1");
		if (ai != XKB_MOD_INVALID && xkb_state_mod_index_is_active(kbd->xkb_state, ai, XKB_STATE_MODS_EFFECTIVE))
			mods |= MOD_ALT;
		xkb_mod_index_t sui = xkb_keymap_mod_get_index(kbd->xkb_keymap, "Mod4");
		if (sui != XKB_MOD_INVALID && xkb_state_mod_index_is_active(kbd->xkb_state, sui, XKB_STATE_MODS_EFFECTIVE))
			mods |= MOD_SUPER;
	}

	if (kbd->handler != NULL)
	{
		kbd->handler(key, state, sym, mods, kbd->user_data);
	}
}

static void keyboard_modifiers(void *data, struct wl_keyboard *keyboard, uint32_t serial, uint32_t mods_depressed, uint32_t mods_latched, uint32_t mods_locked, uint32_t group)
{
	struct keyboard_data *kbd = data;

	if (kbd->xkb_state != NULL)
	{
		xkb_state_update_mask(kbd->xkb_state,
							  mods_depressed, mods_latched, mods_locked,
							  0, 0, group);
	}
}

static void keyboard_repeat_info(void *data, struct wl_keyboard *keyboard, int32_t rate, int32_t delay)
{
	// not implemented
}

const struct wl_keyboard_listener keyboard_listener = {
	.keymap = keyboard_keymap,
	.enter = keyboard_enter,
	.leave = keyboard_leave,
	.key = keyboard_key,
	.modifiers = keyboard_modifiers,
	.repeat_info = keyboard_repeat_info};

void keyboard_set_handler(struct keyboard_data *kbd, keyboard_key_handler_t handler, void *user_data)
{
	kbd->handler = handler;
	kbd->user_data = user_data;
}