//
//    FILE: ClockServer.cpp
// PURPOSE: UDP broadcast sender for fastclock (FREMO clock)
//
//

#include "ClockServer.h"
#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#include <DjFastclockScanner.h>


#ifdef ESP8266
extern "C" {
#include "user_interface.h"
}
#endif

const char * const PROGMEM clockServerConfig[] = {
  "clockServerName:string:DefaultClock",
  "waitBeforeStartingClockServer_ms:int:5000",
  "timeToCollectOtherClocks_ms:int:20000",
  "autoActivateAfter_ms:int:0",
  "sendClockUpdateEvery_ms:int:2000",
  "ipMulticast:string:239.50.50.20",
  "clientListenPort:int:2000",
};

static WiFiUDP udp;

#define CLOCK_PACKET_SIZE 1024
static byte packetBuffer[CLOCK_PACKET_SIZE+1]; //buffer to hold outgoing packets

String ClockServer::name{""};
IPAddress ClockServer::ipMulticast; //.fromString("239.50.50.20");
int ClockServer::clientListenPort{2000};
String ClockServer::text{""};
boolean ClockServer::active{false};
float ClockServer::clockSpeed{1.0};
String ClockServer::clockString{""};
String ClockServer::weekdayName{""};
int ClockServer::weekday{0};
int ClockServer::clockHours{0};
int ClockServer::clockMinutes{0};
int ClockServer::clockSeconds{0};
ClockServerStatus ClockServer::serverStatus = ClockServerStatus::ServerNotStarted;
uint32_t ClockServer::nextServerStatusTime;
int ClockServer::sendClockUpdateEvery_ms;
int ClockServer::autoActivateAfter_ms;

void ClockServer::begin() {
  config.loadFile("clockserver.cfg", clockServerConfig, sizeof(clockServerConfig)/sizeof(clockServerConfig[0]));
  name = config.getString("clockServerName");
  ipMulticast.fromString(config.getString("ipMulticast"));
  clientListenPort = config.getInt("clientListenPort");
  
  sendClockUpdateEvery_ms = config.getInt("sendClockUpdateEvery_ms");
  autoActivateAfter_ms = config.getInt("autoActivateAfter_ms");
  nextServerStatusTime = millis() + config.getInt("waitBeforeStartingClockServer_ms");
  logHeap();
}

void ClockServer::clockTick() {
  if (ClockServer::active == false) return;
  //Debug::outln(F("> Tick"));
  ClockServer::clockSeconds++;
  if (ClockServer::clockSeconds >= 60) {
    ClockServer::clockSeconds = 0;
    ClockServer::clockMinutes++;
    if (ClockServer::clockMinutes >= 60) {
      ClockServer::clockMinutes = 0;
      ClockServer::clockHours++;
      if (ClockServer::clockHours >= 24) {
        ClockServer::clockHours = 0;
        weekday++;
        if (weekday >= 7) {
          weekday = 0;
        }
      }
    }
  }
}

static void clockTick() {
  ClockServer::clockTick();
}

void ClockServer::activateClock() {
  active = true;
  if (clockSpeed < 0.1) {
    clockSpeed = 0.1;
    debug.outln(F("ERROR: clockSpeed was too small, set to 0.1 which still is very small"));
  }
  clockTrigger.attach_ms(1000.0 / clockSpeed, clockTick);
  logHeap();
}

void ClockServer::deactivateClock() {
  active = false;
  clockTrigger.detach();
  logHeap();
}

void ClockServer::setSpeed(float newSpeed) {
  clockSpeed = newSpeed;
  if (active) {
    deactivateClock();
    activateClock();
  }
  logHeap();
}

void ClockServer::sendFastclockMessage() {
  IPAddress ip = WiFi.localIP();
  static String nl = String("\r\n");
  String msg = String("fastclock") + nl + "version=2" + nl;
  msg += "name=" + name + nl;
  msg += "ip-address=" + ip.toString() + nl;
  msg += "ip-port=" + String(clientListenPort) + nl;
  msg += "text=" + text + nl;
  msg += "clocktype=fastclock" + nl;
  msg += "active=" + (active?String("yes"):String("no")) + nl;
  msg += "speed=" + String(clockSpeed) + nl;
  msg += "clock=" + String(clockHours) + ":" + String(clockMinutes) + ":" + String(clockSeconds) + nl;
  msg += "weekday=" + String(weekday) + nl;

  uint8_t result = udp.beginPacketMulticast(ipMulticast, clientListenPort, ip);
  debug.outln(result?"udp.begin":"ERROR on udp.begin");
  size_t sentBytes = udp.write(msg.c_str(),msg.length());
  debug.outln(String(sentBytes) + " bytes sent"); //,sizeof(msg));
  result = udp.endPacket();
  debug.outln(result?"send was OK":"send FAILED");
  debug.out(F("*** ")); debug.outln(msg);

  delay(1);
}

void ClockServer::loop() {
  static String *knownClocks;

  switch (serverStatus) {
    case ClockServerStatus::ServerNotStarted:
      if (millis() > nextServerStatusTime) {
        serverStatus = ClockServerStatus::CollectingExistingClocks;
        nextServerStatusTime = millis() + config.getInt("timeToCollectOtherClocks_ms");
        if (!udp.beginMulticast(WiFi.localIP(), ipMulticast, clientListenPort)) {
          debug.outln(F("ERROR: failed to begin UDP"));
          debug.out(F("local IP=")); debug.out(WiFi.localIP().toString());
          debug.out(F(", multicast IP=")); debug.out(ipMulticast.toString());
          debug.out(F(", Port=")); debug.outln(clientListenPort);
        }

        logHeap();
      }
      break;
    case ClockServerStatus::CollectingExistingClocks:
      // do nothing, we wait for the client to collect the clocks for us
      if (millis() > nextServerStatusTime) {
        serverStatus = ClockServerStatus::StartingServer;
        nextServerStatusTime = millis()-1; // be sure, this will go through the next section on next loop() call
        logHeap();
      } else {
        int length = udp.parsePacket();
        if (length > 0) {
          // debug.out(F("ClockServer received: ")); debug.out(length); debug.outln(F(" bytes."));
          udp.read(packetBuffer, CLOCK_PACKET_SIZE); 
          packetBuffer[length] = '\0';
          
          // interpret Clock Message
          // debug.out(F("> ")); debug.outln( (char *) packetBuffer);
          String msg = String((char *) packetBuffer);
          if (!msg.startsWith("fastclock\r\n")) {
              debug.out(F("ERROR: This is not a fastclock message! Got message=")); debug.outln(msg.substring(0,30));
          }
          msg = msg.substring(11);
          if (!msg.startsWith("version=2\r\n")) {
            debug.out(F("WARNING: Version of fastclock not supported! Got ")); debug.outln(msg.substring(0,10));
          }
          msg = msg.substring(msg.indexOf('\n')+1);
        
          String checkName{""};
          if (msg.startsWith("name=")) {
            checkName = msg.substring(msg.indexOf('=')+1, msg.indexOf('\r'));
            fastclockScanner.addClock(checkName);
          } else { debug.outln(F("ERROR: Clock Message Format invalid! Expected name field.")); return; }          
          msg = String(""); // release string
        }
      }
      break;
    case ClockServerStatus::StartingServer:
      // debug: output the clocks seen during collectingExistingClocks time
      knownClocks = fastclockScanner.getKnownClocks();
      debug.outln(F("--- Following Clocks have been seen during bootup: ---"));
      for (int i=0; i<fastclockScanner.getNumberOfKnownClocks(); ++i) {
        debug.outln(knownClocks[i]);
      }
      debug.outln(F("--- end of list of known clocks"));
      delay(10);
      if (autoActivateAfter_ms > 0) {
        nextServerStatusTime = millis() + autoActivateAfter_ms;
        serverStatus = ClockServerStatus::WaitForAutoActivate;
      } else {
        serverStatus = ClockServerStatus::ServerStarted;
        nextServerStatusTime = millis() + sendClockUpdateEvery_ms;
      }
      break;
    case ClockServerStatus::WaitForAutoActivate:
      if (millis() > nextServerStatusTime) {
        serverStatus = ClockServerStatus::ServerStarted;
        activateClock();
        logHeap();
      }
      break;
    case ClockServerStatus::ServerStarted:
      if (millis() > nextServerStatusTime) {
        if (active) sendFastclockMessage();
        nextServerStatusTime = millis() + sendClockUpdateEvery_ms;
        logHeap();
      }
      break;
    default:
      // this is an error case
      debug.outln(F("ERROR: Unknown server state in ClockServer.cpp. Resetting to ServerNotStarted."));
      serverStatus = ClockServerStatus::ServerNotStarted;
      break;
  }
}