#############################
###
### read_sint - reads signed binary
###
### read_uint - reads unsigned binary
### 
### read_real - reads real number
###
### read_GISS_data_Ts.GHCN.CL
###     ftp://data.giss.nasa.gov/pub/gistemp/GISS_Obs_analysis/ARCHIVE/2008_05/binary_files/Ts.GHCN.CL.5
###     uses: read_record_Ts.GHCN.CL, read_header_Ts.GHCN.C
###
### read_GISS_data_SBBX 
###
### make.grid.info
###
###
###



read_sint <- function(handle) { 
    return(readBin(handle, "int", 1, size=4, signed = TRUE, endian = "big"));
}


read_uint <- function(handle) {   
    return(readBin(handle, "int", 1, size=4, signed = FALSE, endian = "big"));
}


read_real <- function(handle) {
    return(readBin(handle, "numeric", 1, size=4, endian = "big"));
}
 

########################################################################################
### Ts.GHCN.CL

read_GISS_data_Ts.GHCN.CL <- function(handle,method="Ts.GHCN.CL.PA") {
        header_data <- read_header_Ts.GHCN.CL(handle);
        records <- list();
        while(TRUE) {
                record <- read_record_Ts.GHCN.CL(handle,method);
                if( length(record) == 1 ) {
                        return(pairlist(header=header_data, records=records));
            } else {
                    records <- append(records, record);
            }
        }
}

   read_header_Ts.GHCN.CL <- function(handle) {
    len <- read_uint(handle);
    if( len < 9*4 ) {
            print("invalid file format");
         return(NA);
    }
    	vers <- read_sint(handle);  
    unk1 <- read_sint(handle);
    unk2 <- read_sint(handle);
    MTOT <- read_sint(handle);
    MTOT2 <- read_sint(handle);
    iyear1 <- read_sint(handle);
    inv1 <- read_sint(handle);
    inv2 <- read_sint(handle);
    MTOT_again <- read_sint(handle);
    title <- rawToChar(readBin(handle, "raw", len-9*4));
    if( read_uint(handle) != len ) {
         print("invalid file format");
        return(NA);
        }
        return(pairlist(vers=vers, unk1=unk1, unk2=unk2, MTOT=MTOT, MTOT2=MTOT2, iyear1=iyear1, inv1=inv1, inv2=inv2, MTOT_again=MTOT_again, title=title));
  }


   read_record_Ts.GHCN.CL <- function(handle,method="Ts.GHCN.CL.PA") {
    len <- read_uint(handle);
    if( length(len) == 0 ) {
        # no more data
        return(NA);
    }
        if( len <= 44+16 ) {
        print("invalid file format");
        return(NA);
    }
        if(method=="Ts.GHCN.CL.PA") {call2="int"; call3=(len-44-16)/4;call4=TRUE}
	if(method=="fred") {call2="numeric";call3=Mnow; ca;;4=FALSE}
	temp_data <- readBin(handle, call2, call3, size=4, call4, endian = "big");
  	#temp_data <- readBin(handle, "int", (len-44-16)/4, size=4, signed = TRUE, endian = "big");
        #temp_data <- readBin(handle, "numeric", Mnow, size=4, endian = "big");
 
    lato <- read_uint(handle);
    longo <- read_uint(handle);
    id <- read_uint(handle);
    ht <- read_uint(handle);
    name <- rawToChar(readBin(handle, "raw", 36));
    vers <- read_uint(handle);
        MTOT <- read_uint(handle);
        if( read_uint(handle) != len ) {
                print("invalid file format");
        return(NA);
    }
        return(pairlist(temp_data=temp_data, lato=lato, longo=longo, id=id, ht=ht, name=name, vers=vers, MTOT=MTOT));
  }


#############################################################################################

## SBBX

read_sbbx=function(url,method="download") {
	if(method=="download") {download.file(url, "temp.bin",mode="wb");
		loc="temp.bin"} else loc=url

	##url="ftp://data.giss.nasa.gov/pub/gistemp/SBBX1880.Ts.GHCN.CL.PA.250"  #18577
	##download.file(url,"temp.bin",mode="wb")
	handle <- file(loc, "rb");
	(header_data= read_header_SBBX(handle))
	M=header_data$Mnow
	sbbx=array(NA,dim=c(M,8000))
	info= array(NA,dim=c(8000, 10) )
	info=data.frame(info); 
	names(info)=c("len","Next","lats","latn","lonw","lone","nr1","nr2","dl","test")
  
     for(i in 1:8000) {
 	(len= info$len[i]=  try( read_uint(handle)) ) #6272
	 # if ( !(length(len)==0 ) ) {
	 info$Next[i] <- read_sint(handle)
    	 info$lats[i] <- read_sint(handle);
    	 info$latn[i] <- read_sint(handle);
    	 info$lonw[i] <- read_sint(handle);
   	 info$lone[i] <- read_sint(handle);
    	 info$nr1[i] <- read_sint(handle);
    	 info$nr2[i] <- read_sint(handle);
    	 info$dl <- read_uint(handle)
	#info[i,]
    	 if ( !(len==36) )  {y<- readBin(handle, "numeric",M, size=4, signed=TRUE, endian = "big") ; #1570)
	 	y[y==9999]=NA;
	 	sbbx[,i]=y }  else read_real(handle) # this looks like something
	 (info$test[i]=read_uint(handle) )
       }
	return(list(info=info,sbbx=sbbx) )
 }

	#url="ftp://data.giss.nasa.gov/pub/gistemp/SBBX1880.Ts.GHCN.CL.PA.250"  #18577
	#test=read_sbbx(url)




read_GISS_data_SBBX <- function(handle) {
    header_data <- read_header_SBBX(handle);
    Mnow = header_data$Mnow;
    records <- vector("pairlist", 1);
    num <- 1;
    while(TRUE) {
        record <- read_record_SBBX(handle, Mnow);
        if( length(record) == 1 ) {
            return(pairlist(header=header_data, records=records));
        } else {
                        records[[num]] = record;
                        num <- num+1;
            Mnow = record$Next;
        }
    }
}

 
   read_header_SBBX <- function(handle) {
    len <- read_uint(handle);
    if( len < 8*4 ) {
        print("invalid file format");
        return(NA);
    }
        Mnow <- read_sint(handle);
    unk1 <- read_sint(handle);
    unk2 <- read_sint(handle);
    MONM <- read_sint(handle);
    unk3 <- read_sint(handle);
    IYRBEG <- read_sint(handle);
    BAD <- read_sint(handle);
    unk4 <- read_sint(handle);
    title <- rawToChar(readBin(handle, "raw", len-8*4));
    if( read_uint(handle) != len ) {
        print("invalid file format");
        return(NA);
    }
        return(pairlist(Mnow=Mnow, unk1=unk1, unk2=unk2, MONM=MONM, unk3=unk3, IYRBEG=IYRBEG, BAD=BAD, unk4=unk4, title=title));
  }


  read_record_SBBX <- function(handle, Mnow) {
    len <- read_uint(handle);
    if( length(len) == 0 ) {
        # no more data
        return(NA);
    }
        if( len != (8+Mnow)*4 ) {
        print("invalid file format");
        return(NA);
    }
        Next <- read_sint(handle);
    LATS <- read_sint(handle);
    LATN <- read_sint(handle);
    LONW <- read_sint(handle);
    LONE <- read_sint(handle);
    NR1 <- read_sint(handle);
    NR2 <- read_sint(handle);
    DL <- read_sint(handle);
    temp_data <- readBin(handle, "numeric", Mnow, size=4, endian = "big");
    if( read_uint(handle) != len ) {
        print("invalid file format");
        return(NA);
    }
        return(pairlist(temp_data=temp_data, Next=Next, LATS=LATS, LATN=LATN, LONW=LONW, LONE=LONE, NR1=NR1, NR2=NR2, DL=DL));
  }
 

##MAKE GRID INFO
make.grid.info=function (Data){ 
	f=function(X) unlist(X[2:9])
	grid.info=sapply(Data[[2]],f)
	grid.info=t(grid.info)
	grid.info=data.frame(grid.info)
		#the params LATS, LATN, LONW,LONE define the four parameters of the box
		#decimal values appear to be used
	grid.info[,2:5]=grid.info[,2:5]/100
		#order1=order(-grid.info$LATS,grid.info$LONW)
		#grid.info[order1,][1:100,]
	make.grid.info=grid.info
	make.grid.info
	}

##############################################################################
###


read.Zon.Ts=function(url,freqts=12) {
	download.file(url, "temp.bin",mode="wb")  #about 176 kb
	handle <- file("temp.bin", "rb");
        header_data <- read_header_Ts.GHCN.CL(handle);
        records <- list();
	num=1  
   	len <- read_uint(handle);
    	if( length(len) == 0 ) {
          # no more data
          return(NA);
    	}
     	if( len <= 44+16 ) {
           print("invalid file format");
           return(NA);
        }
	chron=NULL
     	for (i in 1:14) {
 	  x<- readBin(handle, "numeric",(len-80)/8, size=4, signed=TRUE, endian = "big");
    	  x[x==9999]=NA
    	   	#plot.ts(x,main=paste(i))
	  chron=cbind(chron,x)
  	  y<- readBin(handle, "numeric",(len+96)/8, size=4, signed=TRUE, endian = "big"); #1570
 	   #plot.ts(y)
     	} #end i
	close(handle)
	dimnames(chron)[[2]]=1:14
	 #dim(chron) #  1560   14
	count=apply(!is.na(chron),1,sum)
	chron=ts(chron[count>0,],start=1880,freq=freqts)
	return(chron)
}  #function 




##############################################################################
### lpl 

read.lpl= function(url) {
	#url="ftp://data.giss.nasa.gov/pub/gistemp/GISS_Obs_analysis/lplots/LOW.Ts.GHCN.CL.PA.lpl"
	fred=read.table(url,skip=4,na.strings="****")
	x=ts( fred[,2],start=c(1880,1),freq=12)
	temp=!is.na(x)
	zon=window(x,end=max(time(x)[temp]) )
	return(zon)
}


use0="pairwise.complete.obs"

###############################################################################
###  Zon.web
######################


read.zon.web=function(url) {
	#url="ftp://data.giss.nasa.gov/pub/gistemp/GISS_Obs_analysis/ARCHIVE/2009_04/ZON/LOTI.zon.web"
	download.file(url, "temp.bin",mode="wb")  #about 303 KB
 	handle <- file("temp.bin", "rb");
     	(len <- read_uint(handle)); #276
	(name0 <- rawToChar(readBin(handle, "raw", 80)))
   	unk1=read_uint(handle)
	unk2= read_uint(handle)
	lat=rep(NA,46)
	for(i in 1:46) lat[i]= read_uint(handle)
	    # [1] -90 -86 -82 -78 -74 -70 -66 -62 -58 -54 -50 -46 -42 -38 -34 -30 -26 -22 -18 -14 -10  -6  -2   2   6  10  14  18  22  26  30  34  38  42  46  50
	   #[37]  54  58  62  66  70  74  78  82  86  90
	na.string=read_real(handle) #9999
	( test= read_uint(handle) ) #276
	num=1; fred=TRUE	
	working=NULL
	while(fred==TRUE) {
	 (len= try( read_uint(handle)) ) #192 
	  if ( !(length(len)==0 ) ) {
	    (year =read_uint(handle)) #1880
	    (month =read_uint(handle)) # 1
	     y<- readBin(handle, "numeric",46, size=4, signed=TRUE, endian = "big") ; #1570)
	     y[y==9999]=NA; # this looks like something
	    (test=read_uint(handle) )
	    working=rbind(working,y)
	    num=num+1 } else {fred=FALSE}
	  }
	dimnames(working)[[2]]=lat
	working=ts(working,start=1880,freq=12)
	close(handle)
	return(working)
}