/**
 *   MIT/X11 License
 *   Modified  (c) 2017 Quentin “Sardem FF7” Glidic
 *
 *   Permission is hereby granted, free of charge, to any person obtaining
 *   a copy of this software and associated documentation files (the
 *   "Software"), to deal in the Software without restriction, including
 *   without limitation the rights to use, copy, modify, merge, publish,
 *   distribute, sublicense, and/or sell copies of the Software, and to
 *   permit persons to whom the Software is furnished to do so, subject to
 *   the following conditions:
 *
 *   The above copyright notice and this permission notice shall be
 *   included in all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 *   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 *   IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 *   CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 *   TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 *   SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#define G_LOG_DOMAIN    "Wayland"
#pragma GCC diagnostic ignored "-Wunused-variable"
#pragma GCC diagnostic ignored "-Wunused-parameter"

#include <config.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <locale.h>
#include <linux/input-event-codes.h>

#include <glib.h>
#include <glib/gstdio.h>
#include <cairo.h>
#include <wayland-client.h>
#include <wayland-cursor.h>
#include <xcb/xkb.h>
#include <libgwater-wayland.h>
#include <xkbcommon/xkbcommon.h>
#include <xkbcommon/xkbcommon-compose.h>

#include <nkutils-bindings.h>

#include "keyb.h"
#include "view.h"

#include "wayland-internal.h"
#include "display.h"
#include "display-internal.h"

#include "wlr-layer-shell-unstable-v1-protocol.h"

typedef struct _display_buffer_pool wayland_buffer_pool;
typedef struct
{
    wayland_stuff    *context;
    uint32_t         global_name;
    struct wl_output *output;
    int32_t          scale;
} wayland_output;

typedef struct
{
    wayland_buffer_pool *pool;
    struct wl_buffer    *buffer;
    uint8_t             *data;
    gboolean            released;
} wayland_buffer;

struct _display_buffer_pool
{
    wayland_stuff  *context;
    uint8_t        *data;
    size_t         size;
    int32_t        width;
    int32_t        height;
    gboolean       to_free;
    wayland_buffer *buffers;
};

static wayland_stuff               wayland_;
wayland_stuff                      *wayland = &wayland_;
static const cairo_user_data_key_t wayland_cairo_surface_user_data;

static void
wayland_buffer_cleanup ( wayland_buffer_pool *self )
{
    if ( !self->to_free ) {
        return;
    }

    size_t i, count = 0;
    for ( i = 0; i < wayland->buffer_count; ++i ) {
        if ( ( self->buffers[i].released ) && ( self->buffers[i].buffer != NULL ) ) {
            wl_buffer_destroy ( self->buffers[i].buffer );
            self->buffers[i].buffer = NULL;
        }
        if ( self->buffers[i].buffer == NULL ) {
            ++count;
        }
    }

    if ( count < wayland->buffer_count ) {
        return;
    }

    munmap ( self->data, self->size );
    g_free ( self );
}

static void
wayland_buffer_release ( void *data, struct wl_buffer *buffer )
{
    wayland_buffer_pool *self = data;

    size_t              i;
    for ( i = 0; i < wayland->buffer_count; ++i ) {
        if ( self->buffers[i].buffer == buffer ) {
            self->buffers[i].released = TRUE;
        }
    }

    wayland_buffer_cleanup ( self );
}

static const struct wl_buffer_listener wayland_buffer_listener = {
    wayland_buffer_release
};

wayland_buffer_pool *
display_buffer_pool_new ( gint width, gint height )
{
    struct wl_shm_pool *wl_pool;
    struct wl_buffer   *buffer;
    int                fd;
    uint8_t            *data;
    width  *= wayland->scale;
    height *= wayland->scale;
    int32_t stride;
    size_t  size;
    size_t  pool_size;

    stride    = cairo_format_stride_for_width ( CAIRO_FORMAT_ARGB32, width );
    size      = stride * height;
    pool_size = size * wayland->buffer_count;

    gchar filename[PATH_MAX];
    g_snprintf ( filename, PATH_MAX, "%s/rofi-wayland-surface", g_get_user_runtime_dir () );
    fd = g_open ( filename, O_CREAT | O_RDWR, 0 );
    g_unlink ( filename );
    if ( fd < 0 ) {
        g_warning ( "creating a buffer file for %zu B failed: %s", pool_size, g_strerror ( errno ) );
        return NULL;
    }
    if ( fcntl ( fd, F_SETFD, FD_CLOEXEC ) < 0 ) {
        g_close ( fd, NULL );
        return NULL;
    }
    if ( ftruncate ( fd, pool_size ) < 0 ) {
        g_close ( fd, NULL );
        return NULL;
    }

    data = mmap ( NULL, pool_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0 );
    if ( data == MAP_FAILED ) {
        g_warning ( "mmap of size %zu failed: %s", pool_size, g_strerror ( errno ) );
        close ( fd );
        return NULL;
    }

    wayland_buffer_pool *pool;
    pool = g_new0 ( wayland_buffer_pool, 1 );

    pool->width  = width;
    pool->height = height;

    pool->buffers = g_new0 ( wayland_buffer, wayland->buffer_count );

    wl_pool = wl_shm_create_pool ( wayland->shm, fd, pool_size );
    size_t i;
    for ( i = 0; i < wayland->buffer_count; ++i ) {
        pool->buffers[i].pool     = pool;
        pool->buffers[i].buffer   = wl_shm_pool_create_buffer ( wl_pool, size * i, width, height, stride, WL_SHM_FORMAT_ARGB8888 );
        pool->buffers[i].data     = data + size * i;
        pool->buffers[i].released = TRUE;
        wl_buffer_add_listener ( pool->buffers[i].buffer, &wayland_buffer_listener, pool );
    }
    wl_shm_pool_destroy ( wl_pool );
    close ( fd );

    return pool;
}

void
display_buffer_pool_free ( wayland_buffer_pool *self )
{
    self->to_free = TRUE;
    wayland_buffer_cleanup ( self );
}

static void
wayland_surface_protocol_enter ( void *data, struct wl_surface *wl_surface, struct wl_output *wl_output )
{
    wayland_output *output;

    output = g_hash_table_lookup ( wayland->outputs, wl_output );
    if ( output == NULL ) {
        return;
    }

    wl_surface_set_buffer_scale ( wl_surface, output->scale );

    if ( wayland->scale != output->scale ) {
        wayland->scale = output->scale;

        // create new buffers with the correct scaled size
        rofi_view_pool_refresh ( );

        RofiViewState *state = rofi_view_get_active ( );
        if ( state != NULL ) {
            rofi_view_set_size( state, -1, -1 );
        }
    }
}

static void
wayland_surface_protocol_leave ( void *data, struct wl_surface *wl_surface, struct wl_output *wl_output )
{
}

static const struct wl_surface_listener wayland_surface_interface = {
    .enter = wayland_surface_protocol_enter,
    .leave = wayland_surface_protocol_leave,
};

static void wayland_frame_callback ( void *data, struct wl_callback *callback, uint32_t time );

static const struct wl_callback_listener wayland_frame_wl_callback_listener = {
    .done = wayland_frame_callback,
};

cairo_surface_t *
display_buffer_pool_get_next_buffer ( wayland_buffer_pool *pool )
{
    wayland_buffer *buffer = NULL;
    size_t         i;
    for ( i = 0; ( buffer == NULL ) && ( i < wayland->buffer_count ); ++i ) {
        buffer = pool->buffers + i;
        if ( !buffer->released ) {
            buffer = NULL;
        }
    }
    if ( buffer == NULL ) {
        return NULL;
    }

    cairo_surface_t *surface;

    surface = cairo_image_surface_create_for_data ( buffer->data, CAIRO_FORMAT_ARGB32, pool->width, pool->height, cairo_format_stride_for_width ( CAIRO_FORMAT_ARGB32, pool->width ) );
    cairo_surface_set_user_data ( surface, &wayland_cairo_surface_user_data, buffer, NULL );
    return surface;
}

void
display_surface_commit ( cairo_surface_t *surface )
{
    if ( surface == NULL ) {
        return;
    }

    wayland_buffer      *buffer = cairo_surface_get_user_data ( surface, &wayland_cairo_surface_user_data );
    wayland_buffer_pool *pool   = buffer->pool;

    cairo_surface_destroy ( surface );

    wl_surface_damage ( wayland->surface, 0, 0, pool->width, pool->height );
    wl_surface_attach ( wayland->surface, buffer->buffer, 0, 0 );
    // FIXME: hidpi
    wl_surface_set_buffer_scale ( wayland->surface, wayland->scale );
    buffer->released = FALSE;

    wl_surface_commit ( wayland->surface );
}

static void
wayland_frame_callback ( void *data, struct wl_callback *callback, uint32_t timestamp )
{
    if ( wayland->frame_cb != NULL ) {
        wl_callback_destroy ( wayland->frame_cb );
        rofi_view_frame_callback ();
    }
    wayland->frame_cb = wl_surface_frame ( wayland->surface );
    wl_callback_add_listener ( wayland->frame_cb, &wayland_frame_wl_callback_listener, wayland );
}

static void
wayland_keyboard_keymap ( void *data, struct wl_keyboard *keyboard, enum wl_keyboard_keymap_format format, int32_t fd, uint32_t size )
{
    wayland_seat *self = data;

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

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

    struct xkb_keymap *keymap = xkb_keymap_new_from_string ( nk_bindings_seat_get_context ( wayland->bindings_seat ), str, XKB_KEYMAP_FORMAT_TEXT_V1, XKB_KEYMAP_COMPILE_NO_FLAGS );
    if ( keymap == NULL ) {
        fprintf ( stderr, "Failed to get Keymap for current keyboard device.\n" );
        return;
    }
    struct xkb_state *state = xkb_state_new ( keymap );
    if ( state == NULL ) {
        fprintf ( stderr, "Failed to get state object for current keyboard device.\n" );
        return;
    }

    nk_bindings_seat_update_keymap ( wayland->bindings_seat, keymap, state );
}

static void
wayland_keyboard_enter ( void *data, struct wl_keyboard *keyboard, uint32_t serial, struct wl_surface *surface, struct wl_array *keys )
{
    wayland_seat *self = data;

    wayland->last_seat = self;
    self->serial       = serial;

    uint32_t *key, *kend;
    for ( key = keys->data, kend = key + keys->size / sizeof ( *key ); key < kend; ++key ) {
        nk_bindings_seat_handle_key ( wayland->bindings_seat, NULL, *key + 8, NK_BINDINGS_KEY_STATE_PRESSED );
    }
}

static void
wayland_keyboard_leave ( void *data, struct wl_keyboard *keyboard, uint32_t serial, struct wl_surface *surface )
{
    wayland_seat *self = data;
    // TODO?
}

static gboolean
wayland_key_repeat ( void *data )
{
    wayland_seat *self = data;

    if ( self->repeat.key == 0 ) {
        self->repeat.source = NULL;
        return G_SOURCE_REMOVE;
    }

    char *text = nk_bindings_seat_handle_key( wayland->bindings_seat, NULL, self->repeat.key, NK_BINDINGS_KEY_STATE_PRESS );

    RofiViewState *state = rofi_view_get_active ( );
    if ( state == NULL ) {
        return G_SOURCE_REMOVE;
    }

    if ( text != NULL ) {
        rofi_view_handle_text ( state, text );
    }

    rofi_view_maybe_update ( state );

    return G_SOURCE_CONTINUE;
}

static gboolean
wayland_key_repeat_delay ( void *data )
{
    wayland_seat *self = data;

    if ( self->repeat.key == 0 ) {
        return FALSE;
    }

    char *text = nk_bindings_seat_handle_key( wayland->bindings_seat, NULL, self->repeat.key, NK_BINDINGS_KEY_STATE_PRESS );

    RofiViewState *state = rofi_view_get_active ( );
    if ( state == NULL ) {
        return G_SOURCE_REMOVE;
    }

    if ( text != NULL ) {
        rofi_view_handle_text ( state, text );
    }

    guint source_id = g_timeout_add ( self->repeat.rate, wayland_key_repeat, data );
    self->repeat.source = g_main_context_find_source_by_id ( NULL, source_id );

    rofi_view_maybe_update ( state );

    return G_SOURCE_REMOVE;
}

static void
wayland_keyboard_key ( void *data, struct wl_keyboard *keyboard, uint32_t serial, uint32_t time, uint32_t key, enum wl_keyboard_key_state kstate )
{
    RofiViewState *state = rofi_view_get_active ( );
    wayland_seat  *self  = data;

    gchar         *text;

    wayland->last_seat = self;
    self->serial       = serial;

    xkb_keycode_t keycode = key + 8;
    if ( kstate == WL_KEYBOARD_KEY_STATE_RELEASED ) {
        if ( keycode == self->repeat.key ) {
            self->repeat.key = 0;
            if ( self->repeat.source != NULL ) {
                g_source_destroy ( self->repeat.source );
                self->repeat.source = NULL;
            }
        }
        nk_bindings_seat_handle_key ( wayland->bindings_seat, NULL, keycode, NK_BINDINGS_KEY_STATE_RELEASE );
    }
    else if ( kstate == WL_KEYBOARD_KEY_STATE_PRESSED ) {
        char *text = nk_bindings_seat_handle_key ( wayland->bindings_seat, NULL, keycode, NK_BINDINGS_KEY_STATE_PRESS );

        if ( self->repeat.source != NULL ) {
            g_source_destroy ( self->repeat.source );
            self->repeat.source = NULL;
        }

        if ( state != NULL ) {
            if ( text != NULL ) {
                rofi_view_handle_text ( state, text );
            }
            self->repeat.key = keycode;
            guint source_id = g_timeout_add ( self->repeat.delay, wayland_key_repeat_delay, data );
            self->repeat.source = g_main_context_find_source_by_id ( NULL, source_id );
        }
    }

    if ( state != NULL ) {
        rofi_view_maybe_update ( state );
    }
}

static void
wayland_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 )
{
    wayland_seat *self = data;
    nk_bindings_seat_update_mask ( wayland->bindings_seat, NULL, mods_depressed, mods_latched, mods_locked, 0, 0, 0 );

    RofiViewState *state = rofi_view_get_active ( );
    if ( state != NULL ) {
        rofi_view_maybe_update ( state );
    }
}

static void
wayland_keyboard_repeat_info ( void *data, struct wl_keyboard *keyboard, int32_t rate, int32_t delay )
{
    wayland_seat *self = data;
    self->repeat.key   = 0;
    self->repeat.rate  = rate;
    self->repeat.delay = delay;
    if ( self->repeat.source != NULL ) {
        g_source_destroy ( self->repeat.source );
        self->repeat.source = NULL;
    }
}

static const struct wl_keyboard_listener wayland_keyboard_listener = {
    .keymap      = wayland_keyboard_keymap,
    .enter       = wayland_keyboard_enter,
    .leave       = wayland_keyboard_leave,
    .key         = wayland_keyboard_key,
    .modifiers   = wayland_keyboard_modifiers,
    .repeat_info = wayland_keyboard_repeat_info,
};

static void
wayland_cursor_set_image ( int i )
{
    struct wl_buffer       *buffer;
    struct wl_cursor_image *image;
    image = wayland->cursor.cursor->images[i];

    wayland->cursor.image = image;
    buffer                = wl_cursor_image_get_buffer ( wayland->cursor.image );
    wl_surface_attach ( wayland->cursor.surface, buffer, 0, 0 );
    wl_surface_damage ( wayland->cursor.surface, 0, 0, wayland->cursor.image->width, wayland->cursor.image->height );
    wl_surface_commit ( wayland->cursor.surface );
}

static void wayland_cursor_frame_callback ( void *data, struct wl_callback *callback, uint32_t time );

static const struct wl_callback_listener wayland_cursor_frame_wl_callback_listener = {
    .done = wayland_cursor_frame_callback,
};

static void
wayland_cursor_frame_callback ( void *data, struct wl_callback *callback, uint32_t time )
{
    int i;

    if ( wayland->cursor.frame_cb != NULL ) {
        wl_callback_destroy ( wayland->cursor.frame_cb );
    }
    wayland->cursor.frame_cb = wl_surface_frame ( wayland->cursor.surface );
    wl_callback_add_listener ( wayland->cursor.frame_cb, &wayland_cursor_frame_wl_callback_listener, wayland );

    i = wl_cursor_frame ( wayland->cursor.cursor, time );
    wayland_cursor_set_image ( i );
}

static void
wayland_pointer_send_events ( wayland_seat *self )
{
    RofiViewState *state = rofi_view_get_active ();

    if ( state == NULL ) {
        return;
    }

    if ( self->motion.x > -1 || self->motion.y > -1 )
    {
        rofi_view_handle_mouse_motion (state, self->motion.x, self->motion.y);
        self->motion.x = -1;
        self->motion.y = -1;
    }

    NkBindingsMouseButton button = -1;
    switch ( self->button.button )
    {
    case BTN_LEFT:
        button = NK_BINDINGS_MOUSE_BUTTON_PRIMARY;
        break;
    case BTN_RIGHT:
        button = NK_BINDINGS_MOUSE_BUTTON_SECONDARY;
        break;
    case BTN_MIDDLE:
        button = NK_BINDINGS_MOUSE_BUTTON_MIDDLE;
        break;
    }

    if ( self->button.button >= 0 ) {
        if ( self->button.pressed ) {
            rofi_view_handle_mouse_motion ( state, self->button.x, self->button.y );
            nk_bindings_seat_handle_button ( wayland->bindings_seat, NULL, button, NK_BINDINGS_BUTTON_STATE_PRESS, self->button.time );
        }
        else {
            nk_bindings_seat_handle_button ( wayland->bindings_seat, NULL, button, NK_BINDINGS_BUTTON_STATE_RELEASE, self->button.time );
        }
        self->button.button = 0;
    }

    if ( self->wheel.vertical != 0 ) {
        nk_bindings_seat_handle_scroll ( wayland->bindings_seat, NULL, NK_BINDINGS_SCROLL_AXIS_VERTICAL, self->wheel.vertical );
        self->wheel.vertical = 0;
    }

    if ( self->wheel.horizontal != 0 ) {
        nk_bindings_seat_handle_scroll ( wayland->bindings_seat, NULL, NK_BINDINGS_SCROLL_AXIS_HORIZONTAL, self->wheel.horizontal );
        self->wheel.horizontal = 0;
    }

    rofi_view_maybe_update ( state );
}

static void
wayland_pointer_enter ( void *data, struct wl_pointer *pointer, uint32_t serial, struct wl_surface *surface, wl_fixed_t x, wl_fixed_t y )
{
    wayland_seat *self = data;

    if ( wayland->cursor.surface == NULL ) {
        return;
    }

    if ( wayland->cursor.cursor->image_count < 2 ) {
        wayland_cursor_set_image ( 0 );
    }
    else{
        wayland_cursor_frame_callback ( wayland, wayland->cursor.frame_cb, 0 );
    }

    wl_pointer_set_cursor ( self->pointer, serial, wayland->cursor.surface, wayland->cursor.image->hotspot_x, wayland->cursor.image->hotspot_y );
}

static void
wayland_pointer_leave ( void *data, struct wl_pointer *pointer, uint32_t serial, struct wl_surface *surface )
{
    wayland_seat *self = data;

    if ( wayland->cursor.frame_cb != NULL ) {
        wl_callback_destroy ( wayland->cursor.frame_cb );
    }
}

static void
wayland_pointer_motion ( void *data, struct wl_pointer *pointer, uint32_t time, wl_fixed_t x, wl_fixed_t y )
{
    wayland_seat *self = data;

    self->button.x    = wl_fixed_to_int ( x );
    self->button.y    = wl_fixed_to_int ( y );
    self->motion.x    = wl_fixed_to_int ( x );
    self->motion.y    = wl_fixed_to_int ( y );
    self->motion.time = time;

    if ( wl_pointer_get_version ( self->pointer ) >= WL_POINTER_FRAME_SINCE_VERSION ) {
        return;
    }

    wayland_pointer_send_events ( self );
}

static void
wayland_pointer_button ( void *data, struct wl_pointer *pointer, uint32_t serial, uint32_t time, uint32_t button, enum wl_pointer_button_state state )
{
    wayland_seat *self = data;

    wayland->last_seat = self;
    self->serial       = serial;

    self->button.time    = time;
    self->button.pressed = ( state == WL_POINTER_BUTTON_STATE_PRESSED );
    self->button.button  = button;

    wayland_pointer_send_events ( self );
}

static void
wayland_pointer_axis ( void *data, struct wl_pointer *pointer, uint32_t time, enum wl_pointer_axis axis, wl_fixed_t value )
{
    wayland_seat *self = data;

    switch ( axis )
    {
    case WL_POINTER_AXIS_VERTICAL_SCROLL:
        self->wheel.vertical += (gint) ( wl_fixed_to_double ( value ) / 10. );
        break;
    case WL_POINTER_AXIS_HORIZONTAL_SCROLL:
        self->wheel.horizontal += (gint) ( wl_fixed_to_double ( value ) / 10. );
        break;
    }

    wayland_pointer_send_events ( self );
}

static void
wayland_pointer_frame ( void *data, struct wl_pointer *pointer )
{
    wayland_seat *self = data;
    wayland_pointer_send_events ( self );
}

static void
wayland_pointer_axis_source ( void *data, struct wl_pointer *pointer, enum wl_pointer_axis_source axis_source )
{
}

static void
wayland_pointer_axis_stop ( void *data, struct wl_pointer *pointer, uint32_t time, enum wl_pointer_axis axis )
{
}

static void
wayland_pointer_axis_discrete ( void *data, struct wl_pointer *pointer, enum wl_pointer_axis axis, int32_t discrete )
{
    wayland_seat *self = data;

    switch ( axis )
    {
    case WL_POINTER_AXIS_VERTICAL_SCROLL:
        self->wheel.vertical += discrete;
        break;
    case WL_POINTER_AXIS_HORIZONTAL_SCROLL:
        self->wheel.horizontal += discrete;
        break;
    }
}

static const struct wl_pointer_listener wayland_pointer_listener = {
    .enter         = wayland_pointer_enter,
    .leave         = wayland_pointer_leave,
    .motion        = wayland_pointer_motion,
    .button        = wayland_pointer_button,
    .axis          = wayland_pointer_axis,
    .frame         = wayland_pointer_frame,
    .axis_source   = wayland_pointer_axis_source,
    .axis_stop     = wayland_pointer_axis_stop,
    .axis_discrete = wayland_pointer_axis_discrete,
};

static void
wayland_keyboard_release ( wayland_seat *self )
{
    if ( self->keyboard == NULL ) {
        return;
    }

    if ( wl_keyboard_get_version ( self->keyboard ) >= WL_KEYBOARD_RELEASE_SINCE_VERSION ) {
        wl_keyboard_release ( self->keyboard );
    }
    else{
        wl_keyboard_destroy ( self->keyboard );
    }

    self->repeat.key = 0;
    if ( self->repeat.source != NULL ) {
        g_source_destroy ( self->repeat.source );
        self->repeat.source = NULL;
    }

    self->keyboard = NULL;
}

static void
wayland_pointer_release ( wayland_seat *self )
{
    if ( self->pointer == NULL ) {
        return;
    }

    if ( wl_pointer_get_version ( self->pointer ) >= WL_POINTER_RELEASE_SINCE_VERSION ) {
        wl_pointer_release ( self->pointer );
    }
    else{
        wl_pointer_destroy ( self->pointer );
    }

    self->pointer = NULL;
}

static void
wayland_seat_release ( wayland_seat *self )
{
    wayland_keyboard_release ( self );
    wayland_pointer_release ( self );

    if ( wl_seat_get_version ( self->seat ) >= WL_SEAT_RELEASE_SINCE_VERSION ) {
        wl_seat_release ( self->seat );
    }
    else{
        wl_seat_destroy ( self->seat );
    }

    g_hash_table_remove ( wayland->seats, self->seat );

    g_free ( self );
}

static void
wayland_seat_capabilities ( void *data, struct wl_seat *seat, uint32_t capabilities )
{
    wayland_seat *self = data;

    if ( ( capabilities & WL_SEAT_CAPABILITY_KEYBOARD ) && ( self->keyboard == NULL ) ) {
        self->keyboard = wl_seat_get_keyboard ( self->seat );
        wl_keyboard_add_listener ( self->keyboard, &wayland_keyboard_listener, self );
    }
    else if ( ( !( capabilities & WL_SEAT_CAPABILITY_POINTER ) ) && ( self->keyboard != NULL ) ) {
        wayland_keyboard_release ( self );
    }

    if ( ( capabilities & WL_SEAT_CAPABILITY_POINTER ) && ( self->pointer == NULL ) ) {
        self->pointer = wl_seat_get_pointer ( self->seat );
        wl_pointer_add_listener ( self->pointer, &wayland_pointer_listener, self );
    }
    else if ( ( !( capabilities & WL_SEAT_CAPABILITY_POINTER ) ) && ( self->pointer != NULL ) ) {
        wayland_pointer_release ( self );
    }
}

static void
wayland_seat_name ( void *data, struct wl_seat *seat, const char *name )
{
    wayland_seat *self = data;

    if ( self->name != NULL ) {
        g_hash_table_remove ( wayland->seats_by_name, self->name );
    }
    self->name = g_strdup ( name );
    g_hash_table_insert ( wayland->seats_by_name, self->name, self );
}

static const struct wl_seat_listener wayland_seat_listener = {
    .capabilities = wayland_seat_capabilities,
    .name         = wayland_seat_name,
};

static void
wayland_output_release ( wayland_output *self )
{
    if ( wl_output_get_version ( self->output ) >= WL_OUTPUT_RELEASE_SINCE_VERSION ) {
        wl_output_release ( self->output );
    }
    else{
        wl_output_destroy ( self->output );
    }

    g_hash_table_remove ( wayland->outputs, self->output );

    g_free ( self );
}

static void
wayland_output_done ( void *data, struct wl_output *output )
{
}

static void
wayland_output_geometry ( void *data, struct wl_output *output, int32_t x, int32_t y, int32_t width, int32_t height, int32_t subpixel, const char *make, const char *model, int32_t transform )
{
}

static void
wayland_output_mode ( void *data, struct wl_output *output, enum wl_output_mode flags, int32_t width, int32_t height, int32_t refresh )
{
}

static void
wayland_output_scale ( void *data, struct wl_output *output, int32_t scale )
{
    wayland_output *self = data;

    self->scale = scale;
}

static const struct wl_output_listener wayland_output_listener = {
    .geometry = wayland_output_geometry,
    .mode     = wayland_output_mode,
    .scale    = wayland_output_scale,
    .done     = wayland_output_done,
};

static const char * const              wayland_cursor_names[] = {
    "left_ptr",
    "default",
    "top_left_arrow",
    "left-arrow",
    NULL
};

static void
wayland_registry_handle_global ( void *data, struct wl_registry *registry, uint32_t name, const char *interface, uint32_t version )
{
    if ( g_strcmp0 ( interface, wl_compositor_interface.name ) == 0 ) {
        wayland->global_names[WAYLAND_GLOBAL_COMPOSITOR] = name;
        wayland->compositor                              = wl_registry_bind ( registry, name, &wl_compositor_interface, MIN ( version, WL_COMPOSITOR_INTERFACE_VERSION ) );
    }
    else if ( g_strcmp0 ( interface, zwlr_layer_shell_v1_interface.name ) == 0 ) {
        wayland->global_names[WAYLAND_GLOBAL_LAYER_SHELL] = name;
        wayland->layer_shell                              = wl_registry_bind ( registry, name, &zwlr_layer_shell_v1_interface, MIN ( version, WL_LAYER_SHELL_INTERFACE_VERSION ) );
    }
    else if ( g_strcmp0 ( interface, wl_shm_interface.name ) == 0 ) {
        wayland->global_names[WAYLAND_GLOBAL_SHM] = name;
        wayland->shm                              = wl_registry_bind ( registry, name, &wl_shm_interface, MIN ( version, WL_SHM_INTERFACE_VERSION ) );
    }
    else if ( g_strcmp0 ( interface, wl_seat_interface.name ) == 0 ) {
        wayland_seat *seat = g_new0 ( wayland_seat, 1 );
        seat->context     = wayland;
        seat->global_name = name;
        seat->seat        = wl_registry_bind ( registry, name, &wl_seat_interface, MIN ( version, WL_SEAT_INTERFACE_VERSION ) );
        g_hash_table_insert ( wayland->seats, seat->seat, seat );

        wl_seat_add_listener ( seat->seat, &wayland_seat_listener, seat );
    }
    else if ( g_strcmp0 ( interface, wl_output_interface.name ) == 0 ) {
        wayland_output *output = g_new0 ( wayland_output, 1 );
        output->context     = wayland;
        output->global_name = name;
        output->output      = wl_registry_bind ( registry, name, &wl_output_interface, MIN ( version, WL_OUTPUT_INTERFACE_VERSION ) );
        output->scale       = 1;

        g_hash_table_insert ( wayland->outputs, output->output, output );

        wl_output_add_listener ( output->output, &wayland_output_listener, output );
    }
}

static void
wayland_registry_handle_global_remove ( void *data, struct wl_registry *registry, uint32_t name )
{
    wayland_global_name i;
    for ( i = 0; i < _WAYLAND_GLOBAL_SIZE; ++i ) {
        if ( wayland->global_names[i] != name ) {
            continue;
        }
        wayland->global_names[i] = 0;

        switch ( i )
        {
        case WAYLAND_GLOBAL_COMPOSITOR:
            wl_compositor_destroy ( wayland->compositor );
            wayland->compositor = NULL;
            break;
        case WAYLAND_GLOBAL_LAYER_SHELL:
            zwlr_layer_shell_v1_destroy ( wayland->layer_shell );
            wayland->layer_shell = NULL;
            break;
        case WAYLAND_GLOBAL_SHM:
            wl_shm_destroy ( wayland->shm );
            wayland->shm = NULL;
            break;
        case _WAYLAND_GLOBAL_SIZE:
            g_assert_not_reached ();
        }
        return;
    }
    if ( ( wayland->cursor.theme != NULL ) && ( ( wayland->compositor == NULL ) || ( wayland->shm == NULL ) ) ) {
        if ( wayland->cursor.frame_cb != NULL ) {
            wl_callback_destroy ( wayland->cursor.frame_cb );
        }
        wayland->cursor.frame_cb = NULL;

        wl_surface_destroy ( wayland->cursor.surface );
        wl_cursor_theme_destroy ( wayland->cursor.theme );
        wayland->cursor.surface = NULL;
        wayland->cursor.image   = NULL;
        wayland->cursor.cursor  = NULL;
        wayland->cursor.theme   = NULL;
    }

    GHashTableIter iter;

    wayland_seat   *seat;
    g_hash_table_iter_init ( &iter, wayland->seats );
    while ( g_hash_table_iter_next ( &iter, NULL, (gpointer *) &seat ) ) {
        if ( seat->global_name != name ) {
            continue;
        }

        g_hash_table_iter_remove ( &iter );
        wayland_seat_release ( seat );
        return;
    }

    wayland_output *output;
    g_hash_table_iter_init ( &iter, wayland->outputs );
    while ( g_hash_table_iter_next ( &iter, NULL, (gpointer *) &output ) ) {
        if ( output->global_name != name ) {
            continue;
        }

        g_hash_table_iter_remove ( &iter );
        wayland_output_release ( output );
        return;
    }
}

static const struct wl_registry_listener wayland_registry_listener = {
    .global        = wayland_registry_handle_global,
    .global_remove = wayland_registry_handle_global_remove,
};

static void wayland_layer_shell_surface_configure ( void *data,
                                                    struct zwlr_layer_surface_v1 *surface,
                                                    uint32_t serial,
                                                    uint32_t width,
                                                    uint32_t height )
{
    wayland->layer_width  = width;
    wayland->layer_height = height;
    zwlr_layer_surface_v1_ack_configure ( surface, serial );
}

static void wayland_layer_shell_surface_closed ( void *data,
                                                 struct zwlr_layer_surface_v1 *surface )
{
    zwlr_layer_surface_v1_destroy ( surface );
    wl_surface_destroy ( wayland->surface );
    wayland->surface = NULL;
}

static const struct zwlr_layer_surface_v1_listener wayland_layer_shell_surface_listener = {
    .configure = wayland_layer_shell_surface_configure,
    .closed    = wayland_layer_shell_surface_closed,
};

static gboolean
wayland_error ( gpointer user_data )
{
    g_main_loop_quit ( wayland->main_loop );
    return G_SOURCE_REMOVE;
}

static gboolean
wayland_display_setup ( GMainLoop *main_loop, NkBindings *bindings )
{
    wayland->main_loop = main_loop;

    char *display = ( char *) g_getenv ( "WAYLAND_DISPLAY" );
    wayland->main_loop_source = g_water_wayland_source_new ( NULL, display );
    if ( wayland->main_loop_source == NULL ) {
        g_warning ( "Could not connect to the Wayland compositor" );
        return FALSE;
    }

    g_water_wayland_source_set_error_callback ( wayland->main_loop_source, wayland_error, NULL, NULL );

    wayland->buffer_count = 3;
    wayland->scale        = 1;

    wayland->outputs       = g_hash_table_new ( g_direct_hash, g_direct_equal );
    wayland->seats         = g_hash_table_new ( g_direct_hash, g_direct_equal );
    wayland->seats_by_name = g_hash_table_new_full ( g_str_hash, g_str_equal, g_free, NULL );

    wayland->display  = g_water_wayland_source_get_display ( wayland->main_loop_source );
    wayland->registry = wl_display_get_registry ( wayland->display );
    wl_registry_add_listener ( wayland->registry, &wayland_registry_listener, NULL );
    wl_display_roundtrip ( wayland->display );

    if ( wayland->compositor == NULL || wayland->shm == NULL || g_hash_table_size ( wayland->outputs ) == 0 || g_hash_table_size ( wayland->seats ) == 0 ) {
        g_error ( "Could not connect to wayland compositor" );
        return FALSE;
    }
    if ( wayland->layer_shell == NULL ) {
        g_error ( "Rofi on wayland requires support for the layer shell protocol" );
        return FALSE;
    }

    wayland->cursor.theme = wl_cursor_theme_load ( wayland->cursor.theme_name, 32, wayland->shm );
    if ( wayland->cursor.theme != NULL ) {
        const char * const *cname = (const char * const *) wayland->cursor.name;
        for ( cname = ( cname != NULL ) ? cname : wayland_cursor_names; ( wayland->cursor.cursor == NULL ) && ( *cname != NULL ); ++cname ) {
            wayland->cursor.cursor = wl_cursor_theme_get_cursor ( wayland->cursor.theme, *cname );
        }
        if ( wayland->cursor.cursor == NULL ) {
            wl_cursor_theme_destroy ( wayland->cursor.theme );
            wayland->cursor.theme = NULL;
        }
        else{
            wayland->cursor.surface = wl_compositor_create_surface ( wayland->compositor );
        }
    }

    wayland->surface = wl_compositor_create_surface ( wayland->compositor );

    wayland->bindings_seat = nk_bindings_seat_new ( bindings, XKB_CONTEXT_NO_FLAGS );

    wayland->wlr_surface = zwlr_layer_shell_v1_get_layer_surface ( wayland->layer_shell, wayland->surface, NULL, ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY, "rofi" );

    // Set size zero and anchor on all corners to get the usable screen size
    // see https://github.com/swaywm/wlroots/pull/2422
    zwlr_layer_surface_v1_set_anchor ( wayland->wlr_surface, ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM | ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT );
    zwlr_layer_surface_v1_set_size ( wayland->wlr_surface, 0, 0 );
    zwlr_layer_surface_v1_set_keyboard_interactivity ( wayland->wlr_surface, 1 );
    zwlr_layer_surface_v1_add_listener ( wayland->wlr_surface, &wayland_layer_shell_surface_listener, NULL );

    wl_surface_add_listener ( wayland->surface, &wayland_surface_interface, wayland );
    wl_surface_commit ( wayland->surface );
    wl_display_roundtrip ( wayland->display );
    wayland_frame_callback ( wayland, wayland->frame_cb, 0 );

    return TRUE;
}

static gboolean
wayland_display_late_setup ( void )
{
    return TRUE;
}

gboolean
display_get_surface_dimensions ( int *width, int *height )
{
    if ( wayland->layer_width != 0 ) {
        if ( width != NULL ) {
            *width = wayland->layer_width;
        }
        if ( height != NULL ) {
            *height = wayland->layer_height;
        }
        return TRUE;
    }
    return FALSE;
}

void
display_set_surface_dimensions ( int width, int height, int loc )
{
    wayland->layer_width  = width;
    wayland->layer_height = height;
    zwlr_layer_surface_v1_set_size ( wayland->wlr_surface, width, height );

    uint32_t wlr_anchor = 0;
    switch ( loc )
    {
    case WL_NORTH_WEST:
        wlr_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP;
        break;
    case WL_NORTH:
        wlr_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP;
        break;
    case WL_NORTH_EAST:
        wlr_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP;
        break;
    case WL_EAST:
        wlr_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
        break;
    case WL_SOUTH_EAST:
        wlr_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
        break;
    case WL_SOUTH:
        wlr_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
        break;
    case WL_SOUTH_WEST:
        wlr_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
        break;
    case WL_WEST:
        wlr_anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT;
        break;
    case WL_CENTER:
    default:
        break;
    }

    if ( height == 0 ) {
        wlr_anchor |= ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP;
    }
    if ( width == 0 ) {
        wlr_anchor |= ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
    }

    zwlr_layer_surface_v1_set_anchor ( wayland->wlr_surface, wlr_anchor );
}

static void
wayland_display_early_cleanup ( void )
{
}

static void
wayland_display_cleanup ( void )
{
    if ( wayland->main_loop_source == NULL ) {
        return;
    }

    if ( wayland->surface != NULL ) {
        wl_surface_destroy ( wayland->surface );
    }

    nk_bindings_seat_free ( wayland->bindings_seat );
    g_hash_table_unref ( wayland->seats_by_name );
    g_hash_table_unref ( wayland->seats );
    g_hash_table_unref ( wayland->outputs );
    wl_registry_destroy ( wayland->registry );
    wl_display_flush ( wayland->display );
    g_water_wayland_source_free ( wayland->main_loop_source );
}

static void
wayland_display_dump_monitor_layout ( void )
{
}

static void
wayland_display_startup_notification ( RofiHelperExecuteContext *context, GSpawnChildSetupFunc *child_setup, gpointer *user_data )
{
}

static int wayland_display_monitor_active ( workarea *mon )
{
    // TODO: do something?
    return FALSE;
}

static const struct _view_proxy* wayland_display_view_proxy ( void )
{
    return wayland_view_proxy;
}

static guint wayland_display_scale ( void )
{
    return wayland->scale;
}

static display_proxy  display_ = {
    .setup                = wayland_display_setup,
    .late_setup           = wayland_display_late_setup,
    .early_cleanup        = wayland_display_early_cleanup,
    .cleanup              = wayland_display_cleanup,
    .dump_monitor_layout  = wayland_display_dump_monitor_layout,
    .startup_notification = wayland_display_startup_notification,
    .monitor_active       = wayland_display_monitor_active,
    .scale                = wayland_display_scale,

    .view                 = wayland_display_view_proxy,
};

display_proxy * const wayland_proxy = &display_;