// Copyright 2019, Collabora, Ltd.
// SPDX-License-Identifier: BSL-1.0
/*!
 * @file
 * @brief  Wayland window code.
 * @author Lubosz Sarnecki <lubosz.sarnecki@collabora.com>
 * @author Jakob Bornecrantz <jakob@collabora.com>
 * @ingroup comp
 */

#ifdef VK_USE_PLATFORM_WAYLAND_KHR

#include <errno.h>
#include <linux/input.h>
#include <poll.h>
#include <stdlib.h>
#include <string.h>
#include <wayland-client.h>

#include "xdg-shell-client-protocol.h"
#include "xrt/xrt_compiler.h"
#include "main/comp_window.h"


/*
 *
 * Private structs.
 *
 */

/*!
 * A Wayland connection and window.
 */
struct comp_window_wayland
{
	struct comp_window base;

	struct wl_display *display;
	struct wl_compositor *compositor;
	struct wl_surface *surface;

	struct xdg_wm_base *wm_base;
	struct xdg_surface *xdg_surface;
	struct xdg_toplevel *xdg_toplevel;

	bool fullscreen_requested;
};


/*
 *
 * Pre declare functions.
 *
 */

static void
comp_window_wayland_destroy(struct comp_window *w);

static bool
comp_window_wayland_init(struct comp_window *w);

static void
comp_window_wayland_update_window_title(struct comp_window *w,
                                        const char *title);

static void
comp_window_wayland_registry_global(struct comp_window_wayland *w,
                                    struct wl_registry *registry,
                                    uint32_t name,
                                    const char *interface);

static void
comp_window_wayland_fullscreen(struct comp_window_wayland *w);

static bool
comp_window_wayland_init_swapchain(struct comp_window *w,
                                   uint32_t width,
                                   uint32_t height);

static VkResult
comp_window_wayland_create_surface(struct comp_window_wayland *w,
                                   VkSurfaceKHR *vk_surface);

static void
comp_window_wayland_flush(struct comp_window *w);

static void
comp_window_wayland_configure(struct comp_window_wayland *w,
                              int32_t width,
                              int32_t height);


/*
 *
 * Functions.
 *
 */

struct comp_window *
comp_window_wayland_create(struct comp_compositor *c)
{
	struct comp_window_wayland *w =
	    calloc(1, sizeof(struct comp_window_wayland));

	w->base.name = "wayland";
	w->base.destroy = comp_window_wayland_destroy;
	w->base.flush = comp_window_wayland_flush;
	w->base.init = comp_window_wayland_init;
	w->base.init_swapchain = comp_window_wayland_init_swapchain;
	w->base.update_window_title = comp_window_wayland_update_window_title;
	w->base.c = c;

	return &w->base;
}

static void
comp_window_wayland_destroy(struct comp_window *w)
{
	struct comp_window_wayland *w_wayland = (struct comp_window_wayland *)w;

	if (w_wayland->surface) {
		wl_surface_destroy(w_wayland->surface);
		w_wayland->surface = NULL;
	}
	if (w_wayland->compositor) {
		wl_compositor_destroy(w_wayland->compositor);
		w_wayland->compositor = NULL;
	}
	if (w_wayland->display) {
		wl_display_disconnect(w_wayland->display);
		w_wayland->display = NULL;
	}

	free(w);
}

static void
comp_window_wayland_update_window_title(struct comp_window *w,
                                        const char *title)
{
	struct comp_window_wayland *w_wayland = (struct comp_window_wayland *)w;
	xdg_toplevel_set_title(w_wayland->xdg_toplevel, title);
}

static void
comp_window_wayland_fullscreen(struct comp_window_wayland *w)
{
	xdg_toplevel_set_fullscreen(w->xdg_toplevel, NULL);
	wl_surface_commit(w->surface);
}

static void
_xdg_surface_configure_cb(void *data,
                          struct xdg_surface *surface,
                          uint32_t serial)
{
	xdg_surface_ack_configure(surface, serial);
}

static void
_xdg_toplevel_configure_cb(void *data,
                           struct xdg_toplevel *toplevel,
                           int32_t width,
                           int32_t height,
                           struct wl_array *states)
{
	struct comp_window_wayland *w = (struct comp_window_wayland *)data;
	comp_window_wayland_configure(w, width, height);
}

static const struct xdg_surface_listener xdg_surface_listener = {
    _xdg_surface_configure_cb,
};

static void
_xdg_toplevel_close_cb(void *data, struct xdg_toplevel *toplevel)
{}

static const struct xdg_toplevel_listener xdg_toplevel_listener = {
    _xdg_toplevel_configure_cb,
    _xdg_toplevel_close_cb,
};

static void
_xdg_wm_base_ping_cb(void *data, struct xdg_wm_base *wm_base, uint32_t serial)
{
	xdg_wm_base_pong(wm_base, serial);
}

static const struct xdg_wm_base_listener xdg_wm_base_listener = {
    _xdg_wm_base_ping_cb,
};

static bool
comp_window_wayland_init_swapchain(struct comp_window *w,
                                   uint32_t width,
                                   uint32_t height)
{
	struct comp_window_wayland *w_wayland = (struct comp_window_wayland *)w;
	VkResult ret;

	ret = comp_window_wayland_create_surface(w_wayland,
	                                         &w->swapchain.surface);
	if (ret != VK_SUCCESS) {
		COMP_ERROR(w->c, "Failed to create surface!");
		return false;
	}

	vk_swapchain_create(
	    &w->swapchain, width, height, w->c->settings.color_format,
	    w->c->settings.color_space, w->c->settings.present_mode);

	return true;
}

static VkResult
comp_window_wayland_create_surface(struct comp_window_wayland *w,
                                   VkSurfaceKHR *vk_surface)
{
	struct vk_bundle *vk = w->base.swapchain.vk;
	VkResult ret;

	VkWaylandSurfaceCreateInfoKHR surface_info = {
	    .sType = VK_STRUCTURE_TYPE_WAYLAND_SURFACE_CREATE_INFO_KHR,
	    .pNext = NULL,
	    .flags = 0,
	    .display = w->display,
	    .surface = w->surface,
	};

	ret = vk->vkCreateWaylandSurfaceKHR(vk->instance, &surface_info, NULL,
	                                    vk_surface);
	if (ret != VK_SUCCESS) {
		COMP_ERROR(w->base.c, "vkCreateWaylandSurfaceKHR: %s",
		           vk_result_string(ret));
		return ret;
	}

	return VK_SUCCESS;
}

static void
comp_window_wayland_flush(struct comp_window *w)
{
	struct comp_window_wayland *w_wayland = (struct comp_window_wayland *)w;

	while (wl_display_prepare_read(w_wayland->display) != 0)
		wl_display_dispatch_pending(w_wayland->display);
	if (wl_display_flush(w_wayland->display) < 0 && errno != EAGAIN) {
		wl_display_cancel_read(w_wayland->display);
		return;
	}

	struct pollfd fds[] = {
	    {
	        .fd = wl_display_get_fd(w_wayland->display),
	        .events = POLLIN,
	        .revents = 0,
	    },
	};

	if (poll(fds, 1, 0) > 0) {
		wl_display_read_events(w_wayland->display);
		wl_display_dispatch_pending(w_wayland->display);
	} else {
		wl_display_cancel_read(w_wayland->display);
	}
}

static void
_registry_global_remove_cb(void *data,
                           struct wl_registry *registry,
                           uint32_t name)
{}

static void
_registry_global_cb(void *data,
                    struct wl_registry *registry,
                    uint32_t name,
                    const char *interface,
                    uint32_t version)
{
	struct comp_window_wayland *w = (struct comp_window_wayland *)data;
	// vik_log_d("Interface: %s Version %d", interface, version);
	comp_window_wayland_registry_global(w, registry, name, interface);
}

static const struct wl_registry_listener registry_listener = {
    _registry_global_cb,
    _registry_global_remove_cb,
};

static void
comp_window_wayland_registry_global(struct comp_window_wayland *w,
                                    struct wl_registry *registry,
                                    uint32_t name,
                                    const char *interface)
{
	if (strcmp(interface, "wl_compositor") == 0) {
		w->compositor = (struct wl_compositor *)wl_registry_bind(
		    registry, name, &wl_compositor_interface, 4);
	} else if (strcmp(interface, "xdg_wm_base") == 0) {
		w->wm_base = (struct xdg_wm_base *)wl_registry_bind(
		    registry, name, &xdg_wm_base_interface, 1);
		xdg_wm_base_add_listener(w->wm_base, &xdg_wm_base_listener, w);
	}
}

static bool
comp_window_wayland_init(struct comp_window *w)
{
	struct comp_window_wayland *w_wayland = (struct comp_window_wayland *)w;

	w_wayland->display = wl_display_connect(NULL);
	if (!w_wayland->display) {
		return false;
	}

	struct wl_registry *registry =
	    wl_display_get_registry(w_wayland->display);
	wl_registry_add_listener(registry, &registry_listener, w_wayland);

	wl_display_roundtrip(w_wayland->display);

	wl_registry_destroy(registry);

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

	if (!w_wayland->wm_base) {
		COMP_ERROR(w->c, "Compositor is missing xdg-shell support");
	}

	w_wayland->xdg_surface =
	    xdg_wm_base_get_xdg_surface(w_wayland->wm_base, w_wayland->surface);

	xdg_surface_add_listener(w_wayland->xdg_surface, &xdg_surface_listener,
	                         w_wayland);

	w_wayland->xdg_toplevel =
	    xdg_surface_get_toplevel(w_wayland->xdg_surface);

	xdg_toplevel_add_listener(w_wayland->xdg_toplevel,
	                          &xdg_toplevel_listener, w_wayland);
	/* Sane defaults */
	xdg_toplevel_set_app_id(w_wayland->xdg_toplevel, "openxr");
	xdg_toplevel_set_title(w_wayland->xdg_toplevel, "OpenXR application");

	wl_surface_commit(w_wayland->surface);

	return true;
}

static void
comp_window_wayland_configure(struct comp_window_wayland *w,
                              int32_t width,
                              int32_t height)
{
	if (w->base.c->settings.fullscreen && !w->fullscreen_requested) {
		COMP_DEBUG(w->base.c, "Setting full screen");
		comp_window_wayland_fullscreen(w);
		w->fullscreen_requested = true;
	}
	// TODO: resize cb
	// resize_cb(m->size.first, m->size.second);
}

#endif