library(dplyr)
library(ggplot2)
library(reshape2)

# Note: this sript assumes that you have saved a Praat Spectrogram 
# using the function "Save to text file. "
# It will not work if you save to a short text file,
# and will not work if you save to a binary file. 

# you should first set the working directory to wherever the spectrogram is saved. 
# change this next line to map to the appropriate directory on your computer
dir_spectrogram_files <- "C:\\Users\\Matt\\Documents\\Website\\tools"
setwd(dir_spectrogram_files)

# Here's the main function: 
convert_spectrogram_to_df <- function(spect_name){
  
  spect <- readLines(spect_name) %>% 
    colsplit(., pattern = " = ", names = c("coordinate","Value")) 
  
  spect <- spect[4:nrow(spect),] %>%
    mutate(Value = as.numeric(Value))
  
  Freq_floor <- spect[spect$coordinate=="ymin", "Value"]
  Freq_max <- spect[spect$coordinate=="ymax", "Value"]
  Time_start <- spect[spect$coordinate=="xmin", "Value"]
  Time_end <- spect[spect$coordinate=="xmax", "Value"]
  num_times <- spect[spect$coordinate=="nx", "Value"]
  time_bin_size <- spect[spect$coordinate=="dx", "Value"]
  num_freq_bins <- spect[spect$coordinate=="ny", "Value"]
  freq_bin_size <- spect[spect$coordinate=="dy", "Value"]
  
  spect_vals <- spect$coordinate[12:length(spect$coordinate)] %>% 
    data.frame(meas = .) %>%
    mutate(meas = as.character(meas)) %>%
    mutate(is.Freqstep = ifelse(grepl(x = meas, pattern=":"), 1, 0)) %>%
    mutate(Freqstep = cumsum(is.Freqstep)) %>%
    mutate(Timestep = {meas %>% 
        colsplit(., pattern = "\\]|\\]", names = c("junk","Timebin")) %>%
        mutate(Timebin = gsub(replacement = "", x = Timebin, pattern="\\[|\\]")) %>%
        mutate(Timebin = as.numeric(Timebin)) %>%
        `[[`(., "Timebin")}) %>%
    mutate(Time = (Timestep - 1) * time_bin_size) %>%
    mutate(Frequency = (Freqstep - 1) * freq_bin_size) 
  
  reference_SP <- 0.00002
  
  df <- cbind(spect[12:nrow(spect),], spect_vals) %>%
    mutate(filename = spect_name) %>%
    select(filename, Timestep, Freqstep, Time, Frequency, Pressure = Value) %>%
    # mutate(Pressure = round(Pressure, 5)) %>%
    mutate(Level = 20 * log10(Pressure / reference_SP))
  
  df <- df[!is.na(df$Time),]
  
  rm(spect, spect_vals)
  return(df)
}

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# Here's how to constrain dynamic range
# (the way you'd do in Praat)
constrain_dynamic_range <- function(spectrogram_object, dynamic_range = 60){
  
  # first make a copy of the Level variable,
  # so that you don't lose information
  spectrogram_object$Level_dr <- spectrogram_object$Level
  
  # remove anything that's more than [DR] below the max level
  spectrogram_object$Level_dr[spectrogram_object$Level_dr < (max(spectrogram_object$Level_dr, na.rm=TRUE) - dynamic_range)] <- NA
  
  return(spectrogram_object)
}

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# this is an example of using this single function to read in 
# lots of spectrogram files into a single big data frame:

# you should first set the working directory to wherever the spectrogram is saved. 
setwd(dir_spectrogram_files)

# make the list of spectrograms
spect_files <- list.files(pattern = "Spectrogram")

# apply the function to the list of spectrogram files,
# combine together
big_spect_df <- spect_files %>% 
  lapply(., convert_spectrogram_to_df) %>%
  bind_rows()

# constrain the dynamic range
big_spect_df <- big_spect_df %>% constrain_dynamic_range()

# verify dynamic range adjustment with plot
hist(big_spect_df$Level)
hist(big_spect_df$Level_dr)


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# Here's an example of how to plot it
setwd(dir_spectrogram_files)

my_spect_file <- "Time.Spectrogram"

single_spect_df <- my_spect_file %>%
  convert_spectrogram_to_df() %>%
  constrain_dynamic_range(dynamic_range = 70)

px_spectrogram <- ggplot(single_spect_df)+
  aes(x = Time, y=Frequency, fill=Level_dr)+
  geom_tile()+
  scale_fill_gradient(high="black", low="white", na.value = "white")+
  coord_cartesian(ylim=c(0, 6200))+
  xlab("Time (s)")+
  scale_y_continuous("Frequency (Hz)", breaks=seq(0, 6000, 2000))+
  theme_bw()+
  theme(legend.position="none",
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank())
px_spectrogram

#%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%#
# # save it!
# ggsave(px_spectrogram, filename = "my_spectrogram.png",
#        height = 3.2, width = 5, dpi = 150)