#include <Ethernet.h>
#include <EthernetUdp.h>
#include <OneWire.h>
#include <SPI.h>

#include <CollectdPacket.h>
#include "ntp_client.h"      # Another personal library ;-)

// The device id of a DS18S20 is 0x10
#define DS18S20 0x10

CollectdPacket packet( "Arduino", 30 );   // Init 'CollectdPacket' class with :
                                          //   client name = Arduino
                                          //   interval    = 30s
                                          
OneWire        ds18s20( 8 );              // Init the OneWire on pin 8

static byte mac[]         = { 0x00, 0x04, 0x25 , 0x15, 0x48, 0x12 };
static byte ip[]          = { 10, 1, 1, 40 };
static byte collectd_ip[] = { 10, 1, 1, 100 };
static byte ntp_ip[]      = { 10, 1, 1, 254 };

// Init the UDP instance
EthernetUDP udp_handler;

void setup()
{
    Serial.begin( 9600 );
    Serial.println( "Initialized a packet for 'Arduino' with interval 30" );
    
    Ethernet.begin( mac, ip );
    udp_handler.begin( 8888 );     // Start an UDP instance listening on port 8888
}

void loop()
{
    float temperature;
    byte ds_addr[8];
    byte ds_buffer[12];
    char ds_idstr[17];   // 16 chars + \0
    
    // Search for the Dallas sensor until found
    while ( ! ds18s20.search( ds_addr ) )
    {
        ds18s20.reset_search();
        delay( 250 );
    }
        
    // Not so beautiful but just for DEBUGING purpose... 8-)
    sprintf( ds_idstr, "%02x%02x%02x%02x%02x%02x%02x%02x", ds_addr[0], ds_addr[1], ds_addr[2], ds_addr[3], ds_addr[4], ds_addr[5], ds_addr[6], ds_addr[7] );
    Serial.print( "Found sensor id : " );
    Serial.println( ds_idstr );
    
    if ( ds_addr[0] != DS18S20 )
    {
        Serial.println( "Found sensor is not a DS18S20, skipping" );
        return;
    }
    
    if ( OneWire::crc8( ds_addr, 7 ) != ds_addr[7] )
    {
        Serial.println("CRC is not valid, skipping...");
        return;
    }

    // Send a mesure command to the sensor
    ds18s20.reset();
    ds18s20.select( ds_addr );
    ds18s20.write( 0x44, 1 );
    
    // Wait for conversion to finish (~750ms)
    // There is no reason to wait it, but as this program is an example
    // we can proceed that way.

    delay( 800 );
    
    // Retrieve mesured data
    ds18s20.reset();
    ds18s20.select( ds_addr );    
    ds18s20.write( 0xBE );      // Read the scratchpad
    ds18s20.read_bytes( ds_buffer, 9 );
    
    unsigned int raw = ( ds_buffer[1] << 8 ) | ds_buffer[0];
    
    raw = raw << 3;             // 9 bit resolution default
    if ( ds_buffer[7] == 0x10 )
    {
        // count remain gives full 12 bit resolution
        raw = ( raw & 0xFFF0 ) + 12 - ds_buffer[6];
    }

    temperature = (float) raw / 16.0;
    Serial.print( "Sensor temperature : " );
    Serial.println( temperature );
    
    Serial.println( "Resetting packet..." );
    packet.resetPacket();
    packet.addTimestampHR( GetTimeFromNTPServer( ntp_ip, 5 ) );
    
    packet.addPlugin( "sensors" );
    packet.addPluginInstance( "ds18s20" );  // Could be 'ds_idstr' if you want...
    packet.addType( "temperature" );
    packet.addValue( VALUE_TYPE_GAUGE, temperature );
    
    Serial.print( "Generated a packet of " );
    Serial.print( packet.getPacketSize() );
    Serial.println( " bytes" );
    
    Serial.print( "Sending packet to 10.1.1." );
    Serial.println( collectd_ip[3] );
    udp_handler.beginPacket( collectd_ip, 25826 );
    udp_handler.write( packet.getPacketBuffer(), packet.getPacketSize() );
    udp_handler.endPacket();

    delay( 29 * 1000 ); // Sleep 29 seconds  (30s - 800ms... ;)) 
}