#!/bin/sh
# This scripts downloads the rpm.rte & yum_bundle.tar
# rpm.rte  which is a prequisite for yum
# yum_bundle.tar contains yum and it's dependent packages.
# It checks if any of the package from yum_bundle is already installed and then
#  installs the packages accordingly.

# flag is used to identify if same, lower or higher version of package is already
#  installed from yum_bundle.
# flag=1 Exact version installed
# flag=2 Higher version already installed
# flag=3 Lower version already installed
# flag=0 No package from yum_bundle is installed.

#Check if we running this as a root user.
if [[ "$(id -u)" != "0" ]]
then
    echo "This script must be run as a root"
    exit 1
fi

#Check if /tmp has enough space to download rpm.rte & yum_bundle and size for
#Extracting rpm packages.
# 45 MB for rpm.rte and 54 MB for yum_bundle.tar, 50 MB for rpm packages extracted.

typeset -i total_req=`echo "(45+54+50)" | bc`
tmp_free=`df -m /tmp | sed -e /Filesystem/d | awk '{print $3}'`
if [[ $tmp_free -le $total_req ]]
then
    echo "Please make sure /tmp is having 149MB of free space to download rpm.rte & yum_bundle.tar files."
    echo "and space required for extracting the rpm packages."
    exit 1
fi

#Check if /opt is having enough space to install the packages from yum_bundle.
#Currently we need around 213MB of free space in /opt filesystem.
typeset -i total_opt=`echo "(213)" | bc`
opt_free=`df -m /opt | sed -e /Filesystem/d | awk '{print $3}'`
if [[ $opt_free -le $total_opt ]]
then
    echo "Total free space required for /opt filesystem to install rpms from yum_bundle is around 213 MB."
    echo "Please increase the /opt space and retry."
    exit 1
fi

#Create a temporary directroy where all downloads should go.
curr_time=`date +%Y%m%d%H%M%S`
mkdir -p /tmp/yum-$curr_time
tmppath=`echo /tmp/yum-$curr_time`
cd $tmppath

#Download will be done through expect script.
username="anonymous"
userpassword="anonymous"

echo "Trying to download rpm.rte & yum_bundle.tar ..."
expect <<YUMEOF
    log_user 0
    spawn ftp ftp.software.ibm.com
    expect "Name (ftp.software.ibm.com:): "
    send "$username\r"
    expect "Password:"
    send "$userpassword\r"
    expect "ftp>"
    send "lcd $tmppath\r"
    expect "ftp>"
    send "bi\r"
    expect "ftp>"
    send "cd aix/freeSoftware/aixtoolbox/INSTALLP/ppc\r"
    expect "ftp>"
    send "get rpm.rte\r"
    set timeout -1
    expect "ftp>"
    send "cd ../../ezinstall/ppc\r"
    expect "ftp>"
    send "bi\r"
    expect "ftp>"
    send "get yum_bundle.tar\r"
    send "bye\r"
    expect eof
YUMEOF

if [[ ! -e rpm.rte ]]
then
    echo "Failed to download rpm.rte"
    cd - >/dev/null 2>&1
	rm -rf $tmppath
    exit 1
fi

if [[ ! -e yum_bundle.tar ]]
then
    echo "Failed to download yum_bundle.tar"
    cd - >/dev/null 2>&1
    rm -rf $tmppath
    exit 1
fi
      
#Update rpm.rte to version.
# From AIX 7.1 TL5 & 7.2 TL2 rpm.rte shipped is 4.13.0.1.
# Installation will be skipped if either 4.9.1.3 or 4.13.0.1 is installed. 
echo "Installing rpm.rte to latest version ..."
echo "Might take minutes depending on the number of rpms installed..."
installp -qacXYd rpm.rte all
#lslpp -L | grep rpm.rte | grep 4.9.1.3
lslpp -Lc rpm.rte >/dev/null 2>&1
if [[ $? -eq 0 ]]
then
    rpm_ver=`lslpp -Lc rpm.rte | awk 'FNR==2' | awk -F':' '{print $3}' | cut -d'.' -f1`
    #One more check to see if rpm.rte is version4 or higher.
    #We mayn't come to this part at all.
    if [[ $rpm_ver -lt 4 ]]
    then
	rpm_inst=`lslpp -Lc rpm.rte | awk 'FNR==2' | awk -F':' '{print $2, $3}'`
	echo "rpm.rte version required is 4.9.1.3 or higher, but the installed version is ${rpm_inst}"
        cd -
        rm -rf $tmppath
        exit 1
    fi
else
    echo "rpm.rte update to latest version failed."
    echo "Please check the /smit.log file and retry the install"
    cd -
    rm -rf $tmppath
    exit 1
fi

echo "Extracting yum_bundle.tar ..."
tar -xvf yum_bundle.tar

#Compares the two packages version number
function cmp_version {
  	large=$(echo  ${pkcurr[1]} ${pkversion[$index]}  | \
      	 awk '{ split($1, a, ".");
      	 split($2, b, ".");
	     x = 0;
      	 for (i = 1; i <= 4; i++)
       	    if (a[i] < b[i]) {
       	        x = 3;
       	        break;
       	    } else if (a[i] > b[i]) {
       	        x = 2;
       	        break;
       	    }
      	 print x;
    	 }')
     return $large
}

#Compares the two packages release number
function cmp_release {
    if [[ $1 < $2 ]]
    then
	    return 3
    elif [[ $1 > $2 ]]
    then
	    return 2
    elif [[ $1 == $2 ]]
    then
    	return 1
    fi
}

#Check if some packages are already installed from the yum_bundle.
echo "\n"
echo "Checking if any of the rpms from yum_bundle is installed already...\n"
set -A pkgname
set -A pkversion
set -A pkgrelease
set -A inst_list

ls *.rpm | while read rpm_file
do
    pkname[${#pkname[*]}]=`rpm -qp --qf "%{NAME}" $rpm_file`
    pkversion[${#pkversion[*]}]=`rpm -qp --qf "%{VERSION}" $rpm_file`
    pkgrelease[${#pkgrelease[*]}]=`rpm -qp --qf "%{RELEASE}" $rpm_file`
done

let "index=0"
for pk in ${pkname[@]}
do
	# We need to match exact package name, as we might have packages like python python-devel etc..
	# Packages name will be followed by the version number with "-" as a seperator.

    set -A pkcurr ""
    let "flag=0"
    rpm_file=`ls *.rpm | grep  "^$pk-[0-9]"`
    line=`rpm -qa | grep "^$pk-[0-9]"`

    if [[ ! -z $line ]]
    then 
		# Special care must be taken for packages name having more than one fields.
		# For example python-devel
        oldIFS=$IFS
        IFS='-'
        set -A name_ver $line
        IFS=$oldIFS
        count=`echo ${#name_ver[@]}` #Count number of fields in a package. 
		# Exclude release, version field plus array index starts with 0.
        let "i=$count-3"
    
        if [[ $i -eq 0 ]]
        then
		    name=`echo "${name_ver[0]}"`
        elif [[ $i -eq 1 ]]
        then
	        name=`echo "${name_ver[0]}-${name_ver[1]}"`
        elif [[ $i -eq 2 ]]
	    then
		    name=`echo "${name_ver[0]}-${name_ver[1]}-${name_ver[2]}"`
        elif [[ $i -eq 3 ]]
	    then
		    name=`echo "${name_ver[0]}-${name_ver[1]}-${name_ver[2]}-${name_ver[3]}"`
        else
	        echo "Package name more than 4 fields"
        fi

		#To get version exclude release field plus 0 index array.
        let "j=$count-2"
        ver=`echo ${name_ver[$j]}`
     
		# Now set the name version field.
        set -A pktest "$name" "$ver"
    elif [[ -z $line ]]
    then
        set -A pktest $line
    fi

	#get the release field from the installed package.
    release=`rpm -qa | grep "^$pk-[0-9]" | awk -F '-' {'print $NF'} | awk -F '.' {'print $1'}`
	# If package from yum_bundle is installed.
    if [[ ${pktest[0]} == $pk ]]
    then
        set -A pkcurr "$name" "$ver"
		#compare versions of installed package & from the yum bundle.
	    cmp_version ${pktest[1]} ${pkversion[$index]}
	    rc=$?
	    if [[ $rc -eq 3 ]]
	    then
            let "flag=3" #Lower version already installed
        elif [[ $rc -eq 2 ]]
	    then
	        let "flag=2" # Higher version already installed
        elif [[ $rc -eq 0 ]]
	    then
			# If version numbers are same then compare the release of packages.
            if [[ ${pktest[1]} == ${pkversion[$index]} ]]
	        then
		        cmp_release $release ${pkgrelease[$index]}
				rc=$?
		        if [[ $rc -eq 3 ]]
		        then
		            let "flag=3"
	            elif [[ $rc -eq 2 ]]
	            then
		            let "flag=2" 
	            elif [[ $rc -eq 1 ]]
	            then
		            let "flag=1"   # Exact version installed
	            fi
	       fi
	   fi
    fi
  
    if [[ "$flag" -eq 1 ]]
    then
        echo "Package ${pkcurr[0]}-${pkcurr[1]}-$release is already installed"
        let "index=index+1"
        continue;
    elif [[ "$flag" -eq 2 ]]
    then
	    echo "Skipping ${pkname[$index]}-${pkversion[$index]}-${pkgrelease[$index]} as higher version is installed already."
	    echo "Please make sure these packages are from toolbox as there is no gurantee that"
	    echo "third party packages may be compatible with toolbox packages.\n"
	    let "index=index+1"
        continue;
    elif [ "$flag" -eq 3 ]
    then
	    echo "${pktest[0]}-${pktest[1]}-$release is installed. Will be updated to ${pkname[$index]}-${pkversion[$index]}-${pkgrelease[$index]} ...."
        inst_list[${#inst_list[*]}+1]=$rpm_file
	    let "index=index+1"
        continue;	
    elif [ "$flag" -eq 0 ]
    then
	    echo "${pkname[$index]}-${pkversion[$index]}-${pkgrelease[$index]} will be installed ...."
        inst_list[${#inst_list[*]}+1]=$rpm_file
	    let "index=index+1"
        continue;
    fi
done

if [[ ${#inst_list[@]} -eq 0 ]]
then
    echo "\nYum and all it's dependencies are installed already..."
    cd - >/dev/null 2>&1
    rm -rf $tmppath
    exit 1
fi

echo "\nInstalling the packages.\n"
rpm -Uvh ${inst_list[@]}

if [[ $? -eq 0 ]]
then
    cd - >/dev/null 2>&1
    rm -rf $tmppath
    echo "\033[1;32mYum installed Successfully.... \033[m"
    echo "\033[1;33mPlease run 'yum update' to update packages to the latest level. \033[m"
    #yum -y update
elif [[ $? -ne 0 ]]
then
   echo "\033[1;31mYum installation failed... \033[m" 
   echo "If the failure was due space requirement then increase the /opt space and retry it using yum.sh"
   echo "or install the downloaded packages from $tmppath manually."
   echo "Other reason of failure could be mixing of Toolbox packages and packages from other sources."
fi