// ==UserScript==
// @name         Bandcamp Downloader
// @namespace    BigDuckie.BandcampDownloader
// @author       Big Duckie
// @copyright    2025, Big Duckie (https://bigduckie.dev)
// @license      MIT
// @version      2025.6.6
// @description  Adds a sidebar to download songs from Bandcamp.
// @include      *://*.bandcamp.com/*
// @require      https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js
// @require      https://cdnjs.cloudflare.com/ajax/libs/jszip/3.9.1/jszip.min.js
// @grant        GM_xmlhttpRequest
// @grant        GM_addStyle
// @grant        GM_download
// @connect      bcbits.com
// ==/UserScript==

// Register Globals
let tracklist = TralbumData.trackinfo;
unsafeWindow.GM_download = GM_download;

(function () {
    "use strict";

    // Sidebar construction
    jQuery("body")
        .append(jQuery("<div/>")
            .addClass("dl-sidebar-container dl-sidebar dl-color-1 hidden")
            .append(jQuery("<p/>").text("Click the files to download, or use the download album button."))
            .append(jQuery("<ol/>").addClass("dl-tracklist"))
            .append(jQuery("<div/>")
                .addClass("dl-all-button dl-progress dl-color-2")
                .append(jQuery("<div/>").addClass("dl-progress-bar"))
                .append(jQuery("<div/>").addClass("dl-progress-text").text("Download Album"))))
        .append(jQuery("<div/>")
            .addClass("dl-sidebar-toggle dl-sidebar dl-color-1 hidden")
            .text("Bandcamp Downloader"));

    tracklist.forEach((track) => {
        jQuery(".dl-tracklist").append(jQuery("<li/>")
            .attr("id", "track-" + track.track_num)
            .append(jQuery("<a/>")
                .addClass("dl-link custom-color")
                .attr("data-url", track.file["mp3-128"])
                .attr("data-trackid", tracklist.indexOf(track))
                .text(track.title)));
    });

    function css(strings) {
        return strings;
    }

    // Style sidebar to match page
    GM_addStyle(css`.dl-sidebar-toggle {
        font-family: biolinum;
        left: 0;
        top: 50px;
        position: fixed;
        transform: rotate(90deg);
        transform-origin: left bottom 0;
        border-top-right-radius: 5px;
        border-top-left-radius: 5px;
        margin: 0;
        padding: 5px;
        z-index: 5001;
        background: inherit;
        border: 1px solid #000000;
        border-bottom: none;
        cursor: pointer
    }

        .dl-sidebar-toggle.active {
            left: 400px
        }

        .dl-sidebar-container {
            display: flex;
            flex-direction: column;
            width: 390px;
            min-height: 300px;
            left: -400px;
            top: 50px;
            max-height: 500px;
            overflow-y: scroll;
            padding: 5px;
            position: fixed;
            z-index: 5000;
            border: 1px solid #000000;
            border-left: none;
            user-select: none;
            cursor: default
        }

        .dl-sidebar-container.active {
            left: 0
        }
        
        .dl-tracklist {
            flex-grow: 1;
        }

        .dl-all-button {
            margin-left: 0;
            margin-right: 0;
            cursor: pointer;
            background-color: rgb(255, 255, 255);
            color: rgb(0, 0, 0);
            border-color: rgb(0, 0, 0)
        }

        .dl-progress {
            position: relative;
            z-index: 5001
        }

        .dl-progress,
        .dl-progress-bar,
        .dl-progress-text {
            height: 25px;
            left: 0;
            right: 0;
            top: 0;
            bottom: 0
        }

        .dl-progress-bar {
            width: 0;
            overflow: hidden;
            z-index: 5002;
            -moz-transition: width 0.2s linear;
            -webkit-transition: width 0.2s linear;
            -o-transition: width 0.2s linear;
            transition: width 0.2s linear;
            background-color: rgb(0, 0, 0)
        }

        .dl-progress-text {
            text-align: center;
            z-index: 5003;
            position: absolute;
            line-height: 25px;
            color: inherit
        }

        .dl-sidebar {
            opacity: 1;
            transition: opacity 1s, left 0.5s
        }

        .dl-sidebar.hidden {
            opacity: 0
        }

        .dl-sidebar::-webkit-scrollbar {
            width: 10px
        }

        .dl-sidebar::-webkit-scrollbar-track {
            background: rgb(0, 0, 0)
        }

        .dl-sidebar::-webkit-scrollbar-thumb {
            background: rgb(255, 255, 255)
        }`);

    jQuery(".dl-color-1").css({
        "background-color": jQuery("#pgBd").css("background-color"),
        color: jQuery("#pgBd").css("color"),
        "border-color": jQuery("#pgBd").css("color"),
    });
    jQuery(".dl-color-2").css({
        "background-color": jQuery("#follow-unfollow").css("background-color"),
        color: jQuery("#follow-unfollow").css("color"),
        "border-color": jQuery("#follow-unfollow").css("border-color"),
    });
    jQuery(".dl-progress-bar").css({
        "background-color": jQuery("#recommendations_container").css("background-color"),
    });

    jQuery(".dl-sidebar").removeClass("hidden");

    // Handle events
    jQuery(".dl-sidebar-toggle").click((e) => {
        jQuery(".dl-sidebar").toggleClass("active");
    });

    jQuery(".dl-link").click((e) => {
        GM_download(jQuery(e.target).attr("data-url"), `[${pad(tracklist[jQuery(e.target).attr("data-trackid")].track_num, 2)}] ${TralbumData.artist} - ${tracklist[jQuery(e.target).attr("data-trackid")].title}.mp3`);
    });

    jQuery(".dl-all-button").click((e) => {
        console.debug("downloading album");
        downloadAlbum();
    });

    // Main functions
    function downloadAlbum() {
        let zip = new JSZip();

        tracklist.forEach((track) => {
            console.debug("downloading track", track);
            zip.file(
                `[${track.track_num}] ${TralbumData.artist} - ${track.title}.mp3`,
                urlToPromise(track.file["mp3-128"]));
        });

        console.debug("generating zip");
        zip.generateAsync({type: "blob"}, (metadata) => {
            console.debug("processing zip");
            jQuery(".dl-progress-bar").css("width", `${metadata.percent}%`);
        })
            .then((blob) => {
                let url = URL.createObjectURL(blob);
                console.debug("compiled zip", url);

                GM_download(url, `${TralbumData.artist} - ${TralbumData.current.title}.zip`);
            }, (e) => {
                console.error(e);
            });
    }

    // Supporting functions
    function pad(n, width = 3, z = 0) {
        return (String(z).repeat(width) + String(n)).slice(String(n).length);
    }

    function urlToPromise(url) {
        return new Promise((resolve, reject) => {
            GM_xmlhttpRequest({
                method: "GET", url: url, responseType: "blob", onload: (response) => {
                    console.debug("fetched song", url, response.response);
                    resolve(response.response);
                }, onerror: (response) => {
                    reject(response.response);
                },
            });
        });
    }
})();