/*
 * Copyright © 2008 Kristian Høgsberg
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

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

#include <linux/input.h>
#include "wayland-client.h"
#include "wayland-glib.h"

#include "cairo-util.h"

#include "window.h"

struct window {
	struct wl_display *display;
	struct wl_compositor *compositor;
	struct wl_surface *surface;
	const char *title;
	struct rectangle allocation, saved_allocation, screen_allocation;
	int minimum_width, minimum_height;
	int margin;
	int drag_x, drag_y;
	int state;
	int fullscreen;
	struct wl_input_device *grab_device;
	uint32_t name;
	int fd;

	struct buffer *buffer;

	window_resize_handler_t resize_handler;
	window_key_handler_t key_handler;
	void *user_data;
};

static void
rounded_rect(cairo_t *cr, int x0, int y0, int x1, int y1, int radius)
{
	cairo_move_to(cr, x0, y0 + radius);
	cairo_arc(cr, x0 + radius, y0 + radius, radius, M_PI, 3 * M_PI / 2);
	cairo_line_to(cr, x1 - radius, y0);
	cairo_arc(cr, x1 - radius, y0 + radius, radius, 3 * M_PI / 2, 2 * M_PI);
	cairo_line_to(cr, x1, y1 - radius);
	cairo_arc(cr, x1 - radius, y1 - radius, radius, 0, M_PI / 2);
	cairo_line_to(cr, x0 + radius, y1);
	cairo_arc(cr, x0 + radius, y1 - radius, radius, M_PI / 2, M_PI);
	cairo_close_path(cr);
}

static void
window_draw_decorations(struct window *window)
{
	cairo_surface_t *surface;
	cairo_t *cr;
	int border = 2, radius = 5;
	cairo_text_extents_t extents;
	cairo_pattern_t *gradient, *outline, *bright, *dim;
	struct wl_visual *visual;
	int width, height;

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

	outline = cairo_pattern_create_rgb(0.1, 0.1, 0.1);
	bright = cairo_pattern_create_rgb(0.8, 0.8, 0.8);
	dim = cairo_pattern_create_rgb(0.4, 0.4, 0.4);

	cr = cairo_create(surface);

	width = window->allocation.width - window->margin * 2;
	height = window->allocation.height - window->margin * 2;

	cairo_translate(cr, window->margin + 7, window->margin + 5);
	cairo_set_line_width (cr, border);
	cairo_set_source_rgba(cr, 0, 0, 0, 0.7);
	rounded_rect(cr, 0, 0, width, height, radius);
	cairo_fill(cr);
	blur_surface(surface, 24 + radius);

	cairo_translate(cr, -7, -5);
	cairo_set_line_width (cr, border);
	rounded_rect(cr, 1, 1, width - 1, height - 1, radius);
	cairo_set_source(cr, outline);
	cairo_stroke(cr);
	rounded_rect(cr, 2, 2, width - 2, height - 2, radius - 1);
	cairo_set_source(cr, bright);
	cairo_stroke(cr);
	rounded_rect(cr, 3, 3, width - 2, height - 2, radius - 1);
	cairo_set_source(cr, dim);
	cairo_stroke(cr);

	rounded_rect(cr, 2, 2, width - 2, height - 2, radius - 1);
	gradient = cairo_pattern_create_linear (0, 0, 0, 100);
	cairo_pattern_add_color_stop_rgb(gradient, 0, 0.6, 0.6, 0.4);
	cairo_pattern_add_color_stop_rgb(gradient, 1, 0.8, 0.8, 0.7);
	cairo_set_source(cr, gradient);
	cairo_fill(cr);
	cairo_pattern_destroy(gradient);

	cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
	cairo_move_to(cr, 10, 50);
	cairo_line_to(cr, width - 10, 50);
	cairo_line_to(cr, width - 10, height - 10);
	cairo_line_to(cr, 10, height - 10);
	cairo_close_path(cr);
	cairo_set_source(cr, dim);
	cairo_stroke(cr);

	cairo_move_to(cr, 11, 51);
	cairo_line_to(cr, width - 10, 51);
	cairo_line_to(cr, width - 10, height - 10);
	cairo_line_to(cr, 11, height - 10);
	cairo_close_path(cr);
	cairo_set_source(cr, bright);
	cairo_stroke(cr);

	cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
	cairo_set_font_size(cr, 14);
	cairo_text_extents(cr, window->title, &extents);
	cairo_move_to(cr, (width - extents.width) / 2, 10 - extents.y_bearing);
	cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
	cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
	cairo_set_line_width (cr, 4);
	cairo_text_path(cr, window->title);
	cairo_set_source_rgb(cr, 0.1, 0.1, 0.1);
	cairo_stroke_preserve(cr);
	cairo_set_source_rgb(cr, 1, 1, 1);
	cairo_fill(cr);
	cairo_destroy(cr);

	window->buffer = buffer_create_from_cairo_surface(window->fd, surface);
	cairo_surface_destroy(surface);

	visual = wl_display_get_premultiplied_argb_visual(window->display);
	wl_surface_attach(window->surface,
			  window->buffer->name,
			  window->buffer->width,
			  window->buffer->height,
			  window->buffer->stride,
			  visual);

	wl_surface_map(window->surface,
		       window->allocation.x - window->margin,
		       window->allocation.y - window->margin,
		       window->allocation.width,
		       window->allocation.height);
}

static void
window_draw_fullscreen(struct window *window)
{
	struct wl_visual *visual;
	int stride = window->allocation.width * 4;

	window->buffer = buffer_create(window->fd,
				       window->allocation.width,
				       window->allocation.height,
				       stride);

	visual = wl_display_get_premultiplied_argb_visual(window->display);
	wl_surface_attach(window->surface,
			  window->buffer->name,
			  window->buffer->width,
			  window->buffer->height,
			  window->buffer->stride,
			  visual);

	wl_surface_map(window->surface,
		       window->allocation.x,
		       window->allocation.y,
		       window->allocation.width,
		       window->allocation.height);
}

void
window_draw(struct window *window)
{
	if (window->fullscreen)
		window_draw_fullscreen(window);
	else
		window_draw_decorations(window);
}

static void
window_handle_acknowledge(void *data,
			  struct wl_compositor *compositor,
			  uint32_t key, uint32_t frame)
{
	struct window *window = data;

	/* The acknowledge event means that the server
	 * processed our last commit request and we can now
	 * safely free the old window buffer if we resized and
	 * render the next frame into our back buffer.. */

	if (key == 0 && window->buffer != NULL) {
		buffer_destroy(window->buffer, window->fd);
		window->buffer = NULL;
	}
}

static void
window_handle_frame(void *data,
		    struct wl_compositor *compositor,
		    uint32_t frame, uint32_t timestamp)
{
}

static const struct wl_compositor_listener compositor_listener = {
	window_handle_acknowledge,
	window_handle_frame,
};

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
};

static void
window_handle_motion(void *data, struct wl_input_device *input_device,
		     int32_t x, int32_t y, int32_t sx, int32_t sy)
{
	struct window *window = data;

	switch (window->state) {
	case WINDOW_MOVING:
		if (window->fullscreen)
			break;
		if (window->grab_device != input_device)
			break;
		window->allocation.x = window->drag_x + x;
		window->allocation.y = window->drag_y + y;
		wl_surface_map(window->surface,
			       window->allocation.x - window->margin,
			       window->allocation.y - window->margin,
			       window->allocation.width,
			       window->allocation.height);
		wl_compositor_commit(window->compositor, 1);
		break;
	case WINDOW_RESIZING_LOWER_RIGHT:
		if (window->fullscreen)
			break;
		if (window->grab_device != input_device)
			break;
		window->allocation.width = window->drag_x + x;
		window->allocation.height = window->drag_y + y;

		if (window->resize_handler)
			(*window->resize_handler)(window,
						  window->user_data);

		break;
	}
}

static void window_handle_button(void *data, struct wl_input_device *input_device,
				 uint32_t button, uint32_t state,
				 int32_t x, int32_t y, int32_t sx, int32_t sy)
{
	struct window *window = data;
	int32_t left = window->allocation.x;
	int32_t right = window->allocation.x +
		window->allocation.width - window->margin * 2;
	int32_t top = window->allocation.y;
	int32_t bottom = window->allocation.y +
		window->allocation.height - window->margin * 2;
	int grip_size = 16, location;
	
	if (right - grip_size <= x && x < right &&
	    bottom - grip_size <= y && y < bottom) {
		location = LOCATION_LOWER_RIGHT;
	} else if (left <= x && x < right && top <= y && y < bottom) {
		location = LOCATION_INTERIOR;
	} else {
		location = LOCATION_OUTSIDE;
	}

	if (button == BTN_LEFT && state == 1) {
		switch (location) {
		case LOCATION_INTERIOR:
			window->drag_x = window->allocation.x - x;
			window->drag_y = window->allocation.y - y;
			window->state = WINDOW_MOVING;
			window->grab_device = input_device;
			break;
		case LOCATION_LOWER_RIGHT:
			window->drag_x = window->allocation.width - x;
			window->drag_y = window->allocation.height - y;
			window->state = WINDOW_RESIZING_LOWER_RIGHT;
			window->grab_device = input_device;
			break;
		default:
			window->state = WINDOW_STABLE;
			break;
		}
	} else if (button == BTN_LEFT &&
		   state == 0 && window->grab_device == input_device) {
		window->state = WINDOW_STABLE;
	}
}

static void
window_handle_key(void *data, struct wl_input_device *input_device,
		  uint32_t button, uint32_t state)
{
	struct window *window = data;

	if (window->key_handler)
		(*window->key_handler)(window, button, state,
				       window->user_data);
}

static const struct wl_input_device_listener input_device_listener = {
	window_handle_motion,
	window_handle_button,
	window_handle_key,
};

void
window_get_child_rectangle(struct window *window,
			   struct rectangle *rectangle)
{
	if (window->fullscreen) {
		*rectangle = window->allocation;
	} else {
		rectangle->x = window->margin + 10;
		rectangle->y = window->margin + 50;
		rectangle->width = window->allocation.width - 20 - window->margin * 2;
		rectangle->height = window->allocation.height - 60 - window->margin * 2;
	}
}

void
window_set_child_size(struct window *window,
		      struct rectangle *rectangle)
{
	if (!window->fullscreen) {
		window->allocation.width = rectangle->width + 20 + window->margin * 2;
		window->allocation.height = rectangle->height + 60 + window->margin * 2;
	}
}

void
window_copy(struct window *window,
	    struct rectangle *rectangle,
	    uint32_t name, uint32_t stride)
{
	wl_surface_copy(window->surface,
			rectangle->x,
			rectangle->y,
			name, stride,
			0, 0,
			rectangle->width,
			rectangle->height);
}

void
window_set_fullscreen(struct window *window, int fullscreen)
{
	window->fullscreen = fullscreen;
	if (window->fullscreen) {
		window->saved_allocation = window->allocation;
		window->allocation = window->screen_allocation;
	} else {
		window->allocation = window->saved_allocation;
	}
}

void
window_set_resize_handler(struct window *window,
			  window_resize_handler_t handler, void *data)
{
	window->resize_handler = handler;
	window->user_data = data;
}

void
window_set_key_handler(struct window *window,
		       window_key_handler_t handler, void *data)
{
	window->key_handler = handler;
	window->user_data = data;
}

static void
window_handle_geometry(void *data,
		       struct wl_output *output,
		       int32_t width, int32_t height)
{
	struct window *window = data;

	window->screen_allocation.x = 0;
	window->screen_allocation.y = 0;
	window->screen_allocation.width = width;
	window->screen_allocation.height = height;
}

static const struct wl_output_listener output_listener = {
	window_handle_geometry,
};

static void
window_handle_global(struct wl_display *display,
		     struct wl_object *object, void *data)
{
	struct window *window = data;

	if (wl_object_implements(object, "compositor", 1)) { 
		window->compositor = (struct wl_compositor *) object;
		wl_compositor_add_listener(window->compositor,
					   &compositor_listener, window);
	} else if (wl_object_implements(object, "output", 1)) {
		struct wl_output *output = (struct wl_output *) object;

		wl_output_add_listener(output,
				       &output_listener, window);
	} else if (wl_object_implements(object, "input_device", 1)) {
		struct wl_input_device *input_device =
			(struct wl_input_device *) object;

		wl_input_device_add_listener(input_device,
					     &input_device_listener, window);
	}
}

struct window *
window_create(struct wl_display *display, int fd,
	      const char *title,
	      int32_t x, int32_t y, int32_t width, int32_t height)
{
	struct window *window;

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

	memset(window, 0, sizeof *window);
	window->display = display;
	window->title = strdup(title);
	window->compositor = wl_display_get_compositor(display);
	window->surface = wl_compositor_create_surface(window->compositor);
	window->allocation.x = x;
	window->allocation.y = y;
	window->allocation.width = width;
	window->allocation.height = height;
	window->saved_allocation = window->allocation;
	window->margin = 16;
	window->state = WINDOW_STABLE;
	window->fd = fd;

	wl_display_add_global_listener(display,
				       window_handle_global, window);

	return window;
}