#!/bin/bash

{ #this curly brace at start and end of script prevents issues when this script edits itself. See: https://stackoverflow.com/a/19430939
DIRECTORY="$(readlink -f "$(dirname "$0")")"

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

#for the will_reinstall() and list_intersect() functions
source "${DIRECTORY}/api" || error "failed to source ${DIRECTORY}/api"

get_date() {
  #number of days since 1/1/1970
  echo $(($(date --utc +%s)/86400))
}

check_update_interval() { #return 0 if update-interval allows update-checking today, exit 1 otherwise
  local lastupdatecheck="$(cat "${DIRECTORY}/data/last-update-check" 2>/dev/null)"
  if [ -z $lastupdatecheck ];then
    echo "Warning: ${DIRECTORY}/data/last-update-check does not exist!" 1>&2
    lastupdatecheck=0
  fi
  
  #write today's date to file. Format is "number of days since 1/1/1970"
  get_date > "${DIRECTORY}/data/last-update-check"
  
  local updateinterval="$(cat "${DIRECTORY}/data/settings/Check for updates")"
  
  #allowed values: Always, Daily, Weekly, Never
  if [ "$updateinterval" == 'Never' ];then
    return 1
  elif [ "$updateinterval" == 'Daily' ];then
    #if updates checked today, don't check
    if [ "$(get_date)" == "$lastupdatecheck" ];then
      return 1
    fi
  elif [ "$updateinterval" == 'Weekly' ];then
    #if updates checked less than 7 days ago, don't check
    if [ "$(get_date)" -le "$((lastupdatecheck + 7))" ];then
      return 1
    fi
  elif [ "$updateinterval" == 'Always' ];then
    return 0
  elif [ -z "$updateinterval" ];then
    echo "Something isn't right. Does '${DIRECTORY}/data/settings/Check for updates' exist?" 1>&2
  else
    echo "Warning: Unrecognized update interval!" 1>&2
  fi
  
  return 0
}

list_files() { #list all files on pi-apps with relative paths - both on main directory and update directory
  if [ ! -d "${DIRECTORY}/update" ];then
    error "${DIRECTORY}/update does not exist. Most likely there is no Internet connection."
  fi
  
  #list all files in update folder
  cd "${DIRECTORY}/update/pi-apps" || error "Failed to enter update directory!"
  local updatefiles="$(find . -type f | cut -c 3- | grep -v '.git/' | grep -v 'apps/' | grep -v 'data/')"

  #list all files in main folder
  cd "${DIRECTORY}"
  local localfiles="$(find . -type f | cut -c 3- | grep -v '.git/' | grep -v 'apps/' | grep -v 'data/' | grep -v 'logs/' | grep -v 'xlunch/')"

  echo -e "${localfiles}\n${updatefiles}" | sort | uniq
  cd $HOME
}

get_updatable_files() { #sets the updatable_files variable
  echo -n "Scanning files... " 1>&2
  
  #get list of pi-apps files without absolute paths. Example line: 'etc/terminal-run'
  local file_list="$(list_files)" || exit 1
  
  updatable_files='' #the variable to be returned
  
  #exclude files mentioned in data/update-exclusion file, ignoring any commented lines
  local IFS=$'\n'
  
  if [ "$speed" == fast ] && [ -f "${DIRECTORY}/data/update-status/updatable-files" ];then
    #speed is set to 'fast' - don't hash anything but rely on past results
    updatable_files="$(cat "${DIRECTORY}/data/update-status/updatable-files")"
    
  else #speed was not set to 'fast', so compare each file to the one in the update folder
    
    for file in $file_list ;do
      
      echo -en "Scanning files... $file\033[0K\r" 1>&2
      if [ ! -f "${DIRECTORY}/${file}" ];then
        #file is missing locally - add to updatable_files list
        updatable_files="${updatable_files}
${file}"
        
      elif [ ! -f "${DIRECTORY}/update/pi-apps/${file}" ];then
        #file is missing in the update folder - local
        true #do not add to updatable_apps list
        
      else #file exists in main-folder and in update-folder
        #hash each file
        newhash=$(sha1sum "${DIRECTORY}/update/pi-apps/${file}" 2>/dev/null | awk '{print $1}')
        oldhash=$(sha1sum "${DIRECTORY}/${file}" 2>/dev/null | awk '{print $1}')
        
        if [ "$newhash" != "$oldhash" ];then
          #files don't match - add to updatable_files list
          updatable_files="${updatable_files}
${file}"
        fi
        
      fi
    done
    #remove initial newline character
    updatable_files="${updatable_files:1}"
  fi
  
  #If an updatable file is listed in update-exclusion, remove it from list and save notification text for later.
  for file in $(cat "${DIRECTORY}/data/update-exclusion" | grep "^[^#;]") ;do
    updatable_files="$(echo "$updatable_files" | grep -v "$file")"
    local exclusion_msg="$exclusion_msg\n'$file' won't be updated - it's listed in data/update-exclusion."
  done
  
  echo "$updatable_files"
  echo -e "Scanning files... Done\033[0K" 1>&2
  
  #if any files were excluded by update-exclusion, list them now, after echoing "Done"
  [ ! -z "$exclusion_msg" ] && echo -e "$exclusion_msg\n" 1>&2
}

get_updatable_apps() { #sets the updatable_apps variable
  
  if [ "$speed" == fast ] && [ -f "${DIRECTORY}/data/update-status/updatable-apps" ];then
    #speed is set to 'fast' - don't hash anything but rely on past results
    cat "${DIRECTORY}/data/update-status/updatable-apps"
    
  else #speed was not set to 'fast', so compare each file to the one in the update folder
    
    updatable_apps="$("${DIRECTORY}/manage" check-all)"
    local exitcode=$?
    
    #if manage output is '.', then clear the variable
    [ "$updatable_apps" == '.' ] && updatable_apps=''
    echo "$updatable_apps"
    
    exit $exitcode #return the same code that the manage script exited with
  fi
}

generate_yad_list() { #input: updatable_apps and updatable_files variables
  local IFS=$'\n'
  
  #If updatable_apps and updatable_files variables empty, set them to the results of the last update-check
  if [ -z "$updatable_apps" ] && [ -z "$updatable_files" ];then
    updatable_apps="$(cat "${DIRECTORY}/data/update-status/updatable-apps")"
    updatable_files="$(cat "${DIRECTORY}/data/update-status/updatable-files")"
  fi
  
  for app in $updatable_apps ;do #generate a yad list for every updatable app
    echo "TRUE
${DIRECTORY}/update/pi-apps/apps/${app}/icon-24.png
$app ($([ ! -d "${DIRECTORY}/apps/${app}" ] && echo 'new ')app$(will_reinstall "$app" && echo ', <b>will be reinstalled</b>'))
app:$app"
  
  done
  
  for file in $updatable_files ;do #generate a yad list for every updatable file
    
    #determine mimetype of updatable_apps file to display an informative icon in the list
    if [ "$(file -b --mime-type "${DIRECTORY}/${file}")" == 'text/x-shellscript' ];then
      #if updatable_apps file in question is a shell script, then display shellscript icon.
      mimeicon="${DIRECTORY}/icons/shellscript.png"
      mimetype='script'
    elif [[ "${DIRECTORY}/${file}" == *.png ]] || [[ "${DIRECTORY}/${file}" == *.svg ]];then
      mimeicon="${DIRECTORY}/icons/image.png"
      mimetype='image'
    else
      #otherwise display txt icon.
      mimeicon="${DIRECTORY}/icons/txt.png"
      mimetype='file'
    fi
    
    echo "TRUE
${mimeicon}
$file ($mimetype)
file:$file"
    
  done
}

list_updates_gui() { #input: updatable_apps and updatable_files variables
  LIST="$(generate_yad_list)"
  #echo "List: ${LIST}EOL"
  
  if [ -z "$LIST" ];then
    echo -e '\e[92mNothing to update. Nothing to do!\e[39m'
    exit 0
  fi
  
  #Display a list of everything updatable
  output="$(echo -e "$LIST" | yad --center --title='Pi-Apps' \
    --window-icon="${DIRECTORY}/icons/logo.png" --width=310 --height=300 \
    --list --checklist --separator='\n' --print-column=4 --no-headers \
    --text="Updates available:"$'\n'"Uncheck an item to skip updating it." \
    --column=:CHK --column=:IMG --column=Name --column=ID:HD \
    --button='Later'!"${DIRECTORY}/icons/exit.png"!"Remind me later":1 \
    --button='Update now'!"${DIRECTORY}/icons/download.png":0)" || exit 0
  
  #remove empty newlines from output
  output="$(echo "$output" | grep .)"
  
  #regenerate list of updatable apps and files, based on what the user selected
  updatable_apps="$(echo "$output" | grep '^app:' | sed 's/^app://g')"
  updatable_files="$(echo "$output" | grep '^file:' | sed 's/^file://g')"
  
}

update_now_gui() { #input: updatable_files and updatable_apps variables
  
  local IFS=$'\n'
  for file in $updatable_files ;do
    mkdir -p "$(dirname "${DIRECTORY}/${file}")"
    
    #copy new version to apps/
    cp -f "${DIRECTORY}/update/pi-apps/${file}" "${DIRECTORY}/${file}" || echo -e "\e[91mFailed to copy ${DIRECTORY}/update/pi-apps/${file}\e[39m!"
    
    echo -e "\e[92m${file} file was copied successfully.\e[39m"
  done
  IFS="$PREIFS"
  
  if [ ! -z "$updatable_apps" ];then
    "${DIRECTORY}/etc/terminal-run" '
      DIRECTORY="'"$DIRECTORY"'"
      updatable_apps="'"$updatable_apps"'"
      trap "sleep 10" EXIT
      PREIFS="$IFS"
      IFS=$'\''\n'\''
      for i in $updatable_apps
      do
        "${DIRECTORY}/manage" update "$i" nofetch
      done
      IFS="$PREIFS"
      echo -e "\e[92mAll updates complete. Closing in 10 seconds.\e[39m"
    ' "Updating $(echo "$updatable_apps" | wc -l) app$([ $(echo "$updatable_apps" | wc -l) != 1 ] && echo s)..."
  fi
  
  #delete .git folder, then copy the new one
  rm -rf "${DIRECTORY}/.git" || sudo rm -rf "${DIRECTORY}/.git" || error "Failed to delete old ${DIRECTORY}/.git folder!"
  cp -a "${DIRECTORY}/update/pi-apps/.git" "${DIRECTORY}" || error "Failed to copy new .git folder!"
  
  echo -e "\e[92mPi-Apps updates complete.\e[39m"
}

update_now_cli() { #input: updatable_files and updatable_apps variables
  
  local IFS=$'\n'
  for file in $updatable_files ;do
    mkdir -p "$(dirname "${DIRECTORY}/${file}")"
    
    #copy new version to apps/
    cp -f "${DIRECTORY}/update/pi-apps/${file}" "${DIRECTORY}/${file}" || echo -e "\e[91mFailed to copy ${DIRECTORY}/update/pi-apps/${file}\e[39m!"
    
    echo -e "\e[92m${file} file was copied successfully.\e[39m"
  done
  
  for app in $updatable_apps ;do
    "${DIRECTORY}/manage" update "$app" nofetch
  done
  
  #delete .git folder, then copy the new one
  rm -rf "${DIRECTORY}/.git" || sudo rm -rf "${DIRECTORY}/.git" || error "Failed to delete old ${DIRECTORY}/.git folder!"
  cp -a "${DIRECTORY}/update/pi-apps/.git" "${DIRECTORY}" || error "Failed to copy new .git folder!"
  
  echo -e "\e[92mPi-Apps updates complete.\e[39m"
}

screen_width="$(xrandr | grep "HDMI-1" | awk '{print $4}' | tr 'x+' ' ' | awk '{print $1}')"
screen_height="$(xrandr | grep "HDMI-1" | awk '{print $4}' | tr 'x+' ' ' | awk '{print $2}')"

runmode="$1"
speed="$2"
if [ ! -z "$speed" ] && [ "$speed" != 'fast' ];then
  error "Unknown value for speed: "\""$speed"\"". Allowed value: fast"
fi

if [ "$runmode" == onboot ];then
  runmode=autostarted
elif [ -z "$runmode" ];then
  runmode=gui
fi

#runmode values: autostarted, get-status, set-status, gui, gui-yes, cli, cli-yes, generate_yad_list

echo "Updater mode: $runmode"
if [ "$runmode" == autostarted ];then #if update-interval allows, and one app installed, display notification on boot
  
  #check if update interval allows update-checks, otherwise exit
  check_update_interval
  if [ $? != 0 ];then
    echo "Won't check for updates today, because of the update interval is set to '$(cat "${DIRECTORY}/data/settings/Check for updates")' in Settings."
    exit 0
  fi
  
  #check that at least one app has been installed by the user
  if [ "$(ls "${DIRECTORY}/data/status" | wc -l)" == 0 ];then
    echo "No apps have been installed yet, so exiting now."
    exit 0
  fi
  
  updatable_apps="$(get_updatable_apps)"
  updatable_files="$(get_updatable_files)"
  [ $? -ne 0 ] && error "'manage check-all' failed! Full output: $updatable_apps"

  if [ -z "$updatable_files" ] && [ -z "$updatable_apps" ];then
    echo "Nothing is updatable."
    exit 0
  fi
  
  echo "Displaying notification in lower-right of screen..."
  { #display notification in lower-right
    output="$(yad --form --text='Pi-Apps updates available.' --separator='\n' \
      --on-top --skip-taskbar --undecorated --close-on-unfocus \
      --geometry=260+$((screen_width-262))+$((screen_height-150)) \
      --image="${DIRECTORY}/icons/logo-64.png" \
      --field='Never show again':CHK FALSE \
      --button="Details!${DIRECTORY}/icons/info.png":0 --button="Close!${DIRECTORY}/icons/exit.png":2)"
    button=$?
    
    #if Details not clicked, and checkbox clicked, launch a dialog to change the update interval
    if [ $button != 0 ];then
      if [ "$(echo "$output" | grep . )" == TRUE ];then
        #User checked the 'Never show again' box, so ask to change update interval
        curval="$(cat "${DIRECTORY}/data/settings/Check for updates")"
        [ -z "$curval" ] && curval="$(cat "${DIRECTORY}/etc/setting-params/Check for updates" | grep -v '#' | head -n1)"
        
        params="$(cat "${DIRECTORY}/etc/setting-params/Check for updates" | grep -v '#')"
        params="$(echo "$params" | grep -x "$curval" | tr '\n' '!')!$(echo "$params" | grep -vx "$curval" | tr '\n' '!')"
        params="$(echo -e "$params" | sed 's/!!/!/g' | sed 's/!$//g' | sed 's/^!//g')"
        
        echo "Params: '$params'"
        
        output="$(yad --center --title='Change Pi-Apps update interval' --width=440 \
          --form --separator='\n' --window-icon="${DIRECTORY}/icons/logo.png" \
          --text="You just requested for Pi-Apps to <i>never check for updates</i> on boot."$'\n'"Are you sure? If so, change the update interval to "\""<b>Never</b>"\"" below." \
          --field='Update interval: ':CB "$params" \
          --button=Cancel!"${DIRECTORY}/icons/exit.png":1 \
          --button=Save!"${DIRECTORY}/icons/check.png":0)"
        button=$?
        
        output="$(echo "$output" | grep .)"
        if [ $button == 0 ];then #save button clicked
          echo "$output" > "${DIRECTORY}/data/settings/Check for updates"
        fi
      fi
      #since Details was not clicked, exit now
      exit 0
    fi
  }
  
  list_updates_gui
  if [ -z "$updatable_files" ] && [ -z "$updatable_apps" ];then
    echo "User did not allow anything to be updated."
    exit 0
  fi
  
  update_now_gui
  
  #display notification saying that pi-apps updates are complete
  yad --form --text='Pi-Apps updates complete.' \
    --on-top --skip-taskbar --undecorated --close-on-unfocus \
    --geometry=260+$((screen_width-262))+$((screen_height-150)) \
    --image="${DIRECTORY}/icons/logo-64.png" \
    --button="Close!${DIRECTORY}/icons/exit.png":1
  
elif [ "$runmode" == 'get-status' ];then #Check if anything was deemed updatable the last time updates were checked for.
  
  if [ -s "${DIRECTORY}/data/update-status/updatable-files" ] || [ -s "${DIRECTORY}/data/update-status/updatable-apps" ];then
    exit 0
  else
    exit 1
  fi
  
elif [ "$runmode" == 'set-status' ];then #check for updates and write updatable apps/files to "${DIRECTORY}/data/update-status"
  updatable_apps="$(get_updatable_apps)"
  updatable_files="$(get_updatable_files)"
  
  echo "$updatable_apps" | grep . > "${DIRECTORY}/data/update-status/updatable-apps"
  echo "$updatable_files" | grep . > "${DIRECTORY}/data/update-status/updatable-files"
  
  "$0" get-status
  exit $?
  
elif [ "$runmode" == gui ];then #dialog-list of updatable apps, with checkboxes and an Update button
  
  updatable_apps="$(get_updatable_apps)"
  updatable_files="$(get_updatable_files)"
  [ $? -ne 0 ] && error "'manage check-all' failed! Full output: $updatable_apps"
  
  if [ -z "$updatable_files" ] && [ -z "$updatable_apps" ];then
    echo "Nothing is updatable."
    exit 0
  fi
  
  list_updates_gui
  if [ -z "$updatable_files" ] && [ -z "$updatable_apps" ];then
    echo "User did not allow anything to be updated."
    exit 0
  fi
  
  update_now_gui
  
elif [ "$runmode" == gui-yes ];then #update now without asking for confirmation
  
  updatable_apps="$(get_updatable_apps)"
  updatable_files="$(get_updatable_files)"
  [ $? -ne 0 ] && error "'manage check-all' failed! Full output: $updatable_apps"
  
  if [ -z "$updatable_files" ] && [ -z "$updatable_apps" ];then
    echo "Nothing is updatable."
    exit 0
  fi
  
  update_now_gui
  
elif [ "$runmode" == cli ];then #return list of updatable apps, and ask the user permission to update
  
  updatable_apps="$(get_updatable_apps)"
  updatable_files="$(get_updatable_files)"
  [ $? -ne 0 ] && error "'manage check-all' failed! Full output: $updatable_apps"
  
  if [ -z "$updatable_files" ] && [ -z "$updatable_apps" ];then
    echo "Nothing is updatable."
    exit 0
  fi
  
  echo "These apps can be updated:"
  echo -n "$updatable_apps" | sed 's/^/  - /g'
  echo
  
  echo "These files can be updated:"
  echo -n "$updatable_files" | sed 's/^/  - /g'
  echo
  
  read -p "Update now? [Y/n] " answer
  
  if [ "$answer" == n ] || [ "$answer" == N ];then
    exit 0
  fi
  
  update_now_cli
  
elif [ "$runmode" == cli-yes ];then #update now without asking for confirmation
  
  updatable_apps="$(get_updatable_apps)"
  updatable_files="$(get_updatable_files)"
  [ $? -ne 0 ] && error "'manage check-all' failed! Full output: $updatable_apps"
  
  if [ -z "$updatable_files" ] && [ -z "$updatable_apps" ];then
    echo "Nothing is updatable."
    exit 0
  fi
  
  echo "These apps can be updated:"
  echo -n "$updatable_apps" | sed 's/^/  - /g'
  
  echo "These files can be updated:"
  echo -n "$updatable_files" | sed 's/^/  - /g'
  echo
  
  update_now_cli
  
else
  error "updater: unknown run mode."
fi

exit 0
} #this curly brace at start and end of script prevents issues when this script updates itself. See: https://stackoverflow.com/a/19430939