#!/bin/bash

YUM=/usr/bin/yum
SYNC_CTL_DIR=/root/.sync_ctl

ask_yn () {
    local msg=$1
    echo -n "$msg"
    echo -n " [y/N]: "

    local answer
    read answer
    [ "$answer" = "Y" -o "$answer" = "y" ] && return 0
    return 1
}

get_last_yum_transaction_id () {
    $YUM history addon-info last | sed -n '/Transaction ID/s/[^0-9]\+\([0-9]\+\)/\1/p'
}

red_output () {
    echo -en "\033[1;31m"
}

normal_output () {
    echo -en "\033[0;39m"
}

# Normal users should not use yum
if [ $( id -u) -ne 0 ]; then
  red_output
  echo "Yum cannot be run under unpriveledged user."
  normal_output
  exit 1
fi

yum_cmd=$1

# Continue with root yum invocations
# check for login WARNING
if [ "$yum_cmd" == "synccheck" ]; then
  if [ -d "$SYNC_CTL_DIR" ]; then
    trans_num=$( ls -1 "$SYNC_CTL_DIR" | wc -l )
    [ $trans_num -eq 0 ] && exit 0
    red_output
    cat <<END
!!!!!!!!!!!!!!!
!!! WARNING !!!             The system is out of sync!
!!!!!!!!!!!!!!! 

There are $trans_num manual yum transactions recorded.
You can find transaction numbers in: $SYNC_CTL_DIR

To display transaction info use: yum history info <id>
To rollback transaction: yum history undo <id>

When conflict is solved remove ID file from directory.
END
    normal_output
  fi
  exit 0
fi

case $yum_cmd in
  # Allow info/search and history manipulations 
  info|list|search|makecache|provides|repolist|version|check|history)
    $YUM $@
    exit $?
  ;;
  nodesync)
    # Allow 'yum nodesync' command which has special meaning
    $YUM makecache fast
    if [ "$2" = "config" ]; then
      $YUM -y update knu-config*
    elif [ "$2" = "deps" ]; then
      $YUM -y update knu-wn-deps
    elif [ "$2" = "hkr" ]; then
      $YUM -y update --disablerepo=* --enablerepo=blackjack-HKR-*
    elif [ "$2" = "all" ]; then
      $YUM -y update
    else
      $YUM -y repo-pkgs blackjack-HKR-x86_64 upgrade
      $YUM -y repo-pkgs blackjack-HKR-noarch upgrade
    fi
    exit $?
  ;; 
esac

# In case of ordinary yum invocation print really HUGE warning
red_output
cat <<END
!!!!!!!!!!!!!!!
!!! WARNING !!!        Installing packages on the node directly is stricly prohibited!
!!!!!!!!!!!!!!!

To install/remove packages please commit changes to 'knu-wn-deps' package and rebuild.
For instant update run:
  yum nodesync        - to update all HKR packages with third-party deps
  yum nodesync hkr    - to update all packages from HKR repos only
  yum nodesync config - to update configuration packages
  yum nodesync deps   - to update WN deps
  yum nodesync all    - to update everything (!!! ENSURE NODE IN PACEMAKER STANDBY !!!)

In case you are willing to proceed anyway for testing purposes, please
DO NOT FORGET TO ROLLBACK YUM TRANSACTION when finished.

END
normal_output
ask_yn "Are you sure you want to continue? "

# if case of root is really whiling to proceed invoke real yum and save transaction ID
if [ $? -eq 0 ]; then
  last_yum_tid=$( get_last_yum_transaction_id )
  $YUM $@
  last_yum_tid_after=$( get_last_yum_transaction_id )
  if [ "$last_yum_tid" != "$last_yum_tid_after" ]; then
    mkdir -p $SYNC_CTL_DIR
    touch $SYNC_CTL_DIR/$last_yum_tid_after
  fi
fi