#include "arduino_i2c.h"
#include <Wire.h>

extern "C" {

extern uint8_t * make_output_buffer(mrb_vm *vm, mrb_value v[], int argc,
                             int start_idx, int *ret_bufsiz);
#if !MRBC_USE_STRING
extern mrbc_value mrbc_array_new_alloc(mrbc_vm *vm, const uint8_t *c_array, int size);
#endif

void c_i2c_new(mrb_vm *vm, mrb_value *v, int argc){
  Wire.begin();
}

void c_i2c_write(mrb_vm *vm, mrb_value *v, int argc){
  uint8_t *buf = 0;
  int bufsiz = 0;
  if( argc>0 ){
    uint8_t adrs = GET_INT_ARG(1);
    Wire.beginTransmission(adrs);
    if(argc>2){
      buf = make_output_buffer( vm, v, argc, 2, &bufsiz );
      Wire.write(buf,bufsiz);
      mrbc_free( vm, buf );
    }
    Wire.endTransmission();
  }
  SET_RETURN( mrbc_integer_value(bufsiz) );
}

void c_i2c_read(mrb_vm *vm, mrb_value *v, int argc){
  uint8_t *buf = 0;
  int bufsiz = 0;
  mrbc_value ret = mrbc_nil_value();
  if( argc >1 ){
    int adrs = GET_INT_ARG(1);
    int size = GET_INT_ARG(2);
    if( argc > 2 ) {
      buf = make_output_buffer( vm, v, argc, 3, &bufsiz );
      Wire.beginTransmission(adrs);
      Wire.write(buf,bufsiz);
      Wire.endTransmission(false);
      mrbc_free( vm, buf );
    }
    buf = (uint8_t*) mrbc_alloc(vm, size);
    Wire.requestFrom(adrs, size);
    int i;
    for(i=0;i<size;i++){
      while(Wire.available()==0){}
      buf[i] = Wire.read();
    }
#if MRBC_USE_STRING
    ret = mrbc_string_new_alloc(vm, buf, size);
#else
    ret = mrbc_array_new_alloc( vm, buf, size);
    mrbc_free( vm, buf );
#endif
  }
  SET_RETURN(ret);
}

void mrbc_init_class_i2c(void){
  mrb_class *i2c = mrbc_define_class(0, "I2C",  mrbc_class_object);
  mrbc_define_method(0, i2c, "new", c_i2c_new);
  mrbc_define_method(0, i2c, "read", c_i2c_read);
  mrbc_define_method(0, i2c, "write", c_i2c_write);
}

} //extern