import { getHiddenTags, processTags } from "applesauce-core/helpers";
import { NostrEvent } from "nostr-tools";
import { v5 as UUIDv5 } from "uuid";
export const PODCAST_GUID_NS = "ead4c236-bf58-58c6-a2c6-a6b28d128cb6";
export const PODCASTS_LIST_KIND = 10104;
export const NAMESPACES = {
atom: "http://www.w3.org/2005/Atom",
itunes: "http://www.itunes.com/dtds/podcast-1.0.dtd",
podcast: "https://podcastindex.org/namespace/1.0",
spotify: "http://www.spotify.com/ns/rss",
content: "http://purl.org/rss/1.0/modules/content/",
} as const;
const resolver: XPathNSResolver = (prefix: string | null): string | null => {
return (prefix && NAMESPACES[prefix as keyof typeof NAMESPACES]) || null;
};
export type FeedPointer = {
guid: string;
url: URL;
};
export function getFeedPointerFromITag(tag: string[]): FeedPointer {
if (tag.length < 3) throw new Error("Tag too short");
const guid = tag[1];
const url = new URL(tag[2]);
return { guid, url };
}
export function getFeedPointers(list: NostrEvent) {
const hidden = getHiddenTags(list);
return processTags(hidden ? [...hidden, ...list.tags] : list.tags, getFeedPointerFromITag);
}
function getNodeDocument(xml: Document | Node | Element) {
if (xml instanceof Document) return xml;
else if (xml instanceof Element) return xml.ownerDocument;
else if (!xml.parentElement) throw new Error("Disconnected node");
else return xml.parentElement instanceof Document ? xml.parentElement : xml.parentElement.ownerDocument;
}
export function getXPathString(xml: Document | Element, selector: string): string;
export function getXPathString(xml: Document | Element, selector: string, safe: true): string | undefined;
export function getXPathString(xml: Document | Element, selector: string, safe: false): string;
export function getXPathString(xml: Document | Element, selector: string, safe = false) {
try {
return getNodeDocument(xml).evaluate(selector, xml, resolver, XPathResult.STRING_TYPE).stringValue;
} catch (error) {
if (!safe) throw error;
}
}
export function getXPathElements(node: Document | Element, selector: string): Element[] {
const iterator = getNodeDocument(node).evaluate(selector, node, resolver, XPathResult.ORDERED_NODE_ITERATOR_TYPE);
const items: Element[] = [];
let item: Node | null;
while ((item = iterator.iterateNext())) {
if (item instanceof Element) items.push(item);
}
return items;
}
export function getPodcastTitle(xml: Document): string {
return getXPathString(xml, "//title");
}
export function getPodcastDescription(xml: Document): string {
return getXPathString(xml, "//description");
}
export function getPodcastImageURL(xml: Document): string {
return xml.evaluate("//image/url", xml, resolver, XPathResult.STRING_TYPE).stringValue;
}
export function getPodcastLink(xml: Document): string {
return getXPathString(xml, "//link");
}
export function getPodcastFeedGUID(url: string) {
return UUIDv5(url.replace(/http?s:\/\//i, ""), PODCAST_GUID_NS);
}
export function getPodcastGUID(xml: Document): string {
let guid = xml.evaluate("//podcast:guid", xml, resolver, XPathResult.STRING_TYPE).stringValue;
if (guid) return guid;
const link = getXPathString(xml, "//atom:link/@href");
return getPodcastFeedGUID(link);
}
export function getPodcastItems(xml: Document) {
return getXPathElements(xml, "//item");
}
export type PodcastPerson = {
href?: string;
image?: string;
name: string;
group?: string;
roll?: string;
};
export function getPodcastPeople(xml: Document | Element) {
const items = getXPathElements(xml, "podcast:person");
const people: PodcastPerson[] = [];
for (const item of items) {
if (!item.textContent) continue;
people.push({
name: item.textContent,
image: item.getAttribute("img") ?? undefined,
href: item.getAttribute("href") ?? undefined,
group: item.getAttribute("group") ?? undefined,
roll: item.getAttribute("roll") ?? undefined,
});
}
return people;
}