plplay

#!/bin/zsh

ID_FILE="$HOME/.scripts/playlist_ids.txt"
declare -a plist_arr
SHUFFLE="shuffle"

function print_usage {
    echo "Usage: plplay [OPTION | command]"
    echo "Select one of your mps-youtube playlists to start playing in the background using tmux"
    echo ""
    echo "Options:"
    echo "   -no-shuffle        Play the selected playlist in its original order"
    echo "   --attach           Attach to the created tmux session once playback starts"
    echo "   --help             Display help information about using the 'plplay' script"
    echo ""
    echo "Commands:"
    echo "   stop               Stop playback, killing the tmux session"
    echo "   update             Select a playlist to update, then play the updated playlist"
    echo "                          NOTE: The selected playlist must be an actual youtube playlist with"
    echo "                                its playlist id stored in ./playlist_ids.txt following the format:"
    echo ""
    echo "                                      '<mpsyt-playlist-name> <youtube-playlist-ID>'"
    echo ""
    echo "   volup              Increase the volume by 10"
    echo "   voldown            Decrease the volume by 10"
}

function play() {
    local pl_num=$1
    local no_interrupt=${2:-0}

    local pl_session=$(tmux list-sessions 2>/dev/null | grep -o "mpsyt_pl")
    # Check if a current mpsyt_pl tmux session is already running
    if [[ $pl_session ]]
    then
        # If $no_interrup is not set, kill the current mpsyt_pl session
        # And unset the $pl_session variable
        [[ $no_interrupt -eq 0 ]] && tmux kill-session -t mpsyt_pl && unset pl_session
    fi
    # Start a new mpsyt_pl tmux session
    [[ -z $pl_session ]] && tmux new -s mpsyt_pl -d "mpsyt open $pl_num, dump, $SHUFFLE all"
}

function update() {
    local pl_id="$1"
    local pl_name="$2"

    if [[ $1 ]] && [[ $2 ]]
    then
        # printf "tmux new -s update_mpsyt_pl -d \"mpsyt pl %s, dump, save %s, exit\n" "$pl_id" "$pl_name"

        tmux new -s update_mpsyt_pl -d "mpsyt pl $pl_id, dump, save $pl_name, exit"
        mpsyt pl $pl_id, dump, save $pl_name, exit > /dev/null &
        wait
    else
        echo "ERR: update() given empty string"
    fi
}

function volume_up() {
    tmux send-keys -N 5 -t mpsyt_pl.0 0
}

function volume_down() {
    tmux send-keys -N 5 -t mpsyt_pl.0 9
}

# get_index:
#
# Return the displayed index value of a specific mpsyt playlist
#
# Get the index value corresponding to the position of playlist name "$1" in the global
# playlist array: '$plist_arr'
#
# NOTE: the display order and thus indexing of the playlists is based on output
# generated from mpsyt, thus the index of a given playlist is subject to change
# across different calls to 'update'.
# It is for this reason that we MUST:
#    - rebuild the playlist array each time
#    - Store the playlist information according to its name
#    - Store the playlists data in $ID_FILE using the format:
#         <mpsyt playlist name> <YouTube playlist id>
#
# Parameters
# ----------
# $1 : string
#       The name of the mpsyt playlist whose index we want to retrieve
#
# Returns
# -------
# $i : integer
#       This should correspond to the index of the playlist as it was displayed
#       on the menu when prompting the user for input.
function get_index() {
    value="$1"

    # Get playlist name from displayed index
    for i in {1.."${#plist_arr[@]}"}
    do
        # echo "$i ${plist_arr[$i]} ${value}" 1>&2
        if [[ "${plist_arr[$i]}" = "${value}" ]]
        then
            echo "${i}"
        fi
    done
}

function main() {
    if [[ "$1" == "-h" ]] || [[ "$1" = "--help" ]]
    then
        print_usage
        exit
    fi

    if [[ "$1" = "--no-shuffle" ]]
    then
        SHUFFLE=""
        shift
    fi

    if [[ "$1" = "--attach" ]]
    then
        pl_num=$1
        no_interrupt=$2

        jl_session=$(tmux list-sessions 2>/dev/null | grep -o "mpsyt_pl")
        if [[ $pl_session = "mpsyt_pl" ]]
        then
            [[ no_interrupt -eq 0 ]] && tmux kill-session -t mpsyt_pl
        fi
        [[ no_interrupt -eq 0 ]] && tmux new -s mpsyt_pl "mpsyt"
    elif [[ $1 = "stop" ]]
    then
        tmux kill-session -t mpsyt_pl
    elif [[ "$1" = "update" ]]
    then
        prompt=$(mpsyt ls, q | sed -n '/Local/,/Enter/p')
        echo "$prompt" | head -n -2
        printf "\nEnter ID to update a playlist\n"

        # Preserve old IFS
        # ORIG_IFS=$IFS
        # plists=$(echo "$prompt" | tail -n +5 | head -n -2 | sed "s/^\s\+//g" | sed "s/\s\+/ /g" | cut -d " " -f 2)
        # local IFS=$'\n' plist_arr=( $(echo "$prompt" | tail -n +5 | head -n -2 | sed "s/^\s\+//g" | sed "s/\s\+/ /g" | cut -d " " -f 2) )
        # IFS=$ORIG_IFS
        # zsh specific way of converting output to array
        plists=$(echo "$prompt" | tail -n +5 | head -n -2 | sed "s/^\s\+//g" | sed "s/\s\+/ /g" | cut -d " " -f 2)
        plist_arr=("${(f)plists}")


        echo -n "> "
        read pl_num
        # if [[ -n $BASH_VERSION ]]
        # then
        #     pl_num=$(($pl_num-1))
        # fi

        # Load the playlist id's into array from external '$ID_FILE'
        # For reference the lines in '$ID_FILE' are formatted as follows:
        # <mpsyt playlist name> <YouTube playlist id>
        declare -a id_list
        while IFS= read line
        do
            # Split the line into array:
            #   [<mpsyt playlist name>, <YouTube playlist id>]
            cur=("${(@s/ /)line}")

            # Calls get_index(<mpsyt playlist name>)
            ind=$(get_index ${cur[1]})

            # Make sure index is not NULL
            # If returned index value is not NULL:
            # store the playlists YouTube ID at index '$ind' in '$id_list'
            # NOTE: ID's are stored in id list based on the position of the
            #       playlist in the global array '$plist_arr' NOT its position
            #       in '$id_list'.
            [[ $ind ]] && id_list[$ind]="${cur[2]}" || echo "No id for ${cur[1]}"
        done < $ID_FILE

        pl_token="${id_list[$pl_num]}"
        pl_name="${plist_arr[$pl_num]}"

        # If the playlist has a corresponding YouTube ID in '$ID_FILE'
        if [[ ! -z $pl_token ]]
        then
            update "$pl_token" "$pl_name"
        fi

        # Play the updated playlist
        play $pl_num 1
    elif [[ "$1" = "volup" ]]
    then
        volume_up
    elif [[ "$1" = "voldown" ]]
    then
        volume_down
    elif [[ ! -z "$1" ]]
    then
        printf "Unrecognized Option: '%s'\n" "$1"
        print_usage
        exit 1
    else
        mpsyt ls, q | sed -n '/Local/,/Enter/p' | head -n -2
        printf "\nEnter <name or ID> to load a playlist\n"

        echo -n "> "
        read pl_num

        play $pl_num
    fi
}

main $@