import { beforeEach, describe, expect, it } from "vitest";
import { SlugConflictError } from "@/lib/services/errors";
import type { PostInput } from "@/lib/services/posts";
import { createPost, updatePost } from "@/lib/services/posts";
import { createPage } from "@/lib/services/pages";
import { resetDb } from "../helpers/db";

const input = (overrides: Partial<PostInput> = {}): PostInput => ({
  title: "My First Post",
  slug: "",
  body: "body",
  authorName: "Tester",
  featuredImageUrl: null,
  featuredImageAlt: null,
  status: "draft",
  tagIds: [],
  newTagNames: [],
  ...overrides,
});

beforeEach(resetDb);

describe("post slug generation", () => {
  it("derives the slug from the title when left blank", async () => {
    const post = await createPost(input());
    expect(post.slug).toBe("my-first-post");
  });

  it("auto-suffixes generated slugs on duplicate titles", async () => {
    const a = await createPost(input());
    const b = await createPost(input());
    const c = await createPost(input());
    expect(a.slug).toBe("my-first-post");
    expect(b.slug).toBe("my-first-post-2");
    expect(c.slug).toBe("my-first-post-3");
  });

  it("normalizes an explicitly chosen slug", async () => {
    const post = await createPost(input({ slug: "  My Custom SLUG!  " }));
    expect(post.slug).toBe("my-custom-slug");
  });

  it("rejects an explicit slug that another post owns", async () => {
    await createPost(input({ slug: "taken" }));
    await expect(createPost(input({ slug: "taken" }))).rejects.toBeInstanceOf(
      SlugConflictError,
    );
  });

  it("lets a post keep its own slug on update", async () => {
    const post = await createPost(input({ slug: "keeper" }));
    const updated = await updatePost(post.id, input({ slug: "keeper", title: "New title" }));
    expect(updated?.slug).toBe("keeper");
    expect(updated?.title).toBe("New title");
  });

  it("rejects updating to a slug owned by another post", async () => {
    await createPost(input({ slug: "occupied" }));
    const other = await createPost(input({ slug: "elsewhere" }));
    await expect(updatePost(other.id, input({ slug: "occupied" }))).rejects.toBeInstanceOf(
      SlugConflictError,
    );
  });

  it("regenerates from the title when the slug is cleared on update", async () => {
    const post = await createPost(input({ slug: "old-slug" }));
    const updated = await updatePost(post.id, input({ slug: "", title: "Renamed Post" }));
    expect(updated?.slug).toBe("renamed-post");
  });
});

describe("page slugs", () => {
  it("share the same policy but live in their own namespace", async () => {
    const page = await createPage({ title: "About", slug: "", body: "", status: "draft" });
    expect(page.slug).toBe("about");
    // A post may use "about" too — pages and posts have separate URL spaces.
    const post = await createPost(input({ slug: "about" }));
    expect(post.slug).toBe("about");
    await expect(
      createPage({ title: "About", slug: "about", body: "", status: "draft" }),
    ).rejects.toBeInstanceOf(SlugConflictError);
  });
});