shopt -s extglob

_hg_command_list()

{

    hg --debug help 2>/dev/null | \

	awk 'function command_line(line) {

		 gsub(/,/, "", line)

		 gsub(/:.*/, "", line)

		 split(line, aliases)

		 command = aliases[1]

		 delete aliases[1]

		 print command

		 for (i in aliases)

		     if (index(command, aliases[i]) != 1)

			 print aliases[i]

	     }

	     /^list of commands:/ {commands=1}

	     commands && /^ debug/ {a[i++] = $0; next;}

	     commands && /^ [^ ]/ {command_line($0)}

	     /^global options:/ {exit 0}

	     END {for (i in a) command_line(a[i])}'

}

_hg_option_list()

{

    hg -v help $1 2> /dev/null | \

        awk '/^ *-/ {

		 for (i = 1; i <= NF; i ++) {

		    if (index($i, "-") != 1)

			 break;

		    print $i;

		 }

	     }'

}

_hg_commands()

{

    local all commands result

    all=$(_hg_command_list)

    commands=${all%%$'\n'debug*}

    result=$(compgen -W '$commands' -- "$cur")

    # hide debug commands from users, but complete them if

    # there is no other possible command

    if [ "$result" = "" ]; then

	local debug

	debug=debug${all#*$'\n'debug}

	result=$(compgen -W '$debug' -- "$cur")

    fi

    COMPREPLY=(${COMPREPLY[@]:-} $result)

}

_hg_paths()

{

    COMPREPLY=(${COMPREPLY[@]:-} $( compgen -W '$paths' -- "$cur" ))

}

_hg_repos()

{

    local i

    for i in $( compgen -d -- "$cur" ); do

        test ! -d "$i"/.hg || COMPREPLY=(${COMPREPLY[@]:-} "$i")

    done

}

_hg_status()

{

    COMPREPLY=(${COMPREPLY[@]:-} $( compgen -W '$files' -- "$cur" ))

}

_hg_tags()

{

    COMPREPLY=( ${COMPREPLY[@]:-} $(compgen -W '$tags' -- "$cur") )

}

# this is "kind of" ugly...

_hg_count_non_option()

{

    local i count=0

    local filters="$1"

    for (( i=1; $i<=$COMP_CWORD; i++ )); do

	if [[ "${COMP_WORDS[i]}" != -* ]]; then

	    if [[ ${COMP_WORDS[i-1]} == @($filters|$global_args) ]]; then

		continue

	    fi

	    count=$(($count + 1))

	fi

    done

    echo $(($count - 1))

}

_hg()

{

    local cur prev cmd opts i

    # global options that receive an argument

    local global_args='--cwd|-R|--repository'

    COMPREPLY=()

    cur="$2"

    prev="$3"

    # searching for the command

    # (first non-option argument that doesn't follow a global option that

    #  receives an argument)

    for (( i=1; $i<=$COMP_CWORD; i++ )); do

	if [[ ${COMP_WORDS[i]} != -* ]]; then

	    if [[ ${COMP_WORDS[i-1]} != @($global_args) ]]; then

		cmd="${COMP_WORDS[i]}"

		break

	    fi

	fi

    done

    if [[ "$cur" == -* ]]; then

	opts=$(_hg_option_list $cmd)

	COMPREPLY=( ${COMPREPLY[@]:-} $(compgen -W '$opts' -- "$cur") )

	return

    fi

    # global options

    case "$prev" in

	-R|--repository)

	    _hg_repos

	    return

	;;

	--cwd)

	    # Stick with default bash completion

	    return

	;;

    esac

    if [ -z "$cmd" ] || [ $COMP_CWORD -eq $i ]; then

	_hg_commands

	return

    fi

    # canonicalize command name

    if [ "$cmd" != status ] && [ "$prev" = -r ] || [ "$prev" = --rev ]; then

	_hg_tags

	return

    fi

    case "$cmd" in

	help)

	    _hg_commands

	;;

	export|manifest|update)

	    _hg_tags

	;;

	pull|push|outgoing|incoming)

	    _hg_paths

	    _hg_repos

	;;

	paths)

	    _hg_paths

	;;

	add)

	    _hg_status "u"

	;;

	commit)

	    _hg_status "mar"

	;;

	remove)

	    _hg_status "d"

	;;

	forget)

	    _hg_status "a"

	;;

	diff)

	    _hg_status "mar"

	;;

	revert)

	    _hg_status "mard"

	;;

	clone)

	    local count=$(_hg_count_non_option)

	    if [ $count = 1 ]; then

		_hg_paths

	    fi

            _hg_repos

	;;

	debugindex|debugindexdot)

	    COMPREPLY=(${COMPREPLY[@]:-} $( compgen -f -X "!*.i" -- "$cur" ))

	;;

	debugdata)

	    COMPREPLY=(${COMPREPLY[@]:-} $( compgen -f -X "!*.d" -- "$cur" ))

	;;

    esac

}

complete -o bashdefault -o default -F _hg hg 2> /dev/null \

    || complete -o default -F _hg hg