#!/bin/bash

## Define exit codes
# General config errors [10-19]
ELOAD=10
EINTERVAL=11
ENOCFG=19
# Source cofig errors [20-29]
# Destination config errors [30-49]
EFORMAT=30
ECHANNEL=31
EFMTINVPARM=49

# config structures
declare -A			\
	destinationchannels	\
	destinationcopymime	\
	destinationformat	\
	destinationfrequency	\
	destinationid		\
	destinationpath		\
	destinationquality	\
	destinationrename	\
	destinationrenamepath	\
	destinationskipmime	\
|| {
	echo "Check your Bash version. You need >= 4.0" >&2
	exit $EBASHVERS
}

declare -r				\
	DOCDIR=./doc			\
	SHAREDIR=./share
declare -r				\
	exampleconf=$DOCDIR/example.cfg	\
	schema=$SHAREDIR/schema.sql	\
					\
	oldIFS="$IFS"

#parse arguments
OPTERR=0
while getopts ':c:l:T:F:hD' opt
do
	case $opt in
		c)
			cffile="$OPTARG"
		;;
		l)
			cliload="$OPTARG"
		;;
		T)
			cliltimer="$OPTARG"
		;;
		F)
			forceall+=("$OPTARG")
		;;
		h)
			help
			exit 0
		;;
		D)
			(( debug++ ))
		;;
		:)
			echo "-$OPTARG requires an argument"
			help
			exit 127
		;;
		*)
			echo "Unrecognized option: -$OPTARG"
			help
			exit 127
		;;
	esac
done

#parse config
getConfigGeneral() {
	case $key in
		'max-load')
			expr='^[0-9]*$'
			if [[ $value =~ $expr ]]
			then
				maxload="$value"
			else
				echo "Invalid max-load value: $value" >&2
				exit $ELOAD
			fi
			unset expr
		;;
		'load-interval')
			expr='^[0-9]*$'
			if [[ $value =~ $expr ]]
			then
				loadinterval="$value"
			else
				echo "Invalid load-interval value: $value" >&2
				exit $EINTERVAL
			fi
			unset expr
		;;
		'temporary-directory')
			tempdir="$value"
		;;
		'database')
			database="$value"
		;;
		debug)
			(( value > debug )) && debug=$value
		;;
	esac
}

getConfigSource() {
	case "$key" in
		'path')
			sourcepath="$value"
		;;
		'id3charset')
			sourceid3charset="$value"
		;;
	esac
}

getConfigDestination() {
	case "$key" in
		'path')
			destinationpath["$destination"]="$value"
		;;
		'format')
			case "$value" in
				'mp3')
					destinationformat["$destination"]=mp3
				;;
				'vorbis')
					destinationformat["$destination"]=vorbis
				;;
				*)
					echo "Unsupported destination format: $value" >2&
					exit $EFORMAT
				;;
			esac
		;;
		'quality')
			expr='^[0-9]*$'
			if ! [[ $value =~ $expr ]]
			then
				echo "Invalid quality value: $value" >&2
				exit $EQUALITY
			fi
			unset expr
			case "${destinationformat["$destination"]}" in
				'vorbis')
					destinationquality["$destination"]="$value"
				;;
				*)
					echo "$Invalid parameter \"$key\" for format \"${destinationformat["$destination"]}\"" >&2
					exit $EFMTINVPARM
				;;
			esac
		;;
		'bitrate')
			expr='^[0-9]*$'
			if ! [[ $value =~ $expr ]]
			then
				echo "Invalid bitrate value: $value" >&2
				exit $EQUALITY
			fi
			unset expr
			case "${destinationformat["$destination"]}" in
				'mp3')
					destinationquality["$destination"]="$value"
				;;
				*)
					echo "$Invalid parameter \"$key\" for format \"${destinationformat["$destination"]}\"" >&2
					exit $EFMTINVPARM
				;;
			esac
		;;
		'channels')
			expr='^[0-9]*$'
			if ! [[ $value =~ $expr ]]
			then
				echo "Invalid channel count: $value" >&2
				exit $ECHANNEL
			fi
			unset expr
			destinationchannels["$destination"]=$value
		;;
		'frequency')
			expr='^[0-9]*$'
			if ! [[ $value =~ $expr ]]
			then
				echo "Invalid frequency value: $value" >&2
				exit $ECHANNEL
			fi
			unset expr
			destinationfrequency["$destination"]=$value
		;;
		'rename')
			case "$value" in
				*/*)
					destinationrenamepath["$destination"]="${value%/*}"
				;;
			esac
			destinationrename["$destination"]="${value##*/}"
		;;
		'skip_mime-type')
			destinationskipmime[$destination]="${destinationskipmime[$destination]:+${destinationskipmime[$destination]}|}$value"
		;;
		'copy_mime-type')
			destinationcopymime[$destination]="${destinationcopymime[$destination]:+${destinationcopymime[$destination]}|}$value"
		;;
	esac
}
getConfig() {
	while read key value
	do
		case $key in
			'#'*)
				#comment
			;;
			'')
				#empty line
			;;
			'[general]')
				context=General
			;;
			'[source]')
				context=Source
			;;
			\[*\])
				context=Destination
				destination="${key#[}"
				destination="${destination%]}"
			;;
			*)
				getConfig$context
			;;
		esac
	done < ~/.atom/atom.cfg
}

#check sanity

openDatabase() {
	if [ ! -d "$tempdir" ]
	then
		mkdir -p "$tempdir"
	fi
	mkfifo "$tempdir"/sqlite.{in,out}
	if [ ! -f "$database" ]
	then
		if [ ! -d "${database%/*}" ]
		then
			mkdir -p "${database%/*}"
		fi
		sqlite3 "$database" < $schema
	fi
	sqlite3 "$database"		\
		< "$tempdir/sqlite.in"	\
		> "$tempdir/sqlite.out"	&
	exec 3> "$tempdir"/sqlite.in
	exec 4< "$tempdir"/sqlite.out
	if (( debug > 2 ))
	then
		exec 5>&3
		exec 3> >(tee -a $tempdir/debug.log >&5)
	fi
}

closeDatabase() {
	echo .quit >&3
	(( debug )) && echo -n "Waiting for SQLite to terminate... "
	wait
	(( debug )) && echo OK
	exec 3>&-
	exec 4<&-
	rm "$tempdir"/sqlite.{in,out}
}

Select() {
#Select table [col1 [col2 [..]]] <	WHERE_key WHERE_operator WHERE_value
#					[WHERE_key WHERE_operator WHERE_value
#					[…]]
	local			\
		table="$1"	\
		col		\
		columns		\
		operator	\
		results		\
		where_statement
	shift
	for col
	do
		(( ${#columns} )) && columns+=','
		columns+="$col"
	done
	while read key operator value
	do
		(( ${#where_statement} )) && where_statement+=( "AND" )
		where_statement+=( "$key $operator "'"'"${value//\"/\"\"}"'"' )
	done
	echo	"SELECT IFNULL("				\
			"(SELECT $columns FROM $table"		\
				"WHERE ${where_statement[@]})"	\
			",'SQL::Select:not found'"		\
		");" >&3
	read -u 4 results
	if ! [[ $results == "SQL::Select:not found" ]]
	then
		echo "$results"
	else
		return 1
	fi
}
Insert() {
#Insert table [no_id] <	key value
#			[key value
#			[…]]
	local			\
		table="$1"	\
		no_id="${2:-0}"	\
		insert_keys	\
		insert_values	\
		results
	while read key value
	do
		(( ${#insert_keys} )) && insert_keys+=","
		insert_keys+='`'"$key"'`'
		(( ${#insert_values} )) && insert_values+=","
		if [[ $value == NULL ]]
		then
			insert_values+="NULL"
		else
			insert_values+='"'"${value//\"/\"\"}"'"'
		fi
	done
	echo	"INSERT INTO $table"				\
				"( $insert_keys )"		\
			"VALUES"				\
				"( $insert_values );" >&3
	(( no_id )) || {
		echo 'SELECT LAST_INSERT_ROWID();' >&3
		read -u 4 results
		echo "$results"
	}
}
Update(){
#Update table set_key set_value [set_key set_value […]] <	where_key where_operator where_value
#								[where_key where_operator where_value
#								[…]]
	local			\
		table="$1"	\
		key		\
		argument	\
		operator	\
		value		\
		set_statement	\
		where_keys	\
		where_values	\
		what		\
		where_statement	\
		results
	shift
	what=key
	for argument
	do
		case $what in
			key)
				set_statement="${set_statement:+${set_statement},}\`$argument\`"
				what=value
			;;
			value)
				set_statement="${set_statement}="'"'"${argument//\"/\"\"}"'"'
				what=key
			;;
		esac
	done
	while read key operator value
	do
		(( ${#where_statement} )) && where_statement+=( "AND" )
		if [[ $value == NULL ]]
		then
			where_statement+=( "$key is NULL" )
		else
			where_statement+=( "$key $operator "'"'"${value//\"/\"\"}"'"' )
		fi
	done
	echo	"UPDATE '$table' SET"		\
			"$set_statement"	\
		"WHERE"				\
			"${where_statement[@]}"	\
		";" >&3
}
InsertIfUnset() {
#InsertIfUnset table [no_id] < key value \n key value
	local			\
		table="$1"	\
		no_id="${2:-0}"	\
		column		\
		key		\
		keys		\
		results		\
		value		\
		values
	while read key value
	do
		keys+=( "$key" )
		values+=( "$value" )
	done
	if (( no_id ))
	then
		column="${keys[0]}"
	else
		column='id'
	fi
	if ! results=$(
		Select "$table" "$column" < <(
			for key in ${!keys[@]}
			do
				echo "${keys[$key]}" = "${values[$key]}"
			done
		)
	)
	then
		results=$(
			Insert "$table" < <(
				for key in ${!keys[@]}
				do
					echo "${keys[$key]}" "${values[$key]}"
				done
			)
		)
	fi
	echo "$results"
}
InsertOrUpdate() {
#InsertOrUpdate table set_key set_value [set_key set_value […]] <	where_key where_value
#									[where_key where_value
#									[…]]
	local			\
		table="$1"	\
		argument	\
		key		\
		keys		\
		set_keys	\
		set_values	\
		value		\
		values		\
		what		\
		results
	shift
	what=key
	for argument
	do
		case $what in
			key)
				set_keys+=( "$argument" )
				what=value
			;;
			value)
				set_values+=( "$argument" )
				what=key
			;;
		esac
	done
	while read key value
	do
		keys+=( "$key" )
		values+=( "$value" )
	done
	if results=$(
		Select "$table" id < <(
			for key in ${!keys[@]}
			do
				echo "${keys[$key]}" = "${values[$key]}"
			done
		)
	)
	then
		Update "$table" "$@" < <(
			for key in ${!keys[@]}
			do
				echo "${keys[$key]}" = "${values[$key]}"
			done
		)
	else
		results=$(
			Insert "$table" < <(
				for key in ${!set_keys[@]}
				do
					echo "${set_keys[$key]}" "${set_values[$key]}"
				done
				for key in ${!keys[@]}
				do
					echo "${keys[$key]}" "${values[$key]}"
				done
			)
		)
	fi
	echo "$results"
}
Delete() {
#Delete table <	where_key where_operator where_value
#		[where_key where_operator where_value
#		[…]]
	local			\
		table="$1"	\
		key		\
		operator	\
		value		\
		where_statement	\
		results
	while read key operator value
	do
		(( ${#where_statement} )) && where_statement+=( "AND" )
		if [[ $value == NULL ]]
		then
			where_statement+=( "$key is NULL" )
		else
			where_statement+=( "$key $operator "'"'"${value//\"/\"\"}"'"' )
		fi
	done
	echo "DELETE from $table WHERE ${where_statement[@]};" >&3
}

createDestinations() {
	for destination in ${!destinationpath[@]}
	do
		if ! [ -d "${destinationpath["$destination"]}" ]
		then
			if ! mkdir -p "${destinationpath["$destination"]}"
			then
				echo "$destination: Could not create ${destinationpath["$destination"]}!"
				exit $EINVDEST
			fi
		fi
		destinationid["$destination"]=$(
			InsertIfUnset destinations <<<"name $destination"
		)
	done
}

getFiles() {
	scantime=$(date +%s)
	# We probably have thousands of files, don't waste time on disk writes
	echo 'BEGIN TRANSACTION;' >&3
	while read time size filename
	do
		if ! Select source_files id >/dev/null <<-EOWhere
				filename = $filename
				mime_type > 0
				last_change >= $time
			EOWhere
		then
			mimetype=$(file -b --mime-type "$sourcepath/$filename")
			mimetypeid=$(
				InsertIfUnset mime_types <<-EOInsert
					mime_text $mimetype
				EOInsert
			)
			InsertOrUpdate source_files	\
				last_change $time	\
				size $size		\
				last_seen $scantime	\
				mime_type $mimetypeid	\
				>/dev/null		\
			<<-EOWhere
				filename $filename
			EOWhere
			(( ++new ))
		else
			Update source_files last_seen $scantime <<-EOWhere
				filename = $filename
			EOWhere
		fi
		case $(( ++count % 4 )) in
			0) echo -ne '\r|' ;;
			1) echo -ne '\r/' ;;
			2) echo -en '\r-' ;;
			3) echo -ne '\r\\' ;;
		esac
	done < <(
		find "$sourcepath" -type f -printf "%T@ %s %P\n"
	)
	echo 'COMMIT;' >&3
	echo -e "\r$count files found, ${new:=0} new or changed."
	unset count
}

updateMimes() {
	Update mime_actions action 1 <<<"action != 1"
	for destination in ${!destinationskipmime[@]}
	do
		IFS='|'
		for mime_type in ${destinationskipmime["$destination"]}
		do
			IFS="$oldIFS"
			Update mime_type_actions action 0 >/dev/null < <(
				cat <<-EOWhere
					destination_id = ${destinationid["$destination"]}
					mime_text LIKE ${mime_type//\*/%}
				EOWhere
			)
		done
	done
	for destination in ${!destinationcopymime[@]}
	do
		IFS='|'
		for mime_type in ${destinationcopymime["$destination"]}
		do
			IFS="$oldIFS"
			Update mime_type_actions action 2 >/dev/null < <(
				cat <<-EOWhere
					destination_id = ${destinationid["$destination"]}
					mime_text LIKE ${mime_type//\*/%}
				EOWhere
			)
		done
	done
}

removeObsoleteFiles() {
	Delete source_files <<-EOWhere
		last_seen < $scantime
	EOWhere
}

getInfos::MP3() {
	:
}

getInfos::Ogg() {
	:
}

getInfos::FLAC() {
	:
}

getInfos::MPC() {
	:
}

getTags() {
	#getType
	#getInfos::<type>
	:
}

encodeFile::MP3() {
	#lame
	:
}

encodeFile::Ogg() {
	#oggenc
	:
}

transcodeFile() {
	#sox -> wav
	for format in $targets["format"]
	do
		#encodeFile::$format
		:
	done
	#signal and of encoding to parent
}

checkFinished() {
	#retrieve info from finished transcodeFile()
	#update counters / metadata
	:
}

checkLoad() {
	#if load > threshold
	#	decrease concurrency
	#elif load < threshold
	#	increase concurrency
	#fi
	:
}

readUserInput() {
	#read + / - / q(uit) / p(ause)
	#initiate shutdown / change load threshold / SIGSTOP all children / SIGCONT all children
	:
}

transcodeLauncher() {
	checkLoad
	checkFinished
	#until running processes < max processes
	#do
		checkLoad
		checkFinished
		readUserInput
	#done
	transcodeFile &
	#update counter / metadata
}

#UI

if [ ! -f ~/.atom/atom.cfg ]
then
	if [ ! -d ~/.atom ]
	then
		mkdir -p ~/.atom
	fi
	sed "s:%HOME%:$HOME:" "$exampleconf" > ~/.atom/atom.cfg
	cat >&2 <<-EOCfgNotice
	No configuration file found!
	An example file has been created as ~/.atom/atom.cfg.
	You should change it to your likings using you favorite editor.

	Bailing out.
	EOCfgNotice
	exit $ENOCFG
fi
getConfig
{
cat <<EOF
General|Load|$maxload
|Load Interval|$loadinterval
|Temp Dir|$tempdir
|Database|$database
|Debug|$debug
Source|Path|$sourcepath
|ID3 Charset|$sourceid3charset
EOF
for destination in ${!destinationpath[@]}
do
cat <<EOF
$destination|Path|${destinationpath[$destination]}
|Format|${destinationformat[$destination]}
|Quality|${destinationquality[$destination]}
|Channels|${destinationchannels[$destination]}
|Frequency|${destinationfrequency[$destination]}
|Path Change|${destinationrenamepath[$destination]}
|File Rename|${destinationrename[$destination]}
EOF
echo "|Skipped mime-type|${destinationskipmime[$destination]//\|/
|Skipped mime-type|}"
echo "|Copied mime-type|${destinationcopymime[$destination]//\|/
|Copied mime-type|}"
done
}|column -t -s'|' -n

openDatabase

createDestinations

getFiles

updateMimes

removeObsoleteFiles

# get files
echo '
	SELECT	COUNT(*)
	FROM	source_files,
		destinations,
		destination_files,
		mime_type_actions
	WHERE	destination_files.last_change < source_files.last_change
	AND	destinations.id = destination_files.destination_id
	AND	mime_type_actions.destination_id = destinations.id
	AND	mime_type_actions.id = source_files.mime_type
	AND	source_files.id = destination_files.source_file_id
	AND	mime_type_actions.action = 1;' >&3
read -u4 filecount
echo '
	SELECT
		destinations.name,
		mime_type_actions.mime_text,
		source_files.filename
	FROM	source_files,
		destinations,
		destination_files,
		mime_type_actions
	WHERE	destination_files.last_change < source_files.last_change
	AND	destinations.id = destination_files.destination_id
	AND	mime_type_actions.destination_id = destinations.id
	AND	mime_type_actions.id = source_files.mime_type
	AND	source_files.id = destination_files.source_file_id
	AND	mime_type_actions.action = 1;

	SELECT "AtOM:NoMoreFiles";' >&3
while read -u4 line
do
	if [[ $line = AtOM:NoMoreFiles ]]
	then
		echo -e "\r$count files to create or update."
		break
	else
		destination=${line%%|*}
		rest=${line#*|}
		mimetype=${rest%%|*}
		filename=${rest#*|}
		echo -en "\rTags: $((++count*100/filecount))%"
		getTags
		#createTask
	fi
done
unset count
closeDatabase

# vim:set ts=8 sw=8: