#!/bin/bash

#this generates a yad-friendly app list. This is run every time the gui script is executed.
#if this script detects nothing has changed since last run, then it will echo back the app list that was generated last time.

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

function error {
  echo -e "\e[91m$1\e[39m" 1>&2
  exit 1
}

#determine if host system is 64 bit arm64 or 32 bit armhf
if [ ! -z "$(file "$(readlink -f "/sbin/init")" | grep 64)" ];then
  arch=64
elif [ ! -z "$(file "$(readlink -f "/sbin/init")" | grep 32)" ];then
  arch=32
else
  error "Failed to detect OS CPU architecture! Something is very wrong."
fi

#yad or xlunch format
format="$1"

if [ -z "$format" ];then
  format=yad
fi

mkdir -p "${DIRECTORY}/data/preload"

mktimestamps() {
  #these directories are checked for changes
  checkdirs="${DIRECTORY}/apps
${DIRECTORY}/data/settings
${DIRECTORY}/data/status"
  
  timestamps=''
  PREIFS="$IFS"
  IFS=$'\n'
  for dir in $checkdirs
  do
    timestamps="$timestamps
${dir}/$(ls -t "$dir" | head -n1)
$(stat -c %Y "${dir}/$(ls -t "$dir" | head -n1)")"
  done
  IFS="$PREIFS"
  #remove first empty newline
  timestamps="${timestamps:1}"
}

reloadlist=0

if [ -f "${DIRECTORY}/data/preload/timestamps" ];then
  #get modified timestamps for directories
  mktimestamps
  
  if [ "$timestamps" == "$(cat "${DIRECTORY}/data/preload/timestamps")" ];then
    #if current timestamps and saved timestamps match, then don't reload the list
    reloadlist=0
    echo "Timestamps match." 1>&2
  else
    #timestamps don't match, so reload the list
    reloadlist=1
    echo "Timestamps don"\'"t match" 1>&2
  fi
else
  #timestamp file not found
  reloadlist=1
fi

if [ ! -f "${DIRECTORY}/data/preload/LIST" ];then
  echo "list file does not exist." 1>&2
  reloadlist=1
fi

if [ $reloadlist == 1 ];then
  echo "Generating list..." 1>&2
  #get list of apps ----------------------------------- and exclude apps mentioned in hidelist file
  APPS="$(echo "$(ls "${DIRECTORY}/apps")" | grep -vxE "$(cat "${DIRECTORY}/data/hidelist" | tr '\n' '|')")"
  #APPS="$(echo "$(ls "${DIRECTORY}/apps")")"
  
  #remove apps that are not compatible with OS architecture
  PREIFS="$IFS"
  IFS=$'\n'
  for i in $APPS
  do
    #if install script doesn't exist -------------------- and if os-specific install script doesn't exist, then...
    if [ ! -f "${DIRECTORY}/apps/${i}/install" ] && [ ! -f "${DIRECTORY}/apps/${i}/install-${arch}" ];then
      #...remove the app from the list
      echo "Removing $i from the list because it is not compatible with your ${arch}-bit OS." 1>&2
      APPS="$(echo "$APPS" | grep -vx "$i")"
    fi
  done
  IFS="$PREIFS"
  
  #shuffle the list if enabled
  if [ "$(cat "${DIRECTORY}/data/settings/Shuffle App list")" == 'Yes' ];then
    APPS="$(echo "$APPS" | shuf)"
  fi
  
  if [ "$format" == yad ];then
    PREIFS="$IFS"
    IFS=$'\n'
    LIST=''
    for i in $APPS
    do
      LIST="$LIST$(echo "${DIRECTORY}/icons/$(cat "${DIRECTORY}/data/status/${i}" 2>/dev/null || echo "none").png")
${DIRECTORY}/apps/${i}/icon-24.png
$i
"\("$(cat "${DIRECTORY}/data/status/${i}" 2>/dev/null || echo "uninstalled")"\)" $(echo "$(cat "${DIRECTORY}/apps/${i}/description" || echo "Description unavailable")" | head -n1)
"
    done
    IFS="$PREIFS"
  elif [ "$format" == xlunch ];then
    PREIFS="$IFS"
    IFS=$'\n'
    LIST=''
    for i in $APPS
    do
      LIST="$LIST
${i} "\("$(cat "${DIRECTORY}/data/status/${i}" 2>/dev/null || echo "uninstalled")"\)";${DIRECTORY}/apps/${i}/icon-64.png;${i}"
    done
    IFS="$PREIFS"
  fi
  LIST="$(echo -e "$LIST")"
  
  #save entire list string to file for future use
  echo "$LIST" > "${DIRECTORY}/data/preload/LIST"
  export CACHED_LIST="$LIST"
  
  #save timestamps to file too
  mktimestamps
  echo "$timestamps" > "${DIRECTORY}/data/preload/timestamps"
else
  if [ -z "$CACHED_LIST" ];then
    echo "Reading list file..." 1>&2
    LIST="$(cat "${DIRECTORY}/data/preload/LIST")"
    export CACHED_LIST="$LIST"
  else
    echo "Reading list variable..." 1>&2
    LIST="$CACHED_LIST"
  fi
fi

(#put icons in cache
PREIFS="$IFS"
IFS=$'\n'
for icon in $(echo "$LIST" | grep icon-24)
do
  cat "$icon" 1>/dev/null
  #echo "Putting $icon in cache..." 1>&2
done
IFS="$PREIFS" ) &

echo "$LIST"