#include <stdio.h>
#include <stdlib.h>
#include <GL/glut.h>
#include <EGL/egl.h>
#include <emscripten.h>

#define MULTILINE(...) #__VA_ARGS__

int touch_started_button = -1;
int touch_started_x = -1;
int touch_started_y = -1;

int touch_ended_button = -1;
int touch_ended_x = -1;
int touch_ended_y = -1;

int result = 0;

void mouseCB(int button, int state, int x, int y)
{
    if(button == GLUT_LEFT_BUTTON)
    {
        if(state == GLUT_DOWN)
        {
            printf("GLUT_DOWN: button: %d, x: %d, y: %d\n", button, x, y);
            touch_started_button = button;
            touch_started_x = x;
            touch_started_y = y;
        }
        else if(state == GLUT_UP)
        {
            printf("GLUT_UP: button: %d, x: %d, y: %d\n", button, x, y);
            touch_ended_button = button;
            touch_ended_x = x;
            touch_ended_y = y;
        }
    }
}

#define abs(x) ((x) < 0 ? -(x) : (x))

int main(int argc, char *argv[])
{
    emscripten_run_script(MULTILINE(
        Module.injectEvent = function(eventType, wantedX, wantedY) {
            // Desktop browsers do not have the event types for touch events,
            // so we fake them by creating a plain-vanilla UIEvent and then
            // filling in the fields that we look for with appropriate values.
            var rect = Module["canvas"].getBoundingClientRect();
            Module['print']('rect corner: ' + rect.left + ',' + rect.top);
            Module['print']('wanted: ' + wantedX + ',' + wantedY);
            var x = wantedX + rect.left;
            var y = wantedY + rect.top;
            var touch = {
                identifier: 0,
                clientX: x,
                clientY: y,
                screenX: x,
                screenY: y,
                pageX: x,
                pageY: y,
                target: Module['canvas']
            };
            var touches = [ touch ];
            touches.item = function(i) { return this[i]; };

            var event = document.createEvent('UIEvent');
            event.target = Module['canvas'];
            event.button = 0;
            event.changedTouches = touches;
            event.initUIEvent(eventType, true, true, window, 1);
            Module['canvas'].dispatchEvent(event);
        }
    ));

    // Fake a touch device so that glut sets up the appropriate event handlers.
    emscripten_run_script("document.documentElement['ontouchstart'] = 1");
    glutInit(&argc, argv);

    glutMouseFunc(&mouseCB);

    emscripten_run_script("Module.injectEvent('touchstart', 101, 112)");
    emscripten_run_script("Module.injectEvent('touchend', 201, 212)");
    result = touch_started_button == 0 && abs(touch_started_x - 101) <= 1 && abs(touch_started_y - 112) <= 1 &&
        touch_ended_button == 0 && abs(touch_ended_x - 201) <= 1 && abs(touch_ended_y - 212) <= 1;
    printf("touchstarted: button:%d x:%d y:%d\n", touch_started_button, touch_started_x, touch_started_y);
    printf("touchended:   button:%d x:%d y:%d\n", touch_ended_button, touch_ended_x, touch_ended_y);
#ifdef REPORT_RESULT
    REPORT_RESULT(result);
#endif
    return 0;
}
