########################################
# Author - Andre Moraes
# Utah State University
# QCNR - Watershed Sciences Department
# andre.moraes@usu.edu

# This script is used to subset cmip6 models.

############ NorESM2-LM ####################

future_dates <- read.csv("~/Documents/scripts/cmip6/2023/future_dates_2023.csv") # all dates for ssp245
historical_dates <- read.csv("~/Documents/scripts/cmip6/2023/historical_dates_2023.csv") # all dates for historical
models <- read.csv("~/Documents/scripts/cmip6/2023/models_2023.csv") #has all the other information necessary to create the HTTPs
variables <- read.csv("~/Documents/scripts/cmip6/2023/Variables.csv")
ssps <- c("historical","ssp245","ssp370","ssp585")

historical_days <- seq(1,12775,1)
ssp_days <- seq(12776,44165,1)

library(ncdf4)
library(dplyr)
library(foreign)


#########################################################################
#####Creating directories--------
# getwd()
# setwd("/scratch/general/vast/u6047395/cmip6/cmip6_subset")
# 
# for (m in 1:17){
#   model = models[m,1]
#   dir.create(model)
# }
# 
# for (m in 1:17){
#   model = models[m,1]
#   for (s in 1:4){
#     ssp = ssps[s]
#     dir = paste0(model,"/",ssp)
#     dir.create(dir)
#   }
# 
# }
# 
# 
# for (m in 1:17){
#   model = models[m,1]
#   for (s in 1:4){
#     ssp = ssps[s]
#     for (i in 1:3){
#       v = vars[i]
#       dir = paste0(model,"/",ssp,"/",v)
#       dir.create(dir)
#     }
#   }
# }
####################################################################
####### SUBSETING m = 17 ###################################----
####################################################################

#Model specific information

lon_res <- 360 / 144 ###### CHANGES FOR EVERY MODEL
lat_res <- 180 / 96

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

m=17 

model = models[m,1]
realization = models[m,4]
grid = models[m,5]
guide <- read.dbf(paste0("/uufs/chpc.utah.edu/common/home/u6047395/Documents/scripts/cmip6/2023/grids/subsets/",model,"_guide.dbf"))

for (s in 1:4){
  ssp = ssps[s]
  print(ssp)
  
  if(ssp == "historical") {dates_n = models[m,6]} # number of files
  if(ssp == "ssp245") {dates_n = models[m,7]}
  if(ssp == "ssp370") {dates_n = models[m,7]}
  if(ssp == "ssp585") {dates_n = models[m,7]}
  
  if(ssp == "historical") {dates = historical_dates[1:dates_n,m]}# creating a vector of the dates
  if(ssp == "ssp245"|ssp == "ssp370"|ssp == "ssp585") {dates = future_dates[1:dates_n,m]}  
  
  for (v in 1:3){
    var = variables[v,3]
    print(var)
    
    if(ssp == "historical") {
      
      
      for (d in 1:length(dates)){
        
        if (d == 1| d==2 | d== 3){
          
          date = dates[d]
          print(date)
          nc_name <- paste0("/scratch/general/vast/u6047395/cmip6/",var,"/",model,"/",ssp,"/",var,"_day_",model,"_",ssp,"_",realization,"_",grid,"_",date,".nc")
          nc <- nc_open(nc_name)
          
          array <- ncvar_get(nc, var)
          
          pixels = rep(-999999, 3650)
          p=1
          for (p in 1:length(guide$lon)){
            
            Y <- ((guide[p,2] + 90)/lat_res)+1 # X is the pixel position in the netcdf. takes the coordinates of the pixel divide by resolution and sums 90 becouse it is in the north hemisphere 
            X <- (guide[p,3]/ lon_res)+1
            
            pixel <- array[X,Y, 1:3650] # change every model
            
            pixels <- cbind(pixels,pixel)}
          
          if (d == 1) { pixels_d1 <- pixels[,-1] }
          if (d == 2) { pixels_d2 <- pixels[,-1] }
          if (d == 3) { pixels_d3 <- pixels[,-1] }
        }
        
        if (d == 4){
          
          date = dates[d]
          print(date)
          nc_name <- paste0("/scratch/general/vast/u6047395/cmip6/",var,"/",model,"/",ssp,"/",var,"_day_",model,"_",ssp,"_",realization,"_",grid,"_",date,".nc")
          nc <- nc_open(nc_name)
          
          array <- ncvar_get(nc, var)
          
          pixels = rep(-999999, 1825)
          p=1
          for (p in 1:length(guide$lon)){
            
            Y <- ((guide[p,2] + 90)/lat_res)+1 # X is the pixel position in the netcdf. takes the coordinates of the pixel divide by resolution and sums 90 becouse it is in the north hemisphere 
            X <- (guide[p,3]/ lon_res)+1
            
            pixel <- array[X,Y, 1:1825] # change every model
            
            pixels <- cbind(pixels,pixel)}
          
          if (d == 4) { pixels_d4 <- pixels[,-1] }
        }
      }
      
      data <- rbind(pixels_d1, pixels_d2, pixels_d3, pixels_d4)
      
      #Creating the nectdf----
      
      getwd()
      setwd(paste0("/scratch/general/vast/u6047395/cmip6/cmip6_subset/",model,"/",ssp,"/",var))
      
      data <- as.data.frame(data)
      rownames(data) <- as.character(1:length(data$pixel))
      colnames(data) <- as.character(1:length(data))
      data <- t(data)
      
      LON_n <- length(unique(guide$lon)) 
      LAT_n <- length(unique(guide$lat))
      TIME_n <- 12775 
      
      data_array <-  array(data, dim = c(LON_n, LAT_n, TIME_n))
      
      nc_name <- paste0(var,"_day_",model,"_",realization,"_",ssp,"_subset.nc")
      dim_name <- variables[v,3]
      dim_long_name <- variables[v,5]
      dim_units <- variables[v,7]
      
      ##defining dimensions
      
      lon_dim <- ncdim_def("lon", units = "degrees_east", longname = "Longitude", vals = unique(guide$lon))
      lat_dim <- ncdim_def("lat", units = "degrees_north", longname = "Latitude", vals = unique(guide$lat))
      time_dim <- ncdim_def("time", units = "days", longname = "days since 19800101", vals = historical_days)
      
      variable_dim <- ncvar_def(name = dim_name, units = dim_units, list(lon_dim, lat_dim, time_dim),
                                missval =  -9999,longname = dim_long_name, prec = "double")
      
      nc_out <- nc_create(nc_name,variable_dim)
      
      ncvar_put(nc_out, variable_dim, data_array)
      
      nc_close(nc_out)
    }
    
    ##########################################################################
    
    if(ssp == "ssp245"|ssp == "ssp370"|ssp == "ssp585") {
      
      d=1
      for (d in 1:length(dates)){
        
        if (d == 1){
          
          date = dates[d]
          print(date)
          nc_name <- paste0("/scratch/general/vast/u6047395/cmip6/",var,"/",model,"/",ssp,"/",var,"_day_",model,"_",ssp,"_",realization,"_",grid,"_",date,".nc")
          nc <- nc_open(nc_name)
         
          array <- ncvar_get(nc, var)
          
          pixels = rep(-999999, 1825)
          p=1
          for (p in 1:length(guide$lon)){
            
            Y <- ((guide[p,2] + 90)/lat_res)+1 # X is the pixel position in the netcdf. takes the coordinates of the pixel divide by resolution and sums 90 becouse it is in the north hemisphere 
            X <- (guide[p,3]/ lon_res)+1
            
            pixel <- array[X,Y, 1:1825] # change every model
            
            pixels <- cbind(pixels,pixel)}
          
          if (d == 1) { pixels_d1 <- pixels[,-1] }
          
        }
        
        if (d==2 | d== 3 | d == 4| d == 5| d == 6| d == 7 | d== 8 | d == 9) {
          
          date = dates[d]
          print(date)
          nc_name <- paste0("/scratch/general/vast/u6047395/cmip6/",var,"/",model,"/",ssp,"/",var,"_day_",model,"_",ssp,"_",realization,"_",grid,"_",date,".nc")
          nc <- nc_open(nc_name)
          
          array <- ncvar_get(nc, var)
          
          pixels = rep(-999999, 3650)
          p=1
          for (p in 1:length(guide$lon)){
            
            Y <- ((guide[p,2] + 90)/lat_res)+1 # X is the pixel position in the netcdf. takes the coordinates of the pixel divide by resolution and sums 90 becouse it is in the north hemisphere 
            X <- (guide[p,3]/ lon_res)+1
            
            pixel <- array[X,Y, 1:3650] # change every model
            
            pixels <- cbind(pixels,pixel)}
          
          if (d == 2) { pixels_d2 <- pixels[,-1] }
          if (d == 3) { pixels_d3 <- pixels[,-1] }
          if (d == 4) { pixels_d4 <- pixels[,-1] }
          if (d == 5) { pixels_d5 <- pixels[,-1] }
          if (d == 6) { pixels_d6 <- pixels[,-1] }
          if (d == 7) { pixels_d7 <- pixels[,-1] }
          if (d == 8) { pixels_d8 <- pixels[,-1] }
          if (d == 9) { pixels_d9 <- pixels[,-1] }
          
        }
      }
      
      data <- rbind(pixels_d1, pixels_d2, pixels_d3, pixels_d4, pixels_d5, pixels_d6,
                    pixels_d7, pixels_d8, pixels_d9)
      
      #Creating the nectdf----
      
      getwd()
      setwd(paste0("/scratch/general/vast/u6047395/cmip6/cmip6_subset/",model,"/",ssp,"/",var))
      
      data <- as.data.frame(data)
      rownames(data) <- as.character(1:length(data$pixel))
      colnames(data) <- as.character(1:length(data))
      data <- t(data)
      
      LON_n <- length(unique(guide$lon)) 
      LAT_n <- length(unique(guide$lat))
      TIME_n <- 31390 
      
      data_array <-  array(data, dim = c(LON_n, LAT_n, TIME_n))
      
      nc_name <- paste0(var,"_day_",model,"_",realization,"_",ssp,"_subset.nc")
      dim_name <- variables[v,3]
      dim_long_name <- variables[v,5]
      dim_units <- variables[v,7]
      
      ##defining dimensions
      
      lon_dim <- ncdim_def("lon", units = "degrees_east", longname = "Longitude", vals = unique(guide$lon))
      lat_dim <- ncdim_def("lat", units = "degrees_north", longname = "Latitude", vals = unique(guide$lat))
      time_dim <- ncdim_def("time", units = "days", longname = "days since 19800101", vals = ssp_days)
      
      variable_dim <- ncvar_def(name = dim_name, units = dim_units, list(lon_dim, lat_dim, time_dim),
                                missval =  -9999,longname = dim_long_name, prec = "double")
      
      nc_out <- nc_create(nc_name,variable_dim)
      
      ncvar_put(nc_out, variable_dim, data_array)
      
      nc_close(nc_out)
      
    }
  }
}


# Fim