#!/bin/bash
#
#   Software Updater - autocompletion script
#
#      Copyright © 2016 Intel Corporation.
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, version 2 or later of the License.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
#   This program creates a _swupd function to be used by completion built-in
#   bash command to complete swup.
#   It reads options and subcommands from swup --help and then it reads
#   options for each subcommand recursively.


SCRIPTNAME="swupd.bash"
COMPLETIONFUNCTION="_swupd"
SWUPDCOMMAND="./swupd"

optionsfromhelp=""
subcommandsfromhelp=()

#Checks if swupd commad exists in current shell
if [ ! -e $SWUPDCOMMAND ] ; then
  echo "Error: No swupd found"
  exit 1
fi

currenttype=""
nexttype=""
#reads "swupd --help" line by line
while read word1 word2 rest
do
    #For each line checks in what section is
    if [[ "$word1 $word2" == "Help Options:" ]]; then
	currenttype="options"
	continue
    fi
    if [[ "$word1" == "Subcommands:" ]]; then
	currenttype="subcommand"
	continue
    fi
    if [[ "$word1" == "" ]]; then
	currenttype=""
	continue
    fi
    case $currenttype in
	#In case of subcommand it inserts first word of line in an array
	("subcommand")
	    subcommandsfromhelp+=("$word1") ;;
	#For options it reads short and long options, remove the commma from short
	("options")
	    optionsfromhelp="${optionsfromhelp} ${word1%,} ${word2}" ;;
	#For the rest do nothing
	("") : ;;
    esac
done < <($SWUPDCOMMAND --help 2>&1)

# Construct sed script
#Convert all tabs to spaces
SEDSCRIPT=$'s/\t/ /g'
#get rid of anything that does not start with a -
SEDSCRIPT+=';/^ *-/!d'
#remove leading spaces
SEDSCRIPT+=';s/^ *//'
# remove commas, any extra spaces between options
SEDSCRIPT+=';s/,  *-/ -/'
# Strip trailing junk, anything after = or the second word
SEDSCRIPT+=';s/=.*//'
SEDSCRIPT+=';s/^\([^ ]* [^ ]*\).*/\1/'
# See if there is only one option on line
SEDSCRIPT+=';/ -/!s/ .*//'

#Autocomplete script creation
{
cat  <<EOM
#!/bin/bash
#   WARNING: This is an autogenerated script
#   Software Updater - autocompletion script
#
#      Copyright © 2017 Intel Corporation.
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, version 2 or later of the License.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
#


#declares the completion function
${COMPLETIONFUNCTION}()
{
    # \$1 is the command being completed, \$2 is the current word being expanded
    local opts IFS=\$' \t\n'
    local -i i installed
    COMPREPLY=()
    for ((i=COMP_CWORD-1;i>=0;i--))
    do case "\${COMP_WORDS[\$i]}" in
EOM

  #This adds options for all subcommands

  printf '\t    ("$1")\n\t\topts="%s"\n' "$optionsfromhelp ${subcommandsfromhelp[*]}"
  printf '\t    break;;\n'
  for i in "${subcommandsfromhelp[@]}"; do
      printf '\t    ("%s")\n' "$i"
      C="$($SWUPDCOMMAND $i --help 2>&1 | sed -e "$SEDSCRIPT" | tr '\n' ' ')"
      printf '\t\topts="%s"\n' "$C"
      printf '\t\tbreak;;\n'
  done

# The tail of the script
cat >> $SCRIPTNAME << 'EOM'
	esac
    done
    # Add in additional completion options if we need to
    if (( $i >= 0 ))
    then
	case "${COMP_WORDS[$i]}" in
	    ("bundle-add")
		if [ -r /var/lib/swupd/version ] &&
		       installed=$(</var/lib/swupd/version) &&
		       [ -r /var/lib/swupd/$installed/Manifest.MoM ]
		then
		    opts+="$( sed '1,/^$/d; s/^.*\t/ /' /var/lib/swupd/$installed/Manifest.MoM | LC_ALL=C sort )"
		fi ;;
	    ("bundle-remove")
		opts+=" $(unset CDPATH; test -d /usr/share/clear/bundles && \
			cd /usr/share/clear/bundles && ls | grep -v '^os-core' )"
		;;
	esac
    fi

    COMPREPLY=($(compgen -W "${opts}" -- ${2}));
    return 0
}
if [ ${BASH_VERSINFO[0]} -gt 4 ] || ( [ ${BASH_VERSINFO[0]} -eq 4 ] && [ ${BASH_VERSINFO[1]} -ge 4 ] )
then
	complete -F _swupd -o nosort swupd
else
	complete -F _swupd swupd
fi

EOM
} > $SCRIPTNAME