import type { ConnectorConnection } from "@tactical-media-broadcast-hub/core";
/**
 * Provider publishing policies, declared at the composition boundary so the
 * SDK publish/deletePublication signatures stay unchanged.
 */
export interface PublishingPolicy {
  /**
   * "token": the provider dedupes repeated sends carrying the same
   * idempotency key, so an ambiguous send may be replayed with that key.
   * "none": no key and no lookup — an ambiguous send is never replayed.
   */
  idempotency: "token" | "none";
  /**
   * How long after the attempt's first dispatch a same-key replay is trusted.
   * Applies only to "token" policies and only on deployment-verified origins.
   */
  dedupeWindowMs?: number;
}

/**
 * Mastodon documents Idempotency-Key retention of up to one hour; 30 minutes
 * from first dispatch is the deployment cutoff (forks may keep less).
 */
export const MASTODON_DEDUPE_WINDOW_MS = 30 * 60 * 1000;

export const PUBLISHING_POLICIES: Readonly<Record<string, PublishingPolicy>> = {
  mastodon: { idempotency: "token", dedupeWindowMs: MASTODON_DEDUPE_WINDOW_MS },
  telegram: { idempotency: "none" },
  // Graph media_publish takes no idempotency key: an ambiguous send is never replayed.
  instagram: { idempotency: "none" },
};

/** Unknown providers get the safe default: never replay an ambiguous send. */
export function publishingPolicyFor(provider: string): PublishingPolicy {
  return PUBLISHING_POLICIES[provider] ?? { idempotency: "none" };
}

export function verifiedDedupeOrigin(origin: string, configured = process.env.MASTODON_PUBLISH_DEDUPE_ORIGINS ?? ""): boolean {
  return configured.split(",").map((value) => value.trim()).filter(Boolean).some((value) => {
    try { const url = new URL(value); return url.protocol === "https:" && url.origin === value && url.origin === origin; } catch { return false; }
  });
}

export function isPublishingProvider(provider: string): boolean { return Object.hasOwn(PUBLISHING_POLICIES, provider); }
export function publishingDispatchPolicy(connection: ConnectorConnection): { policy: PublishingPolicy; origin: string; dedupeVerified: boolean } {
  const policy = publishingPolicyFor(connection.provider);
  let origin = "";
  try { origin = new URL(connection.fields.instanceUrl ?? "").origin; } catch { /* invalid origins never authorize dedupe */ }
  return { policy, origin, dedupeVerified: policy.idempotency === "token" && verifiedDedupeOrigin(origin) };
}