#!/bin/bash

set -e

YTDLP=$(which yt-dlp)
JQ=$(which jq)
FFMPEG=$(which ffmpeg)

download() {
    DOWNLOAD_LINK="${1}"
    SAVE_PATH="${2}"

    # cd "${SAVE_PATH}"

    ${YTDLP} -o "${SAVE_PATH}/%(id)s.%(ext)s" \
        -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best' \
        --write-auto-subs --write-subs --sub-lang en,ru --convert-subs srt --sub-format txt \
        ${DOWNLOAD_LINK}
}

create_structure() {
    PLAYLIST="${1}"
    JSON="$(${YTDLP} --flat-playlist -j "${PLAYLIST}" 2>/dev/null)"
    TITLE="$(echo ${JSON} | ${JQ} -r '.playlist_title' | head -n 1)"
    VIDEOS="$(echo ${JSON} | ${JQ} -r '.title')"
    IDS="$(echo ${JSON} | ${JQ} -r '.id')"
    LINKS="$(echo ${JSON} | ${JQ} -r '.original_url')"
    ALL_LINES=$(echo "${JSON}" | wc -l)
    
    mkdir -v "${TITLE}"

    for ((NUMBER=1; NUMBER<=ALL_LINES; NUMBER++)); do
        VIDEO="$(echo "${VIDEOS}" | awk "NR==${NUMBER}")"
        LINK="$(echo "${LINKS}" | awk "NR==${NUMBER}")"
        VIDEO="${VIDEO//\//-}"
        DIR_NAME="${NUMBER} - ${VIDEO}"

        mkdir -v "${TITLE}/${DIR_NAME}"

        download "${LINK}" "${TITLE}/${DIR_NAME}"
    done
}

main() {
    COMMAND="${1}"
    [ ! -z ${COMMAND} ] && shift

    while [[ $# -gt 0 ]]; do
        KEY="${1}"
        VALUE="${2}"
        case "${KEY}" in
            -p|--playlist)
                PLAYLIST="${VALUE}"
                shift
                ;;
            *)
                ;;
        esac
        shift
    done

    case "${COMMAND}" in
        create)
            [ -z "${PLAYLIST}" ] && echo "Playlist link unknown" && exit 1
            create_structure "${PLAYLIST}"
            ;;
        *)
            exit 1
            ;;
    esac
}

main "${@}"