/*
 * Copyright © 2010 Benjamin Franzke
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stddef.h>
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>

#include <wayland-client.h>
#include <wayland-egl.h>

#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
#include <EGL/egl.h>
#include <EGL/eglext.h>

#include "compositor.h"

struct wayland_compositor {
	struct wlsc_compositor	 base;

	struct {
		struct wl_display *display;
		struct wl_compositor *compositor;
		struct wl_shell *shell;
		struct wl_output *output;

		struct {
			int32_t x, y, width, height;
		} screen_allocation;

		struct wl_event_source *wl_source;
		uint32_t event_mask;
	} parent;

	struct wl_list input_list;
};

struct wayland_output {
	struct wlsc_output	base;

	struct {
		struct wl_surface	*surface;
		struct wl_egl_window	*egl_window;
	} parent;
	EGLSurface egl_surface;
};

struct wayland_input {
	struct wayland_compositor *compositor;
	struct wl_input_device *input_device;
	struct wl_list link;
};

static int
wayland_input_create(struct wayland_compositor *c)
{
	struct wlsc_input_device *input;

	input = malloc(sizeof *input);
	if (input == NULL)
		return -1;

	memset(input, 0, sizeof *input);
	wlsc_input_device_init(input, &c->base);

	c->base.input_device = &input->input_device;

	return 0;
}

static int
wayland_compositor_init_egl(struct wayland_compositor *c)
{
	EGLint major, minor;
	EGLint n;
	const char *extensions;
	EGLint config_attribs[] = {
		EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
		EGL_RED_SIZE, 1,
		EGL_GREEN_SIZE, 1,
		EGL_BLUE_SIZE, 1,
		EGL_DEPTH_SIZE, 1,
		EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
		EGL_NONE
	};
	static const EGLint context_attribs[] = {
		EGL_CONTEXT_CLIENT_VERSION, 2,
		EGL_NONE
	};

	c->base.display = eglGetDisplay(c->parent.display);
	if (c->base.display == NULL) {
		fprintf(stderr, "failed to create display\n");
		return -1;
	}

	if (!eglInitialize(c->base.display, &major, &minor)) {
		fprintf(stderr, "failed to initialize display\n");
		return -1;
	}

	extensions = eglQueryString(c->base.display, EGL_EXTENSIONS);
	if (!strstr(extensions, "EGL_KHR_surfaceless_opengl")) {
		fprintf(stderr, "EGL_KHR_surfaceless_opengl not available\n");
		return -1;
	}

	if (!eglBindAPI(EGL_OPENGL_ES_API)) {
		fprintf(stderr, "failed to bind EGL_OPENGL_ES_API\n");
		return -1;
	}
   	if (!eglChooseConfig(c->base.display, config_attribs,
			     &c->base.config, 1, &n) || n == 0) {
		fprintf(stderr, "failed to choose config: %d\n", n);
		return -1;
	}

	c->base.context = eglCreateContext(c->base.display, c->base.config,
					   EGL_NO_CONTEXT, context_attribs);
	if (c->base.context == NULL) {
		fprintf(stderr, "failed to create context\n");
		return -1;
	}

	if (!eglMakeCurrent(c->base.display, EGL_NO_SURFACE,
			    EGL_NO_SURFACE, c->base.context)) {
		fprintf(stderr, "failed to make context current\n");
		return -1;
	}

	return 0;
}

static void
frame_callback(struct wl_surface *surface, void *data, uint32_t time)
{
	struct wlsc_output *output = data;

	wlsc_output_finish_frame(output, time);
}

static int
wayland_output_prepare_render(struct wlsc_output *output_base)
{
	struct wayland_output *output = (struct wayland_output *) output_base;
	struct wlsc_compositor *ec = output->base.compositor;

	if (!eglMakeCurrent(ec->display, output->egl_surface,
			    output->egl_surface, ec->context)) {
		fprintf(stderr, "failed to make current\n");
		return -1;
	}

	return 0;
}

static int
wayland_output_present(struct wlsc_output *output_base)
{
	struct wayland_output *output = (struct wayland_output *) output_base;
	struct wayland_compositor *c =
		(struct wayland_compositor *) output->base.compositor;

	if (wayland_output_prepare_render(&output->base))
		return -1;

	eglSwapBuffers(c->base.display, output->egl_surface);
	wl_display_frame_callback(c->parent.display,
				  output->parent.surface,
				  frame_callback, &output->base);

	return 0;
}

static int
wayland_output_prepare_scanout_surface(struct wlsc_output *output_base,
				       struct wlsc_surface *es)
{
	return -1;
}

static int
wayland_output_set_cursor(struct wlsc_output *output_base,
			  struct wl_input_device *input)
{
	return -1;
}

static int
wayland_compositor_create_output(struct wayland_compositor *c,
				 int width, int height)
{
	struct wayland_output *output;
	struct wl_visual *visual;

	output = malloc(sizeof *output);
	if (output == NULL)
		return -1;
	memset(output, 0, sizeof *output);

	wlsc_output_init(&output->base, &c->base, 0, 0, width, height,
			 WL_OUTPUT_FLIPPED);
	output->parent.surface =
		wl_compositor_create_surface(c->parent.compositor);
	wl_surface_set_user_data(output->parent.surface, output);

	visual = wl_display_get_premultiplied_argb_visual(c->parent.display);

	output->parent.egl_window =
		wl_egl_window_create(output->parent.surface,
				     width, height, visual);
	if (!output->parent.egl_window) {
		fprintf(stderr, "failure to create wl_egl_window\n");
		goto cleanup_output;
	}

	output->egl_surface =
		eglCreateWindowSurface(c->base.display, c->base.config,
				       output->parent.egl_window, NULL);
	if (!output->egl_surface) {
		fprintf(stderr, "failed to create window surface\n");
		goto cleanup_window;
	}

	if (!eglMakeCurrent(c->base.display, output->egl_surface,
			    output->egl_surface, c->base.context)) {
		fprintf(stderr, "failed to make surface current\n");
		goto cleanup_surface;
		return -1;
	}

	wl_surface_map_toplevel(output->parent.surface);

	glClearColor(0, 0, 0, 0.5);

	output->base.prepare_render = wayland_output_prepare_render;
	output->base.present = wayland_output_present;
	output->base.prepare_scanout_surface =
		wayland_output_prepare_scanout_surface;
	output->base.set_hardware_cursor = wayland_output_set_cursor;

	wl_list_insert(c->base.output_list.prev, &output->base.link);

	return 0;

cleanup_surface:
	eglDestroySurface(c->base.display, output->egl_surface);
cleanup_window:
	wl_egl_window_destroy(output->parent.egl_window);
cleanup_output:
	/* FIXME: cleanup wlsc_output */
	free(output);

	return -1;
}

/* Events received from the wayland-server this compositor is client of: */

/* parent output interface */
static void
display_handle_geometry(void *data,
			struct wl_output *output,
			int32_t x, int32_t y,
			int32_t width, int32_t height)
{
	struct wayland_compositor *c = data;

	c->parent.screen_allocation.x = x;
	c->parent.screen_allocation.y = y;
	c->parent.screen_allocation.width = width;
	c->parent.screen_allocation.height = height;
}

static const struct wl_output_listener output_listener = {
	display_handle_geometry,
};

/* parent shell interface */
static void
handle_configure(void *data, struct wl_shell *shell,
		 uint32_t time, uint32_t edges,
		 struct wl_surface *surface, int32_t width, int32_t height)
{
#if 0
	struct output *output = wl_surface_get_user_data(surface);

	/* FIXME: add resize? */
#endif
}

static const struct wl_shell_listener shell_listener = {
	handle_configure,
};

/* parent input interface */
static void
input_handle_motion(void *data, struct wl_input_device *input_device,
		     uint32_t time,
		     int32_t x, int32_t y, int32_t sx, int32_t sy)
{
	struct wayland_input *input = data;
	struct wayland_compositor *c = input->compositor;

	notify_motion(c->base.input_device, time, sx, sy);
}

static void
input_handle_button(void *data,
		     struct wl_input_device *input_device,
		     uint32_t time, uint32_t button, uint32_t state)
{
	struct wayland_input *input = data;
	struct wayland_compositor *c = input->compositor;

	notify_button(c->base.input_device, time, button, state);
}

static void
input_handle_key(void *data, struct wl_input_device *input_device,
		  uint32_t time, uint32_t key, uint32_t state)
{
	struct wayland_input *input = data;
	struct wayland_compositor *c = input->compositor;

	notify_key(c->base.input_device, time, key, state);
}

static void
input_handle_pointer_focus(void *data,
			    struct wl_input_device *input_device,
			    uint32_t time, struct wl_surface *surface,
			    int32_t x, int32_t y, int32_t sx, int32_t sy)
{
	struct wayland_input *input = data;
	struct wayland_output *output;
	struct wayland_compositor *c = input->compositor;

	if (surface) {
		output = wl_surface_get_user_data(surface);
		notify_pointer_focus(c->base.input_device,
				     time, &output->base, sx, sy);
	} else {
		notify_pointer_focus(c->base.input_device, time, NULL, 0, 0);
	}
}

static void
input_handle_keyboard_focus(void *data,
			     struct wl_input_device *input_device,
			     uint32_t time,
			     struct wl_surface *surface,
			     struct wl_array *keys)
{
	struct wayland_input *input = data;
	struct wayland_compositor *c = input->compositor;
	struct wayland_output *output;

	if (surface) {
		output = wl_surface_get_user_data(surface);
		notify_keyboard_focus(c->base.input_device,
				      time, &output->base, keys);
	} else {
		notify_keyboard_focus(c->base.input_device, time, NULL, NULL);
	}
}

static const struct wl_input_device_listener input_device_listener = {
	input_handle_motion,
	input_handle_button,
	input_handle_key,
	input_handle_pointer_focus,
	input_handle_keyboard_focus,
};

static void
display_add_input(struct wayland_compositor *c, uint32_t id)
{
	struct wayland_input *input;

	input = malloc(sizeof *input);
	if (input == NULL)
		return;

	memset(input, 0, sizeof *input);

	input->compositor = c;
	input->input_device = wl_input_device_create(c->parent.display, id, 1);
	wl_list_insert(c->input_list.prev, &input->link);

	wl_input_device_add_listener(input->input_device,
				     &input_device_listener, input);
	wl_input_device_set_user_data(input->input_device, input);
}

static void
display_handle_global(struct wl_display *display, uint32_t id,
		      const char *interface, uint32_t version, void *data)
{
	struct wayland_compositor *c = data;

	if (strcmp(interface, "wl_compositor") == 0) {
		c->parent.compositor = wl_compositor_create(display, id, 1);
	} else if (strcmp(interface, "wl_output") == 0) {
		c->parent.output = wl_output_create(display, id, 1);
		wl_output_add_listener(c->parent.output, &output_listener, c);
	} else if (strcmp(interface, "wl_input_device") == 0) {
		display_add_input(c, id);
	} else if (strcmp(interface, "wl_shell") == 0) {
		c->parent.shell = wl_shell_create(display, id, 1);
		wl_shell_add_listener(c->parent.shell, &shell_listener, c);
	}
}

static int
update_event_mask(uint32_t mask, void *data)
{
	struct wayland_compositor *c = data;

	c->parent.event_mask = mask;
	if (c->parent.wl_source)
		wl_event_source_fd_update(c->parent.wl_source, mask);

	return 0;
}

static int
wayland_compositor_handle_event(int fd, uint32_t mask, void *data)
{
	struct wayland_compositor *c = data;

	if (mask & WL_EVENT_READABLE)
		wl_display_iterate(c->parent.display, WL_DISPLAY_READABLE);
	if (mask & WL_EVENT_WRITEABLE)
		wl_display_iterate(c->parent.display, WL_DISPLAY_WRITABLE);

	return 1;
}

static void
wayland_destroy(struct wlsc_compositor *ec)
{
	free(ec);
}

struct wlsc_compositor *
wayland_compositor_create(struct wl_display *display, int width, int height)
{
	struct wayland_compositor *c;
	struct wl_event_loop *loop;
	int fd;

	c = malloc(sizeof *c);
	if (c == NULL)
		return NULL;

	memset(c, 0, sizeof *c);

	c->parent.display = wl_display_connect(NULL);

	if (c->parent.display == NULL) {
		fprintf(stderr, "failed to create display: %m\n");
		return NULL;
	}

	wl_list_init(&c->input_list);
	wl_display_add_global_listener(c->parent.display,
				display_handle_global, c);

	wl_display_iterate(c->parent.display, WL_DISPLAY_READABLE);

	c->base.wl_display = display;
	if (wayland_compositor_init_egl(c) < 0)
		return NULL;

	c->base.destroy = wayland_destroy;

	/* Can't init base class until we have a current egl context */
	if (wlsc_compositor_init(&c->base, display) < 0)
		return NULL;

	if (wayland_compositor_create_output(c, width, height) < 0)
		return NULL;

	if (wayland_input_create(c) < 0)
		return NULL;

	loop = wl_display_get_event_loop(c->base.wl_display);

	fd = wl_display_get_fd(c->parent.display, update_event_mask, c);
	c->parent.wl_source =
		wl_event_loop_add_fd(loop, fd, c->parent.event_mask,
				     wayland_compositor_handle_event, c);
	if (c->parent.wl_source == NULL)
		return NULL;

	return &c->base;
}

struct wlsc_compositor *
backend_init(struct wl_display *display, char *options)
{
	int width = 1024, height = 640, i;
	char *p, *value;

	static char * const tokens[] = { "width", "height", NULL };
	
	p = options;
	while (i = getsubopt(&p, tokens, &value), i != -1) {
		switch (i) {
		case 0:
			width = strtol(value, NULL, 0);
			break;
		case 1:
			height = strtol(value, NULL, 0);
			break;
		}
	}

	return wayland_compositor_create(display, width, height);
}