mv++

#!/usr/bin/env bash

#
# Waring: Obviusly this script is only interactive and shoud not be used in background scripts
#

set -eu
shopt -s nullglob dotglob
IFS=''

echoerr(){ echo >&2 "$@"; }
exit-dry(){ exit "$@"; } # function is changed when --drry-run argument passed
TODO(){ echoerr $'\e[1;33mTODO:\e[m' "$@"; exit-dry 5; }
err(){ echoerr $'\e[1;31mERROR:\e[m' "$1"; [[ ${2:-''} = 0 ]] || exit-dry "${2:-1}"; }
warn(){ echoerr $'\e[1;36mWARNING:\e[m' "$@"; }
info(){ echoerr $'\e[1;34mINFO:\e[m' "$@"; }

yn='[y/n]' # used for string replacement bellow
confirm(){ # confirm(prompt_questin, default=y)
	local p
	read -p "$1 ${yn^^${2:-y}} " p &&
	# [[ $p = [Yy]* || ( ! $2 && ! $p ) ]]
	if [[ ${2:-y} = [Nn]* ]]
	then [[ $p = [Yy]* ]]
	else [[ $p = ?([Yy]*) ]]
	fi
	return $?
}

v=--verbose
i=--interactive
debug=0
# __mvPP_dryrun is keept from the envirometn
tmp=.mv++_$$~ # temp name for swapping files

for _i; do
	case $_i in
		--) shift;break;;
		--help) TODO write help message;;
		--debug|--dbg|-x) debug=1;shift;;
		--dry-run|--dry|-d) __mvPP_dryrun=1; shift;;
		--no-verbose|-V) v=; shift;; # is this even usefull ?, TODO: consider dropping it
		--no-interactive|-I) i=; shift;;
		--verbose|-v) v=--verbose; shift;;
		--interactive|-i) i=--interactive; shift;;
		[^-]*|'') break;; # stop when no more arguments # TODO: dont stop and use `shify $index`

		--*) echoerr "invalid option ${_i@Q}"; exit 1;;
		-*) echoerr "unrecognized option -- ${_i@Q}"; exit 1;;
		# TODO: support multiple arguments with 1 dash, example: -vid => --vefbose --interactive --dey-run
	esac
done
(( $# )) || TODO write help message
: ${__mvPP_dryrun:=0} # get it from arguments OR enviroment and set to false if not set


d(){ dirname -- "$@";}
b(){ basename -- "$@";}

mv-(){ mv $v $i -- "$@";}
# mvt-(){ mv $v $i --target-directory="${@:$#:1}" -- "${@:1:$#-1}"; }
mvT-(){ mv $v $i --no-target-directory -- "$@"; }
mkdir-(){ mkdir $v --parents -- "$@"; }
rmdir-(){ rmdir $v --parents --ignore-fail-on-non-empty -- "$@"; }

isonlydir(){ # checks if $2 contain only $1 (sub directory included) # todo: berrer explain this fn
	local a=("${2%/}"/*) # shopt -s nullglob dotglob
	[[ ${#a[@]} = 1 && ${1%/} = "${a#./}"?(/*) ]]
}

isemptydir(){ # checks is the directory empty
	local a=("${1%/}"/*) # shopt -s nullglob dotglob
	[[ -d $1 && ${#a[@]} = 0 && ! -e $t ]]
}

crmdir(){ # Confirm to Rmdir Dirname
	local t=$(d "$1")
	local m=
	isemptydir "$t" || return 0
	[[ $t = . ]] && t=../${PWD##*/} && m=' (curretn directory)'
	confirm "delete LEFTOVER dirnames of SOURCE$m" || return 0 # dry-run replace relyes on this line bellow
	rmdir- "$t"
}

(( __mvPP_dryrun )) &&
	eval 'function '{rmdir,mv,mkdir,exit-dry}' () { echo " $ ${FUNCNAME%-dry}" "${@@Q}"; }; ' &&
	eval "$(_i=$(declare -f crmdir); echo "${_i/'isemptydir "$t"'/'warn "$FUNCNAME fn may differ in not dry-run"; isonlydir "$1" "$t" && [[ "$t" != "$(d "$2")" ]]'}")"

(( debug )) && echoerr "${@@A}" && set -x

[[ $# != 2 ]] && err 'only 1 SOURCE argument is supported'
if [[ $1 = @(?(*/).?(.)?(/*)) || $2 = ?(*/).?(.)?(/*) ]]; then # if contain .. or . in SOURCE or TARGET
	info "using readlink because relarive path '..' or '.' found"
	source=$(readlink -e -- "$1") &&
	target=$(readlink -f -- "$2") &&
	set -- "$source${1##*[^/]}" "$target${2##*[^/]}" ||
	err 'readling failed'
	# TODO: test `readlink -e` and '-f'
else
	set -- "${1##+(./)}" "${2##+(./)}" # remove './' example: ./foo OR ./././foo --> foo
	set -- "${@//\/\//\/}"             # replace '//' with single '/'
fi

# when many arguments: [[ "$(printf '%c' "$@")" = @(+(/)|+([^/]) ]] || {
[[ ${1:0:1}${2:0:1} = @(//|[^/][^/]) ]] || {
	err 'SOURCE and TARGET are with different type of path /absolute and ./relative' 0
	confirm 'Use readlink?' n && {
		source=$(readlink -e -- "$1") &&
		target=$(readlink -f -- "$2") &&
		set -- "$source${1##*[^/]}" "$target${2##*[^/]}" ||
		{ err 'readling failed' 0; false; }
	} ||
	confirm 'Try anyway' n || exit 1
}
[[ ! -e $1 ]] && err 'SOURCE file must exist'
[[ ${1%/} = "$2" && ( $2 != */ || ${2%/*}/${1##*/} = "$2" ) ]] && err 'SOURCE and TARGET are the same file'


inner_dir(){
	mvT- "$1" "${1%/}$tmp" &&
	mkdir- "${2%/*}" &&
	if [[ $2 = */ ]]
	then mvT- "${1%/}$tmp" "${2%/*}/$(b "$1")" # using basename to remove $tmp  # todo: "${2%/*}/" instead of "$2/" - foo//bar is the same as foo/bar ?
	else mvT- "${1%/}$tmp" "$2"
	fi
}

upper_dir(){
	mvT- "$1" "${2%/}$tmp" &&
	rmdir- "$(d "${1#./}")" &&
	mvT- "${2%/}$tmp" "$2"
}

merge(){
	TODO "implement $FUNCNAME function"
}

swap(){
	mvT- "$1" "${1%/}$tmp" &&
	mvT- "$2" "$1" &&
	mvT- "${1%/}$tmp" "$2"
}

target(){
	mkdir- "${2%/*}" &&
	mv- "$@"
}

main(){
	# TODO: check which "mv" needs --target-directory

	[[ $2 = "${1%/}"/* ]] && confirm 'move in INNER directory with saame name?' && {
		inner_dir "$@"
		return $?
	}

	[[ $1 = "${2%/}"/* ]] && confirm 'move in UPPER directory with saame name?' && {
		isonlydir "$@" || {
			warn 'SOURCE is not directly only content in TARGET directory'
			confirm 'try anyway?' n
		} && {
			upper_dir "$@"
			return $?
		}
	}

	[[ -e $2 && ${1##*[^/]} = "${2##*[^/]}" ]] && {
		# will not match if SOUCE or TARGET end with 2 or more at end //
		[[ -d $1 && -d $2 ]] && confirm 'MERGE directoryes? (no for swap files)' && {
			merge "$@" || return $?
			crmdir "$@"
			return $?
		}
		confirm 'SWAP files?' && {
			swap "$@"
			return $?
		}
	}

	# requires '/' to be in TARGET argument, (just put it at end if you want to force creating TARGET dir)
	# dont use dirname since it can be target directory ( when ends with '/' | mv++ foo 'bar/' )
	[[ $2 = */* && ! -d ${2%/*} ]] && confirm 'make TARGET dirname and use regular MV?' && {
		target "$@" || return $?
		crmdir "$@"
		return $?
	}

	confirm 'use regular MV?' && {
		mv- "$@" || return $?
		crmdir "$@"
		return $?
	}

	err 'there is nothing to do' 4
	return 4
}
main "$@"
exit $?

# TODO:
# rmdit:
# todo: is this bad practice for absolute path ?
# WARNING: this is not good for absolute path      # AND also for ../../parrent-dirs ( not anymore, because uses readlink )
# `[[ $@ = . ]] && rmdir ...` was used before readlink # '.' is current directory and shoud not try to remove it?

# TODO: check if $() keeps tabs spaces and NEW LINE

# test -e # FILE exists
# test -d # FILE exists and is a directory