#!/bin/bash

setupDestination() {
	cat <<-EODesc

        Format:
            vorbis, opus or mp3. Other formats may appear in the future.
	EODesc
	comeagain() {
		read						\
			-e					\
			${destinationformat["$destination"]+-i"${destinationformat["$destination"]}"}\
			-p 'Format: '				\
			value
		case "$value" in
			'mp3')
				destinationformat["$destination"]=mp3
				lameneeded=1
			;;
			'opus')
				destinationformat["$destination"]=opus
				opusencneeded=1
			;;
			'vorbis'|'ogg')
				destinationformat["$destination"]=vorbis
				oggencneeded=1
			;;
			*)
				echo "Unsupported destination format: $value" >&2
				comeagain
			;;
		esac
	}
	comeagain
	cat <<-EODesc

        Path (path):
            Where to store transcoded files (will be created if it does not
            exist).
	EODesc
	read							\
		-e						\
		-p'Path: '					\
		${destinationpath["$destination"]+-i"${destinationpath["$destination"]}"}\
		destinationpath["$destination"]
	case ${destinationformat["$destination"]} in
		vorbis)
			cat <<-EODesc

        Quality (integer):
            The quality parameter of oggenc. See man oggenc for more info.
			EODesc
			expr='^[0-9]*$'
			comeagain() {
				read 					\
					-p'Quality: '			\
					-e				\
					-i				\
					${destinationquality["$destination"]:-3}\
					value
				if ! [[ $value =~ $expr ]]
				then
					echo "Invalid quality value: $value" >&2
					comeagain
				fi
			}
			comeagain
			destinationquality["$destination"]=$value
		;;
		opus)
			cat <<-EODesc

        Bitrate (kbps, integer):
            Set (VBR) bitrate to <bitrate>. Note that while Opus allows for
            decimal values, AtOM does not. The reason for this is simple: we do
            numeric comparisons, and Bash only manipulates integers.
			EODesc
			expr='^[0-9]*$'
			comeagain() {
				read					\
					-e				\
					-i				\
					${destinationquality["$destination"]:-128}\
					-p 'Bitrate: '			\
					value
				if ! [[ $value =~ $expr ]]
				then
					echo "Invalid bitrate value: $value" >&2
					comeagain
				fi
			}
			comeagain
			destinationquality["$destination"]=$value
			cat <<-EODesc

        Loss (percent, integer):
            If you intend to stream the resulting files over an unreliable
            protocol, you may want to make use of Opus' Forward Error
            Correction algorythm. See the Opus-codec.org website for details.
			EODesc
			comeagain() {
				read					\
					-e				\
					-i				\
					${destinationloss["$destination"]:-0}\
					-p 'Loss: '			\
					value
				if ! [[ $value =~ $expr ]]
				then
					echo "Invalid loss value: $value" >&2
					comeagain
				fi
			}
			comeagain
			destinationloss["$destination"]=$value
		;;
		mp3)
			cat <<-EODesc

        Bitrate (kbps, integer):
            Set (ABR) bitrate to <bitrate>.
			EODesc
			expr='^[0-9]*$'
			comeagain() {
				read					\
					-e				\
					-i				\
					${destinationquality["$destination"]:-128}\
					-p 'Bitrate: '			\
					value
				if ! [[ $value =~ $expr ]]
				then
					echo "Invalid bitrate value: $value" >&2
					comeagain
				fi
			}
			comeagain
			destinationquality["$destination"]=$value
			cat <<-EODesc

        Prevent resampling (boolean):
            LAME may decide to encode your file to a lower sampling-rate if you
            use a low bitrate. Setting this to yes will append --resample
            <original file's rate>, preventing any resampling from happening.
			EODesc
			case ${destinationnoresample["$destination"]} in
				0)	initialvalue=n		;;
				1)	initialvalue=y		;;
				*)	unset initialvalue	;;
			esac
			comeagain() {
				read					\
					-e				\
					${initialvalue+-i $initialvalue}\
					-p'Prevent resampling (y/N): '	\
					value
				case $value in
					[yY])
						destinationnoresample["$destination"]=1
					;;
					''|[nN])
						destinationnoresample["$destination"]=0
					;;
					*)
						comeagain
					;;
				esac
			}
			comeagain
		;;
	esac
	cat <<-EODesc

        [Optional parameters]
            Now you will have the opportunity to configure "advanced" parameters
            for $destination. You may leave any of these fields blank.
	EODesc
	cat <<-EODesc

        Normalize (boolean):
            Normalize output files.
	EODesc
	case ${destinationnormalize["$destination"]} in
		0)	initialvalue=n		;;
		1)	initialvalue=y		;;
		*)	unset initialvalue	;;
	esac
	comeagain() {
		read					\
			-e				\
			${initialvalue+-i $initialvalue}\
			-p'Normalize (y/N): '		\
			value
		case $value in
			[yY])
				destinationnormalize["$destination"]=1
			;;
			''|[nN])
				destinationnormalize["$destination"]=0
			;;
			*)
				comeagain
			;;
		esac
	}
	comeagain
	cat <<-EODesc

        Rename (string):
            Destination files will be named according to <string>, after
            expansion of special strings:
                %{album},
                %{albumartist},
                %{artist},
                %{disc},
                %{genre},
                %{title},
                %{track},
                %{year}.
            Untagged files or files in unrecognized formats will not be changed.

            Leave blank if you don't want file renaming.
	EODesc
	initialvalue="${destinationrenamepath["$destination"]}"
	initialvalue+="${initialvalue+/}"
	initialvalue+="${destinationrename["$destination"]}"
	read						\
		-e					\
		${initialvalue+-i"$initialvalue"}	\
		-p'Rename pattern: '			\
		value
	case "$value" in
		*/*)
			destinationrenamepath["$destination"]="${value%/*}"
		;;
	esac
	destinationrename["$destination"]="${value##*/}"
	cat <<-EODesc

        FAT32 Compatibility (boolean):
            Rename files for compatibility with FAT32 filesystems.
	EODesc
	case ${destinationfat32compat["$destination"]} in
		0)	initialvalue=n		;;
		1)	initialvalue=y		;;
		*)	unset initialvalue	;;
	esac
	comeagain() {
		read					\
			-e				\
			${initialvalue+-i $initialvalue}\
			-p'FAT32 Compatibility (y/N): '		\
			value
		case $value in
			[yY])
				destinationfat32compat["$destination"]=1
			;;
			''|[nN])
				destinationfat32compat["$destination"]=0
			;;
			*)
				comeagain
			;;
		esac
	}
	comeagain
	cat <<-EODesc

        Skip mime-type (mime-type, string):
            Files with mime-type <mime-type> will not be included in that
            destination. The '*' character is a wildcard.

            This prompt will loop until an empty string is encountered.
	EODesc
	destinationskipmime["$destination"]="${destinationskipmime["$destination"]}|"
	while [[ ${destinationskipmime["$destination"]} =~ / ]]
	do
		skippedmimes+=("${destinationskipmime["$destination"]%%|*}")
		destinationskipmime["$destination"]="${destinationskipmime["$destination"]#*|}"
	done
	count=${#skippedmimes[@]}
	unset destinationskipmime["$destination"]
	for (( i=0 ; 1 ; i++ ))
	do
		read							\
			-e						\
			${skippedmimes[i]+-i"${skippedmimes[i]}"}	\
			-p 'Skip mime-type: '				\
			value
		if [ -n "$value" ]
		then
			destinationskipmime[$destination]="${destinationskipmime[$destination]:+${destinationskipmime[$destination]}|}$value"
		elif (( i < count ))
		then
			continue
		else
			break
		fi
	done
	unset skippedmimes
	cat <<-EODesc

        Copy mime-type (mime-type, string):
            Files with mime-type <mime-type> will be copied as-is to the
            destination. E.g. image/* will copy covers and other images to the
            destination.  The '*' character is a wildcard.

            This prompt will loop until an empty string is encountered.
	EODesc
	destinationcopymime["$destination"]="${destinationcopymime["$destination"]}|"
	while [[ ${destinationcopymime["$destination"]} =~ / ]]
	do
		copiedmimes+=("${destinationcopymime["$destination"]%%|*}")
		destinationcopymime["$destination"]="${destinationcopymime["$destination"]#*|}"
	done
	count=${#copiedmimes[@]}
	unset destinationcopymime["$destination"]
	for (( i=0 ; 1 ; i++ ))
	do
		read							\
			-e						\
			${copiedmimes[i]+-i"${copiedmimes[i]}"}	\
			-p 'Copy mime-type: '				\
			value
		if [ -n "$value" ]
		then
			destinationcopymime[$destination]="${destinationcopymime[$destination]:+${destinationcopymime[$destination]}|}$value"
		elif (( i < count ))
		then
			continue
		else
			break
		fi
	done
	unset copiedmimes
	cat <<-EODesc

        Channels (integer):
            Produced files should have this many channels, no more, no less.
	EODesc
	expr='^[0-9]*$'
	comeagain() {
		read							\
			-e						\
			${destinationchannels["$destination"]+-i${destinationchannels["$destination"]}}\
			-p'Channel count: '				\
			value
		if ! [[ $value =~ $expr ]]
		then
			echo "Invalid channel count: $value" >&2
			comeagain
		fi
	}
	comeagain
	destinationchannels["$destination"]=$value
	cat <<-EODesc
	EODesc
	comeagain() {
		:
	}
	comeagain
	cat <<-EODesc
	EODesc
	comeagain() {
		:
	}
	comeagain
}