//+------------------------------------------------------------------+
//|                                                   SavePrices.mq4 |
//|                                                      John Taylor |
//|                          http://www.linkedin.com/in/johntaylorhk |
//+------------------------------------------------------------------+
#property copyright "John Taylor"
#property link      "http://www.linkedin.com/in/johntaylorhk"

#include <stdlib.mqh>

extern string FileNameRoot="DailyPrices";

int init() {

   return(0);
}

int deinit() {
   return(0);
}

int start() {
   static datetime prevTime=0;
   if (prevTime!=Time[0]) {
      if (prevTime!=0) { // ensure 1st tick is on a candle start
         SavePrices();
      }
      prevTime=Time[0];
   }
   return(0);
}

void SavePrices() {
   string fileName=StringConcatenate(TimeToStr(Time[0],TIME_DATE)," - ",Symbol()," - ",FileNameRoot,".csv");
   int handle=FileOpen(fileName,FILE_CSV|FILE_WRITE|FILE_READ,",");
   
   if(handle>=0) {
      FileSeek(handle,0,SEEK_END);
   }
   else {
      handle=FileOpen(fileName,FILE_CSV|FILE_WRITE,",");
   }
   
   if(handle<0)
      Alert("No file called ", fileName,"could be opened or created");
   else {
      if(FileWrite(handle,Symbol(),
                          TimeToStr(Time[0]),
                          DoubleToStr(Open [1],Digits),
                          DoubleToStr(High [1],Digits),
                          DoubleToStr(Low  [1],Digits),
                          DoubleToStr(Close[1],Digits),
                          Volume[1])<0) {
         Alert("SavePrices: FileWrite failed - ",ErrorDescription(GetLastError()));
      }
   }

   if(handle>=0) FileClose(handle);
}