#!/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	\
	destinationpath		\
	destinationquality	\
	destinationrename	\
	destinationrenamepath	\
	destinationskipmime	\
|| {
	echo "Check your Bash version. You need >= 4.0" >&2
	exit $EBASHVERS
}

DOCDIR=./doc
SHAREDIR=./share
exampleconf=$DOCDIR/example.cfg
schema=$SHAREDIR/schema.sql

#parse arguments
#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)
			#unimplemented
		;;
	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" < $schema
	fi
	sqlite3 -line "$database"	\
		< "$tempdir/sqlite.in"	\
		> "$tempdir/sqlite.out"	&
	exec 3> "$tempdir"/sqlite.in
	exec 4< "$tempdir"/sqlite.out
}

closeDatabase() {
	exec 3>&-
	exec 4<&-
	rm "$tempdir"/sqlite.{in,out}
}

Select() {
#Select table [col1 [col2 [..]]] <	WHERE_key WHERE_value
#					[WHERE_key WHERE_value
#					[…]]
	local			\
		table="$1"	\
		col		\
		columns		\
		results		\
		where_statement
	shift
	for col
	do
		(( ${#columns} )) && columns+=','
		columns+="$col"
	done
	while read key value
	do
		(( ${#where_statement} )) && where_statement+=( "AND" )
		if [[ $value == NULL ]]
		then
			where_statement+=( "$key is NULL" )
		else
			where_statement+=( "$key='$value'" )
		fi
	done
	echo	"SELECT IFNULL("				\
			"(SELECT $columns FROM $table"		\
				"WHERE ${where_statement[@]})"	\
			",'SQL::Select:not found'"		\
		");" >&3
	read -u 4 results
	results="${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"				\
				"( $insert_values );" >&3
	(( no_id )) || {
		echo 'SELECT LAST_INSERT_ROWID();' >&3
		read -u 4 results
		results="${results#* = }"
		echo "$results"
	}
}
Update(){
#Update table set_key set_value [set_key set_value […]] <	where_key where_value
#								[where_key where_value
#								[…]]
	local			\
		table="$1"	\
		key		\
		argument	\
		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 value
	do
		(( ${#where_statement} )) && where_statement+=( "AND" )
		if [[ $value == NULL ]]
		then
			where_statement+=( "$key is NULL" )
		else
			where_statement+=( "$key='$value'" )
		fi
	done
	echo	"UPDATE '$table' SET"		\
			"$set_statement"	\
		"WHERE"				\
			"${where_statement[@]}"	\
		";" >&3
}
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[$key]}"
				done
			)
		)
	fi
	results="${results#* = }"
	echo "$results"
}

getFiles() {
	:
}

getType() {
	:
}

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 / check 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

closeDatabase

# vim:set ts=8 sw=8: