#!/bin/bash
#
# ctct - a simple console contact manager
#
# Copyright 2015, 2016 Einhard Leichtfuß
#
# ctct is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# ctct 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with ctct.  If not, see <http://www.gnu.org/licenses/>.
#

## DEFAULT SETTINGS:
system_config_dir="@default_confdir@"
user_config_dir="@default_user_config_dir@"
datadir="@default_datadir@"
fallback_editor="@default_fallback_editor@"
default_editor=						# none - use $EDITOR
input_program="@default_input_program@"
output_program="@default_output_program@"
visual_program="@default_visual_program@"
confirm_deletion=@default_confirm_deletion@
confirm_default_yes=@default_confirm_default_yes@

## USER SETTINGS:
test -f "$system_config_dir/config.sh" \
	&& source "$system_config_dir/config.sh"
test -f "$user_config_dir/config.sh" \
	&& source "$user_config_dir/config.sh"

## CONSTANTS:
exec_name="${0##*/}"
TRUE=0
FALSE=1


function print_help() {
cat << EOF
usage:
  $exec_name <name>                   - show contact
  $exec_name -l                       - list all entries
  $exec_name [-s] <part> [...]        - search by name
  $exec_name -S <part> [...]          - search by data
  $exec_name -e <name>                - edit / create entry
  $exec_name -d <name> [...]          - delete entries
  $exec_name --rename <old> <new>     - rename entry
  $exec_name --version                - show version information
  $exec_name -h                       - print this help
EOF
}

function main()
{
	if ! test -d "$datadir" && ! mkdir "$datadir"
	then
		print_error "$exec_name: $datadir could not be created, quitting..."
		exit 1
	fi
	test $# -eq 0 && print_help && exit 1
	
	if [ "$1" = "-h" ] || ( [[ "--help" =~ ^"$1" ]] && [ ${#1} -ge 3 ] )
	then
		print_help; exit 0
	elif [[ "--version" =~ "$1" ]] && [ ${#1} -ge 3 ]
	then
		print_version; exit 0
	elif [ "$1" = "-l" ] || \
		( [[ "--list-all" =~ ^"$1" ]] && [ ${#1} -ge 3 ] )
	then
		list_all; exit $?
	elif [ "$1" = "-s" ] || \
		( [[ "--search-by-name" =~ ^"$1" ]] && [ ${#1} -ge 13 ] )
	then
		shift; find_similar "Found:" "$@"; exit $?
	elif [ "$1" = "-S" ] || \
		( [[ "--search-by-data" =~ ^"$1" ]] && [ ${#1} -ge 13 ] )
	then
		shift; search_file "Found:" "$@"; exit $?
	elif [ "$1" = "-e" ] || ( [[ "--edit" =~ ^"$1" ]] && [ ${#1} -ge 3 ] )
	then
		test $# -lt 2 && print_error "$exec_name: no entry specified." \
			&& exit 1
		edit_file "$2"; exit $?
	elif [ "$1" = "-d" ] || \
		( [[ "--delete" =~ ^"$1" ]] && [ ${#1} -ge 3 ] )
	then
		test $# -lt 2 && print_error "$exec_name: no entry to be deleted." \
			&& exit 1
		shift; delete_file "$@"; exit $?
	elif [[ "--rename" =~ ^"$1" ]] && [ ${#1} -ge 3 ]
	then
		( test $# -lt 2 && print_error "$exec_name: no entry specified." ) || \
		 	( test $# -lt 3 && print_error "$exec_name: no new name specified." ) \
			&& exit 1
		rename_file "$2" "$3"; exit $?
	elif [[ "$1" =~ ^- ]]; then
		print_error "$exec_name: unknown option '$1'"; exit 1
	fi
	
	if ! find_exact "$1"
	then
		find_similar "Did you mean:" "$@" || print_msg "No match found."
	fi
}

function print_msg()
{
	printf "%s\n" "$@"
}

function print_error()
{
	printf "%s\n" "$@" >&2
}

function find_exact()
{
	local file
	file="$datadir/$(get_filename "$1")" || return $FALSE
	
	if test "$visual_program" = "cat"
	then
		"$output_program" < "$file"
	else
		eval "$output_program" < "$file" | "$visual_program"
	fi
	return $TRUE
}

# $1: initial success message;  $2-${$#}: search-patterns
function find_similar()
{
	local found=false msg="$1" name bool file pattern
	shift	1					# skip $1
	
	# disallow '.' in any pattern
	# - any pattern should be either part of the first or the last name
	#   else the reverse order (last.first) would have to be checked as well
	if [[ "$*" =~ \. ]]
	then
		return $FALSE
	fi
	
	for file in "$datadir"/*
	do
		name="${file##*/}"
		bool=true
		for pattern in "${@,,}"
		do
			if ! [[ "${name,,}" =~ "$pattern" ]]
			then
				bool=false
				break
			fi
		done
		if $bool
		then
			! $found && print_msg "$msg" && found=true
			print_msg " $name"
		fi
	done
	$found && return $TRUE || return $FALSE
}

function search_file()
{
	local found=false msg="$1" valid file pattern
	shift	1					# skip $1
	
	for file in "$datadir"/*
	do
		valid=true
		if test "$output_program" = "cat"
		then
			for pattern in "$@"
			do
				! grep -qi "$pattern" "$file" && valid=false && break
			done
		else
			for pattern in "$@"
			do
			! eval "$output_program" < "$file" | \
				grep -qi "$pattern" "$file" && valid=false && break
			done
		fi
		if $valid
		then
			! $found && print_msg "$msg" && found=true
			print_msg " ${file##*/}"
		fi
	done
	$found && return $TRUE || return $FALSE
}

function list_all()
{
	ls -1 "$datadir"
}

function edit_file()
{
	local file tmp_file editor new=false
	
	if ! file="$datadir/$(get_filename "$1")"
	then
		check_syntax "$1" && file="$datadir/$1" && new=true || return $FALSE
	fi
	
	if test -n "$default_editor"
	then
		editor="$default_editor"
	elif test -n "$EDITOR" && which "$EDITOR" >/dev/null 2>&1
	then
		editor="$EDITOR"
	else
		editor="$fallback_editor"
	fi
	
	if test "$input_program" = "cat" -a "$output_program" = "cat"
	then
		$new && touch "$file"		# vim does not save an empty file
		"$editor" "$file"
	else
		tmp_file="$(mktemp)"
		# output_program may contain further arguments:
		! $new && eval "$output_program" < "$file" > "$tmp_file"
		"$editor" "$tmp_file"
		eval "$input_program" < "$tmp_file" > "$file"
	fi
}

function rename_file()
{
	check_syntax "$2" || return $FALSE

	local file
	if file="$datadir/$(get_filename "$1")"
	then
		if get_filename "$2" > /dev/null
		then
			print_error "$exec_name: Entry \"$2\" does already exist."
		else
			mv "$file" "$datadir/$2"
		fi
	else
		print_error "$exec_name: Entry \"$1\" does not exist."
		return 1
	fi
}

function delete_file()
{
	local i files name file str
	typeset -i i=0
	typeset -a files
	
	# check for existance of all to be deleted files
	for name in "$@"
	do
		if file="$(get_filename "$name")"
		then
			files[i++]="$file"
		else
			print_error "$exec_name: Contact \"$file\" does not exist, aborting..."
			return 1
		fi
	done
	
	if "$confirm_deletion"; then
		# prepare confirmation
		if test $# -eq 1; then
			str="Do you really want to delete the entry ${files[0]}"
		else
			print_msg "Entries to be deleted:"
			for file in "${files[@]}"; do
				print_msg " $file"
			done
			str="Are you sure to delete all these entries"
		fi
		
		# confirm and delete
		if confirm "$str"; then
			for file in "${files[@]}"; do
				rm "$datadir/$file"
			done
		fi
	else # simply delete
		for file in "${files[@]}"; do
			rm "$datadir/$file"
		done
	fi
}

function get_filename()
{
	local rev
	
	if test -f "$datadir/$1"; then
		printf "%s\n" "$1"
	elif [[ "$1" =~ \. ]]
	then
		rev=( ${1/\./ } )
		rev="${rev[1]}.${rev[0]}"
		if test -f "$datadir/$rev"; then
			printf "%s\n" "$rev"
		else
			return $FALSE
		fi
	else
		return $FALSE
	fi
}

# $1: confirmation string
function confirm()
{
	local str="$1 " var
	if $confirm_default_yes; then
		str+="[Y/n]? "
	else
		str+="[y/N]? "
	fi
	printf "%s" "$str"
	
	read var
	if test -z "$var"; then
		$confirm_default_yes && return $TRUE || return $FALSE
	fi
	
	var="${var,,}"
	if test "$var" = "y" -o "$var" = "yes"; then
		return $TRUE
	else
		return $FALSE
	fi
}

function check_syntax()
{
	if [[ "$1" =~ ^[A-Za-z]+([-_][A-Za-z]+)*(\.[A-Za-z]+([-_][A-Za-z]+)*)?$ ]]
	then
		return $TRUE
	else
		print_error "$exec_name: invalid name \"$1\"" \
			" An entry name may only contain letters," \
			" '-' and '_' as separators and exactly one dot ('.')"
		return $FALSE
	fi
}

function print_version() {
cat << EOF
ctct - Version @PACKAGE_VERSION@
Copyright 2015, 2016 Einhard Leichtfuß.
License AGPLv3+: GNU Affero General Public License, version 3 or later
                 - <http://gnu.org/licenses/agpl.html>
This is free software: You are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
EOF
}

main "$@"

# vim: ts=2 sw=2