import crypto from "crypto";
import { db } from "@epicure/db";
import { webhooks, webhookDeliveries } from "@epicure/db";
import { eq, and } from "@epicure/db";
import { safeFetch } from "@/lib/validate-webhook-url";
import { decrypt } from "@/lib/encrypt";

// Secrets created before encryption-at-rest was added are a bare 64-char hex
// string (crypto.randomBytes(32).toString("hex")) with no ":" separators —
// encrypt()'s output is always "iv:authTag:ciphertext". Fall back to treating
// the value as already-plaintext rather than a hard migration, since this is
// only reached with a value this app itself generated (never user input).
function decryptWebhookSecret(stored: string): string {
  return stored.split(":").length === 3 ? decrypt(stored) : stored;
}

export const WEBHOOK_EVENTS = [
  "recipe.created",
  "recipe.updated",
  "recipe.published",
  "recipe.deleted",
  "meal_plan.updated",
  "shopping_list.completed",
  "comment.added",
] as const;

export type WebhookEvent = (typeof WEBHOOK_EVENTS)[number];

export async function dispatchWebhook(userId: string, event: WebhookEvent, payload: object) {
  const hooks = await db
    .select()
    .from(webhooks)
    .where(and(eq(webhooks.userId, userId), eq(webhooks.active, true)));

  const filtered = hooks.filter((h) => h.events.length === 0 || h.events.includes(event));

  await Promise.allSettled(
    filtered.map(async (hook) => {
      const body = JSON.stringify({ event, payload, timestamp: new Date().toISOString() });
      const sig = crypto.createHmac("sha256", decryptWebhookSecret(hook.secret)).update(body).digest("hex");
      let statusCode = 0;
      let success = false;
      try {
        // safeFetch resolves and pins the connection to a single validated IP
        // (and re-validates + re-pins every redirect hop), so there's no
        // separate re-resolution for a rebinding attack to exploit.
        const res = await safeFetch(hook.url, {
          method: "POST",
          headers: {
            "Content-Type": "application/json",
            "X-Epicure-Signature": `sha256=${sig}`,
            "X-Epicure-Event": event,
          },
          body,
          signal: AbortSignal.timeout(10000),
        });
        statusCode = res.status;
        success = res.ok;
      } catch {
        // delivery failed; statusCode stays 0, success stays false
      }
      await db.insert(webhookDeliveries).values({
        id: crypto.randomUUID(),
        webhookId: hook.id,
        event,
        payload: payload as Record<string, unknown>,
        statusCode,
        success,
        attempts: 1,
        createdAt: new Date(),
      });
    })
  );
}
