#!/usr/bin/env bash
#
# Show help for Cogito commands.
# Copyright (c) Petr Baudis, 2005
#
# Takes an optional argument describing the command to show the help for.
# The command can be specified either as 'COMMAND' or 'cg-COMMAND'.
# If the argument is left out an overview of all the Cogito commands will
# be shown.
#
# Note, short help for a command is also available by passing `--help` or
# `-h` to the command. The complete command manual is shown when passing
# `--long-help` (and is the same as doing "`cg-help command`").
#
# OPTIONS
# -------
# -c::	Colorize
#	Colorize the output.

USAGE="cg-help [-c] [cg-COMMAND | COMMAND]"
_git_repo_unneeded=1

. "${COGITO_LIB}"cg-Xlib || exit 1

setup_colors()
{
	local color_none="$(tput op)"
	local emphasize="$(tput setaf 1)"
	local desclist="$(tput setaf 3)"
	local cgcmd="$(tput setaf 2)"
	local codesnippet="$(tput setaf 6)"
	local usage="$(tput setaf 3)"
	local section="$(tput setaf 5)"
	local copyright="$(tput setaf 4)"

	apply_colors="
	s/^\(-.*\)::.*/$desclist\1$color_none:/
	s/^\(.*\)::/$desclist\1$color_none:/
	s/\`\(cg-[a-z-]*\)\`/$cgcmd\1$color_none/g
	s/\`\([^\`]*\)\`/$codesnippet&$color_none/g
	s/[^A-Z0-9a-z_-]\$ .*/$codesnippet&$color_none/g
	s/'\([^ ]*\)'/$emphasize&$color_none/g
	s/'\(-[A-Z0-9a-z_-]* [^']*\)'/$emphasize&$color_none/g
	s/^Usage: .*/$usage&$color_none/
	/^[A-Z -_]*/,/^---*$/s/^[A-Z -_]*\$/$section&$color_none/
	s/^Copyright .*/$copyright&$color_none/
	"
}

print_command_listing()
{
	for command in "$@"; do
		[ -f "$command" -a ! -L "$command" ] || continue
		cmdname="$(basename "$command")"

		shortdesc="$(sed -n 'n;n;p;q' <"$command")"
		# Some minimal sanity check that we didn't pick up some
		# random binary named cg-*
		[ "${shortdesc:0:1}" = "#" ] || continue
		printf "	%-18s %s\n" "$cmdname" "${shortdesc:2}"
	done
}

colorize() {
	sed -e "$apply_colors" | pager
}


apply_colors=
while optparse; do
	if optparse -c; then
		setup_colors
	else
		optfail
	fi
done

bin_path="$(dirname "$0")"


if [ "$ARGS" = "admin" ]; then
	echo "The advanced (low-level, dangerous, or administrative) commands:"
	IFS=$'\n' print_command_listing $(ls "$bin_path"/cg-admin*)
	exit
elif [ "$ARGS" = "branch" ]; then
	echo "The branch commands family:"
	IFS=$'\n' print_command_listing $(ls "$bin_path"/cg-branch*)
	exit
elif [ "$ARGS" = "tag" ]; then
	echo "The tag commands family:"
	IFS=$'\n' print_command_listing $(ls "$bin_path"/cg-tag*)
	exit
elif [ "$ARGS" ]; then
	cmd="$(echo "${ARGS[0]}" | sed 's/^cg-//')"
	print_help long "$cmd" | colorize
	[ "${PIPESTATUS[0]}" -eq 0 ] && exit
	echo "cg-help: no help available for command \"${ARGS[0]}\""
	echo "Call cg-help without any arguments for the list of available commands"
	exit 1
fi


REGULAR_COMMANDS="$(ls "$bin_path"/cg-* | grep -v /cg-X | grep -v /cg-admin | grep -v /cg-branch | grep -v /cg-tag)"
# TODO: Some uberevil `column` tricks...
BRANCH_COMMANDS="$(ls "$bin_path"/cg-branch* | sed 's#.*/##' | tr '\n' ' ')"
TAG_COMMANDS="$(ls "$bin_path"/cg-tag* | sed 's#.*/##' | tr '\n' ' ')"
ADVANCED_COMMANDS="$(ls "$bin_path"/cg-admin-* | sed 's#.*/##' | tr '\n' ' ')"

IFS=$'\n' colorize <<__END__
The Cogito version control system  $(cg-version)

Available regular commands:
$(print_command_listing $REGULAR_COMMANDS)

Special command families:
	cg-help admin       ($ADVANCED_COMMANDS)
	cg-help branch      ($BRANCH_COMMANDS)
	cg-help tag         ($TAG_COMMANDS)

These expressions can be used interchangeably as "ID"s:
	empty string, "this" or "HEAD" (current HEAD)
	branch name (as registered with cg-branch-add)
	tag name (as registered with cg-tag)
	date string (as recognized by the date tool)
	shortcut hash (shorted unambiguous hash lead)
	commit object hash (as returned by cg-object-id -c)
	tree object hash (accepted only by some commands)

For details on individual commands, do e.g.:
	cg-help cg-log
	cg-log --long-help
(both variants are equivalent)
__END__