#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <i915_drm.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <math.h>
#include <time.h>
#include <cairo.h>
#include <glib.h>

#include <GL/gl.h>
#include <eagle.h>

#include "wayland-client.h"
#include "wayland-glib.h"
#include "gears.h"

static const char gem_device[] = "/dev/dri/card0";
static const char socket_name[] = "\0wayland";

static void die(const char *msg)
{
	fprintf(stderr, "%s", msg);
	exit(EXIT_FAILURE);
}

static uint32_t name_cairo_surface(int fd, cairo_surface_t *surface)
{
	struct drm_i915_gem_create create;
	struct drm_gem_flink flink;
	struct drm_i915_gem_pwrite pwrite;
	int32_t width, height, stride;
	void *data;

	width = cairo_image_surface_get_width(surface);
	height = cairo_image_surface_get_height(surface);
	stride = cairo_image_surface_get_stride(surface);
	data = cairo_image_surface_get_data(surface);

	memset(&create, 0, sizeof(create));
	create.size = height * stride;

	if (ioctl(fd, DRM_IOCTL_I915_GEM_CREATE, &create) != 0) {
		fprintf(stderr, "gem create failed: %m\n");
		return 0;
	}

	pwrite.handle = create.handle;
	pwrite.offset = 0;
	pwrite.size = height * stride;
	pwrite.data_ptr = (uint64_t) (uintptr_t) data;
	if (ioctl(fd, DRM_IOCTL_I915_GEM_PWRITE, &pwrite) < 0) {
		fprintf(stderr, "gem pwrite failed: %m\n");
		return 0;
	}

	flink.handle = create.handle;
	if (ioctl(fd, DRM_IOCTL_GEM_FLINK, &flink) != 0) {
		fprintf(stderr, "gem flink failed: %m\n");
		return 0;
	}

#if 0
	/* We need to hold on to the handle until the server has received
	 * the attach request... we probably need a confirmation event.
	 * I guess the breadcrumb idea will suffice. */
	struct drm_gem_close close;
	close.handle = create.handle;
	if (ioctl(fd, DRM_IOCTL_GEM_CLOSE, &close) < 0) {
		fprintf(stderr, "gem close failed: %m\n");
		return 0;
	}
#endif

	return flink.name;
}

struct window {
	struct wl_surface *surface;
	int x, y, width, height, stride;
	int drag_x, drag_y, last_x, last_y;
	int state;
	uint32_t name;
	int fd;
	int redraw_scheduled;

	GLfloat gears_angle;
	struct gears *gears;
	EGLDisplay display;
	EGLContext context;
	EGLConfig config;
	EGLSurface egl_surface;
};

static gboolean
draw_window(void *data)
{
	struct window *window = data;
	cairo_surface_t *surface;
	cairo_t *cr;
	int border = 2, radius = 5, h;
	int margin = (border + 1) / 2;
	cairo_text_extents_t extents;
	const static char title[] = "Wayland First Post";

	surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24,
					     window->width,
					     window->height);

	cr = cairo_create(surface);
	cairo_set_line_width (cr, border);
	cairo_move_to(cr, margin, margin + radius);
	cairo_arc(cr, margin + radius, margin + radius, radius,
		  M_PI, 3 * M_PI / 2);
	cairo_line_to(cr, window->width - radius - margin, margin);
	cairo_arc(cr, window->width - margin - radius, margin + radius, radius,
		  3 * M_PI / 2, 2 * M_PI);
	cairo_line_to(cr, window->width - margin,
		      window->height - margin);
	cairo_line_to(cr, margin, window->height - margin);
	cairo_close_path(cr);
	cairo_set_source_rgba(cr, 0.2, 0.2, 0.2, 0.9);
	cairo_fill_preserve(cr);
	cairo_set_source_rgba(cr, 0, 0, 0, 1);
	cairo_set_font_size(cr, 14);
	cairo_text_extents(cr, title, &extents);
	h = margin + radius + extents.height + 10;
	cairo_move_to(cr, margin, h);
	cairo_line_to(cr, margin + window->width, h);
	cairo_stroke(cr);

	cairo_move_to(cr, (window->width - extents.width) / 2, 10 - extents.y_bearing);
	cairo_show_text(cr, title);

	cairo_destroy(cr);

	window->stride = cairo_image_surface_get_stride(surface);

	window->name = name_cairo_surface(window->fd, surface);
	cairo_surface_destroy(surface);

	wl_surface_attach(window->surface, window->name,
			  window->width, window->height, window->stride);
			  
	wl_surface_map(window->surface, 
		       window->x, window->y,
		       window->width, window->height);

	if (window->egl_surface != EGL_NO_SURFACE)
		eglDestroySurface(window->display, window->egl_surface);

	/* FIXME: We need to get the stride right here in a chipset
	 * independent way.  Maybe do it in name_cairo_surface(). */
	window->egl_surface = eglCreatePixmapForName(window->display,
						     window->config, window->name,
						     window->width, window->height,
						     window->stride, NULL);

	if (surface == NULL)
		die("failed to create surface\n");

	if (!eglMakeCurrent(window->display,
			    window->egl_surface, window->egl_surface, window->context))
		die("failed to make context current\n");

	glViewport(border, window->height - h - margin - 300, 300, 300);

	if (window->gears != NULL)
		gears_draw(window->gears, window->gears_angle);

	window->redraw_scheduled = 0;

	return FALSE;
}

enum window_state {
	WINDOW_STABLE,
	WINDOW_MOVING,
	WINDOW_RESIZING_UPPER_LEFT,
	WINDOW_RESIZING_UPPER_RIGHT,
	WINDOW_RESIZING_LOWER_LEFT,
	WINDOW_RESIZING_LOWER_RIGHT
};

enum location {
	LOCATION_INTERIOR,
	LOCATION_UPPER_LEFT,
	LOCATION_UPPER_RIGHT,
	LOCATION_LOWER_LEFT,
	LOCATION_LOWER_RIGHT,
	LOCATION_OUTSIDE
};

void event_handler(struct wl_display *display,
		   uint32_t opcode,
		   uint32_t arg1, uint32_t arg2, void *data)
{
	struct window *window = data;
	int location, border = 4;
	int grip_size = 16;

	if (opcode == 0) {
		window->last_x = arg1;
		window->last_y = arg2;
		switch (window->state) {
		case WINDOW_MOVING:
			window->x = window->drag_x + arg1;
			window->y = window->drag_y + arg2;
			wl_surface_map(window->surface, window->x, window->y,
				       window->width, window->height);
			break;
		case WINDOW_RESIZING_LOWER_RIGHT:
			window->width = window->drag_x + arg1;
			window->height = window->drag_y + arg2;
			if (!window->redraw_scheduled) {
				window->redraw_scheduled = 1;
				g_idle_add(draw_window, window);
			}
			break;
		}
	}

	if (window->x + border <= window->last_x &&
	    window->last_x < window->x + window->width - border &&
	    window->y + border <= window->last_y &&
	    window->last_y < window->y + window->height - border) {
		location = LOCATION_INTERIOR;
	} else if (window->x + window->width - grip_size <= window->last_x &&
		   window->last_x < window->x + window->width &&
		   window->y + window->height - grip_size <= window->last_y &&
		   window->last_y < window->y + window->height) {
		location = LOCATION_LOWER_RIGHT;
	} else {
		location = LOCATION_OUTSIDE;
	}

	if (opcode == 1 && arg1 == 0 && arg2 == 1) {
		switch (location) {
		case LOCATION_INTERIOR:
			window->drag_x = window->x - window->last_x;
			window->drag_y = window->y - window->last_y;
			window->state = WINDOW_MOVING;
			break;
		case LOCATION_LOWER_RIGHT:
			window->drag_x = window->width - window->last_x;
			window->drag_y = window->height - window->last_y;
			window->state = WINDOW_RESIZING_LOWER_RIGHT;
			break;
		default:
			window->state = WINDOW_STABLE;
			break;
		}
	} else if (opcode == 1 && arg1 == 0 && arg2 == 0) {
		window->state = WINDOW_STABLE;
	}
}

static struct window *
window_create(struct wl_display *display, int fd)
{
	EGLint major, minor, count;
	EGLConfig configs[64];
	struct window *window;

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

	window->surface = wl_display_create_surface(display);
	window->x = 200;
	window->y = 200;
	window->width = 450;
	window->height = 500;
	window->state = WINDOW_STABLE;
	window->fd = fd;
	window->gears = NULL;

	window->display = eglCreateDisplayNative("/dev/dri/card0", "i965");
	if (window->display == NULL)
		die("failed to create display\n");

	if (!eglInitialize(window->display, &major, &minor))
		die("failed to initialize display\n");

	if (!eglGetConfigs(window->display, configs, 64, &count))
		die("failed to get configs\n");

	window->config = configs[24];
	window->context = eglCreateContext(window->display, window->config, NULL, NULL);
	if (window->context == NULL)
		die("failed to create context\n");

	window->egl_surface = EGL_NO_SURFACE;

	draw_window(window);

	window->gears = gears_create();
	window->gears_angle = 0.0;

	return window;
}

static gboolean
draw(gpointer data)
{
	struct window *window = data;

	gears_draw(window->gears, window->gears_angle);
	wl_surface_damage(window->surface, 0, 0,
			  window->width, window->height);
	window->gears_angle += 1;

	return TRUE;
}

int main(int argc, char *argv[])
{
	struct wl_display *display;
	int fd;
	struct window *window;
	GMainLoop *loop;
	GSource *source;

	fd = open(gem_device, O_RDWR);
	if (fd < 0) {
		fprintf(stderr, "drm open failed: %m\n");
		return -1;
	}

	display = wl_display_create(socket_name);
	if (display == NULL) {
		fprintf(stderr, "failed to create display: %m\n");
		return -1;
	}

	loop = g_main_loop_new(NULL, FALSE);
	source = wayland_source_new(display);
	g_source_attach(source, NULL);

	window = window_create(display, fd);

	draw_window(window);

	wl_display_set_event_handler(display, event_handler, window);

	g_timeout_add(20, draw, window);

	g_main_loop_run(loop);

	return 0;
}