/**

* Normalize a Discord outbound target for delivery. Bare numeric IDs are

* prefixed with "channel:" to avoid the ambiguous-target error in

* parseDiscordTarget. All other formats pass through unchanged.

* parseDiscordTarget, unless the ID is explicitly configured as an allowed DM

* sender. All other formats pass through unchanged.

*/

export function normalizeDiscordOutboundTarget(

to?: string,

allowFrom?: readonly string[],

): { ok: true; to: string } | { ok: false; error: Error } {

const trimmed = to?.trim();

if (!trimmed) {

};

}

if (/^\d+$/.test(trimmed)) {

if (allowFromContainsDiscordUserId(allowFrom, trimmed)) {

return { ok: true, to: `user:${trimmed}` };

}

return { ok: true, to: `channel:${trimmed}` };

}

return { ok: true, to: trimmed };

}

export function allowFromContainsDiscordUserId(

allowFrom: readonly string[] | undefined,

userId: string,

): boolean {

const normalizedUserId = userId.trim();

if (!normalizedUserId) {

return false;

}

return (allowFrom ?? []).some(

(entry) => normalizeAllowFromDiscordUserId(entry) === normalizedUserId,

);

}

function normalizeAllowFromDiscordUserId(entry: string): string | undefined {

const trimmed = entry.trim().toLowerCase();

if (!trimmed || trimmed === "*") {

return undefined;

}

const mentionMatch = /^<@!?(\d+)>$/.exec(trimmed);

if (mentionMatch) {

return mentionMatch[1];

}

// Accept both current and legacy allowFrom forms for Discord user IDs.

const prefixedMatch = /^(?:discord:)?user:(\d+)$/.exec(trimmed);

if (prefixedMatch) {

return prefixedMatch[1];

}

const discordMatch = /^discord:(\d+)$/.exec(trimmed);

if (discordMatch) {

return discordMatch[1];

}

return /^\d+$/.test(trimmed) ? trimmed : undefined;

}

export function looksLikeDiscordTargetId(raw: string): boolean {

const trimmed = raw.trim();

if (!trimmed) {