#Program:
#    This program gets the fastest ubuntu software sources from SOURCES_MIRRORS_FILE
#    and backup && update /etc/apt/sources.list

#Author:  KJlmfe    www.freepanda.me

#History:
#    2012/12/6    KJlmfe    First release

VERSION="precise"  # precise is code of Ubuntu 12.04 if your ubuntu is not 12.04 please change
TEST_NETCONNECT_HOST="www.baidu.com"
SOURCES_MIRRORS_FILE="sources_mirrors.list"   
MIRRORS_SPEED_FILE="mirrors_speed.list"

function get_ping_speed()    #return average ping $1 time
{
    local speed=`ping -W1 -c1 $1 2> /dev/null | grep "^rtt" |  cut -d '/' -f5`
    echo $speed
}

function test_mirror_speed()    #
{
    rm $MIRRORS_SPEED_FILE 2> /dev/null; touch $MIRRORS_SPEED_FILE
   
     cat $SOURCES_MIRRORS_FILE | while read mirror
    do
        if [ "$mirror" != "" ]; then
            echo -e "Ping $mirror c"
            local mirror_host=`echo $mirror | cut -d '/' -f3`    #change mirror_url to host
   
            local speed=$(get_ping_speed $mirror_host)
   
            if [ "$speed" != "" ]; then
                echo "Time is $speed"
                echo "$mirror $speed" >> $MIRRORS_SPEED_FILE
            else
                echo "Connected failed."
            fi
        fi
    done
}

function get_fast_mirror()
{
    sort -k 2 -n -o $MIRRORS_SPEED_FILE $MIRRORS_SPEED_FILE
    local fast_mirror=`head -n 1 $MIRRORS_SPEED_FILE | cut -d ' ' -f1`
    echo $fast_mirror
}

function backup_sources()
{
    echo -e "Backup your sources.list.n"
    sudo mv /etc/apt/sources.list /etc/apt/sources.list.`date +%F-%R:%S`
}

function update_sources()
{
    local COMP="main restricted universe multiverse"
    local mirror="$1"
    local tmp=$(mktemp)

    echo "deb $mirror $VERSION $COMP" >> $tmp
    echo "deb $mirror $VERSION-updates $COMP" >> $tmp
    echo "deb $mirror $VERSION-backports $COMP" >> $tmp
    echo "deb $mirror $VERSION-security $COMP" >> $tmp
    echo "deb $mirror $VERSION-proposed $COMP" >> $tmp

    echo "deb-src $mirror $VERSION $COMP" >> $tmp
    echo "deb-src $mirror $VERSION-updates $COMP" >> $tmp
    echo "deb-src $mirror $VERSION-backports $COMP" >> $tmp
    echo "deb-src $mirror $VERSION-security $COMP" >> $tmp
    echo "deb-src $mirror $VERSION-proposed $COMP" >> $tmp

    sudo mv "$tmp" /etc/apt/sources.list
    echo -e "Your sources has been updated, and maybe you want to run "sudo apt-get update" now.n";
}

echo -e "nTesting the network connection.nPlease wait...   c"

if [ "$(get_ping_speed $TEST_NETCONNECT_HOST)" == "" ]; then
    echo -e "Network is bad.nPlease check your network."; exit 1
else
    echo -e "Network is good.n"
    test -f $SOURCES_MIRRORS_FILE

    if [ "$?" != "0" ]; then 
        echo -e "$SOURCES_MIRRORS_FILE is not exist.n"; exit 2
    else
        test_mirror_speed
        fast_mirror=$(get_fast_mirror)

        if [ "$fast_mirror" == "" ]; then
            echo -e "Can't find the fastest software sources. Please check your $SOURCES_MIRRORS_FILEn"
            exit 0
        fi

        echo -e "n$fast_mirror is the fastest software sources. Do you want to use it? [y/n] c"   
        read choice

        if [ "$choice" != "y" ]; then
            exit 0
        fi

        backup_sources
        update_sources $fast_mirror
    fi
fi

exit 0