import type { AtpAgent } from "@atproto/api";
import type { Database } from "@atbb/db";
import { categories, forums } from "@atbb/db";
import { eq, and } from "drizzle-orm";
import { deriveSlug } from "../slug.js";

interface CreateCategoryInput {
  name: string;
  description?: string;
  slug?: string;
  sortOrder?: number;
}

interface CreateCategoryResult {
  created: boolean;
  skipped: boolean;
  uri?: string;
  cid?: string;
  existingName?: string;
}

/**
 * Create a space.atbb.forum.category record on the Forum DID's PDS
 * and insert it into the database.
 * Idempotent: skips if a category with the same name already exists.
 */
export async function createCategory(
  db: Database,
  agent: AtpAgent,
  forumDid: string,
  input: CreateCategoryInput
): Promise<CreateCategoryResult> {
  // Check if category with this name already exists
  const [existing] = await db
    .select()
    .from(categories)
    .where(and(eq(categories.did, forumDid), eq(categories.name, input.name)))
    .limit(1);

  if (existing) {
    return {
      created: false,
      skipped: true,
      uri: `at://${existing.did}/space.atbb.forum.category/${existing.rkey}`,
      cid: existing.cid,
      existingName: existing.name,
    };
  }

  // Look up forum row for FK reference (optional — null if forum not yet in DB)
  const [forum] = await db
    .select()
    .from(forums)
    .where(and(eq(forums.did, forumDid), eq(forums.rkey, "self")))
    .limit(1);

  if (!forum?.id) {
    console.warn(
      "Forum record not found in DB — inserting category with forumId: null",
      JSON.stringify({ forumDid })
    );
  }

  const slug = input.slug ?? deriveSlug(input.name);
  const now = new Date();

  const response = await agent.com.atproto.repo.createRecord({
    repo: forumDid,
    collection: "space.atbb.forum.category",
    record: {
      $type: "space.atbb.forum.category",
      name: input.name,
      ...(input.description && { description: input.description }),
      slug,
      ...(input.sortOrder !== undefined && { sortOrder: input.sortOrder }),
      createdAt: now.toISOString(),
    },
  });

  const rkey = response.data.uri.split("/").pop()!;

  await db.insert(categories).values({
    did: forumDid,
    rkey,
    cid: response.data.cid,
    name: input.name,
    description: input.description ?? null,
    slug,
    sortOrder: input.sortOrder ?? null,
    forumId: forum?.id ?? null,
    createdAt: now,
    indexedAt: now,
  });

  return {
    created: true,
    skipped: false,
    uri: response.data.uri,
    cid: response.data.cid,
  };
}