#!/bin/bash

set -a #export all functions and variables for child processes like runonce()

DIRECTORY="$(readlink -f "$(dirname "$0")")"

function error {
  echo -e "\e[91m$1\e[39m"
  exit 1
}

if ! command -v yad &>/dev/null;then
  error "YAD needs to be installed to run pi-apps."
fi

#launch splash screen
yad --undecorated --title=Pi-Apps --image="${DIRECTORY}/icons/splashscreen.png" --center --no-buttons --skip-taskbar &
splashpid=$!

#for the text_editor(), runonce() and app_status() functions
source "${DIRECTORY}/api" || error "failed to source ${DIRECTORY}/api"

generate_logo

#Variable 1 is used to view the details of the specified app
if [ ! -z "$1" ];then
  app="$1"
fi

(
#mark wine and box86 as installed, if twisteros
runonce <<"EOF"
  if [ -f /usr/local/bin/twistver ] && command -v wine >/dev/null ;then
    echo 'disabled' > "${DIRECTORY}/data/status/Wine (x86)"
  fi
  if [ -f /usr/local/bin/twistver ] && command -v box86 >/dev/null ;then
    echo 'disabled' > "${DIRECTORY}/data/status/Box86"
  fi
EOF

#move some apps to the new multimedia category
runonce <<"EOF"
  "${DIRECTORY}/etc/categoryedit" "Chromium Widevine" Multimedia >/dev/null
  "${DIRECTORY}/etc/categoryedit" "FreeTube" Multimedia >/dev/null
  "${DIRECTORY}/etc/categoryedit" "Sonic Pi 3.2" Multimedia >/dev/null
  "${DIRECTORY}/etc/categoryedit" "TBOPlayer" Multimedia >/dev/null
  "${DIRECTORY}/etc/categoryedit" "WACUP (new WinAmp)" Multimedia >/dev/null
  "${DIRECTORY}/etc/categoryedit" "YouTubuddy" Multimedia >/dev/null
  "${DIRECTORY}/etc/categoryedit" "OBS Studio" Multimedia >/dev/null
  
  #move some apps to tools category
  
  "${DIRECTORY}/etc/categoryedit" 'Snapdrop' Tools >/dev/null
  "${DIRECTORY}/etc/categoryedit" 'Node.js' Tools >/dev/null
EOF

#re-run install script on twistos lite to re-show some previously hidden apps
runonce <<"EOF"
if [ -f /usr/local/bin/twistver ] && [[ "$(twistver)" != 'Twister OS version'* ]];then
  "${DIRECTORY}/install"
fi
EOF

#remove old apps and migrate chromium downgrading apps to the new "Chromium Downgrade" app
runonce <<"EOF"
  #rework chromium downgrading apps to one single new app: 'Downgrade Chromium'
  rm -rf "${DIRECTORY}/apps/Back to Chromium v86"
  rm -rf "${DIRECTORY}/apps/Back to Chromium v78"
  if [ "$(cat "${DIRECTORY}/data/status/Back to Chromium v78" 2>/dev/null)" == installed ] || [ "$(cat "${DIRECTORY}/data/status/Back to Chromium v86" 2>/dev/null)" == installed ];then
    echo "installed" > "${DIRECTORY}/data/status/Downgrade Chromium"
  fi
  
  rm -rf "${DIRECTORY}/apps/FreeCAD (precompiled)"
  rm -rf "${DIRECTORY}/apps/Chromium Media Edition"
  rm -rf "${DIRECTORY}/apps/Cordless"
  rm -rf "${DIRECTORY}/apps/Retropie"
  
  #rename 'Turbo Scratch' app to 'Turbowarp'
  rm -rf "${DIRECTORY}/apps/Turbo Scratch"
  mv -f "${DIRECTORY}/data/status/Turbo Scratch" "${DIRECTORY}/data/status/Turbowarp" 2>/dev/null
  
  #rename 'Pi-Apps Terminal Plugin' app to 'Pi-Apps Terminal Plugin (python)'
  rm -rf "${DIRECTORY}/apps/Pi-Apps Terminal Plugin"
  mv -f "${DIRECTORY}/data/status/Pi-Apps Terminal Plugin" "${DIRECTORY}/data/status/Pi-Apps Terminal Plugin (python)" 2>/dev/null
  true
EOF

#rename xlunch setting to xlunch-dark
runonce <<"EOF"
  if [ "$(cat "${DIRECTORY}/data/settings/App List Style")" == xlunch ];then
    echo 'xlunch-dark' > "${DIRECTORY}/data/settings/App List Style"
  fi
EOF

#for old installs prior to having categories, re-run install script
runonce <<"EOF"
  if [ ! -e "${DIRECTORY}/data/categories" ];then
    "${DIRECTORY}/install"
  fi
EOF

#ensure curl is installed
runonce <<"EOF"
  if ! command -v curl >/dev/null ;then
    sudo apt install -y curl
  fi
EOF

#install aria2c for faster downloading
runonce <<"EOF"
  if ! command -v aria2c >/dev/null ;then
    sudo apt install -y aria2
  fi
EOF
) &

#check for updates in background
"${DIRECTORY}/updater" set-status &>/dev/null &

install() {
  app="$1" #one app name per line
  
  #terminal title text
  linecount="$(echo "$app" | wc -l)"
  if [ $linecount -eq 1 ];then
    title="Installing $app"
  elif [ $linecount -lt 4 ];then
    title="Installing $(echo -n "$app" | tr '\n' '|' | sed 's/|/, /g')"
  else
    title="Installing $linecount apps"
  fi
  "${DIRECTORY}/etc/terminal-run" '
    DIRECTORY="'"$DIRECTORY"'"
    source "${DIRECTORY}/api"
    generate_logo
    if "${DIRECTORY}/manage" multi-install "'"$app"'" ;then
      echo -e "\nClosing in 30 seconds."
      sleep 30
    else
      echo -e "\nClose this window to exit."
      read enter #technically you could press Enter to exit.
    fi
    ' "$title"
  
  #re-preload all categories in background
  "${DIRECTORY}/etc/preload-daemon" "$format" &>/dev/null &
}

uninstall() {
  app="$1" #one app name per line
  
  #terminal title text
  linecount="$(echo "$app" | wc -l)"
  if [ $linecount -eq 1 ];then
    title="Uninstalling $app"
  elif [ $linecount -lt 4 ];then
    title="Uninstalling $(echo -n "$app" | tr '\n' '|' | sed 's/|/, /g')"
  else
    title="Uninstalling $linecount apps"
  fi
  "${DIRECTORY}/etc/terminal-run" '
    DIRECTORY="'"$DIRECTORY"'"
    source "${DIRECTORY}/api"
    generate_logo
    if "${DIRECTORY}/manage" multi-uninstall "'"$app"'" ; then
      echo -e "\nClosing in 30 seconds."
      sleep 30
    else
      echo -e "\nClose this window to exit."
      read enter #technically you could press Enter to exit.
    fi
    ' "$title"
  
  #re-preload all categories in background
  "${DIRECTORY}/etc/preload-daemon" "$format" &>/dev/null &
}

#Determine message of the day. If announcements file missing or over a day old, download it.
if [ ! -f "${DIRECTORY}/data/announcements" ] || [ ! -z "$(find "${DIRECTORY}/data/announcements" -mtime +1 -print)" ]; then
  wget https://raw.githubusercontent.com/Botspot/pi-apps-announcements/main/message -qO "${DIRECTORY}/data/announcements"
fi
#retrieve a random line from the announcements file for this session
motd="$(shuf -n 1 "${DIRECTORY}/data/announcements")"

#app list mode. Allowed values: 'yad', 'xlunch'
guimode="$(cat "${DIRECTORY}/data/settings/App List Style")"
[ -z "$guimode" ] && guimode=yad
#mode=yad

prefix=''
action='main-window'

while true;do
  
  [ ! -z "$prefix" ] && echo "Prefix: $prefix"
  echo "App: ${app}"
  echo "Action: $action"
  echo "Prevaction: $prevaction"
  
  #most actions need the app variable to be filled. These don't: main-window, search, exit, back, unknown, view-updates
  if [ -z "$app" ] && ! echo "$action" | grep -q 'main-window\|search\|exit\|back\|unknown\|view-updates';then
    action='mind-reading'
    echo "Action has been changed to 'mind-reading'"
  fi
  
  if [ "$action" == main-window ];then
    
    #generate the list for the yad window
    LIST="$("${DIRECTORY}/preload" $guimode "$prefix")"
    
    #now that list has been generated, kill the splash screen
    (sleep 1; kill "$splashpid" 2>/dev/null) &
    
    if [ "$guimode" == yad ];then
      if [ -z "$prefix" ];then
        buttons=("--button=!${DIRECTORY}/icons/search.png!Search:5" \
        "--button=!${DIRECTORY}/icons/install.png!Install:4" \
        "--button=!${DIRECTORY}/icons/uninstall.png!Uninstall:2" \
        "--button=!${DIRECTORY}/icons/info.png!View more about the selected software:0" )
      else
        buttons=("--button=!${DIRECTORY}/icons/back.png!Back:3" \
        "--button=!${DIRECTORY}/icons/install.png!Install:4" \
        "--button=!${DIRECTORY}/icons/uninstall.png!Uninstall:2" \
        "--button=!${DIRECTORY}/icons/info.png!Details:0" )
      fi
      
      app="$(echo -e "$LIST" | yad --center --title='Pi-Apps'"$([ ! -z "$prefix" ] && echo ": $(echo "$prefix" | tr '/' '>')")" --width=310 --height=400 --no-headers \
        --text="$([ -z "$prefix" ] && echo "$motd" || echo "Viewing $(echo "$prefix" | tr '/' '>') category")" --image="${DIRECTORY}/icons/logo-64.png" --image-on-top \
        --list --multiple --separator='\n' --window-icon="${DIRECTORY}/icons/logo.png" \
        --column=:IMG --column=:IMG --column=Name --column=Sysname:HD --column=tip:HD \
        --print-column=4 --tooltip-column=5 \
        "${buttons[@]}" \
      )"
      button=$? #get exit code to determine which button was pressed
      
      prevaction="$action" #remember the pervious action we came from
      
      case $button in
      1)
        action=exit
        ;;
      252)
        action=exit
        ;;
      3)
        action=back
        ;;
      0)
        action=details
        ;;
      2)
        action=uninstall
        ;;
      4)
        action=install
        ;;
      5)
        action=search
        ;;
      *)
        action=unknown
        ;;
      esac
      
    elif [[ "$guimode" == xlunch* ]];then
      if [ ! -d "${DIRECTORY}/xlunch" ] || [ ! -f /usr/bin/xlunch ];then
        #uninstall xlunch first
        sudo rm -rf /etc/xlunch /usr/share/xlunch /usr/bin/xlunch /usr/bin/genentries /usr/bin/updateentries /usr/bin/genentries.desktop.sh /usr/share/icons/hicolor/48x48/apps/xlunch_ghost.png /usr/share/icons/hicolor/48x48/apps/xlunch.png /usr/share/applications/genentries.desktop
        
        #signal files
        rm -f /tmp/xlunchfailed /tmp/xlunchfinished /tmp/terminalexit
        echo '' > /tmp/terminalexit
        "${DIRECTORY}/etc/terminal-run" "
          function error {
            echo -e "\""\e[91m$1\e[39m"\""
            echo 'Close this terminal to exit.'
            echo '' > /tmp/xlunchfailed
            sleep infinity
          }
          trap 'echo "\"""\"" > /tmp/terminalexit' EXIT
          rm -f /tmp/terminalexit
          sudo rm -rf /usr/bin/xlunch "\""$DIRECTORY/xlunch"\"" 2>/dev/null
          sudo apt install -y libimlib2-dev libx11-dev || error 'APT failed to install libimlib2-dev and libx11-dev packages!'
          cd "\""$DIRECTORY"\""
          git clone https://github.com/Tomas-M/xlunch || error 'Failed to clone xlunch repository!'
          cd "\""$DIRECTORY/xlunch"\""
          echo 'Running make...'
          echo "\"""\$"(cat '${DIRECTORY}/xlunch/Makefile' | grep -v 'genentries \|cp -r svgicons/')"\"" > '${DIRECTORY}/xlunch/Makefile'
          make -j8 || error 'make command failed!'
          echo 'Running sudo make install...'
          sudo make install || error 'sudo make install failed!'
          sudo rm -f /usr/share/applications/genentries.desktop
          cd $HOME
          if [ ! -f /usr/bin/xlunch ];then
            error 'xlunch should be installed now, but /usr/bin/xlunch does not exist!'
          fi
          echo '' > /tmp/xlunchfinished
        " 'Compiling xlunch...'
        #if terminal doesn't start in 3 seconds, then /tmp/terminalexit will exist.
        sleep 3
        #check for an exit status code from the running terminal
        while true; do
          if [ -f /tmp/xlunchfinished ];then
            echo "xlunch finished installing."
            break
          elif [ -f /tmp/xlunchfailed ];then
            #revert back to yad
            echo 'yad' > "{DIRECTORY}/data/settings/App List Style"
            error "xlunch failed to compile!"
          elif [ -f /tmp/terminalexit ];then #if terminal doesn't start in 3 seconds, then /tmp/terminalexit will exist.
            #revert back to yad
            echo 'yad' > "{DIRECTORY}/data/settings/App List Style"
            error "The xlunch compilation terminal exited prematurely."
          else
            sleep 1
          fi
        done
      fi
      #xlunch compiled
      
      screen_width="$(xdpyinfo | grep 'dimensions:' | tr 'x' '\n' | tr ' ' '\n' | sed -n 7p)"
      screen_height="$(xdpyinfo | grep 'dimensions:' | tr 'x' '\n' | tr ' ' '\n' | sed -n 8p)"
      height=700
      width=800
      xposition=$(((screen_width/2)-(width/2)))
      yposition=$(((screen_height/2)-(height/2)))
      
      if false;then
        scrot -a "$((xposition+1)),$((yposition+33)),${width},${height}" blur.png #blur_init.png
        convert -blur 10x5 ~/blur.png ~/blur.png
      fi
      
      if [ ! -z "$prefix" ] && ! echo "$LIST" | grep -q 'Back;' ;then
        echo "Adding back button to xlunch..."
        LIST="Back;${DIRECTORY}/icons/back-64.png;./
$LIST"
        LIST="$(echo "$LIST" | grep .)"
      fi
      
      if [ -z "$prefix" ];then
        searchbox="Search: "
      else
        searchbox="Viewing $(echo "$prefix" | tr '/' '>'). Search: "
      fi
      
      if [ "$guimode" == xlunch-light-3d ];then
        #light mode
        app="$(echo -e "$LIST" | xlunch -WoCS -s 64 --bc e0e0e000 --tc 000000 --pc 6060ffff --hc ffffff50 \
          -p "$searchbox" -a -c $([ $width -lt 550 ] && echo 1 || echo 2) --title "Pi-Apps: Raspberry Pi app store" \
          --icon "${DIRECTORY}/icons/logo.png" --scrollbarcolor ffffff40 --scrollindicatorcolor 0000ff80 \
          --width $width --height $height --xposition $xposition --yposition $yposition \
          --button "${DIRECTORY}/icons/logo-3d.png;;$((($width/2)-(300/2))),0;pi-apps-homepage1" \
          -g "${DIRECTORY}/icons/background-3d.png"
          )"
      elif [ "$guimode" == xlunch-dark-3d ];then
        #dark mode, 3d opaque version
        app="$(echo -e "$LIST" | xlunch -WoCS -s 64 --bc 2F313600 --tc DCDDDE --pc ffffffa0 --hc ffffff30 \
          -p "$searchbox" -a -c $([ $width -lt 550 ] && echo 1 || echo 2) --title "Pi-Apps: Raspberry Pi app store" \
          --icon "${DIRECTORY}/icons/logo.png" --scrollbarcolor ffffff20 --scrollindicatorcolor ffffff40 \
          --width $width --height $height --xposition $xposition --yposition $yposition \
          --button "${DIRECTORY}/icons/logo-3d-dark.png;;$((($width/2)-(300/2))),0;pi-apps-homepage1" \
          -g "${DIRECTORY}/icons/background-3d-dark.png"
          )"
      else
        #dark mode, transparent version
        app="$(echo -e "$LIST" | xlunch -WoCS -s 64 --bc 000000A0 --tc ffffffff --pc 6060ffff --hc 60606010 \
          -p "$searchbox" -a -c $([ $width -lt 550 ] && echo 1 || echo 2) --title "Pi-Apps: Raspberry Pi app store" \
          --icon "${DIRECTORY}/icons/logo.png" --scrollbarcolor ffffff40 --scrollindicatorcolor 0000ff80 \
          --width $width --height $height --xposition $xposition --yposition $yposition \
          --button "${DIRECTORY}/icons/logo-128-trans.png;;$((($width/2)-(128/2))),0;pi-apps-homepage1" \
          --button "${DIRECTORY}/icons/logo-trans.png;;$([ -z "$prefix" ] && echo '45' || echo '65'),$([ -z "$prefix" ] && echo '10' || echo '0');pi-apps-homepage1"
          #-g ~/blur.png
          )"
      fi
      prevaction="$action" #remember the previous action we came from
      action=details
      
      if [ -z "$app" ];then
        #no app was clicked on, then the window must have been closed.
        exit 0
      fi
      
      #homepage button
      if [ "$app" == 'pi-apps-homepage1' ];then
        chromium-browser https://github.com/Botspot/pi-apps &
        app=''
        action=main-window
      fi
    else
      error "Unrecognized app list style '$guimode'!"
    fi
    app="$(echo "$app" | grep .)"
    
    if [ "$app" == 'Updates/' ];then
      action=view-updates
      app=''
    fi
    
  elif [ "$action" == exit ];then
    exit 0
  elif [ "$action" == back ];then
    prefix="$(dirname "$prefix" | tr -d '.')"
    
    action="$prevaction" #return to previous action
    
  elif [ "$action" == details ];then
    
    if echo "$app" | grep -q '/$' ;then
      #folder
      if [ "$app" == './' ];then
        prefix="$(dirname "$prefix" | tr -d '.')"
      else
        prefix="$prefix/$app"
        prefix="${prefix::-1}"
        prefix="$(echo "$prefix" | sed 's+^/++')"
      fi
      app=''
      action='main-window'
    else
      #app
      app="$(echo "$app" | head -n1)"
      
      if [ -f "${DIRECTORY}/data/installed-packages/${app}" ] && [ ! -z "$(cat "${DIRECTORY}/data/installed-packages/${app}")" ];then
        installedpackages="
This app installed these packages: $(cat "${DIRECTORY}/data/installed-packages/${app}" | sort | uniq | tr '\n' ' ')"
      else
        installedpackages=''
      fi
      
      #text below the app icon
      description="$(cat "${DIRECTORY}/apps/${app}/description" || echo 'Description unavailable')$installedpackages"
      
      #text to the right of the app icon
      abovetext="<b>$app</b>
- Current status: $(echo "$(app_status "${app}")" | sed 's/corrupted/corrupted (installation failed)/g' | sed 's/disabled/disabled (installation is prevented on your system)/g')"
      if [ -f "${DIRECTORY}/apps/${app}/website" ];then
        #show website if it exists
        abovetext="$abovetext
- Website: <a href="\""$(cat "${DIRECTORY}/apps/${app}/website" | head -n1)"\"">$(cat "${DIRECTORY}/apps/${app}/website" | head -n1)</a>"
        
      fi
      
      if [ -z "$clicklist" ];then
        source "${DIRECTORY}/api"
        clicklist="$(usercount)"
      fi
      
      usercount="$(echo "$clicklist" | grep " $app"'$' | awk '{print $1}' | head -n1)"
      if [ ! -z "$usercount" ] && [ "$usercount" -gt 20 ];then
        abovetext="$abovetext
- <b>$(printf "%'d" "$usercount")</b> users"
        
        if [ "$usercount" -ge 1500 ] && [ "$usercount" -lt 10000 ];then
          #if a lot of users, add an exclamation point!
          abovetext="${abovetext}!"
        elif [ "$usercount" -ge 10000 ];then
          #if a crazy number of users, add two exclamation points!
          abovetext="${abovetext}!!"
        fi
      fi
      
      #array holding various buttons that may be passed to yad
      whichbutton=()
      
      if [ "$(cat "${DIRECTORY}/data/settings/Show Edit button")" == 'Yes' ];then
        #if edit button enabled, show it
        whichbutton+=("--button=Edit!${DIRECTORY}/icons/edit.png!Make changes to the app:8")
      fi
      if [ -f "${DIRECTORY}/apps/${app}/credits" ];then
        #if credits file exists, display credits button
        whichbutton+=("--button=Credits!!See who made the app and who put it on Pi-Apps:10")
      fi
      #display buttons based on app's status file
      if [ "$(app_status "${app}")" == 'installed' ];then
        #if installed, display uninstall button
        whichbutton+=("--button=!${DIRECTORY}/icons/uninstall.png:2")
      elif [ "$(app_status "${app}")" == 'uninstalled' ];then
        #if uninstalled, display install button
        whichbutton+=("--button=!${DIRECTORY}/icons/install.png:4")
      elif [ "$(app_status "${app}")" == 'disabled' ];then
        #if disabled, display no buttons
        whichbutton+=("--button=<b>Enable</b>!!Force this app to install on your system."$'\n'"This app was disabled for a reason so if you enable it..."$'\n'"YOU HAVE BEEN WARNED.:12")
      else
        #if app status is 'corrupted', and a log file exists for this app, then display a button to view the log file
        if [ "$(app_status "${app}")" == 'corrupted' ];then
          logfile="$(ls "$DIRECTORY/logs"/* -t | grep "fail-${app}" | head -n1)"
          if [ ! -z "$logfile" ];then
            whichbutton+=("--button=Errors!${DIRECTORY}/icons/log-file.png!$app failed to $(echo "$(basename "$logfile")" | awk -F'-' '{print $1}'). Click this button to view the error output saved in the log file.:14")
          fi
        fi
        #if status is corrupted or unknown, then show both buttons
        whichbutton+=("--button=!${DIRECTORY}/icons/uninstall.png:2" "--button=!${DIRECTORY}/icons/install.png:4")
      fi
      
      echo "$description" | yad --text-info --fontname=12 --wrap --show-uri --text="$(echo "$abovetext" | sed 's/&/&amp;/g')" \
        --image="${DIRECTORY}/apps/${app}/icon-64.png" --image-on-top \
        --title="Details of ${app}" --window-icon="${DIRECTORY}/icons/logo.png" --center --width=700 --height=300 \
        --button=Back!"${DIRECTORY}/icons/back.png":0 \
        --button=Scripts!"${DIRECTORY}/icons/shellscript.png"!"Feel free to see how an app is installed!"$'\n'"Perfect for learning or troubleshooting.":6 \
        "${whichbutton[@]}"
      button=$? #get exit code to determine which button was pressed
      
      prevaction="$action" #remember the pervious action we came from
      
      case $button in
      1)
        action=exit
        ;;
      0)
        action=main-window
        ;;
      2)
        action=uninstall
        ;;
      4)
        action=install
        ;;
      6)
        action=scripts
        ;;
      8)
        action=edit
        ;;
      10)
        action=credits
        ;;
      12)
        action=enable
        ;;
      14)
        action=viewlog
        ;;
      *)
        action=unknown
        ;;
      esac
    fi
    
  elif [ "$action" == uninstall ];then
    #uninstall
    if ! echo "$app" | grep -q '/' ;then
      uninstall "$app"
      #clear output var to prompt main window to open next
    else
      motd="Sorry, you can't uninstall folders."
      prefix=''
    fi
    
    action="$prevaction" #return to previous action
    
  elif [ "$action" == install ];then
    #install
    if ! echo "$app" | grep -q '/' ;then
      install "$app"
      #clear output var to prompt main window to open next
    else
      motd="Sorry, you can't install folders."
      prefix=''
    fi
    
    action="$prevaction" #return to previous action
    
  elif [ "$action" == search ];then
    #search
    echo "Search"
    app="$(app_search_gui)"
    
    if [ -z "$app" ];then
      #no app selected from results
      action=main-window
    else
      action=details #view selected app
      
      #set the current category to be the category that the app belongs in
      prefix="$(dirname "$(app_categories | grep -v "^All Apps/" | grep -v "^Installed/" | grep "/$app"'$' | head -n1)")"
      [ "$prefix" == '.' ] && prefix=''
    fi
    
  elif [ "$action" == scripts ];then
    #view app's scripts
    #determine path to app's install script
    if [ -f "${DIRECTORY}/apps/${app}/install-${arch}" ];then
      install_script="${DIRECTORY}/apps/${app}/install-${arch}"
    elif [ -f "${DIRECTORY}/apps/${app}/install" ];then
      install_script="${DIRECTORY}/apps/${app}/install"
    fi
    
    uninstall_script="${DIRECTORY}/apps/${app}/uninstall"
    
    text_editor "$uninstall_script" &
    sleep 0.1
    text_editor "$install_script" &
    
    action="$prevaction" #return to previous action
    
  elif [ "$action" == edit ];then
    "${DIRECTORY}/createapp" "$app"
    
    action="$prevaction" #return to previous action
    
  elif [ "$action" == credits ];then
    cat "${DIRECTORY}/apps/${app}/credits" | yad --text-info --fontname=12 --wrap \
      --image="${DIRECTORY}/apps/${app}/icon-64.png" --image-on-top \
      --title="Credits of ${app}" --window-icon="${DIRECTORY}/icons/logo.png" --center --width=700 --height=300 \
      --button=Close!"${DIRECTORY}/icons/exit.png":0
    
    action="$prevaction" #return to previous action
    
  elif [ "$action" == enable ];then
    echo "Enabling $app..."
    app="$app"
    #remove status file containing 'disabled'
    rm -f "${DIRECTORY}/data/status/${app}"
    
    action="$prevaction" #return to previous action
    
  elif [ "$action" == viewlog ];then
    echo "Viewing error log of $app..."
    echo "Log filepath: $logfile"
    "${DIRECTORY}/etc/viewlog" "$logfile"
    
    action="$prevaction" #return to previous action
    
  elif [ "$action" == mind-reading ];then
    yad --center --title='Pi-Apps' --width=310 \
      --window-icon="${DIRECTORY}/icons/logo.png" \
      --image="${DIRECTORY}/icons/mind-reading.png" \
      --text="Mind reading is not supported.
(You didn't select an App)" \
      --button=OK:0 || exit 0
    
    action='main-window'
    
  elif [ "$action" == view-updates ];then
    "${DIRECTORY}/updater" gui fast
    action="$prevaction" #return to previous action
    
  elif [ "$action" == unknown ];then
    error "Unknown button: $button"
  fi
  
done