generate_thumbnails

#!/bin/bash

# Website:       https://github.com/antonionarcilio
# Author:        Antonio Narcilio
# Maintenance:   Antonio Narcilio
# Version:       2.0.1
#
# --------------------------------------------------------------------------- #
# 💡  DEPENDENCIES REQUIRED
# 1.  ffmpeg
# 2.  ImageMagick 
# 3.  kdialog
#
# --------------------------------------------------------------------------- #
# 💡  WHAT DOES THIS SCRIPT DO ?
#     This script installs the necessary dependencies for the contact sheet 
#     creation script to work correctly
#
# --------------------------------------------------------------------------- #
#
# 💡  HOW TO USE IT?
# 
# 1.  Run in the terminal via the command line:
# 1.1 $ generate_thumbnails "video_name.mp4"
#
#     Or
#
# 2.  Run in the dolphin manager:
# 2.1 Right-click on the video you want to generate the thumbnail, in the 
#     context menu that opens select "GENERATE THUMBNAILS" and wait for the 
#     thumbnail creation process
# 
# --------------------------------------------------------------------------- #
# 
# 💡  FOR MORE INFORMATION, READ README.MD
#
#
# config shellcheck
# shellcheck disable=SC2116
#
# - - - - - - - - - - - - - -  GLOBAL VARIABLES  - - - - - - - - - - - - - -  #

# You may change
KD_ICON="an-effects";
KD_ICON_ERROR="an-error";
KD_ICON_WARNING="an-alert";

VIDEO_FORMAT=("avi" "mp4" "m4v" "mov" "mpg" "mpeg" "wmv" "mkv" "ts");
IS_IT_A_VALID_FORMAT=1;

# NOT CHANGE
CURRENT_DIR=$(dirname "$1");
FILE=$(realpath "$1");
FILE_NAME=$(basename -- "$FILE");
EXTENSION="${FILE_NAME##*.}";
FILE_NAME="${FILE_NAME%.*}";
SUFFIX_EXTENSION="webp";

TMP_DIR=/tmp/thumbnails-$FILE_NAME-${RANDOM}/;
TMP_TILE_FILE="$TMP_DIR/.grid";
# FONT=/usr/local/share/fonts/r/Roboto_Regular.ttf;
FONT=Roboto-Regular.ttf;
LOG=/tmp/log_generate_thumbnails;

# Getting display size
AXIS_X=$(xrandr -q | grep Screen | awk '{ print $8 }');
AXIS_Y=$(xrandr -q | grep Screen | awk '{ print $10 }' | awk -F"," '{ print $1 }');
# ASK=/tmp/.kdialog-dontagain;

# touch ${ASK};
mkdir -p "$TMP_DIR";


# - - - - - - - - - - - - - -  KDIALOG FUNCTIONS  - - - - - - - - - - - - - - #

# Expect to pass 3 parameters "TITLE" "MESSAGE" "TIME"
function kdialogPopUp() {
  kdialog \
    --title "$1" \
    --icon $KD_ICON \
    --passivepopup "<h5>$2</h5>" "$3";
}
# Expect to pass 2 parameters "TITLE" "MESSAGE"
function kdialogPopUpWarning() {
  kdialog \
    --title "$1" \
    --icon $KD_ICON_WARNING \
    --passivepopup "<h5>$2</h5>" 10;
}
# No parameters needed
function kdialogError() {
  kdialog \
    --title "Error ❌" \
    --icon $KD_ICON_ERROR \
    --error "Something unexpected happened 😢";
  exit 0 > /dev/null 2>&1;
}
# Expect to pass 2 parameters "TITLE" "MESSAGE"
# function kdialogYesNo() {
#   kdialog \
#     --icon "$KD_ICON" \
#     --title "$1" \
#     --yesno "<h4>$2</h4>" \
#     --dontagain ${ASK}:do-not-show;
#   KD_YESNO_STATUS=$?;
# }
# Expect to pass 2 parameters "TITLE" "MESSAGE"
function kdialogWarning() {
  kdialog \
    --title "$1" \
    --icon $KD_ICON_WARNING \
    --warningcontinuecancel "$2";
}
# EXPECTED 1 ARGUMENTS → "FILE.txt"
function kdialogTextBox() {
  kdialog \
    --title "⚠ Errors found ⚠" \
    --textbox "$1" \
    --geometry 500x300+"${AXIS_X}"+"${AXIS_Y}";
  exit 0 > /dev/null 2>&1;
}


# - - - - - - - - - - - - - - - - FUNCTIONS - - - - - - - - - - - - - - - -  #

function generatingThumbnail() {
  kdialogPopUp "Please wait..." "Thumbnail generation process started !" 5;

  function kdialogComboBox() {
    kd_option=('6x6' '5x5' '4x4' '3x3');

    CHOOSE_USER=$(kdialog --title "$1" \
        --icon $KD_ICON \
        --combobox "$2" "${kd_option[0]}" "${kd_option[1]}" "${kd_option[2]}" "${kd_option[3]}" \
        --geometry 300x50+"$AXIS_X"+"$AXIS_Y" \
        --default "${kd_option[1]}");
    KD_COMBOXBOX_STATUS=$?;

    echo "$CHOOSE_USER" > "$TMP_TILE_FILE";
    sed -i 's/x/\n/g' "$TMP_TILE_FILE" 2>> $LOG;

    index=0;
    while IFS= read -r line; do
      TILE[$index]=$(echo "$line" 2>> $LOG);
      index=$((index + 1));
    done < "$TMP_TILE_FILE";
  } 
  kdialogComboBox "Choose an option" "<h4><b>The thumbnail will have a grid of how much ?</b></h4>";


  if [[ $KD_COMBOXBOX_STATUS -eq 0 ]]; then
    file_output="${CURRENT_DIR}/${FILE_NAME}_${CHOOSE_USER}-preview.jpeg";
    tmp_file_output="$TMP_DIR/$FILE_NAME"-tmp_preview.${SUFFIX_EXTENSION};
    add_zero="${TMP_DIR}/.add-zero.txt";

    nframes=$(echo "scale=0;${TILE[0]}*${TILE[1]}" | bc);
    duration=$(ffmpeg -i "$FILE" 2>&1 | grep "Duration"| cut -d ' ' -f 4 | sed s/,// | sed 's@\..*@@g' | awk '{ split($1, A, ":"); split(A[3], B, "."); print 3600*A[1] + 60*A[2] + B[1] }');

    # -------------------------- ADITIONAL FRAMES -------------------------- #
    # Adding 2 frames, which will be removed at the end of the process.
    # They are added to prevent the first frame from going blank or a frame 
    # from appearing where the video itself 'hasn't been initialized yet'.
    nframes=$((nframes +2));

    for (( variable=0; variable < nframes; variable++ ))  do

      offset=$(echo "scale=2;${variable}*${duration}/${nframes}+${duration}/${nframes}/2" | bc);
      # |-> Time of the video where a print will be taken

      # Solution if the returned value is similar to .18 (millisecond), ffmpeg returns an error
      # stating that it doesn't recognize this value, so add a zero before the 
      # value, making the problem no longer happen
      echo "$offset" > "$add_zero";
      sed -i 's/^/0/' "$add_zero";

      while IFS= read -r line; do
        offset=$(echo "$line" 2>> $LOG);
      done < "$add_zero";

      if [ "$variable" -gt 9 ];then
        zeros="00";
      elif [ "$variable" -gt 99 ];then
        zeros="0";
      elif  [ "$variable" -gt 999 ];then
        zeros="";
      else
        zeros="000";
      fi;
      

      ffmpeg -start_at_zero -copyts -ss "$offset" -i "$FILE" \
        -vf "scale=-2:1080,setsar=1:1,\
              drawbox=x=1660:\y=1020:w=in_w:h=65:color=black@0.5:t=fill, \
              drawtext=fontfile=${FONT}:\
              fontsize=60:\
              fontcolor=white:\
              shadowcolor=black@0.5:\
              shadowx=2:\
              shadowy=2:\
              box=1:\
              boxcolor=black@0:\
              x=(W-tw)/1.0050:y=H-th-7:\
              text='%{pts\:gmtime\:0\:%H\\\\\:%M\\\\\:%S}'" \
        -vframes 1 "${TMP_DIR}${zeros}${variable}.${SUFFIX_EXTENSION}" 2>> $LOG;

      [[ $? -eq 1 ]] && kdialogTextBox "$LOG" && return 1 > /dev/null 2>&1;

    done;

    # ----------------------- REMOVE ADITIONAL FRAMES ----------------------- #
    # remove the first and the ultimate thumbnail
    rm -rf "${TMP_DIR}/0000.${SUFFIX_EXTENSION}" "${TMP_DIR}/${zeros}$((variable -1)).${SUFFIX_EXTENSION}" 2>> $LOG;

    function montageThumbnail() {
      # going back to the original value
      nframes=$((nframes - 2));

        function thumbnailThreeByThree() {
          montage "${TMP_DIR}"/{0001..0003}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_1.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0004..0006}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_2.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0007..009}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_3.${SUFFIX_EXTENSION}" && \

          montage "${TMP_DIR}"/line_{1..2}."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "${TMP_DIR}/montage-1.${SUFFIX_EXTENSION}" 2> $LOG && \
          montage "${TMP_DIR}"/line_3."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "${TMP_DIR}/montage-2.${SUFFIX_EXTENSION}" 2> $LOG && \
          
          creatingFinalFile() {
            montage "${TMP_DIR}"/montage*."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "$tmp_file_output" 2> $LOG; 
          }        

          processorUsage creatingFinalFile;
          # expect to pass 1 argument - "function" 

          [[ $? -eq 1 ]] && kdialogTextBox "$LOG";
        } # end of thumbnailThreeByThree function

        function thumbnailFourByFour() {
          montage "${TMP_DIR}"/{0001..0004}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_1.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0005..0008}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_2.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0009..0012}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_3.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0013..0016}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_4.${SUFFIX_EXTENSION}";

          montage "${TMP_DIR}"/line_{1..2}."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "${TMP_DIR}/montage-1.${SUFFIX_EXTENSION}" 2> $LOG && \
          montage "${TMP_DIR}"/line_{3..4}."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "${TMP_DIR}/montage-2.${SUFFIX_EXTENSION}" 2> $LOG && \
          
          creatingFinalFile() {
            montage "${TMP_DIR}"/montage*."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "$tmp_file_output" 2> $LOG; 
          }        

          processorUsage creatingFinalFile;
          # expect to pass 1 argument - "function" 

          [[ $? -eq 1 ]] && kdialogTextBox "$LOG";
        } # end of thumbnailFourByFour function

        function thumbnailFiveByFive() {
          montage "${TMP_DIR}"/{0001..0005}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_1.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0006..0010}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_2.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0011..0015}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_3.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0016..0020}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_4.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0021..0025}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_5.${SUFFIX_EXTENSION}";

          montage "${TMP_DIR}"/line_{1..2}."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "${TMP_DIR}/montage-1.${SUFFIX_EXTENSION}" 2> $LOG && \
          montage "${TMP_DIR}"/line_{3..4}."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "${TMP_DIR}/montage-2.${SUFFIX_EXTENSION}" 2> $LOG && \
          
          creatingFinalFile() {
            montage "${TMP_DIR}"/montage*."${SUFFIX_EXTENSION}" "${TMP_DIR}"/line_5*."${SUFFIX_EXTENSION}" -background white -geometry +1+3 -tile "1x3" "$tmp_file_output" 2> $LOG; 
          }

          processorUsage creatingFinalFile;
          # expect to pass 1 argument - "function" 

          [[ $? -eq 1 ]] && kdialogTextBox "$LOG";
        } # end of thumbnailFiveByFive function

        function thumbnailSixBySix() {
          montage "${TMP_DIR}"/{0001..0006}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_1.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0007..0012}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_2.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0013..0018}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_3.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0019..0024}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_4.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0025..0030}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_5.${SUFFIX_EXTENSION}" && \
          montage "${TMP_DIR}"/{0031..0036}."${SUFFIX_EXTENSION}" -background white -geometry +"${TILE[0]}"+1 -tile "${TILE[0]}x1" "${TMP_DIR}/line_6.${SUFFIX_EXTENSION}";

          montage "${TMP_DIR}"/line_{1..2}."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "${TMP_DIR}/montage-1.${SUFFIX_EXTENSION}" 2> $LOG && \
          montage "${TMP_DIR}"/line_{3..4}."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "${TMP_DIR}/montage-2.${SUFFIX_EXTENSION}" 2> $LOG && \
          montage "${TMP_DIR}"/line_{5..6}."${SUFFIX_EXTENSION}" -background white -geometry +1+2 -tile "1x2" "${TMP_DIR}/montage-3.${SUFFIX_EXTENSION}" 2> $LOG && \
          
          creatingFinalFile() {
            montage "${TMP_DIR}"/montage*."${SUFFIX_EXTENSION}" -background white -geometry +1+3 -tile "1x3" "$tmp_file_output" 2> $LOG;
          }
          
          processorUsage creatingFinalFile;
          # expect to pass 1 argument - "function" 
          
          [[ $? -eq 1 ]] && kdialogTextBox "$LOG";
        } # end of thumbnailSixBySix function

      case ${nframes} in 
        9) processorUsage thumbnailThreeByThree;;
        16) processorUsage thumbnailFourByFour;;
        25) processorUsage thumbnailFiveByFive;;
        36) processorUsage thumbnailSixBySix;;
        *) processorUsage thumbnailFiveByFive;;
      esac;


      rm -rf "${TMP_DIR}"/line_*."${SUFFIX_EXTENSION}" "${TMP_DIR}"/montage*."${SUFFIX_EXTENSION}" ;
    }

    processorUsage montageThumbnail;
    # expect to pass 1 argument - "function"

    convert "${tmp_file_output}" -resize 1920x1080 "${file_output}" 2>> $LOG;
    status=$?;
    [[ $status -eq 1 ]] && kdialogTextBox "$LOG";

    if [[ "$status" -eq 0 ]]; then
      kdialogPopUp "Finish 🏁" "Successfully ✅ generated thumbnails 🥳<br>Saved to: 👇<br><a href='${file_output}'>${file_output}</a>" 5;
      # |-> Expect to pass 3 parameters "TITLE" "MESSAGE" "TIME"
    else
      kdialogPopUpWarning "Ops ! 😐" "An error occurred while generating the thumbnail<br>Thumbnail cannot be generated! 😢";
      # |-> Expect to pass 2 parameters "TITLE" "MESSAGE"
    fi

  else
    kdialogPopUp "Canceled !" "Thumbnail will not be generated !" 5;
    # |-> Expect to pass 3 parameters "TITLE" "MESSAGE" "TIME"
  fi;
}

function checkingFileFormat() {
  index=0;
  for index in "${!VIDEO_FORMAT[@]}"; do
    [[ $EXTENSION == "${VIDEO_FORMAT[index]}" ]] &&  IS_IT_A_VALID_FORMAT=0;
  done;

  if [[ $IS_IT_A_VALID_FORMAT -eq 0 ]]; then
    processorUsage generatingThumbnail;
    # expect to pass 1 argument - "function"
  else
    kdialogPopUpWarning "Nothing found !" "No files of type <b>${VIDEO_FORMAT[*]}</b> were found!";
    # |-> Expect to pass 2 parameters "TITLE" "MESSAGE"
  fi;
}

function main() {
  echo "" > $LOG;
  # Parameter exist ?
  if [[ $FILE != '' ]]; then
    # kdialogYesNo "Choose an option" "Do you want to create a thumbnail of the video ? 👇<br><u>$FILE_NAME</u>";
    # |-> Expect to pass 2 parameters "TITLE" "MESSAGE"

    # ⚠️ Prevention in case the user runs the script on dolphin 'unintentionally'
    # if [[ $KD_YESNO_STATUS -eq 0 ]]; then
      checkingFileFormat;
    # elif [[ $KD_YESNO_STATUS -eq 1 ]]; then
    #   kdialogPopUp "Canceled !" "Thumbnail will not be generated !" 5;
    #   # |-> Expect to pass 3 parameters "TITLE" "MESSAGE" "TIME"
    # else
    #   kdialogError;
    # fi
  # Parameter does not exist ?
  elif [[ $FILE == '' ]]; then
    kdialogPopUpWarning "Nothing found !" "No files of type <b>${VIDEO_FORMAT[*]}</b> were found!";
    # |-> Expect to pass 2 parameters "TITLE" "MESSAGE"
  else
    kdialogError;
  fi
}

# - - - - - - - - - - - - CHECK IF DEPENDENCIES EXIST - - - - - - - - - - - - #

function verifyDependencies() {
  # imagemagick is isntall ?
  function imagemagickVerify() {
    convert --version > /dev/null 2>&1;
    is_exist_imagemagick=$?;

    if [[ $is_exist_imagemagick -ne 0 ]]; then
      msg=("ImageMagic is required !" "Access the site: <a href='https://imagemagick.org/script/download.php'>ImageMagick</a> for more,<br>or run the command<br><b>sudo \"apt/pacman -S\" imagemagick</b>");
      kdialogPopUpWarning "${msg[0]}" "${msg[1]}";
      # |-> Expect to pass 2 parameters "TITLE" "MESSAGE"
      echo -e "\e[1;33m${msg[0]}\e[0m";
    fi;
  }
  # ffmpeg is isntall ?
  function ffmpegVerify() {
    ffmpeg -version  > /dev/null 2>&1;
    is_exist_ffmpeg=$?;

    if [[ $is_exist_ffmpeg -ne 0 ]]; then
      msg=("FFMPEG is required !" "Access the site: <a href='https://ffmpeg.org/download.html'>FFMPEG</a> for more,<br>or run the command<br><b>sudo \"apt/pacman -S\" ffmpeg</b>");
      kdialogPopUpWarning "${msg[0]}" "${msg[1]}";
      # |-> Expect to pass 2 parameters "TITLE" "MESSAGE"
      echo -e "\e[1;33m${msg[0]}\e[0m";
    fi;

  }
  # kdialog is isntall ?
  function kdialogVerify() {
    kdialog --version  > /dev/null 2>&1;
    is_exist_kdialog=$?;

    if [[ $is_exist_kdialog -eq 0 ]]; then
      imagemagickVerify;
      ffmpegVerify;
    else
      echo -e "Kdialog is required!\nRun the command:\n\e[1;33msudo \"apt/pacman -S\" ffmpeg\e[0m";
      exit 0 > /dev/null 2>&1;
    fi;
  }

  kdialogVerify;

  if [[ $is_exist_kdialog -eq 0 && is_exist_ffmpeg -eq 0 && $is_exist_imagemagick -eq 0 ]]; then
    processorUsage main;
  else
    exit 0 > /dev/null 2>&1;
  fi
}


# - - - - - - - - - - - - -  PC CRASH PREVENTION  - - - - - - - - - - - - -  #

# expect to pass 1 argument - "function"
function processorUsage() {
  checkProcessUsage () {
    PROCESSOR_USAGE=$(awk -v a="$(awk '/cpu /{print $2+$4,$2+$4+$5}' /proc/stat; sleep 1)" '/cpu /{split(a,b," "); print 100*($2+$4-b[1])/($2+$4+$5-b[2])}'  /proc/stat);
    PROCESSOR_USAGE=$(echo "${PROCESSOR_USAGE}" | awk '{printf("%d\n",$1)}');
    # echo $PROCESSOR_USAGE;
    PERCENTAGE=90;
  }
  checkProcessUsage;

  if [[ ${PROCESSOR_USAGE} -gt ${PERCENTAGE} ]]; then
    cont_final_process=0;
    while [[ ${PROCESSOR_USAGE} -gt ${PERCENTAGE} ]]; do
      echo -e "\e[2;33mProcessor consuming more than ${PERCENTAGE}%, await ...\e[0m";
      [[ ${cont_final_process} == 20 ]] && kdialogPopUpWarning 'Process terminated' 'Process terminated due to excessive CPU consumption!';
      
      sleep 20;
      cont_final_process=$((cont_final_process + 1));
      checkProcessUsage;
    done;
    $1;
  else 
    $1;
  fi;

}


# - - - - - - - - - - - - - - - - EXECUTION - - - - - -  - - - - - -  - - - - #

processorUsage verifyDependencies;
# expect to pass 1 argument - "function"