# bash completion for the Mercurial distributed SCM

# Docs:
#
# If you source this file from your .bashrc, bash should be able to
# complete a command line that uses hg with all the available commands
# and options and sometimes even arguments.
#
# Mercurial allows you to define additional commands through extensions.
# Bash should be able to automatically figure out the name of these new
# commands and their options.  If you also want to tell it how to
# complete non-option arguments, see below for how to define an
# _hg_cmd_foo function.
#
#
# Notes about completion for specific commands:
#
# - the completion function for the email command from the patchbomb
#   extension will try to call _hg_emails to get a list of e-mail
#   addresses.  It's up to the user to define this function.  For
#   example, put the addresses of the lists that you usually patchbomb
#   in ~/.patchbomb-to and the addresses that you usually use to send
#   the patchbombs in ~/.patchbomb-from and use something like this:
#
#      _hg_emails()
#      {
#          if [ -r ~/.patchbomb-$1 ]; then
#              cat ~/.patchbomb-$1
#          fi
#      }
# 
#
# Writing completion functions for additional commands:
#
# If it exists, the function _hg_cmd_foo will be called without
# arguments to generate the completion candidates for the hg command
# "foo".
#
# In addition to the regular completion variables provided by bash,
# the following variables are also set:
# - $hg - the hg program being used (e.g. /usr/bin/hg)
# - $cmd - the name of the hg command being completed
# - $cmd_index - the index of $cmd in $COMP_WORDS
# - $cur - the current argument being completed
# - $prev - the argument before $cur
# - $global_args - "|"-separated list of global options that accept
#                  an argument (e.g. '--cwd|-R|--repository')
# - $canonical - 1 if we canonicalized $cmd before calling the function
#                0 otherwise
# 

shopt -s extglob

_hg_commands()
{
    local commands
    commands="$("$hg" debugcomplete "$cur" 2>/dev/null)" || commands=""
    COMPREPLY=(${COMPREPLY[@]:-} $(compgen -W '$commands' -- "$cur"))
}

_hg_paths()
{
    local paths="$("$hg" paths 2>/dev/null | sed -e 's/ = .*$//')"
    COMPREPLY=(${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()
{
    local files="$("$hg" status -n$1 . 2>/dev/null)"
    COMPREPLY=(${COMPREPLY[@]:-} $(compgen -W '$files' -- "$cur"))
}

_hg_tags()
{
    local tags="$("$hg" tags -q 2>/dev/null)"
    local IFS=$'\n'
    COMPREPLY=(${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 cmd_index opts i
    # global options that receive an argument
    local global_args='--cwd|-R|--repository'
    local hg="$1"

    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="${COMP_WORDS[i]}"
		cmd_index=$i
		break
	    fi
	fi
    done

    if [[ "$cur" == -* ]]; then
	opts=$("$hg" debugcomplete --options "$cmd" 2>/dev/null)

	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

    # try to generate completion candidates for whatever command the user typed
    local help
    local canonical=0
    if _hg_command_specific; then
	return
    fi

    # canonicalize the command name and try again
    help=$("$hg" help "$cmd" 2>/dev/null)
    if [ $? -ne 0 ]; then
	# Probably either the command doesn't exist or it's ambiguous
	return
    fi
    cmd=${help#hg }
    cmd=${cmd%%[$' \n']*}
    canonical=1
    _hg_command_specific
}

_hg_command_specific()
{
    if [ "$(type -t "_hg_cmd_$cmd")" = function ]; then
	"_hg_cmd_$cmd"
	return 0
    fi

    if [ "$cmd" != status ] && [ "$prev" = -r ] || [ "$prev" == --rev ]; then
	if [ $canonical = 1 ]; then
	    _hg_tags
	    return 0
	elif [[ status != "$cmd"* ]]; then
	    _hg_tags
	    return 0
	else
	    return 1
	fi
    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"))
	;;
	*)
	    return 1
	;;
    esac

    return 0
}

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


# Completion for commands provided by extensions

# mq
_hg_ext_mq_patchlist()
{
    local patches=$("$hg" $1 2>/dev/null)
    COMPREPLY=(${COMPREPLY[@]:-} $(compgen -W '$patches' -- "$cur"))
}

_hg_ext_mq_queues()
{
    local root=$("$hg" root 2>/dev/null)
    local n
    for n in $(cd "$root"/.hg && compgen -d -- "$cur"); do
	# I think we're usually not interested in the regular "patches" queue
	# so just filter it.
	if [ "$n" != patches ] && [ -e "$root/.hg/$n/series" ]; then
	    COMPREPLY=(${COMPREPLY[@]:-} "$n")
	fi
    done
}

_hg_cmd_qpop()
{
    if [[ "$prev" = @(-n|--name) ]]; then
	_hg_ext_mq_queues
	return
    fi
    _hg_ext_mq_patchlist qapplied
}

_hg_cmd_qpush()
{
    if [[ "$prev" = @(-n|--name) ]]; then
	_hg_ext_mq_queues
	return
    fi
    _hg_ext_mq_patchlist qunapplied
}

_hg_cmd_qdelete()
{
    _hg_ext_mq_patchlist qseries
}

_hg_cmd_qsave()
{
    if [[ "$prev" = @(-n|--name) ]]; then
	_hg_ext_mq_queues
	return
    fi
}

_hg_cmd_strip()
{
    _hg_tags
}

_hg_cmd_qcommit()
{
    local root=$("$hg" root 2>/dev/null)
    # this is run in a sub-shell, so we can't use _hg_status
    local files=$(cd "$root/.hg/patches" 2>/dev/null &&
                  "$hg" status -nmar 2>/dev/null)
    COMPREPLY=(${COMPREPLY[@]:-} $(compgen -W '$files' -- "$cur"))
}


# hbisect
_hg_cmd_bisect()
{
    local i subcmd

    # find the sub-command
    for ((i=cmd_index+1; i<=COMP_CWORD; i++)); do
	if [[ ${COMP_WORDS[i]} != -* ]]; then
	    if [[ ${COMP_WORDS[i-1]} != @($global_args) ]]; then
		subcmd="${COMP_WORDS[i]}"
		break
	    fi
	fi
    done

    if [ -z "$subcmd" ] || [ $COMP_CWORD -eq $i ] || [ "$subcmd" = help ]; then
	COMPREPLY=(${COMPREPLY[@]:-} 
		   $(compgen -W 'bad good help init next reset' -- "$cur"))
	return
    fi

    case "$subcmd" in
	good|bad)
	    _hg_tags
	    ;;
    esac

    return
}


# patchbomb
_hg_cmd_email()
{
    case "$prev" in
	-c|--cc|-t|--to|-f|--from)
	    # we need an e-mail address. let the user provide a function 
	    # to get them
	    if [ "$(type -t _hg_emails)" = function ]; then
		local arg=to
		if [[ "$prev" == @(-f|--from) ]]; then
		    arg=from
		fi
		local addresses=$(_hg_emails $arg)
		COMPREPLY=(${COMPREPLY[@]:-}
			   $(compgen -W '$addresses' -- "$cur"))
	    fi
	    return
	    ;;
	-m|--mbox)
	    # fallback to standard filename completion
	    return
	    ;;
	-s|--subject)
	    # free form string
	    return
	    ;;
    esac

    _hg_tags
    return
}


# gpg
_hg_cmd_sign()
{
    _hg_tags
}