/*
 * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
 *                    2013  Kevin Lange <klange@dakko.us>
 * 
 * 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
 * BRIAN PAUL 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.
 */
#include <stdlib.h>
#include <math.h>
#include <syscall.h>

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

#include "lib/yutani.h"
#include "lib/graphics.h"
#include "lib/pthread.h"

struct timeval {
	unsigned int tv_sec;
	unsigned int tv_usec;
};

static unsigned int frames = 0;
static unsigned int start_time = 0;

void fps() {
	struct timeval now;
	syscall_gettimeofday(&now, NULL); //time(NULL);
	frames++;
	if (!start_time) {
		start_time = now.tv_sec;
	} else if (now.tv_sec - start_time >= 5) {
		syscall_gettimeofday(&now, NULL); //time(NULL);
		GLfloat seconds = now.tv_sec - start_time;
		GLfloat fps = frames / seconds;
		printf("%d frames in %3.1f seconds = %6.3f FPS\n", frames, seconds, fps);
		start_time = now.tv_sec;
		frames = 0;
	}
}

static GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0;
static GLint gear1, gear2, gear3;
static GLfloat angle = 0.0;

static void gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width, GLint teeth, GLfloat tooth_depth) {
	GLint i;
	GLfloat r0, r1, r2;
	GLfloat angle, da;
	GLfloat u, v, len;

	r0 = inner_radius;
	r1 = outer_radius - tooth_depth / 2.0;
	r2 = outer_radius + tooth_depth / 2.0;

	da = 2.0 * M_PI / teeth / 4.0;

	glShadeModel(GL_FLAT);

	glNormal3f(0.0, 0.0, 1.0);

	/* draw front face */
	glBegin(GL_QUAD_STRIP);
	for (i = 0; i <= teeth; i++) {
		angle = i * 2.0 * M_PI / teeth;
		glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
		glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
		if (i < teeth) {
			glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
			glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5);
		}
	}
	glEnd();

	/* draw front sides of teeth */
	glBegin(GL_QUADS);
	da = 2.0 * M_PI / teeth / 4.0;
	for (i = 0; i < teeth; i++) {
		angle = i * 2.0 * M_PI / teeth;

		glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
		glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
		glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5);
		glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5);
	}
	glEnd();

	glNormal3f(0.0, 0.0, -1.0);

	/* draw back face */
	glBegin(GL_QUAD_STRIP);
	for (i = 0; i <= teeth; i++) {
		angle = i * 2.0 * M_PI / teeth;
		glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
		glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
		if (i < teeth) {
			glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5);
			glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
		}
	}
	glEnd();

	/* draw back sides of teeth */
	glBegin(GL_QUADS);
	da = 2.0 * M_PI / teeth / 4.0;
	for (i = 0; i < teeth; i++) {
		angle = i * 2.0 * M_PI / teeth;

		glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5);
		glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5);
		glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
		glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
	}
	glEnd();

	/* draw outward faces of teeth */
	glBegin(GL_QUAD_STRIP);
	for (i = 0; i < teeth; i++) {
		angle = i * 2.0 * M_PI / teeth;

		glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
		glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
		u = r2 * cos(angle + da) - r1 * cos(angle);
		v = r2 * sin(angle + da) - r1 * sin(angle);
		len = sqrt(u * u + v * v);
		u /= len;
		v /= len;
		glNormal3f(v, -u, 0.0);
		glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
		glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
		glNormal3f(cos(angle), sin(angle), 0.0);
		glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),  width * 0.5);
		glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5);
		u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);
		v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);
		glNormal3f(v, -u, 0.0);
		glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5);
		glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5);
		glNormal3f(cos(angle), sin(angle), 0.0);
	}

	glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5);
	glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5);

	glEnd();

	glShadeModel(GL_SMOOTH);

	/* draw inside radius cylinder */
	glBegin(GL_QUAD_STRIP);
	for (i = 0; i <= teeth; i++) {
		angle = i * 2.0 * M_PI / teeth;
		glNormal3f(-cos(angle), -sin(angle), 0.0);
		glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
		glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
	}
	glEnd();
}

static void draw(void) {
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glPushMatrix();
	glRotatef(view_rotx, 1.0, 0.0, 0.0);
	glRotatef(view_roty, 0.0, 1.0, 0.0);
	glRotatef(view_rotz, 0.0, 0.0, 1.0);

	glPushMatrix();
	glTranslatef(-3.0, -2.0, 0.0);
	glRotatef(angle, 0.0, 0.0, 1.0);
	glCallList(gear1);
	glPopMatrix();

	glPushMatrix();
	glTranslatef(3.1, -2.0, 0.0);
	glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
	glCallList(gear2);
	glPopMatrix();

	glPushMatrix();
	glTranslatef(-3.1, 4.2, 0.0);
	glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0);
	glCallList(gear3);
	glPopMatrix();

	glPopMatrix();
}

/* new window size or exposure */
static void reshape(int width, int height) {
	GLfloat h = (GLfloat) height / (GLfloat) width;

	glViewport(0, 0, (GLint) width, (GLint) height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	glTranslatef(0.0, 0.0, -40.0);
}

static void init(void) {
	static GLfloat pos[4] = { 5.0, 5.0, 10.0, 0.0 };
	static GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
	static GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
	static GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };

	glLightfv(GL_LIGHT0, GL_POSITION, pos);
	glEnable(GL_CULL_FACE);
	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);
	glEnable(GL_DEPTH_TEST);

	/* make the gears */
	gear1 = glGenLists(1);
	glNewList(gear1, GL_COMPILE);
	glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
	gear(1.0, 4.0, 1.0, 20, 0.7);
	glEndList();

	gear2 = glGenLists(1);
	glNewList(gear2, GL_COMPILE);
	glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
	gear(0.5, 2.0, 2.0, 10, 0.7);
	glEndList();

	gear3 = glGenLists(1);
	glNewList(gear3, GL_COMPILE);
	glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
	gear(1.3, 2.0, 0.5, 10, 0.7);
	glEndList();

	glEnable(GL_NORMALIZE);
}

int resize(gfx_context_t * ctx, OSMesaContext gl_ctx) {

	if (!OSMesaMakeCurrent(gl_ctx, ctx->backbuffer, GL_UNSIGNED_BYTE, ctx->width, ctx->height))
		return 1;

	OSMesaPixelStore(OSMESA_Y_UP, 0);

	reshape(ctx->width, ctx->height);
	return 0;
}

static yutani_t * yctx;
static yutani_window_t * wina;
static gfx_context_t * ctx;
static int should_exit = 0;

void * draw_thread(void * glctx) {
	OSMesaContext gl_ctx = (OSMesaContext)glctx;

	while (!should_exit) {
		fps();
		angle += 0.2;
		draw();
		flip(ctx);
		yutani_flip(yctx, wina);
		syscall_yield();
	}

	pthread_exit(0);
}

int main (int argc, char ** argv) {
	int left = 30;
	int top  = 30;

	int width  = 500;
	int height = 500;

	yctx = yutani_init();
	wina = yutani_window_create(yctx, width, height);
	yutani_window_move(yctx, wina, left, top);
	ctx = init_graphics_yutani_double_buffer(wina);
	draw_fill(ctx, rgb(0,0,0));

	OSMesaContext gl_ctx = OSMesaCreateContext(OSMESA_BGRA, NULL);
	if (resize(ctx, gl_ctx)) {
		fprintf(stderr, "%s: Something bad happened.\n", argv[0]);
		goto finish;
	}

	init();

	/* XXX add a method to query if there are available packets in pex */
	pthread_t thread;
	pthread_create(&thread, NULL, draw_thread, NULL);

	while (!should_exit) {
		yutani_msg_t * m = yutani_poll(yctx);
		if (m) {
			switch (m->type) {
				case YUTANI_MSG_KEY_EVENT:
					{
						struct yutani_msg_key_event * ke = (void*)m->data;
						if (ke->event.action == KEY_ACTION_DOWN) {
							switch (ke->event.keycode) {
								case 'q':
									should_exit = 1;
									free(m);
									goto finish;
								case KEY_ARROW_LEFT:
									view_roty += 5.0;
									break;
								case KEY_ARROW_RIGHT:
									view_roty -= 5.0;
									break;
								case KEY_ARROW_UP:
									view_rotx += 5.0;
									break;
								case KEY_ARROW_DOWN:
									view_rotx -= 5.0;
									break;
								default:
									break;
							}
						}
					}
					break;
#if 0
					/* XXX resizing */
						/* Fix up the GL context as well */
						resize(ctx, gl_ctx);
#endif
				default:
					break;
			}
			free(m);
		}
	}

finish:
	OSMesaDestroyContext(gl_ctx);
	yutani_close(yctx, wina);

	return 0;
}