#include "touch.h"

#ifndef DIRECT_TOUCH

int touchInit(Touch *touch, App *app, const char *dev) { return 0; }

void touchDeinit(Touch *touch) { }

int touchGet(Touch *touch, int *x, int *y, int *p) { return 0; }

#else // DIRECT_TOUCH

#include <math.h></math.h>

#include <mtdev.h></mtdev.h>

#include <stdio.h></stdio.h>

#include <unistd.h></unistd.h>

#include <fcntl.h></fcntl.h>

static int touch_field_codes[TOUCH_FIELDS] =

  { ABS_MT_POSITION_X, ABS_MT_POSITION_Y, ABS_MT_PRESSURE };

int touchInit(Touch *touch, App *app, const char *dev) {

  if (!app || !dev) return 0;

  LOGDBG("touch: init");

  touch->fd = open(dev, O_RDONLY | O_NONBLOCK);

  if (touch->fd < 0)

    return LOGERR("touch: init: cannot open file: %s", dev);

  int ret = mtdev_open(&touch->dev, touch->fd);

  if (ret) {

    close(touch->fd);

    touch->fd = 0;

    return LOGERR("touch: init: cannot open device: %s", dev);

  }

  for(int i = 0; i < TOUCH_FIELDS; ++i) {

    int *f = touch->fields[i];

    f[0] = mtdev_get_abs_minimum(&touch->dev, touch_field_codes[i]);

    f[1] = mtdev_get_abs_maximum(&touch->dev, touch_field_codes[i]);

    if (f[0] >= f[1]) {

      mtdev_close(&touch->dev);

      close(touch->fd);

      return LOGERR("touch: init: cannot get field bounds for device: %s (field %d:%d)", dev, i, touch_field_codes[i]);

    }

    f[2] = 0;

    if (f[2] > f[1]) f[2] = f[1];

    if (f[2] < f[0]) f[2] = f[0];

  }

  touch->app = app;

  touch->slot = 0;

  touch->id = -1;

  touch->pressed = 0;

  return 1;

}

void touchDeinit(Touch *touch) {

  if (touch->app) {

    mtdev_close(&touch->dev);

    close(touch->fd);

  }

  touch->app = NULL;

}

int touchGet(Touch *touch, int *x, int *y, int *p) {

  if (!touch->app) return 0;

  struct input_event ev;

  while(mtdev_get(&touch->dev, touch->fd, &ev, 1) > 0) {

    if (ev.type == EV_SYN) {

      // return event

      double f[TOUCH_FIELDS];

      for(int i = 0; i < TOUCH_FIELDS; ++i) {

          int *tf = touch->fields[i];

          f[i] = (tf[2] - tf[0])/(double)(tf[1] - tf[0]);

      }

      double fx = f[0], fy = f[1], fp = f[2];

      App *app = touch->app;

      if (app->sr & RR_Rotate_90)

        { double v = fx; fx = 1-fy; fy = v; }

      if (app->sr & RR_Rotate_180)

        { fx = 1-fx; fy = 1-fy; }

      if (app->sr & RR_Rotate_270)

        { double v = fx; fx = fy; fy = 1-v; }

      if (app->sr & RR_Reflect_X)

        fx = 1-fx;

      if (app->sr & RR_Reflect_Y)

        fy = 1-fy;

      *x = (int)round(fx*app->sw - app->x);

      *y = (int)round(fy*app->sh - app->y);

      *p = touch->id >= 0 && fp > (touch->pressed ? TOUCH_THRESHOLD0 : TOUCH_THRESHOLD1);

      touch->pressed = *p;

      return 1;

    }

    if (ev.type != EV_ABS)

      continue; // ignore non ABS events

    if (ev.code == ABS_MT_SLOT)

      { touch->slot = ev.value; continue; }  // switch slot

    if (touch->slot != 0)

      continue;  // handle only first slot

    if (ev.code == ABS_MT_TRACKING_ID)

      { touch->id = ev.value; continue; } // set track id

    for(int i = 0; i < TOUCH_FIELDS; ++i)

      if (ev.code == touch_field_codes[i])

        touch->fields[i][2] = ev.value;

  }

  return 0;

}

#endif // DIRECT_TOUCH