#!/bin/bash
#
# Misc httracker functions.
#

# Set common httrack options
function httracker_opts {
  OPTS=" --mirror                 \
         --continue               \
         --depth=${DEPTH}         \
         --ext-depth ${EXT_DEPTH} \
         --near                   \
         --purge-old=0            \
         --index                  \
         --cookies=1              \
         --path ${TARGET}"
}

# Download URLs, mirror mode
function httracker_get {
  # Options
  local url="$1"
  local hash="`echo $1 | sha1sum | cut -d ' ' -f 1`"
  local first="`echo $hash | cut -c 1-2`"
  local second="`echo $hash | cut -c 3-4`"

  echo -n "Processing $url..."

  # Set target and make sure it exists
  # We use two levels of directories used for hashing,
  # to prevent too many things ending up in any one directory.
  # See https://git-annex.branchable.com/internals/
  TARGET="$MIRRORS/$first/$second/$hash"
  mkdir -p $TARGET

  # We already got this one
  if [ -e "$TARGET/httracker-ok" ]; then
    echo " skipping as it's already downloaded as $hash..."
    return
  else
    echo ""
  fi

  # Basic options
  httracker_opts

  # Additional options
  if [ "`whoami`" == "root" ]; then
    OPTS="$OPTS --user $USER"
  fi

  # Fix permissions
  if [ "`whoami`" != "$USER" ] && [ "`whoami`" == "root" ]; then
    echo "Fixing $TARGET permissions..."
    chown -R $USER.$GROUP $TARGET/
  fi

  # Get each URL
  httrack ${OPTS} ${url}

  if [ "$?" == "0" ]; then
    # Mark as downloaded
    date +%s > $TARGET/httracker-ok
  else
    echo "Error fetching $url."
    rm -rf $TARGET
  fi

  # Add PDF symlink if needed
  url_lower="$(echo "$url" | tr '[:upper:]' '[:lower:]')"
  url_base="$(basename "$url")"
  if [ "$(basename "$url_lower")" != "$(basename "$url_lower" .pdf)" ]; then
    ( cd $TARGET && find -iname '*.pdf' -exec ln -s {} "$url_base" \; )
  fi

  # Save as PDF
  if [ "$WKHTMLTOPDF" == "1" ] && which xvfb-run &> /dev/null && which wkhtmltopdf &> /dev/null; then
    xvfb-run -a wkhtmltopdf "$url" $TARGET/screenshot.pdf
  fi

  # Save as PNG
  if [ "$WKHTMLTOIMAGE" == "1" ] && which xvfb-run &> /dev/null && which wkhtmltoimage &> /dev/null; then
    xvfb-run -a wkhtmltoimage "$url" $TARGET/screenshot.png
  fi

  # See https://www.insecure.ws/linux/serverless_screenshot.html
  #     http://gfdsa.gfdsa.org/2012/08/15/making-web-pages-screenshots-with-webkit2png-flash-included/
  if [ ! -d "$TARGET/screenshot.pdf" ]; then
    if [ "$WEBKIT2PDF" == "1" ] && which xvfb-run &> /dev/null && which webkit2pdf &> /dev/null; then
      ( cd $TARGET && xvfb-run -a webkit2pdf "$url" && mv 0000.pdf screenshot.pdf )
    fi
  fi

  # Get a screenshot
  # https://github.com/paulhammond/webkit2png/
  # https://github.com/adamn/python-webkit2png
  # https://snippets.aktagon.com/snippets/504-how-to-generate-screenshots-on-debian-linux-with-python-webkit2png
  if [ ! -d "$TARGET/screenshot.png" ]; then
    if [ "$WEBKIT2PNG" == "1" ] && which xvfb-run &> /dev/null; then
      xvfb-run -a $DIRNAME/webkit2png/webkit2png/webkit2png.py -o $TARGET/screenshot.png "$url"
    fi
  fi

  # Fix permissions again
  if [ "`whoami`" != "$USER" ] && [ "`whoami`" == "root" ]; then
    echo "Fixing $TARGET permissions..."
    chown -R $USER.$GROUP $TARGET/
  fi

  # Done here
  echo ""
}

# Download URLs, incremental mode
function httracker_get_incremental {
  # Create TARGET dir
  year=`date +%Y`
  month=`date +%m`
  day=`date +%d`
  TARGET=${MIRRORDIR}/${year}/${month}
  sudo -u ${USER} mkdir -p ${TARGET}

  # Basic options
  httracker_opts

  # Additional options
  if [ "`whoami`" == "root" ]; then
    OPTS="--user $USER"
  fi

  # Grab URLs from the network
  httrack ${OPTS} --list ${URLS}

  # Fix permissions
  if [ "`whoami`" != "$USER" ] && [ "`whoami`" == "root" ]; then
    chown -R $USER.$GROUP $TARGET/
  fi
}

# Get SemanticScuttle parameter
function httracker_scuttle_config {
  grep ${1} ${CONFIGFILE} | sed -e s/\[^\'\]\*\'// -e s/\'\.\*\$//
}

# Query a mysql database
function httracker_sqlquery {
  mysql --skip-column-names --batch \
        --user=${DBUSER}          \
        --password=${DBPASS}      \
        --database=${DBNAME}      \
        --host=${DBHOST}          \
        --execute="${1}"
}

# Iterate over all URLs
function httracker_iterate {
  local i=1
  local t="`wc -l $URLS | cut -d ' ' -f 1`"

  for link in `cat $URLS | xargs`; do
    # Fix entities
    link="`echo $link | sed -f $BASE/lib/httracker/html.sed`"

    echo "Processing item $i from $t total..."
    httracker_get "$link"
    let i++
  done
}

# Create basic folders
function httracker_setup_folders {
  mkdir -p $MIRRORS $TMP

  if [ "`whoami`" == "root" ]; then
    echo "Fixing $MIRRORS permissions..."
    chown $USER.$GROUP $MIRRORS
    chown $USER.$GROUP $TMP
  fi
}

# Set basic environment
function httracker_initialize {
  BASE="`dirname $0`"
  source $BASE/config.default || exit 1

  # Load custom config
  if [ -e "$BASE/config" ]; then
    source $BASE/config || exit 1
  fi

  # Check if httrack is available
  if ! which httrack &> /dev/null; then
    echo "error: httrack not avalable"
    exit 1
  fi

  # Create folders
  httracker_setup_folders

  # Lockfile
  LOCKFILE="${TMP}/`basename $0`.lock"
  httracker_check_lockfile
  httracker_set_lockfile

  # Logfile
  #LOG="${TMP}/`basename $0`.log"
}

# Cleanup environment
function httracker_teardown {
  httracker_unset_lockfile
  rm -rf $URLS
}

# Create lockfile
function httracker_set_lockfile {
  if [ ! -z "$LOCKFILE" ]; then
    mkdir -p `dirname $LOCKFILE`
    if ( set -o noclobber; echo "$$" > "$LOCKFILE" ) &> /dev/null; then
      trap 'httracker_unset_lockfile' INT TERM EXIT
    else
      echo "Could not create lockfile $LOCKFILE, exiting"
      exit 1
    fi
  fi
}

# Remove lockfile
function httracker_unset_lockfile {
  if [ ! -z "$LOCKFILE" ]; then
    rm -f $LOCKFILE || echo "Could not remove lockfile $LOCKFILE"
  fi
}

# Check lockfile
function httracker_check_lockfile {
  local pid process

  if [ ! -z "$LOCKFILE" ] && [ -f "$LOCKFILE" ]; then
    pid="`cat $LOCKFILE`"
    process="`ps --no-headers -o comm $pid`"
    if [ "$?" == "0" ] && [ "`ps --no-headers -o comm $$`" == "$process" ]; then
      echo "Another program is running for $LOCKFILE, skipping run"
      exit
    else
      echo "Found old lockfile $LOCKFILE, removing it"
      httracker_unset_lockfile
    fi
  fi
}

# Initialize
httracker_initialize