#!/bin/bash
#
# util.sh
#
# Copyright 2019 Luigi Santivetti <luigi.santivetti@gmail.com>

# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice (including the next
# paragraph) shall be included in all copies or substantial portions of the
# Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

# Set log line max width
if [ -n "$COLUMNS" ]; then
	declare -ir prn_wmax="$COLUMNS"
elif [ -n "$(tput cols 2>/dev/null)" ]; then
	declare -ir prn_wmax="$(tput cols)"
else
	declare -ir prn_wmax="135" # my size :)
fi

# Set width ration for description
if [ "${LOG_D:-0}" -eq "1" ]; then
	declare -ir prn_wdesc_ratio="35"
	# Set log description max width
	declare -ir prn_wdesc="$prn_wmax / 100 * $prn_wdesc_ratio"
else
	declare -ir prn_wdesc="0"
fi

# Set log tags
declare -Ar prn_tag=( \
	["W"]="WARNING" ["E"]="ERROR"  ["D"]="DEBUG" \
	["I"]="INFO"    ["A"]="ASKING" ["X"]="PIPE" \
)

# Set log tag max width
declare -ir prn_wtag="$(for t in ${prn_tag[@]}; do \
	echo -ne $t | wc -m; done | sort -r | head -1)"

# Set log offset for symbols and whitespaces
declare -ir prn_wofs="8"

# Set log message max width
declare -ir prn_wmsg="$prn_wmax - $prn_wdesc - $prn_wtag - $prn_wofs"

# Some color
declare -rA c=( \
	[LGREEN]="\033[1;32m" [LGREY]="\033[0;37m" [LCYAN]="\033[96m" \
	[YELLOW]="\033[1;33m" [LRED]="\033[1;31m" [LBLUE]="\033[1;34m" \
	[NONE]="\033[0m" \
)

if which fold &>/dev/null; then
	function prn_line
	{
		echo -en "$1\n" | fold -s -w "$prn_wmsg"
	}
else
	function prn_line
	{
		echo -e "$1\n"
	}
fi

# @return : stdout, absolute path to the main script, assume it is one level up '..'
function get_script_dir
{
	pushd \
		"$(dirname "$(readlink -f ${BASH_SOURCE[0]} 2>/dev/null)" 2>/dev/null)" \
		&>/dev/null && {
		echo "$(realpath "$(pwd)"/..)"
		popd &>/dev/null
	}
}

# @return : stdout, runtime timestamp at lauching time
function get_script_now
{
	local now="$(date +'%d%m%Y%H%M%S')" && echo "$now"
}

# @desc   : main routine for handling basic stdout messages
function prn
{
	local nl colr ltag lmsg desc line fdesc ftag fmt_ltag fmt

	fdesc="^"
	ftag="^"

	# Order here should match the invocation order in log()
	while [ ${#} -gt 0 ]; do
		case "$1" in
			-n) nl="\n"; shift ;;
			-d) desc="$2"; shift 2 ;;
			-t) ltag="$2"; shift 2 ;;
			-c) colr="$2"; shift 2 ;;
			-x) ftag="$2"; line="$2\n"; shift 2 ;;
			-l)	line="$(prn_line "$line$2\n")"; shift 2 ;;
			*) shift ;;
		esac
	done

	# Build the format output string
	fmt_ltag="$colr%*s${c[NONE]}"
	fmt="%*.*s $fmt_ltag %.*s$nl"

	# Process stdout
	while read -r lmsg; do
		printf "$fmt" $prn_wdesc $prn_wdesc $desc \
			   $prn_wtag ${ltag:0:$prn_wtag} $prn_wmsg "$lmsg"

		# If printing folded lines, remove func and tag
		desc=$fdesc && ltag=$ftag
	done < <(cat <<EOF
$line
EOF
			)
}

# @1      : text to be sent to stdout via prn
# @return : Success if user enters y, error if n, otherwise it keeps
#         : asking for input.
function ask
{
	local desc="${FUNCNAME[2]}:${BASH_LINENO[1]}"
	local ans=""

	[ "$answer" = 'y' ] && return $s_ok
	[ "$answer" = 'n' ] && return $s_err

	prn -d $desc -t ${prn_tag[A]} -c ${c[LBLUE]} -l "${*} [y/n]" 1>&2
	while [ "$ans" != 'y' ] && [ "$ans" != 'n' ]; do read -s -n 1 ans; done

	printf " $ans\n" 1>&2; [ "$ans" = "y" ] && return $s_ok || return $s_err
}

# @       : list of options and arguments (-x, -w, -d, -e, -i and --phew). For
#         : -d, debug and -i, info, --phew overrides the color to green.
# @desc   : main routine for logging facilities. Note, all logs are redirected
#         : to stderr and logging error (-e) returns an error (return 1) 
function log
{
	local -i do_print=0
	local -a msg=( )
	local desc=""
	local ltag=""
	local colr=""
	local xlog=""

	[ $LOG_D -eq 1 ] && desc="-d ${FUNCNAME[2]}:${BASH_LINENO[1]}" || desc="-d ''"

	case "${1}" in
		-x) [ $LOG_X -eq 1 ] && {
				shift
				[ -n "$1" ] && xlog="-x $1"
				shift
				colr="-c ${c[LCYAN]}"
				do_print=1
				msg=( "${*:-$(</dev/stdin)}" )
				ltag=${prn_tag[X]}
			} ;;
		-w) [ $LOG_W -eq 1 ] && {
				shift
				colr="-c ${c[YELLOW]}"
				do_print=1
				msg=( "${*}" )
				ltag=${prn_tag[W]}
			} ;;
		-d) [ $LOG_D -eq 1 ] && {
				shift
				[ "$1" = "--phew" ] && {
					shift
					colr="-c ${c[LGREEN]}"
				} || colr="-c ${c[LGREY]}"
				do_print=1
				msg=( "${*}" )
				ltag=${prn_tag[D]}
			} ;;
		-i) [ $LOG_I -eq 1 ] && {
				shift
				[ "$1" = "--phew" ] && {
					shift
					colr="-c ${c[LGREEN]}"
				} || colr="-c ${c[NONE]}"
				do_print=1
				msg=( "${*}" )
				ltag=${prn_tag[I]}
			} ;;
		-e) # Always print errors
			shift
			prn -n $desc -t ${prn_tag[E]} -c ${c[LRED]} -l "${*}" 1>&2
			return $s_err ;;
	esac

	[ $do_print -eq 1 ] && {
		prn -n $desc -t $ltag $colr $xlog -l "${msg[*]}" 1>&2
	}; return $s_ok
}

function is_set
{
	[ "$(set -o | grep $1 | grep -oE "(on|off)")" = "on" ]
}

# desc    : util handler
function lets
{
	is_set "xtrace" && local xtrace="set -x" && set +x
	local -i ret

	case "$1" in
		-l|--log) shift && log ${@}; ret=$? ;;
		-a|--ask) shift && ask ${@}; ret=$? ;;
		-d|--die) shift && die ${@}; ret=$? ;;
		*) eval ${xtrace}; return $s_err ;;
	esac

	eval ${xtrace}; return $ret
}

# @1      : string compliant with unix file system node addressing
# @desc   : using ${*} to get it to fail if passed in with multiple words
function is_unix_path
{
	[ ! -z "${*}" ] && pathchk -P -- "${*}" &>/dev/null
}

# @1      : absolute path to file
# @2      : absolute path to directory
# @return : success if @2 exists and @1 is a valid unix path and @1 is a node in @2,
#         : error otherwise.
# @desc   : useful when @1 is a prospective file, but not a file just yet
function is_in_tree
{
	[ -d "${2}" ] && is_unix_path "${1}" || return 1

	case "${1}" in "${2}"*) return 0 ;; *) return 1 ;; esac
}

# @1      : absolute path to a prospective file
# @return : success if the named file in @1 is or will be in the $instance_d tree
function is_in_tree_instance_d
{
	is_in_tree "${1}" "${instance_d}"
}

# @1      : file mode permission
# @2      : file owner and group mode permission
# @3      : (optional) recursive flag -R
# @       : list of files and/or directories
# @return : Success if it could chmod and chown a valid file
function set_mode
{
	local mode=$1; shift
	local own=$1; shift
	local t

	if [ "$1" = "-R" ]; then local flags=$1; shift; fi

	for t in ${@}; do
		if [ -f "$t" ] || [ -d "$t" ]; then
			sudo chmod $flags $mode "$t" && sudo chown $own:$own "$t" || return 1
		else
			lets -l -e "invalid: $t"
		fi
	done
}

# @1      : list of packages
function util_install_dependency
{
	local pkg

	for pkg in ${@}; do
		sudo apt-get install -y --fix-missing $pkg 2>&1 | lets -l -x "apt-get"
		[ ${PIPESTATUS[0]} -eq 0 ] || {
			lets -l -e "failed to install $pkg"; return 1
		}
	done
}

# @1      : absolute path
# @desc   : Validate a prospective directory path
function is_valid_new_dir
{
	is_unix_path "${*}" && [ ! -e "${*}" ]
}

# @desc   : remove trailing and leading whitespaces
function get_wtrim
{
	echo "${*}"
}

# @1      : absolute path to a generic file
# @return : basename without extension
# @desc   : convert an absolute path to a lhs suitable variable name. This
#         : means stripping anything after the dot
function get_stripname
{
	local stripped

	stripped="$(basename $1)"; stripped="${stripped%%.*}"
	echo "$stripped"
}

# @1      : array variable name
# @desc   : check if the vriable named in @1 is set and is an array
function is_array_set
{
	declare -p -- "${*}" | grep -q "declare \-a"
}

# @1      : function name
# @desc   : check if the vriable named in @1 is set
function is_function_set
{
	declare -F "${*}" &>/dev/null
}

function is_system_ready
{
	case "$BASH_VERSION" in
		''|[123].*|4.[0123]) echo "ERROR: Bash 4.4 required" >&2; return 1 ;;
	esac
}

# @1      : asoblute path to output file
# @2      : fd variable name reference
# @3      : char representing file mode operation - r,w,rw
# @desc   : in preparation to add support for dedicated fds for logs and output
function fdopen
{
	local -n out_fd=$2
	local -r file=$1

	[ -z "$out_fd" ] || { lets -l -e "invalid out fd"; return 1; }

	case "$3" in
		rw|wr) [ -n "$file" ] && [ ! -f "$file" ] && \
				   is_unix_path $file && exec {fd}<> $file ;;
		w    ) [ ! -f "$file" ] && \
				   is_unix_path $file && exec {fd}> $file ;;
		r    ) [ -r "$file" ] && exec {fd}< $file ;;
	esac

	# Posix bash dynamic fd allocation is from 9 on
	[ -f "$file" ] && [ $fd -gt 9 ] && out_fd=$fd && return

	lets -l -e "failed to open fd=$1"
	return 1
}

# @1      : fd int
# @2      : char representing file mode operation - r,w,rw
# @desc   : in preparation to add support for dedicated fds for logs and output
function fdclose
{
	local -ri fd=$1

	[ $fd -gt 9 ] || { lets -l -e "invalid file fd"; return 1; }

	case "$2" in
		rw|wr) exec {fd}>&- && { lets -l -d "$fd closed"; return; }
			   exec {fd}<&- && { lets -l -d "$fd closed"; return; } ;;
		w    ) exec {fd}>&- && { lets -l -d "$fd closed"; return; } ;;
		r    ) exec {fd}<&- && { lets -l -d "$fd closed"; return; } ;;
	esac

	lets -l -e "failed to close fd=$2"
	return 1
}

function get_hunk_indexes
{
	local begin="$rex_legal_manifest_hook_begin"
	local ended="$rex_legal_manifest_hook_ended"
	local -a idx

	idx=( $(grep -n -e "$begin" -e "$ended" $manifest_f | cut -f1 -d':') )
	local -i mod="${#idx[@]} % 2"

	[ $mod -eq 0 ] && echo ${idx[@]} || lets -l -e "invalid $manifest_f"
}

function get_hunk_pair
{
	local -i head; local -i tail; local -a pair
	local -i from=$1; shift

	pair=( ${@:$from:2} )
	[ ${#pair[@]} -eq 2 ] || { [ ${#pair[@]} -eq 0 ] && return $s_ok; } || \
		return $s_err

	tail=${pair[0]}; head=${pair[1]};
	tail="$head - $tail + 1"

	echo "$head $tail"
}

function get_hunk
{
	cat $manifest_f | head -n $1 | tail -n $2
}

# @1      : remote address
# @2      : branch name
# @3      : mirror name
function get_new_sha_upstream
{
	local remote_sha

	remote_sha="$(git ls-remote $1 $2 | head -1 | cut -f 1)"

	if [ -d "$3" ]; then
		[ -f "$3/$__version" ] || {
			lets -l -e "${3:-uknown mirror} not versioned"
			return $s_err2
		}
	else
		mkdir -p "$3" || { lets -l -e "mkdir failed: $3"; return $s_err2; }
		echo $remote_sha; return $s_ok
	fi

	[ "$(< "$3/$__version")" != "$remote_sha" ] && {
		lets -l -d "$3: $remote_sha"
		rm -rf $3; echo $remote_sha; return $s_ok
	} || {
		lets -l -i "$3 is up to date"; 
	}

	return $s_err
}

function __git_archive
{
	local mirror="$1"
	local remote="$4"
	local staging_d="$(dirname $2)"
	local flags="--prefix=$mirror/" # need trailing slash
	flags+=" --output=$2"
	flags+=" --format=$3"
	flags+=" --remote=$remote"
#	flags+=" --verbose"
	local branch="$5"
	local remote_sha

	remote_sha="$(get_new_sha_upstream $remote $branch $staging_d/$mirror)"
	case "$?" in
		$s_err2 ) return $s_err ;; # no new sha, an error occurred
		$s_err ) return $s_ok ;; # no new sha, no need to update
	esac

	git archive $flags $branch 2>&1 | lets -l -x "git"

	[ ${PIPESTATUS[0]} -eq $s_ok ] && {
		tar -xf $2 -C "${2%/*}" 2>&1 | lets -l -x "tar"
		[ ${PIPESTATUS[0]} -eq $s_ok ] && rm -rf $2 || {
				lets -l -w "tar failed: $2. Clean up needed"
				return $s_err
			}
		echo $remote_sha > "${2%/*}/$mirror/$__version"
	}

	return ${PIPESTATUS[0]}
}

function __git_clone
{
	local mirror_d="$3"
	local branch="$1"
	local remote="$2"
	local flags="--single-branch"
	flags+=" --depth=1"
	flags+=" --branch=$branch"
	flags+=" --verbose"
	local remote_sha

	remote_sha="$(get_new_sha_upstream $remote $branch $mirror_d)"
	case "$?" in
		$s_err2 ) return $s_err ;; # no new sha, an error occurred
		$s_err ) return $s_ok ;; # no new sha, no need to update
	esac

	git clone $flags $remote $3 2>&1 | lets -l -x "git"
	[ ${PIPESTATUS[0]} -eq $s_ok ] || return $s_err

	echo $remote_sha > "$mirror_d/$__version"
}

function __wget_file
{
	local output="-O $1"
	local remote="$2"
	local flags="-nv"

	if [ ! -f "$1" ]; then
		wget $flags $output $remote 2>&1 | lets -l -x "wget"
		[ ${PIPESTATUS[0]} -eq 0 ] || {
			lets -l -d "failed wget $(basename $1)"
			return $s_err
		}
	else
		lets -l -i "$1 up to date"
	fi;	[ -f "$1" ]	
}

# @1      : module name
# @2      : output dir
function process_manifest
{
	local -i from=1 # $@ is 1 indexed
	local -a hunks
	local -a pair

	[ -z "$1" ] && { lets -l -e "invalid module name"; return $s_err; }

	hunks=( $(get_hunk_indexes) )
	case "$?" in $s_err ) return $s_err ;; esac

	pair=( $(get_hunk_pair $from ${hunks[@]}) )
	case "$?" in $s_err ) return $s_err ;; esac

	while [ -n "$pair" ]; do
		(
			# Clean up manifest fields before sourcing
			modname=""; mirror=""; protocol=""; branch=""; host=""; user="";
			method=""; format=""; file=""

			set -e
			source <(get_hunk ${pair[@]}) && set +e || { set +e; return $s_err3; }

			[ "$1" = "$modname" ] || return $s_ok # no error, try again

			case "$method" in
				git-archive )
					[ -n "$user" ] && user="$user@"
					[ -n "$protocol" ] && protocol="$protocol://"
					[ -n "$format" ] || return $s_err4

					local remote="${protocol:-}${user:-}$host/$mirror"
					local tarball="$2/$mirror.$format"

					__git_archive \
						$mirror $tarball $format $remote $branch || return $s_err5 ;;
				git-clone )
					[ -n "$user" ] && user="$user@"
					[ -n "$protocol" ] && protocol="$protocol://"

					local remote="${protocol:-}${user:-}$host/$mirror"

					__git_clone $branch $remote $2/$mirror || return $s_err6 ;;
				wget-file )
					[ -n "$file" ] || return $s_err7
					[ -n "$format" ] && file="$file.$format"

					__wget_file $2/$file $host/$file || return $s_err8 ;;
				*) return $s_err9 ;;
			esac
		) || {
			case "$?" in
				$s_err3 ) lets -l -e "$1: failed to source manifest" ;;
				$s_err4 ) lets -l -e "$1: manifest missing format"   ;;
				$s_err5 ) lets -l -e "$1: failed git archive"        ;;
				$s_err6 ) lets -l -e "$1: failed git clone"          ;;
				$s_err7 ) lets -l -e "$1: manifest missing file"     ;;
				$s_err8 ) lets -l -e "$1: failed wget file"          ;;
				$s_err9 ) lets -l -e "$1: invalid manifest method"   ;;
			esac; return $s_err
		}

		from="$from + 2"; pair=( $(get_hunk_pair $from ${hunks[@]}) )
		[ $? -eq 0 ] || return $s_err
	done; return $s_ok
}

function get_all_modules
{
	ls -Ad $module_d/*/ | xargs -n1 basename
}

function get_modules_optarg
{
	local modname; local -a mods=( ); local -a imods=( )

	if [ -z "${*}" ]; then
		imods=( $(get_all_modules) )
	else
		imods=( "${@}" )
	fi

	for modname in ${imods[@]}; do
		[ -n "$modname" ] && [ -d "$module_d/$modname" ] || {
			lets -l -w "$modname not found"
			continue
		}

		__is_in_array "$modname" "${BLMODULES[@]}" && [ $modall -eq 0 ] && {
			lets -l -d "$modname is blacklisted, set MODALL=1 to force"
			continue
		}

		mods+=( $modname )
	done

	[ -n "${mods[*]}" ] && echo "${mods[@]}"
}

function is_opt
{
	local k

	for k in ${!OPTIONS[@]}; do
		[ ${OPTIONS[$k]} -eq 1 ] && \
			case "${*}" in *"$k"* ) return $s_ok ;; esac
	done

	return $s_err
}

function get_opt
{
	local k

	for k in ${!OPTIONS[@]}; do
		[ ${OPTIONS[$k]} -eq 1 ] && echo $k
	done
}

function __is_in_array
{
	printf "%s\n" "${@:2}" | grep -qFx -- "$1"
}

# @       : list of items to be merged
# @desc   : very inefficient way for ensuring uniqueness without sorting
function __merge_array
{
	cat -n <(printf "%s\n" "${@}") | sort -t$'\t' -k2,2 -u | \
		sort -t$'\t' -k1,1 | cut -d$'\t' -f 2
}

function __append_item
{
	# emulating `+=` which adds items to the end of the list
	local -ar __tmp_a=( "${@:2}" "$1" )
	__merge_array "${__tmp_a[@]}"
}

function is_in_options
{
	__is_in_array "$1" ${!OPTIONS[@]}
}

function is_in_modules
{
	__is_in_array "$1" ${MODULES[@]}
}

function are_in_modules
{
	local i
	for i in "${@}"; do __is_in_array "$i" "${MODULES[@]}" || return $s_err; done 
}

function is_in_optarg
{
	__is_in_array "$1" ${OPTARG[@]}
}

function module_enable
{
	MODULES=( $(__append_item "$1" "${MODULES[@]}") )
}

function getflag
{
	local -ar flags=( ${2//:/ } )

	__is_in_array "$1" ${flags[@]} && echo "true" || echo "false"
}

function setflag
{
	echo "${*// /:}"
}