#!/bin/bash
# insert block of line into the file

export LANG=en_EN.UTF-8
export PATH=$PATH:/sbin:/usr/sbin

[[ -z $DEBUG  ]] && DEBUG=0
TMP=/opt/webdir/logs
LOG=$TMP/bx_blocklines.log
[[ $DEBUG -gt 0  ]] 2>/dev/null && echo -n "" > $LOG

debug() {
    msg=$1

    [[ $DEBUG -gt 1  ]] && printf "%s: %d: %s\n" "$(date +%F-%H-%M-%S)" "$$" "$msg" >> $LOG
}

# print error message
print_error() {
  msg=$1
  echo "{\"changed\":false,\"failed\":true,\"msg\":\"$msg\"}"
  exit 1
}

# print timezone info
print_ok() {
  msg=$1

  echo "{\"changed\":true,\"msg\":\"$msg\"}"
  exit 0
}

print_notchanged() {
  msg=$1

  echo "{\"changed\":false,\"msg\":\"$msg\"}"
  exit 0

}

update_file(){

    [[ -z $from_file ]] && print_error "No defined the file with block of strings from_file= opt."
    insertafter_line=$(grep -n "$insertafter" $dest | \
        head -n 1 | awk -F':' '{print $1}')
    if [[ -z $insertafter_line ]]; then
        print_error "Not found insertafter=$insertafter in the file=$dest"
    fi

    {
        head -n $(( $insertafter_line )) $dest
        cat $from_file
        tail -n +$(( $insertafter_line+1 )) $dest
    } > $tmp_dest
    mv -f $tmp_dest $dest
    print_ok "Update file dest=$dest"
}

delete_file(){
    insertafter_line=$(grep -n "$insertafter" $dest | \
        head -n 1 | awk -F':' '{print $1}')
    if [[ -z $insertafter_line ]]; then
        print_notchanged "Not found insertafter=$insertafter in the file=$dest"
    fi

    [[ -z $insertbefore ]] && insertbefore="${insertafter}" 

    insertbefore_line=$(grep -n "$insertbefore" $dest | \
        tail -n 1 | awk -F':' '{print $1}')
    if [[ -z $insertbefore_line ]]; then
        print_notchanged "Not found insertafter=$insertbefore_line in the file=$dest"
    fi

    {
        head -n $(( $insertafter_line-1 )) $dest
        tail -n +$(( $insertbefore_line+1 )) $dest
    } > $tmp_dest
    mv -f $tmp_dest $dest
    print_ok "Update file dest=$dest"
}

dest_link(){
    if [[ -L $dest ]]; then
        orig_file=$(file $dest | \
            grep "symbolic link to" | awk -F'`' '{print $2}' | sed -e "s/'$//" )
        dest="$orig_file"
    fi
}

# get ansible variables
source ${1} 2>/dev/null

[[ -z $dest ]] && print_error "Not defined the file to modify dest=."
[[ -z $insertafter ]] && print_error "Not defined specified regular expression insertafter=."
[[ -z $state ]] && state="update"
debug "from_file=$from_file dest=$dest insertafter=$insertafter insertbefore=$insertbefore state=$state"

# convert link to orig file name and update it
dest_link

bn_dest=$(basename "$dest")
dn_dest=$(dirname "$dest")
tmp_dest="${dn_dest}/$(date +%s)_${bn_dest}"

case "$state" in
    "update") update_file;;
    "delete") delete_file;;
    *) print_error "Unknown state option";;
esac