itunes

#!/bin/bash
#
#  A simple command-line wrapper for Apple's iTunes.
#
#  Install or symlink into your path and "itunes -h" or "itunes help" for help.
#
#  Copyright 2012-2014 Sam Graham.  http://www.illusori.co.uk/
#  This work is licensed under a
#  Creative Commons Attribution-Share Alike 2.0 UK: England & Wales License
#  http://creativecommons.org/licenses/by-sa/2.0/uk/
#  In human-readble terms: you're free to copy, distribute and modify
#  providing you maintain attribution and licence.
#
#  Use at your own risk, no fitness for purpose implied, etc, etc.

version='2.1.0'
progname=`basename $0`
config_dir="$HOME/.bash-itunes"
plugins_dir="$config_dir/plugins"

#
# You can override the config values below in ~/.bash-itunes/config
#

# Filename of a mid3v2-compatible tags editor.
# If you use MacPorts rather than Brew you may need to set this to mid3v2-2.4 or something.
id3v2_editor="mid3v2"
# id3v2 tags record ratings against an email address so files can have ratings by multiple people.
# If this is something you care about, set your email address in this variable.
# This *will* embed your email address for everyone to read within the file metadata though.
# Some programs just embed the name of the player rather than use the email for this reason.
id3v2_email="Bash iTunes"

# Add the commented-out line to your ~/.bash-itunes/config if you're still using iTunes.app.
#itunes_app="iTunes"
itunes_app="Music"

#  Version and help.

function _cmd_version() {
    echo "$progname version $version"
}

function _help_help() {
    _cmd_help
}

function _cmd_help() {
    if [ -z "$*" ]; then
        _cmd_version
        echo "Usage: $progname [-v] [-h] [-d] <command> [<args>]

Switches:
    -v          Show version information and exit.
    -h          Show this help and exit.
    -d          Enable debug messages, additional -d options increase verbosity.

Navigation commands:
    play        Resume playing or choose track.
    pause       Pause playing.
    stop        Stop playing.
    next        Skip to next track.
    prev        Skip back to previous track.
    info        View info about current track.
    search      Search for tracks.
    shuffle     View or set shuffle status.
    repeat      View or set repeat status.
    playlist    View or choose playlist.
    playlists   List all playlists.

Volume commands:
    vol[ume]    View or adjust iTunes volume 'up', 'down' or percentage.
    mute        Mutes iTunes.
    unmute      Unmutes iTunes, restoring previous volume level.
    sysvol[ume] View or adjust system volume 'up', 'down' or percentage.
    sysmute     Mute system sound.
    sysunmute   Unmute system sound.

Application commands:
    open        Start iTunes running.
    quit        Quit iTunes.
    show        Hide the iTunes window.
    hide        Show the iTunes window.

Editing commands:
    rate        Set the iTunes star rating.
    heart       Add heart/loved status to a track.
    unheart     Remove heart/loved status from a track.
    sync        Sync ratings to or from audio files files and iTunes database.

Additional commands:
    version     Show version information and exit.
    help        Show this help and exit.
    plugins     Show a list of plugins installed."
    else
        #  Dispatch to _help_<cmd> if they've supplied a command name.
        orig_cmd="$1"
        shift
        _normalize_cmd_name "cmd" "$orig_cmd"
        if [ -z "$cmd" ]; then
            _cmd_unknown "$orig_cmd"
        else
            #  TODO: check the functions exists. Say no help available if it doesn't.
            local something_shown=0
            declare -f "_usage_${cmd}" >/dev/null
            if [ "$?" = 0 ]; then
                _usage_${cmd} "$@"
                something_shown=1
            fi
            declare -f "_help_${cmd}" >/dev/null
            if [ "$?" = 0 ]; then
                if [ "$something_shown" = 1 ]; then
                    echo
                fi
                _help_${cmd} "$@"
                something_shown=1
            fi
            if [ "$something_shown" = 0 ]; then
                echo "No help found for '$progname $cmd', try the general help at '$progname help'."
            fi
        fi
    fi
}

function _cmd_unknown() {
    echo "Unknown command '$*', try '$progname help' for a list of valid commands."
}

#  Helper functions

function _err() {
    echo "$*" 1>&2
}

function _err_func() {
    ${1} 1>&2
}

function _log() {
    if [ "$debug" -ge "$1" ]; then
        shift;
        _err "$*"
    fi
}

function _pluralize() {
    if [ "$1" = 1 ]; then
        echo "$1 $2"
    else
        if [ -n "$3" ]; then
            echo "$1 $3"
        else
            echo "$1 ${2}s"
        fi
    fi
}

#  mid3v2 communication hackery.
function _find_id3v2_editor() {
    if [ -n "is_id3v2_editor_installed" ]; then
        # -s option to which isn't supported in older OS X.
        which "$id3v2_editor" >/dev/null
        is_id3v2_editor_installed=$[!$?]
    fi
}

#  AppleScript communication hackery.

function _quote_for_applescript_string() {
    local value="$*"

    value="${value//\\/\\\\}"
    value="${value//\"/\\\"}"

    _log 4 "Escaping '$*' to '$value' for use in applescript string"

    echo "$value"
}

function _osascript() {
    _log 2 "Run: osascript -e \"$*\""
    if [ "$debug" -gt 0 ]; then
        osascript -e "$*"
    else
        osascript -e "$*" 2>&-
    fi
}

function _tell_itunes() {
    _osascript "tell application \"${itunes_app}\" to $*"
}

function _ask_itunes() {
    _osascript "tell application \"${itunes_app}\"
            $*
            set AppleScript's text item delimiters to \"\\n\"
            ret as text
        end tell"
}

#  Fetch from iTunes from the data-structures in $1 into the array
#  variables constructed from prefix $2 and column names $3+ the
#  given columns in the data-structure.
#  If that's clear.
#  No?
#  Anyone?
function _fetch_from_itunes() {
    local source="$1"
    local use_loop=0
    if [ "$source" = "LOOP" ]; then
        use_loop=1
        source="$2"
        shift
    fi
    local prefix="$2"
    shift 2
    #  Yet more hacks, this allows multi-word AppleScript properties
    #  such as "database id" to end up in "database_id".
    #  You can also do this by messing with $IFS and ${var//search/replace}
    #  but, although I got it working, I had a brief outbreak of sanity and
    #  chose this instead...
    local columns=''
    local script_columns=''
    local column_defaults=''
    for column in "$@"; do
        underscored_column="${column// /_}"
        columns="${columns} ${underscored_column}"
        script_columns="${script_columns}, ${column}"
        #  "missing value" is what AppleScript uses to stringify missing values, may as well emulate
        column_defaults="${column_defaults}, ${underscored_column}:\"missing value\""
    done
    columns="${columns:1}"
    script_columns="${script_columns:2}"
    if [ $# = 1 ]; then
        column_defaults='"missing value"'
    else
        column_defaults="{${column_defaults:2}}"
    fi

    _log 4 "source '$structure', prefix '$prefix', columns '$columns', script_columns '$script_columns'"

    #  Best if we don't loop within AppleScript, it can be painfully slow
    #  for large arrays, but on the other hand, for columns that are
    #  actually expressions rather than properties, we appear to have to loop.
    #  Same deal appears to be the case if we need to safeguard against properties
    #  that may or may not exist on the track objects (file location for example)
    if [ "$use_loop" = 0 ]; then
        local result=$(_ask_itunes "set ret to ($script_columns) of ($source)")
        _log 4 "result '$result'"
        _read_rows_from_value_lines_grouped_by_column "$prefix" "$result" $columns
    else
        #  Error -1728 is property doesn't exist. It'd be nice to catch it on a per
        #  property basis, but that's a task for another day. Probably should rethrow
        #  the error if it isn't a -1728 too.
        #  Using ((properties of v) & $column_defaults was a possibility, but unfortunately
        #  the properties property on iTunes tracks doesn't actually include all the
        #  properties of the object, including some we want. AppleScript, I really hate you.
        local result=$(_ask_itunes "set ret to {}
            repeat with v in $source as list
                try
                    copy ($script_columns) of v to the end of ret
                on error errorMessage number errorNumber
                    if errorNumber = -1728 then
                        copy ($column_defaults) to the end of ret
                    end if
                end try
            end repeat")
        _log 4 "result '$result'"
        _read_rows_from_value_lines "$prefix" "$result" $columns
    fi
}

#  Low-level row/rowset fetching/clearing. This stuff is nasty.

#  This function is lifted from my bash-snippets repo on GitHub,
#  gawp in horror at its unspeakable glory.
function _read_rows_from_value_lines_grouped_by_column() {
    local prefix="$1"
    local content="$2"
    shift 2
    local columns
    read -r -a columns <<< "$*"

    local row_count=$(($(wc -l <<< "$content") / ${#columns[*]}))

    for column in "${columns[@]}"; do
        unset "${prefix}_${column}"
    done

    local row_idx=0
    local column_idx=0
    local value
    while read value; do
        column=${columns[column_idx]}
        #  Ho hum, I gave up and used eval, couldn't get this working with $(())
        printf -v value "%q" "$value"
        eval "${prefix}_${column}[${row_idx}]=$value"

        row_idx=$((row_idx + 1))
        if [ "$row_idx" -ge "$row_count" ]; then
            row_idx=0
            column_idx=$((column_idx + 1))
        fi
        #_log 5 "Column is $column, column_idx now $column_idx, row_idx now $row_idx, value $value"
    done <<< "$content"
}
function _read_rows_from_value_lines() {
    local prefix="$1"
    local content="$2"
    shift 2
    local columns
    read -r -a columns <<< "$*"

    for column in "${columns[@]}"; do
        #echo "Scrubbing ${prefix}_${column}"
        unset "${prefix}_${column}"
    done

    local row_idx=0
    local column_idx=0
    local value
    while read value; do
        column=${columns[column_idx]}
        #  Ho hum, I gave up and used eval, couldn't get this working with $(())
        printf -v value "%q" "$value"
        eval "${prefix}_${column}[${row_idx}]=$value"

        column_idx=$((column_idx + 1))
        if [ "$column_idx" -ge "${#columns[*]}" ]; then
            column_idx=0
            row_idx=$((row_idx + 1))
        fi
        #_log 5 "Column is $column, column_idx now $column_idx, row_idx now $row_idx"
    done <<< "$content"
}

function _scrub_rows() {
    local prefix="$1"
    shift
    local columns="$@"

    for column in $columns; do
        local full_column="${prefix}_${column}"
        _log 6 "Scrubbing \$$full_column"
        unset $full_column
    done
}

#  Schema stuff.

function _load_schema() {
    if [ "$supports_hearting" = "true" ]; then
	_track_columns="name artist album year rating loved time id"
    else
	_track_columns="name artist album year rating time id"
    fi
    _playlist_columns="name time id"
}

#  Fetchers/scrubbers for the objects in the schema.

function _fetch_tracks() {
    _fetch_from_itunes "$@" $_track_columns
    if [ "$1" = "LOOP" ]; then
        shift
    fi
    local source="$1"
    local prefix="$2"
    #  Can't just add location to _track_columns because not all tracks define it.
    #  (Streams, Home Sharing, etc)
    #  Can't just get only file tracks because then indexes don't line up.
    #  Can't just use the LOOP fetch safeguard either because we need to transform
    #  to POSIX path, which you can't do in an array copy.
    #  As usual AppleScript randomly decides it needs a temporary variable too.
    #  AppleScript, you never make life easy do you?
    #_fetch_from_itunes LOOP "$source" "$prefix" "location"
    local result=$(_ask_itunes "set ret to {}
        repeat with v in $source as list
            try
                set loc to location of v
                if loc is missing value then
                    copy \"missing value\" to the end of ret
                else
                    copy POSIX path of loc to the end of ret
                end if
            on error errorMessage number errorNumber
                if errorNumber = -1728 then
                    copy \"missing value\" to the end of ret
                else
                    error \"Unhandled error: \" & errorMessage & \", number: \" & errorNumber number 1001
                end if
            end try
        end repeat")
    _log 4 "result '$result'"
    _read_rows_from_value_lines "$prefix" "$result" "location"
}
function _scrub_tracks() {
    local prefix="$1"
    _scrub_rows "$prefix" $_track_columns
    _scrub_rows "$prefix" "location"
}

function _fetch_playlists() {
    local source="$1"
    local prefix="$2"
    _fetch_from_itunes "$@" $_playlist_columns
    _fetch_from_itunes LOOP "$source" "$prefix" "count tracks"
}
function _scrub_playlists() {
    local prefix="$1"
    _scrub_rows "$prefix" $_playlist_columns
    _scrub_rows "$prefix" count_tracks
}

#  Fetchers/scrubbers for specific global objects.

function _fetch_current_track() {
    if [ -z "$current_track_name" ]; then
        _fetch_tracks "current track" current_track
        _fetch_track_id3v2 "current track" current_track
    fi
    if [ -z "$current_track_pos" ]; then
        current_track_pos=$(_tell_itunes "player position as integer")
        local min=$((current_track_pos / 60))
        local sec=$(printf "%02d" $((current_track_pos % 60)))
        current_track_pos="${min}:${sec}"
        _log 3 "Fetched trackpos '$current_track_pos'"
    fi
}
function _scrub_current_track() {
    _scrub_tracks "current_track"
    unset "current_track_pos"
}

function _fetch_current_playlist() {
    if [ -z "$current_playlist_name" ]; then
        _fetch_playlists "current playlist" current_playlist
    fi
}
function _scrub_current_playlist() {
    _scrub_playlists "current_playlist"
}

function _fetch_track_id3v2() {
    _find_id3v2_editor
    if [ "$is_id3v2_editor_installed" != 1 ]; then
        _log 1 "id3v2 editor not found."
        return
    fi
    local source="$1"
    local prefix="$2"
    local row_idx="${3:-0}"

    eval "local location=\${${prefix}_location[row_idx]}"

    local rating=0
    if [ -z "$location" -o "$location" = "missing value" ]; then
        rating=0
    else
        # TODO: test with multple ratings
        # TODO: should match same rating email as configured? or prefer at least?
        rating=$($id3v2_editor -l "$location" | grep POPM | cut -f 3 -d '=' | cut -f 2 -d ' ' | cut -f 1 -d '/')
    fi
    #echo "rating '$rating'"
    eval "${prefix}_id3v2_rating[${row_idx}]=\"$rating\"";
}

#  Views.

function _show_track() {
    local row_prefix="$1"
    local row_idx="${2:-0}"
    local brief="${3:-0}"
    local preamble="$4"

    #  Ho ho.
    eval "local name=\${${row_prefix}_name[row_idx]}"
    eval "local artist=\${${row_prefix}_artist[row_idx]}"
    eval "local album=\${${row_prefix}_album[row_idx]}"
    eval "local year=\${${row_prefix}_year[row_idx]}"
    eval "local rating=\${${row_prefix}_rating[row_idx]}"
    eval "local time=\${${row_prefix}_time[row_idx]}"
    eval "local id=\${${row_prefix}_id[row_idx]}"
    eval "local loved=\${${row_prefix}_loved[row_idx]}"
    eval "local location=\${${row_prefix}_location[row_idx]}"
    eval "local id3v2_rating=\${${row_prefix}_id3v2_rating[row_idx]}"

    if [ "$loved" = "true" ]; then
        heart="<3 "
    else
        heart=""
    fi
    if [ -n "$preamble" ]; then
        preamble="$preamble "
        if [ -z "$heart" ] && [ "$supports_hearting" = "true" ]; then
            heart="   "
        fi
    fi

    echo -n "$preamble$heart\"$name\""
    if [ -n "$artist" ]; then
        echo -n " by $artist"
    fi
    if [ -n "$album" ]; then
        echo -n ", from \"$album\""
        if [ -n "$year" -a "$year" != 0 ]; then
            echo -n " ($year)"
        fi
    fi
    if [ -n "$current_track_id" -a -n "$current_track_pos" -a "$current_track_id" = "$id" ]; then
        echo " ($current_track_pos of $time)"
    else
        echo " ($time)"
    fi
    if [ "$brief" = 0 ]; then
        if [ -n "$rating" -a "$rating" != 0 ]; then
            rating=$((rating / 20))
            # z=1;printf -v zs "%-.*s%-.*s\n" $((z+1)) '******' $((6-z)) '......';echo "[${zs:1:5}]"
            echo "You've rated this track $rating out of 5."
        fi
        if [ -n "$location" -a "$location" != "missing value" ]; then
            echo "File location is \"$location\"."
        fi
        if [ -n "$id3v2_rating" -a "$id3v2_rating" != 0 ]; then
            # z=1;printf -v zs "%-.*s%-.*s\n" $((z+1)) '******' $((6-z)) '......';echo "[${zs:1:5}]"
            echo "You've rated this track ${id3v2_rating} out of 255 in another program."
        fi
    fi

}

function _show_current_track() {
    local preamble="$1"
    local brief="${2:-0}"

    _fetch_current_track
    _show_track current_track 0 $brief "$preamble"
}

function _show_tracks() {
    local prefix="$1"
    local brief="${2:-0}"

    local track_idx=0
    eval "local track_name=\${${prefix}_name[track_idx]}"
    eval "local track_id=\${${prefix}_id[track_idx]}"
    while [ -n "$track_name" ]; do
        if [ "$current_track_id" = "$track_id" ]; then
            preamble="*"
        else
            preamble=" "
        fi
        _show_track $prefix $track_idx $brief "$preamble"
        track_idx=$((track_idx + 1))
        eval "track_name=\${${prefix}_name[track_idx]}"
        eval "track_id=\${${prefix}_id[track_idx]}"
    done
}

function _show_playlist() {
    local row_prefix="$1"
    local row_idx="${2:-0}"
    local brief="${3:-0}"
    local preamble="$4"

    #  Ho ho.
    eval "local name=\${${row_prefix}_name[row_idx]}"
    eval "local time=\${${row_prefix}_time[row_idx]}"
    eval "local id=\${${row_prefix}_id[row_idx]}"
    eval "local count_tracks=\${${row_prefix}_count_tracks[row_idx]}"

    if [ -n "$preamble" ]; then
        preamble="$preamble "
    fi

    echo -n "$preamble\"${name}\" (${time}) ("
    echo -n $(_pluralize "${count_tracks}" 'track')
    echo -n ")"
    if [ "$brief" = 0 ]; then
        echo ":"
        _show_tracks "${row_prefix}_tracks" 1
    else
        echo
    fi
}

function _show_current_playlist() {
    local preamble="$1"
    local brief="${2:-0}"

    _fetch_current_track
    _fetch_current_playlist
    _fetch_tracks "every track of current playlist" current_playlist_tracks

    _show_playlist current_playlist 0 $brief "$preamble"
}

#  Navigation commands: play, pause, stop, next, prev, playlist

function _cmd_play() {
    if [ -z "$*" ]; then
        _tell_itunes "play"
        _scrub_current_track
        _show_current_track "Resuming" 1
    else
        _tell_itunes "play item 1 of ((tracks of current playlist whose name is \"$*\") & (tracks of current playlist whose name contains \"$*\") & (tracks whose name is \"$*\") & (tracks whose name contains \"$*\"))"
        _scrub_current_track
        _show_current_track "Now playing" 1
    fi
}

function _cmd_pause() {
    echo "Pausing iTunes."
    _tell_itunes "pause"
}

function _cmd_stop() {
    echo "Stopping iTunes."
    _tell_itunes "stop"
}

function _cmd_next() {
    _tell_itunes "next track"
    _scrub_current_track
    _show_current_track "Skipping to next track," 1
}

function _cmd_prev() {
    _tell_itunes "previous track"
    _scrub_current_track
    _show_current_track "Skipping to previous track," 1
}

function _cmd_info() {
    if [ -z "$*" ]; then
        _cmd_info_track
    else
        local cmd="$1"
        shift
        case "$cmd" in
            track)
                _cmd_info_track "$@"
                ;;
            playlist)
                _cmd_info_playlist "$@"
                ;;
        esac
    fi
}

function _cmd_info_track() {
    if [ -z "$*" ]; then
        _show_current_track "Currently playing"
    else
        _fetch_tracks "track \"$*\"" track
        _fetch_track_id3v2 "track \"$*\"" track
        _show_track track 0 0
    fi
}

function _cmd_info_playlist() {
    if [ -z "$*" ]; then
        _show_current_playlist "Currently listening to playlist" 0
    else
        _fetch_playlists "playlist \"$*\"" playlist
        _fetch_tracks "every track of playlist \"$*\"" playlist_tracks
        _show_playlist playlist 0 0
    fi
}

function _usage_search() {
    echo "Usage: $progname search [<all | track | albumn | artist >] <search term>"
}

function _cmd_search() {
    if [ -z "$*" ]; then
        _err_func _usage_search
    else
        local target
        local desc
        case "$1" in
            track | tracks | song | songs)
                              target='songs';   desc='name';        shift ;;
            album | albums)   target='albums';  desc='album title'; shift ;;
            artist | artists) target='artists'; desc='artist';      shift ;;
            all)              target='all';     desc='anything';    shift ;;
            *)                target='all'      desc='anything' ;;
        esac
        local search_term="$*"
        local escaped_search_term=$(_quote_for_applescript_string "$search_term")
        _fetch_tracks LOOP "(search playlist \"Library\" for \"$escaped_search_term\" only $target)" search_tracks
        echo "Searching for tracks with $desc containing \"$search_term\":"
        _show_tracks "search_tracks" 1
    fi
}

function _cmd_shuffle() {
    if [ -z "$1" ]; then
        local curshuffle=$(_ask_itunes "set ret to false
            try
                set ret to shuffle of current playlist
            on error number -10001
                set ret to shuffle enabled
            end try")
        _log 3 "Fetched shuffle is '$curshuffle'"
        if [ "$curshuffle" = "true" ]; then
            echo "Current shuffle setting is on."
        else
            echo "Current shuffle setting is off."
        fi
    else
        case "$1" in
            "on")
                echo "Switching shuffle on."
                local success=$(_ask_itunes "set ret to true
                    try
                        set shuffle of current playlist to true
                    on error number -10001
                        set shuffle enabled to true
                    end try")
                ;;
            "off")
                echo "Switching shuffle off."
                local success=$(_ask_itunes "set ret to true
                    try
                        set shuffle of current playlist to false
                    on error number -10001
                        set shuffle enabled to false
                    end try")
                ;;
            *)
                _err "Shuffle must be one of 'on' or 'off'."
                ;;
        esac
    fi
}

function _cmd_repeat() {
    if [ -z "$1" ]; then
        local currepeat=$(_ask_itunes "set ret to false
            try
                set ret to song repeat of current playlist
            on error number -1728
                set ret to song repeat
            end try")
        _log 3 "Fetched repeat is '$currepeat'"
        echo "Current repeat setting is $currepeat."
    else
        case "$1" in
            "off" | "one" | "all")
                echo "Switching repeat to $1."
                local success=$(_ask_itunes "set ret to true
                    try
                        set song repeat of current playlist to $1
                    on error number -1731
                        set song repeat to $1
                    end try")
                ;;
            *)
                _err "Repeat must be one of 'one', 'all' or 'off'."
                ;;
        esac
    fi
}

function _cmd_playlist() {
    if [ -z "$1" ]; then
        _cmd_info_playlist
    else
        _tell_itunes "play item 1 of ((playlists whose name is \"$*\") & (playlists whose name contains \"$*\"))"
        _scrub_current_track
        _scrub_current_playlist
        _fetch_current_playlist
        _show_current_track "Now listening to playlist \"${current_playlist_name}\" (${current_playlist_time}), playing" 1
    fi
}

function _cmd_playlists() {
    _fetch_playlists "playlists" playlist
    echo "Playlists"
    local playlist_idx=0
    while [ -n "${playlist_name[playlist_idx]}" ]; do
        _show_playlist playlist $playlist_idx 1 " "
        playlist_idx=$((playlist_idx + 1))
    done
}

#  Volume commands: volume, mute, unmute

function _cmd_volume() {
    curvol=$(_tell_itunes "sound volume as integer")
    _log 3 "Fetched volume is '$curvol'"
    if [ -z "$1" ]; then
        echo "Current iTunes volume is $curvol%"
    else
        newvol=-1
        case "$1" in
            "up")     newvol=$(($curvol + 10)) ;;
            "down")   newvol=$(($curvol - 10)) ;;
            "mute")   _cmd_mute                ;;
            "unmute") _cmd_unmute              ;;
            *)
                if [ "$1" -ge 0 -a "$1" -le 100 2>&- ] ; then
                    newvol=$1
                else
                    _err "Volume must be one of 'up', 'down', 'mute', 'unmute' or an integer between 0 and 100."
                fi
                ;;
        esac
        if [ $newvol != -1 ]; then
            echo "Changing iTunes volume level from $curvol to $newvol%"
            _tell_itunes "set sound volume to $newvol"
        fi
    fi
}

function _cmd_mute() {
    echo "Muting iTunes."
    _tell_itunes "set mute to true"
}

function _cmd_unmute() {
    echo "Unmuting iTunes."
    _tell_itunes "set mute to false"
}

#  Not strictly iTunes, but likely to be useful anyway.
function _cmd_sysvolume() {
    curvol=$(_osascript "output volume of (get volume settings)")
    _log 3 "Fetched volume is '$curvol'"
    if [ -z "$1" ]; then
        echo "Current system volume is $curvol%"
    else
        newvol=-1
        case "$1" in
            "up")     newvol=$(($curvol + 10)) ;;
            "down")   newvol=$(($curvol - 10)) ;;
            "mute")   _cmd_sysmute             ;;
            "unmute") _cmd_sysunmute           ;;
            *)
                if [ "$1" -ge 0 -a "$1" -le 100 2>&- ] ; then
                    newvol=$1
                else
                    _err "Volume must be one of 'up', 'down', 'mute', 'unmute' or an integer between 0 and 100."
                fi
                ;;
        esac
        if [ $newvol != -1 ]; then
            echo "Changing system volume level from $curvol to $newvol%"
            _osascript "set volume output volume $newvol"
        fi
    fi
}

function _cmd_sysmute() {
    echo "Muting system sound."
    _osascript "set volume output muted true"
}

function _cmd_sysunmute() {
    echo "Unmuting system sound."
    _osascript "set volume output muted false"
}

#  Application commands: open, quit

function _cmd_open() {
    echo "Opening iTunes."
    open -a iTunes
}

function _cmd_quit() {
    echo "Quitting iTunes."
    _tell_itunes "quit"
}

function _cmd_show() {
    echo "Showing iTunes window."
    _osascript "tell application \"System Events\" to set visible of process \"${itunes_app}\" to true"
}

function _cmd_hide() {
    echo "Hiding iTunes window."
    _osascript "tell application \"System Events\" to set visible of process \"${itunes_app}\" to false"
}

function _cmd_plugins() {
    echo "Installed plugins:"
    local GLOBIGNORE="*~"
    local glob="$plugins_dir/*"
    local plugins=($glob)
    if [ -z "${plugins[*]}" -o "${plugins[*]}" = "$glob" ]; then
        echo "  No plugins installed."
    else
        for plugin in "${plugins[@]}"; do
            local plugin_cmd=`basename $plugin`
            echo -n "  $plugin_cmd - "
            if [ -f "$plugin" ]; then
                . "$plugin"
                if [ -z "$PLUGIN_NAME" ]; then
                    PLUGIN_NAME="Missing PLUGIN_NAME"
                fi
                if [ -z "$PLUGIN_VERSION" ]; then
                    PLUGIN_VERSION="Missing PLUGIN_VERSION"
                fi
                if [ -z "$PLUGIN_BRIEF" ]; then
                    PLUGIN_BRIEF="Missing PLUGIN_BRIEF"
                fi
                echo "$PLUGIN_NAME ($PLUGIN_VERSION)"
                echo "    $PLUGIN_BRIEF"
                unset PLUGIN_NAME
                unset PLUGIN_VERSION
                unset PLUGIN_BRIEF
            else
                echo "Not a plugin file"
            fi
        done
    fi
}

function _usage_heart() {
    echo "Usage: $progname heart [<track>]"
}

function _cmd_heart() {
    local track="$*"
    if [ -z "$track" ]; then
	_fetch_current_track
	local track_name="${current_track_name[0]}"
	local location="${current_track_location[0]}"
	echo "Hearting track '$track_name'..."
	_tell_itunes "set loved of current track to true"
    else
	_fetch_tracks "track \"$track\"" track
	local track_name="${track_name[0]}"
	local location="${track_location[0]}"
	echo "Hearting track '$track_name'..."
	_tell_itunes "set loved of track \"$track\" to true"
    fi
}

function _usage_unheart() {
    echo "Usage: $progname unheart [<track>]"
}

function _cmd_unheart() {
    local track="$*"
    if [ -z "$track" ]; then
	_fetch_current_track
	local track_name="${current_track_name[0]}"
	local location="${current_track_location[0]}"
	echo "Unhearting track '$track_name'..."
	_tell_itunes "set loved of current track to false"
    else
	_fetch_tracks "track \"$track\"" track
	local track_name="${track_name[0]}"
	local location="${track_location[0]}"
	echo "Unhearting track '$track_name'..."
	_tell_itunes "set loved of track \"$track\" to false"
    fi
}

function _usage_rate() {
    echo "Usage: $progname rate [<track>] <rating>"
}

function _cmd_rate() {
    if [ -z "$*" ]; then
        _err_func _usage_rate
    else
        local rating="${!#}"
        local track="${@:1:$#-1}"
        if [ ! -z "${rating##*[!0-9]*}" ]; then
            if ((rating >= 0 && rating <= 5)); then
                # iTunes stores ratings as 0-100.
                local itunes_rating=$((rating * 20))
		# id3v2 POPM-tag rating is 0-255.
		local popm_rating=$((rating * 51))
                if [ -z "$track" ]; then
                    _fetch_current_track
                    local track_name="${current_track_name[0]}"
                    local location="${current_track_location[0]}"
                    echo "Setting iTunes rating to '$rating' for track '$track_name'..."
                    _tell_itunes "set rating of current track to $itunes_rating"
                else
                    _fetch_tracks "track \"$track\"" track
                    local track_name="${track_name[0]}"
                    local location="${track_location[0]}"
                    echo "Setting iTunes rating to '$rating' for track '$track_name'..."
                    _tell_itunes "set rating of track \"$track\" to $itunes_rating"
                fi
                if [ -n "$location" ]; then
                    _find_id3v2_editor
                    if [ "$is_id3v2_editor_installed" = 1 ]; then
			`$id3v2_editor --POPM "${id3v2_email}:${popm_rating}" "$location"`
			# no output on error, errors cause output on stdout
			# echo `$id3v2_editor -l "$location"`
		    fi
                fi
            else
                _err "Track rating must be a number between 0 and 5, got: '$rating'."
            fi
        else
            _err "Track rating must be a number between 0 and 5, got: '$rating'."
        fi
    fi
}

function _err_need_id3v2_editor() {
    _err "$id3v2_editor was not found on your system, $*."
    _err "The default editor (mid3v2) is usually found as part of the mutagen python package, so try installing that. 'sudo easy_install mutagen' usually does the trick."
}

function _cmd_sync_ratings_from_itunes() {
    _find_id3v2_editor
    if [ "$is_id3v2_editor_installed" != 1 ]; then
        _err_need_id3v2_editor "unable to edit mp3 tags"
        return
    fi

    echo "Scanning track catalogue. This may take a minute."
    # Yikes.
    _fetch_tracks "every file track" all_tracks
    #_fetch_tracks "every track whose artist = \"A7ie\"" all_tracks

    local prefix="all_tracks"
    local track_idx=0
    eval "local track_name=\${${prefix}_name[track_idx]}"
    eval "local location=\${${prefix}_location[track_idx]}"
    eval "local rating=\${${prefix}_rating[track_idx]}"
    while [ -n "$track_name" ]; do
        if [ -n "$location" -a "$location" != "missing value" ]; then
	    echo -ne "\r\033[KScanning ratings ($track_idx/${#all_tracks_name[@]}): ${track_name}..."
	    _fetch_track_id3v2 "every file track" "all_tracks" "$track_idx"
	    eval "local id3v2_rating=\${${prefix}_id3v2_rating[track_idx]}"
	    local stars="0"
	    if [ -n "$rating" -a "$rating" != 0 ]; then
		stars=$((rating / 20))
#echo "found stars ${stars}"
	    fi
	    local id3v2_stars="0"
	    if [ -n "$id3v2_rating" -a "$id3v2_rating" != 0 ]; then
		id3v2_stars=$((id3v2_rating / 51))
	    fi
	    if [ "$stars" != "$id3v2_stars" ]; then
		echo -ne "\r\033[KExporting ratings ($track_idx/${#all_tracks_name[@]}): ${track_name}..."
		id3v2_rating=$((stars * 51))
		`$id3v2_editor --POPM "${id3v2_email}:${id3v2_rating}" "$location"`
	    fi
        fi
        track_idx=$((track_idx + 1))
        eval "track_name=\${${prefix}_name[track_idx]}"
        eval "location=\${${prefix}_location[track_idx]}"
        eval "rating=\${${prefix}_rating[track_idx]}"
    done

    echo
}

function _cmd_sync_ratings_from_mp3() {
    _find_id3v2_editor
    if [ "$is_id3v2_editor_installed" != 1 ]; then
        _err_need_id3v2_editor "unable to edit mp3 tags"
        return
    fi

    echo "Scanning track catalogue. This may take a minute."
    # Yikes.
    _fetch_tracks "every file track" all_tracks

    local prefix="all_tracks"
    local track_idx=0
    eval "local track_name=\${${prefix}_name[track_idx]}"
    eval "local track_id=\${${prefix}_id[track_idx]}"
    eval "local location=\${${prefix}_location[track_idx]}"
    eval "local rating=\${${prefix}_rating[track_idx]}"
    while [ -n "$track_name" ]; do
        if [ -n "$location" -a "$location" != "missing value" ]; then
	    echo -ne "\r\033[KScanning ratings ($track_idx/${#all_tracks_name[@]}): ${track_name}..."
	    _fetch_track_id3v2 "every file track" "all_tracks" "$track_idx"
	    eval "local id3v2_rating=\${${prefix}_id3v2_rating[track_idx]}"
	    local stars="0"
	    if [ -n "$rating" -a "$rating" != 0 ]; then
		stars=$((rating / 20))
	    fi
	    local id3v2_stars="0"
	    if [ -n "$id3v2_rating" -a "$id3v2_rating" != 0 ]; then
		id3v2_stars=$((id3v2_rating / 51))
	    fi
	    if [ "$stars" != "$id3v2_stars" ]; then
		echo -ne "\r\033[KImporting ratings ($track_idx/${#all_tracks_name[@]}): ${track_name}..."
		rating=$((id3v2_stars * 20))
                _tell_itunes "set rating of track id \"$track_id\" to $rating"
	    fi
        fi
        track_idx=$((track_idx + 1))
        eval "track_name=\${${prefix}_name[track_idx]}"
        eval "track_id=\${${prefix}_id[track_idx]}"
        eval "location=\${${prefix}_location[track_idx]}"
        eval "rating=\${${prefix}_rating[track_idx]}"
    done

    echo
}

function _usage_sync_ratings() {
    echo "Usage: $progname sync ratings [<from>] <mp3 | itunes>"
}

function _cmd_sync_ratings() {
    if [ -z "$*" ]; then
        _err_func _usage_sinc_ratings
    else
        if [ "$1" = "from" ]; then
            shift
        fi
        subcmd="$1"
        shift
        case "$subcmd" in
            itunes) _cmd_sync_ratings_from_itunes "$@" ;;
            mp3)    _cmd_sync_ratings_from_mp3    "$@" ;;
            *)      _err_func _usage_sync_ratings      ;;
        esac
    fi
}

function _usage_sync() {
    echo "Usage: $progname sync ratings [<from>] <mp3 | itunes>"
}

function _cmd_sync() {
    if [ -z "$*" ]; then
        _err_func _usage_sync
    else
        subcmd="$1"
        shift
        case "$subcmd" in
            ratings) _cmd_sync_ratings "$@" ;;
            *)       _err_func _usage_sync  ;;
        esac
    fi
}

function _normalize_cmd_name() {
    #  Clunky way to return value because $() runs in subshell and we want to
    #  auto-source plugins into the main bash-itunes shell. But we also don't
    #  want to screw around with fd redirect voodoo at the calling point each
    #  time to capture process output without a subshell.
    local _varname="$1"
    local _cmd="$2"
    case "$_cmd" in
        #  Navigation commands.
        play|resume|unpause)
                     _cmd="play"      ;;
        pause)       _cmd="pause"     ;;
        stop)        _cmd="stop"      ;;
        next)        _cmd="next"      ;;
        prev)        _cmd="prev"      ;;
        info)        _cmd="info"      ;;
        search)      _cmd="search"    ;;
        shuffle)     _cmd="shuffle"   ;;
        repeat)      _cmd="repeat"    ;;
        playlist)    _cmd="playlist"  ;;
        playlists)   _cmd="playlists" ;;
        #  Volume commands.
        vol|volume)  _cmd="volume"    ;;
        mute)        _cmd="mute"      ;;
        unmute)      _cmd="unmute"    ;;
        sysvol|sysvolume)
                     _cmd="sysvolume" ;;
        sysmute)     _cmd="sysmute"   ;;
        sysunmute)   _cmd="sysunmute" ;;
        #  Application commands.
        open)        _cmd="open"      ;;
        quit)        _cmd="quit"      ;;
        show|reveal) _cmd="show"      ;;
        hide)        _cmd="hide"      ;;
        #  Editing commands.
        rate)        _cmd="rate"      ;;
        heart|love)  _cmd="heart"     ;;
        unheart|unlove)
                     _cmd="unheart"   ;;
        sync)        _cmd="sync"      ;;
        #  Extra commands.
        version)     _cmd="version"   ;;
        ""|help)     _cmd="help"      ;;
        plugins)     _cmd="plugins"   ;;
        *)
            if [ -f "$plugins_dir/$_cmd" ]; then
                . "$plugins_dir/$_cmd"
            else
                _cmd=""
            fi
            ;;
    esac
    eval "${_varname}=\"${_cmd}\""
}

#  Argument processing and dispatch

function _dispatch() {
    orig_cmd="$1"
    shift
    _normalize_cmd_name "cmd" "$orig_cmd"
    if [ -z "$cmd" ]; then
        _cmd_unknown "$orig_cmd"
    else
        _cmd_${cmd} "$@"
    fi
}

debug=0
if [ "${BASH_SOURCE[0]}" = "$0" ]; then
    # Being run directly, do our command processing.
    while getopts "hvd" "OPTNAME"; do
        case $OPTNAME in
            h) _cmd_help;    exit 0  ;;
            v) _cmd_version; exit 0  ;;
            d) debug=$(($debug + 1)) ;;
            *) exit -1               ;;
        esac
    done
    shift $(($OPTIND - 1))
fi

# Run rc file after options processing so that it can inspect arguments.
if [ -f "$config_dir/config" ]; then
    . "$config_dir/config"

    if [ -z "$supports_hearting" ]; then
        if [ "$itunes_app" = "Music" ]; then
            supports_hearting='true'
        else
            supports_hearting='false'
        fi
    fi

    _load_schema
fi

if [ "${BASH_SOURCE[0]}" = "$0" ]; then
    # Resume "being run directly" behaviour.
    _dispatch "$@"
fi