import { db, transaction } from "../db/connection.ts";
import { APIErrorCode } from "../../shared/api.ts";
import { APIException } from "../lib/api-exception.ts";

export function createAttachment(id: string, mime: string): void {
  db.prepare(
    "INSERT INTO attachments (id, mime, created_at) VALUES (?, ?, ?)",
  ).run(id, mime, new Date().toISOString());
}

export function getAttachment(attachmentId: string): { mime: string } {
  const row = db.prepare(
    "SELECT mime FROM attachments WHERE id = ?",
  ).get(attachmentId) as { mime: string } | undefined;

  if (!row) {
    throw new APIException(
      APIErrorCode.NOT_FOUND,
      404,
      "Attachment not found",
    );
  }

  return { mime: row.mime };
}

// UUID pattern used to extract attachment IDs from markdown/text bodies.
const ATTACHMENT_RE =
  /\/api\/attachments\/([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})/g;

/**
 * Parse `text` for attachment URLs and bind any unowned attachments to
 * `resourceId`. Only updates rows where resource_id IS NULL so a user cannot
 * claim attachments that already belong to another resource.
 */
export function linkAttachments(text: string, resourceId: string): void {
  const ids = [...text.matchAll(ATTACHMENT_RE)].map((m) => m[1]);
  if (ids.length === 0) return;
  const update = db.prepare(
    "UPDATE attachments SET resource_id = ? WHERE id = ? AND resource_id IS NULL",
  );
  transaction(() => {
    for (const id of ids) update.run(resourceId, id);
  });
}