#!/bin/bash -e

if [ -z "$1" -o -z "$2" ]; then
    echo "Usage: $0 --bluray-device|--dvd-device SOMEDIRECTORY"
    exit 1
fi

device_param="$1"
device_path="$2"
if [ "$device_param" = "--bluray-device" ]; then
    device_scheme="bd"
elif [ "$device_param" = "--dvd-device" ]; then
    device_scheme="dvd"
else
    echo "Unknown device type: $device_param"
    exit 1
fi

function mpv_wrap {
    mpv 2> /dev/null \
        --quiet \
        --ao=null \
        --vo=null \
        --frames 1 \
        --no-cache \
        --no-config \
        "$@"
}

function get_highest_title {
    mpv_wrap \
        "$device_param" "$device_path" "${device_scheme}://" \
        --term-playing-msg='${disc-title-list}TITLE_LIST_END' \
    | grep -B2 'TITLE_LIST_END' \
    | head -n1 \
    | cut -d':' -f1
}

function get_length {
    mpv_wrap \
        "$device_param" "$device_path" "${device_scheme}://${1}" \
        --term-playing-msg='TITLE_LENGTH=${duration}' \
    | grep 'TITLE_LENGTH' \
    | head -n1 \
    | cut -d'=' -f2
}

highest_title="$(get_highest_title)"
for title in $(seq 0 "$highest_title"); do
    echo -n "$title "
    get_length "$title"
done