# -*- shell-script -*-
# help.sh - gdb-like "help" debugger command
#
#   Copyright (C) 2002-2006, 2008, 2010-2011, 2015
#   Rocky Bernstein <rocky@gnu.org>
#
#   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; either version 2, or
#   (at your option) any later version.
#
#   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; see the file COPYING.  If not, write to
#   the Free Software Foundation, 59 Temple Place, Suite 330, Boston,
#   MA 02111 USA.

if [[ $0 == ${BASH_SOURCE[0]} ]]  {
    setglobal dirname = $(BASH_SOURCE[0]%/*)
    [[ $dirname == $0 ]] && setglobal top_dir = ''..'' || setglobal top_dir = "$(dirname)/.."
    for file in [help alias]  { source $top_dir/lib/$(file).sh; }
}

_Dbg_help_add help \
'**help** [*command* [*subcommand* ..]]

If no arguments are given, print a list of command names.
With a command name give help for that command. For many commands
you can get further detailed help by listing the subcommand name.

Examples:
---------

  help
  help up
  help set
  help set args' 1 _Dbg_complete_help

proc _Dbg_complete_help {
    typeset -a words;
    setglobal IFS = '' ',' words = ''( $COMP_LINE )
    typeset subcmds
    setglobal subcmds = $(!_Dbg_command_help[@])
    if sh-expr ' ${#words[@]} == 1 ' {
	setglobal COMPREPLY = ''( $subcmds )
    } elif sh-expr ' ${#words[@]} == 2 '  {
	typeset commands="$(!_Dbg_command_help[@])"
	setglobal COMPREPLY = ''( $(compgen -W  "$subcmds" "${words[1]}") )
    } else {
	setglobal COMPREPLY = ''()
    }
}

# print help command
proc _Dbg_do_help {

    # We have to use be careful to make sure globbing, e.g. * isn't
    # done.

    # Treat "help *" the same as help
    [[ "$_Dbg_args" == '*' ]] && setglobal _Dbg_args = ''''

    if [[ '' == $_Dbg_args ]]  {
      _Dbg_help_sort_command_names
      _Dbg_section 'Available commands:'
      typeset -a list=("${_Dbg_sorted_command_names[@]}")
      _Dbg_list_columns
      _Dbg_msg ''
      _Dbg_msg 'Readline command line editing (emacs/vi mode) is available.'
      _Dbg_msg 'Type "help" followed by command name for full documentation.'
      return 0
    } else {
	typeset dbg_cmd="$1"
	if [[ -n ${_Dbg_command_help[$dbg_cmd]} ]]  {
 	    _Dbg_msg_rst $(_Dbg_command_help[$dbg_cmd])
	} else {
	    _Dbg_alias_expand $dbg_cmd
	    setglobal dbg_cmd = $expanded_alias
	    if [[ -n ${_Dbg_command_help[$dbg_cmd]} ]]  {
 		_Dbg_msg_rst $(_Dbg_command_help[$dbg_cmd])
	    } else {
		match $dbg_cmd {
		    with i | in | inf | info 
			_Dbg_info_help $2
			return
			
		    with sh | sho | show 
			_Dbg_help_show $2
			
		    with se | set 
			_Dbg_help_set $2
			
		    with * 
			# Look for a unique abbreviation
			typeset -i count=0
			typeset found_cmd
			typeset list; setglobal list = $(!_Dbg_command_help[@])
			for try in [$list]  {
			    if [[ $try =~ ^$dbg_cmd ]]  {
				setglobal found_cmd = $try
				sh-expr 'count++'
			    }
			}
			sh-expr 'found=(count==1)'
			if sh-expr 'found' {
 			    _Dbg_msg $(_Dbg_command_help[$found_cmd])
			} else {
  			    _Dbg_errmsg "Undefined command: \"$dbg_cmd\".  Try \"help\"."
  			    return 1
			}
			
		}
	    }
	}
	setglobal aliases_found = ''''
	_Dbg_alias_find_aliased $dbg_cmd
	if [[ -n $aliases_found ]]  {
	    _Dbg_msg ''
	    _Dbg_msg "Aliases for $dbg_cmd: $aliases_found"
	}
	return 2
    }
}

_Dbg_alias_add 'h' help
_Dbg_alias_add '?' help

# Demo it.
if [[ $0 == ${BASH_SOURCE[0]} ]]  {
    for file in [sort columnize list msg]  {
	source $top_dir/lib/$(file).sh;
    }
    # source /usr/local/share/bashdb/bashdb-trace
    # _Dbg_debugger
    _Dbg_do_help
    echo '---'
    setglobal _Dbg_args = ''help''
    _Dbg_do_help help
}