library(warbleR)
library(tuneR)

# Set the inputs directory
dir = "/home/ortion/records/"
indir = paste0(dir, 'raw')
outdir = paste0(dir, 'exp')

# Set name prefix
car = "721035"
year = 2021
pass = 0
point = "Z2"
prefix = paste0("Car", car, "-", year, "-", "Pass", pass, "-", point, "-")

# Create the output directory
dir.create(outdir)

# Create a list of ".WAV" files
wav_list=list.files(indir,"*.WAV")

# To handle quite frequent crashes in mp32wav function
wav_list=list.files(indir, pattern=".wav$")
mp3_list=list.files(indir, pattern=".mp3$")
while(length(wav_list)<length(mp3_list)) 
{
  Sys.time()
  try(mp32wav())
  Sys.time()
  wav_list=list.files(indir,pattern=".wav$")
  mp3_list=list.files(indir,pattern=".mp3$")
  print(paste(length(wav_list),length(mp3_list),sep="/"))
}

# Split into 5 seconds files and apply X10 time expansion
for (j in 1:length(wav_list))
{
  dur=0
  if (is.null(wav_list[j]) || is.na(file.size(wav_list[j]) || file.size(wav_list[j]) == 0)) {
    next
  }
  else if(file.size(wav_list[j]) > 50000)
  {
    wav_tmp = readWave(wav_list[j])
    dur = duration(wav_tmp)
    if (dur > 0)
    {
      for(k in 1:ceiling(dur/5))
      {
        left_channel_tmp = cutw(channel(wav_tmp,which="left"),from=(k-1)*5,to=min(dur,k*5),output="Wave")
        left_channel_tmp = normalize(left_channel_tmp,level=0.3)
        suf = formatC(x = k, width = 3, flag = "0") #create a suffix as 001, 000
        savewav(left_channel_tmp,filename=paste0(SplitDir,substr(wav_list[j],1,nchar(wav_list[j])-4),"_",suf,".wav"))
        if (length(wav_tmp@right) > 0){
          right_channel_tmp = cutw(channel(wav_tmp,which="right"),from=(k-1)*5,to=min(dur,k*5),output="Wave",normalize= "16")
          right_channel_tmp = normalize(right_channel_tmp,level=0.3)
          savewav(right_channel_tmp,filename = paste0(SplitDir,substr(wav_list[j],1,nchar(wav_list[j])-4),"_",suf,".wav"))
        }
      }
    }
  }
  print(paste(j,wav_list[j],dur))
}