#!/bin/bash

LVM_DEFINED=0
LVM_PREFIX="patchy_snap"
LVM_COUNT=0
VHD_SIZE="1G"

function init_lvm() {
    if [ "$1" == "" ]; then
        echo "Error: Invalid argument supplied"
        return 1
    fi
    LVM_COUNT=$1

    if [ "$2" != "" ]; then
        VHD_SIZE=$2
    fi

    local b
    local i

    if [ "$B1" = "" ]; then
        B1=$B0
    fi

    for i in `seq 1 $LVM_COUNT`; do
        b="B$i"
        if [ "${!b}" = "" ]; then
            echo "Error: $b not defined."
            echo "Please run launch_cluster with atleast $LVM_COUNT nodes"
            return 1
        fi

        eval "L$i=${!b}/${LVM_PREFIX}_mnt"
        l="L$i"
        mkdir -p ${!l}
        if [ $? -ne 0 ]; then
            echo "Error: failed to create dir ${!l}"
            return 1
        fi

        eval "VG$i=${LVM_PREFIX}_vg_${i}"
    done

    LVM_DEFINED=1
    return 0
}

function setup_lvm() {
    init_lvm $@ || return 1
    _setup_lvm
    return 0
}

function cleanup_lvm() {
    pkill gluster
    if [ "$LVM_DEFINED" = "1" ]; then
        _cleanup_lvm
    fi

    _cleanup_lvm_again >/dev/null 2>&1
    return 0
}

########################################################
# Private Functions
########################################################
function _setup_lvm() {
    local count=$LVM_COUNT
    local b
    local i

    for i in `seq 1 $count`; do
        b="B$i"

        _create_vhd ${!b} $i
        _create_lv ${!b} $i
        _mount_lv $i
    done
}

function _cleanup_lvm() {
    local count=$LVM_COUNT
    local b
    local i

    for i in `seq 1 $count`; do
        b="B$i"
        _umount_lv $i
        _remove_lv $i
        _remove_vhd ${!b}
    done
}

function _cleanup_lvm_again() {
    local file

    mount | grep $LVM_PREFIX | awk '{print $3}' | xargs -r umount -f

    /sbin/vgs | grep $LVM_PREFIX | awk '{print $1}' | xargs -r vgremove -f

    find $B0 -name "${LVM_PREFIX}_loop" | xargs -r losetup -d

    find $B0 -name "${LVM_PREFIX}*" | xargs -r rm -rf

    find /run/gluster/snaps -name "*${LVM_PREFIX}*" | xargs -r rm -rf

    for file in `ls /run/gluster/snaps`; do
        find /run/gluster/snaps/$file -mmin -2 | xargs -r rm -rf
    done
}

########################################################
########################################################
function _create_vhd() {
    local dir=$1
    local num=$2
    local loop_num=`expr $2 + 8`

    fallocate -l${VHD_SIZE} $dir/${LVM_PREFIX}_vhd
    mknod -m660 $dir/${LVM_PREFIX}_loop b 7 $loop_num
    /sbin/losetup $dir/${LVM_PREFIX}_loop $dir/${LVM_PREFIX}_vhd
}

function _create_lv() {
    local dir=$1
    local num=$2
    local vg="VG$num"

    /sbin/pvcreate $dir/${LVM_PREFIX}_loop
    /sbin/vgcreate ${!vg} $dir/${LVM_PREFIX}_loop

    /sbin/lvcreate -l 100%FREE -T /dev/${!vg}/thinpool
    /sbin/lvcreate -V $VHD_SIZE -T /dev/${!vg}/thinpool -n brick_lvm

    mkfs.xfs -f /dev/${!vg}/brick_lvm
}

function _mount_lv() {
    local num=$1
    local vg="VG$num"
    local l="L$num"

    mount -t xfs -o nouuid /dev/${!vg}/brick_lvm ${!l}
}

function _umount_lv() {
    local num=$1
    local l="L$num"

    umount -f ${!l} 2>/dev/null || true
    rmdir ${!l} 2>/dev/null || true
}

function _remove_lv() {
    local num=$1
    local vg="VG$num"

    vgremove -f ${!vg}
}

function _remove_vhd() {
    local dir=$1

    losetup -d $dir/${LVM_PREFIX}_loop
    rm -f $dir/${LVM_PREFIX}_loop
    rm -f $dir/${LVM_PREFIX}_vhd
}

########################################################
# Utility Functions
########################################################
function snapshot_exists() {
        local volname=$1
        local snapname=$2
        $CLI snapshot list $volname | egrep -q "^$snapname\$"
        return $?
}

#Create N number of snaps in a given volume
#Arg1 : <Volume Name>
#Arg2 : <Count of snaps to be created>
#Arg3 : <Snap Name Pattern>
#Return: Returns 0 if all snaps are created ,
#        if not will return exit code of last failed
#        snap create command.
function create_n_snapshots() {
        local vol=$1
        local snap_count=$2
        local snap_name=$3
        local ret=0
        for i in `seq 1 $snap_count`; do
                $CLI_1 snapshot create $snap_name$i ${vol}&
                PID_1=$!
                wait $PID_1
                ret=$?
                if [ "$ret" != "0" ]; then
                        break
                fi
         done
         return $ret
}


#Delete N number of snaps in a given volume
#Arg1 : <Volume Name>
#Arg2 : <Count of snaps to be deleted>
#Arg3 : <Snap Name Pattern>
#Return: Returns 0 if all snaps are Delete,
#        if not will return exit code of last failed
#        snap delete command.
function delete_n_snapshots() {
        local vol=$1
        local snap_count=$2
        local snap_name=$3
        local ret=0
        for i in `seq 1 $snap_count`; do
                $CLI_1 snapshot delete $snap_name$i &
                PID_1=$!
                wait $PID_1
                temp=$?
                if [ "$temp" != "0" ]; then
                        ret=$temp
                fi
         done
         return $ret
}

#Check for the existance of N number of snaps in a given volume
#Arg1 : <Volume Name>
#Arg2 : <Count of snaps to be checked>
#Arg3 : <Snap Name Pattern>
#Return: Returns 0 if all snaps exists,
#        if not will return exit code of last failed
#        snapshot_exists().
function snapshot_n_exists() {
        local vol=$1
        local snap_count=$2
        local snap_name=$3
        local ret=0
        for i in `seq 1 $snap_count`; do
                snapshot_exists $snap_name$i
                ret=$?
                if [ "$ret" != "0" ]; then
                        break
                fi
         done
         return $ret
}