/**
 * nip-29 (managed relay-based groups) event kinds and tag helpers.
 * managed groups: the relay keeps membership/metadata and enforces access.
 */
export const NIP29_KINDS = {
	/** chat message posted to a group. */
	chat: 9,
	/** threaded reply (we show it like chat for the mvp). */
	threadReply: 11,
	/** admin adds a user to a group (kind 9000). */
	putUser: 9000,
	/** admin removes a user from a group (kind 9001). */
	removeUser: 9001,
	/** admin edits group metadata — name/about (kind 9002). */
	editMetadata: 9002,
	/** join request (kind 9021). */
	joinRequest: 9021,
	/** leave request (kind 9022). */
	leaveRequest: 9022,
	/** group metadata (name/about/picture). */
	metadata: 39000,
	/** group admins list. */
	admins: 39001,
	/** group members list. */
	members: 39002
} as const;

/** addressable nip-29 list kinds the client subscribes to for group state. */
export const GROUP_META_KINDS: number[] = [
	NIP29_KINDS.metadata,
	NIP29_KINDS.admins,
	NIP29_KINDS.members
];

/** pull all `p` tag pubkeys out of an event's tags. */
export function pubkeysFromTags(tags: string[][]): string[] {
	return tags.filter((t) => t[0] === 'p' && typeof t[1] === 'string').map((t) => t[1] as string);
}

/** value of the first tag with the given name, or undefined. */
export function tagValue(tags: string[][], name: string): string | undefined {
	return tags.find((t) => t[0] === name)?.[1];
}

/** kinds we treat as showable chat messages in a room timeline. */
export const CHAT_KINDS: number[] = [NIP29_KINDS.chat, NIP29_KINDS.threadReply];

/** the `h` tag carries the group id on every nip-29 event. */
export function groupTag(groupId: string): string[] {
	return ['h', groupId];
}

/** pull the group id out of an event's tags, if it's there. */
export function groupIdFromTags(tags: string[][]): string | undefined {
	const h = tags.find((t) => t[0] === 'h');
	return h?.[1];
}