defmodule Blogex.SEOTest do
  use ExUnit.Case, async: true

  import Blogex.Test.PostBuilder
  alias Blogex.SEO

  defmodule StubBlog do
    def base_path, do: "/blog/eng"
    def title, do: "Engineering Blog"
    def description, do: "Our engineering insights"
  end

  @base_url "https://example.com"

  describe "meta_tags/3" do
    test "includes post title and description" do
      post = build(title: "My Title", description: "My Description")

      meta = SEO.meta_tags(post, @base_url, StubBlog)

      assert meta.title == "My Title"
      assert meta.description == "My Description"
    end

    test "builds canonical URL from base_url and post id" do
      post = build(id: "hello-world")

      meta = SEO.meta_tags(post, @base_url, StubBlog)

      assert meta.og_url == "https://example.com/blog/eng/hello-world"
    end

    test "includes OpenGraph article metadata" do
      post = build(author: "Alice", date: ~D[2026-06-15], tags: ["a", "b"])

      meta = SEO.meta_tags(post, @base_url, StubBlog)

      assert meta.og_type == "article"
      assert meta.article_author == "Alice"
      assert meta.article_published_time == "2026-06-15"
      assert meta.article_tags == ["a", "b"]
    end

    test "includes og_image when post has an image" do
      post = build(image: "/images/cover.png")

      meta = SEO.meta_tags(post, @base_url, StubBlog)

      assert meta.og_image == "https://example.com/images/cover.png"
    end

    test "og_image is nil when post has no image" do
      post = build()

      meta = SEO.meta_tags(post, @base_url, StubBlog)

      assert meta.og_image == nil
    end

    test "og_image uses absolute URL with base_url prefix" do
      post = build(image: "/assets/post-hero.jpg")

      meta = SEO.meta_tags(post, "https://myapp.dev", StubBlog)

      assert meta.og_image == "https://myapp.dev/assets/post-hero.jpg"
    end
  end

  describe "meta_tags_for_blog/2" do
    test "returns website type" do
      meta = SEO.meta_tags_for_blog(StubBlog, @base_url)

      assert meta.og_type == "website"
    end

    test "includes blog title and description" do
      meta = SEO.meta_tags_for_blog(StubBlog, @base_url)

      assert meta.og_title == "Engineering Blog"
      assert meta.og_description == "Our engineering insights"
    end

    test "has no og_image for blog listing" do
      meta = SEO.meta_tags_for_blog(StubBlog, @base_url)

      assert meta.og_image == nil
    end

    test "builds correct blog URL" do
      meta = SEO.meta_tags_for_blog(StubBlog, @base_url)

      assert meta.og_url == "https://example.com/blog/eng"
    end

    test "uses summary twitter card for blog listing" do
      meta = SEO.meta_tags_for_blog(StubBlog, @base_url)

      assert meta.twitter_card == "summary"
    end
  end

  describe "sitemap/2" do
    defmodule BlogA do
      def base_path, do: "/blog/a"
      def all_posts, do: [Blogex.Test.PostBuilder.build(id: "post-a", date: ~D[2026-01-01])]
    end

    defmodule BlogB do
      def base_path, do: "/blog/b"
      def all_posts, do: [Blogex.Test.PostBuilder.build(id: "post-b", date: ~D[2026-02-01])]
    end

    test "includes URLs from all blog modules" do
      xml = SEO.sitemap([BlogA, BlogB], @base_url)

      assert xml =~ "<loc>https://example.com/blog/a/post-a</loc>"
      assert xml =~ "<loc>https://example.com/blog/b/post-b</loc>"
    end

    test "produces valid sitemap XML" do
      xml = SEO.sitemap([BlogA], @base_url)

      assert xml =~ ~s(<?xml version="1.0")
      assert xml =~ ~s(<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">)
      assert xml =~ "</urlset>"
    end

    test "includes lastmod from post date" do
      xml = SEO.sitemap([BlogA], @base_url)

      assert xml =~ "<lastmod>2026-01-01</lastmod>"
    end
  end
end