#!/bin/bash

# file: playlist-m3u.sh 
# script to create an M3U Playlist using full albums (all tracks/album)

# Pete Nesbitt Sept 2024

# expects dir structure of "/..../artist_dir/album_dir/tracks"
# 		            /music/Steely_Dan/Katy_Lied/[tracks]

##########################
# vars
# *** CHANGE THESE TO MATCH ENVIRONMENT
SQUEEZE_DIR="/data/media/music/squeezebox"
PLAYLIST_DIR="/data/media/music/squeezebox-playlists"
TITLE="Playlist Creator"
SCREEN_COLOURS="`setterm --term linux --background \"blue\" --foreground \"white\"`"

# *** DO NOT CHANGE THESE (unless you know what you are doing)
PL_TITLE="new list"  #place holder, replaced at prompt
TRACK_COUNT=0 # for looping thru each track in build_list function
FINAL="no"  # for printing either in-progress or final summary
LAST_ART="b" # place holder, used in show_summary
LAST_ALB="b" # place holder, used in show_summary

#array to hold Artist or Album lines. Print at summary.
SUMMARY_LINES=()


##########################
# functions

get_title(){
# get Playlist Title, and also output file name

echo -e "\n EXISTING PLAYLISTS:"
EXISTING_LISTS="`ls -1 ${PLAYLIST_DIR} | sed -e 's/\.m3u$//g' -e 's/_/ /g'`"
echo "${EXISTING_LISTS[@]}" | sed -E 's/(\w)(\w*)/\U\1\L\2/g' # sed upper's first letter each word
echo -e "\n **Playlist Title use Letters Numbers dashes underscores or spaces ONLY**\n"
read -p 'Enter the TITLE for this Playlist: ' PL_TITLE

# create output file based on PL_TITLE
PL_OUTFILE=(`echo "${PL_TITLE}.m3u" |sed -e 's/ /_/g' | tr '[:upper:]' '[:lower:]'`) #proper file format
FQ_OUT="${PLAYLIST_DIR}/${PL_OUTFILE}"
# does it already exist?
ls ${FQ_OUT} &>/dev/null
EXISTS=$?
if [ ${EXISTS} -eq 0  ]; then # file exists!
   echo
   printf " Playlist Name already in use. Replace it? [y|N]:  "
     read REPLACE
     if [ "${REPLACE}" == "y" ] || [ "${REPLACE}" == "Y" ]; then
        echo "Replacing Playlist ${PL_TITLE}"
        rm ${FQ_OUT} &> /dev/null
     else
        echo -e "\n\n\tPlaylist Exists, exiting script\n"
        exit
     fi
fi
clear -x
touch ${FQ_OUT}

} # end of get_title

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

build_list() {  # assemble playlist based on user input via a loop
# display a list of artists
echo
cd ${SQUEEZE_DIR}
CD_OK=$?
    if [ ${CD_OK} -ne 0 ]; then
      echo -e "\n\n\t ERROR, could not access ${SQUEEZE_DIR}"
      exit
    fi
echo

ARTIST_ENTRY="a"  # so it is not null on first test
ALBUM_ENTRY="a"  # so it is not null on first test

FIRST_RUN="y"  # build is only called once so okay to set here

# UNTIL LOOP -START
  until [[ -z "${ARTIST_ENTRY}" ]]
   do
    clear -x  # added -x for troubleshooting to scroll back

    FIRST_RUN="n"
    show_summary

    cd ${SQUEEZE_DIR}
    CD_OK=$?
     if [ ${CD_OK} -ne 0 ]; then
        echo -e "\n\n\t ERROR, could not access ${SQUEEZE_DIR}"
        exit
     fi
    
    echo -e "\n\n\t----------------------------------------------\n"
    echo -e "\n\t Artist List:\n"
    ls
    echo
    #after album selection, maybe do a add confirm, then write vars to file
    read -p 'enter or copy Artist Name from above. (or blank when done): ' ARTIST_ENTRY
      #if blank, start at top of Until Loop
      test -z "${ARTIST_ENTRY}" && continue

    # set current Artist, for use in summary
    CUR_ART="`echo ${ARTIST_ENTRY} | sed -e 's/_/ /g'`"

    #now show albums in that dir
     cd ${SQUEEZE_DIR}/${ARTIST_ENTRY} && ls
     echo #-e "\n\tSelect Album Name from above list\n"
     read -p 'enter or copy Album Name from above. (or blank for artists): ' ALBUM_ENTRY
       #if blank, start top of Until Loop
      test -z "${ALBUM_ENTRY}" && continue

     CUR_ALB="`echo ${ALBUM_ENTRY} | sed -e 's/_/ /g'`"  # for summary

     # ask if ok to add this album to playlist  (could show tracks??)
     echo -e "\n\n\tAdd ${ARTIST_ENTRY}/${ALBUM_ENTRY} to Playlist?\n\n"
     printf " Press Y, y or enter to Add, 'n' to skip: [Y|n]:  "
     read OK_ADD
     if [ "${OK_ADD}" == "n" ] || [ "${OK_ADD}" == "N" ]; then
        echo -e "\n\nNew Entry Skipped\n"
        continue
     fi

     # write Artist (if new) to Summary
     if [ "${CUR_ART}"  !=  "${LAST_ART}" ]; then #new artist
        SUMMARY_LINES+=("${CUR_ART}\n") # append Artist to array
     fi

     # cd into album, do listing and loop for each to add
     cd ${SQUEEZE_DIR}/${ARTIST_ENTRY}/${ALBUM_ENTRY}
     CD_OK=$?
      if [ ${CD_OK} -ne 0 ]; then
       echo -e "\n\n\t ERROR, could not access ${ALBUM_ENTRY}"
       exit
      fi

     # write Album into summary
     CUR_ALB="`basename \`pwd\` | sed -e 's/_/ /g'`"
     SUMMARY_LINES+=("\t\t${CUR_ALB}\n") # append Album to array

     TRACK_COUNT=0
     for track in `ls`
      do
       let TRACK_COUNT++
       # clean up $track as it is a file name not a nice entry
       TRK_NAME="`echo ${track%.flac} | sed -e 's/_/ /g' `"

     cat >> ${FQ_OUT} << eoe
#EXTINF:${TRACK_COUNT}, ${ARTIST_ENTRY} - ${TRK_NAME}
#EXTART: ${ARTIST_ENTRY}
#EXTALB: ${ALBUM_ENTRY}
${SQUEEZE_DIR}/${ARTIST_ENTRY}/${ALBUM_ENTRY}/${track}

eoe
      done

   LAST_ART=${CUR_ART}
   LAST_ALB=${CUR_ALB}

  done
#
}  # end of build_list

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

show_summary() {

clear -x
# summarize playlist (artist/Album).

# centre script title
tput bold
printf "%*s\n" $(((${#TITLE}+$COLUMNS)/2)) "${TITLE}"
tput rmso

# see is called while still building
if [ "${FINAL}" == "yes" ];then
   STAT_STRING="Final Playlist"
   echo -e "\n\n"
   printf "%*s\n" $(((${#STAT_STRING}+$COLUMNS)/2)) "${STAT_STRING}"
   echo -e "\n\n"
else
   STAT_STRING="Playlist So Far"
   echo -e "\n\n"
   printf "%*s\n" $(((${#STAT_STRING}+$COLUMNS)/2)) "${STAT_STRING}"
   echo -e "\n\n"
fi

# below PL Title should be case set already, but upper first letter (^)
cat << oes

 Playlist Name: ${PL_TITLE^}
 Playlist Filename: ${PL_OUTFILE}

oes

# check if summary already artists in list, if so add the Includes: to heading
test ${#SUMMARY_LINES[@]} -ne 0 && echo -e "Includes:\n"

printf '%b' "${SUMMARY_LINES[@]}"

} # end of show_summary


##########################
##########################
# start
echo ${SCREEN_COLOURS}
clear # add -x to disable scroll

# script title
tput bold
printf "%*s\n" $(((${#TITLE}+$COLUMNS)/2)) "${TITLE}"
tput rmso

# get playlist title
get_title

#do some initial stuff at top of playlist file
cat > ${FQ_OUT} << eoh
#EXTM3U

#PLAYLIST: ${PL_TITLE}

eoh

# sort out what to include
build_list

FINAL="yes"
show_summary

# pause before exit (& clear screen)

echo -e "\n\n   ######################\n"
echo "   Save and EXIT press <ENTER>"
echo
  END_NOW="no"
  until [[ -z "${END_NOW}" ]]
     do
      read -p "Press <enter-key> to Quit"  END_NOW 
     done

tput init   # resets screen colours
clear -x    # clear screen, keep scroll buffer
#eof