package web

import (
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"testing/fstest"

	"khosra/internal/content"
	"khosra/internal/render"
)

func crawlerHandler(t *testing.T, settings content.Settings, extra fstest.MapFS) http.Handler {
	t.Helper()
	fsys := fstest.MapFS{
		"content/posts/hello.md":    {Data: []byte("---\ntitle: Hello\ndate: 2026-03-08\n---\nx\n")},
		"content/posts/hello.bn.md": {Data: []byte("---\ntitle: হ্যালো\ndate: 2026-03-08\n---\nx\n")},
		"content/pages/about.md":    {Data: []byte("---\ntitle: About\n---\nx\n")},
	}
	for name, file := range extra {
		fsys[name] = file
	}
	bundles, err := content.Scan(fsys)
	if err != nil {
		t.Fatal(err)
	}
	r, err := render.New(nil, settings, nil)
	if err != nil {
		t.Fatal(err)
	}
	return Handler(Fixed(content.NewSite(bundles)), r, fsys, nil, settings)
}

func TestSitemapListsEveryVariantAbsolutely(t *testing.T) {
	h := crawlerHandler(t, content.Settings{Base: "https://khosra.example"}, nil)
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/sitemap.xml", nil))
	if rec.Code != http.StatusOK {
		t.Fatalf("got %d, want 200", rec.Code)
	}
	if ct := rec.Header().Get("Content-Type"); !strings.HasPrefix(ct, "application/xml") {
		t.Errorf("content-type = %q — a sitemap served as HTML is a sitemap nothing reads", ct)
	}
	body := rec.Body.String()
	for _, want := range []string{
		"<loc>https://khosra.example/posts/hello/</loc>",
		"<loc>https://khosra.example/bn/posts/hello/</loc>", // each language is its own URL
		"<loc>https://khosra.example/pages/about/</loc>",
		"<lastmod>2026-03-08</lastmod>",
	} {
		if !strings.Contains(body, want) {
			t.Errorf("missing %q:\n%s", want, body)
		}
	}
	if strings.Contains(body, "<lastmod></lastmod>") {
		t.Error("an undated bundle should carry no lastmod at all")
	}
}

func TestNoBaseMeansNoSitemap(t *testing.T) {
	// The format has no room for a relative URL, so the honest answer is that the file does not exist
	// (ADR-0039) rather than one full of paths no crawler can resolve.
	h := crawlerHandler(t, content.Settings{}, nil)
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/sitemap.xml", nil))
	if rec.Code != http.StatusNotFound {
		t.Errorf("got %d, want 404", rec.Code)
	}
}

func TestRobotsIsGeneratedOrTheSitesOwn(t *testing.T) {
	h := crawlerHandler(t, content.Settings{Base: "https://khosra.example"}, nil)
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/robots.txt", nil))
	body := rec.Body.String()
	if !strings.Contains(body, "User-agent: *") || !strings.Contains(body, "Sitemap: https://khosra.example/sitemap.xml") {
		t.Errorf("generated robots should point at the sitemap:\n%s", body)
	}
	if ct := rec.Header().Get("Content-Type"); !strings.HasPrefix(ct, "text/plain") {
		t.Errorf("content-type = %q", ct)
	}

	// A site that ships its own has said something deliberate.
	h = crawlerHandler(t, content.Settings{Base: "https://khosra.example"},
		fstest.MapFS{"robots.txt": {Data: []byte("User-agent: *\nDisallow: /drafts/\n")}})
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/robots.txt", nil))
	if got := rec.Body.String(); !strings.Contains(got, "Disallow: /drafts/") || strings.Contains(got, "Sitemap:") {
		t.Errorf("the site's own robots.txt should be served verbatim:\n%s", got)
	}
}

func TestRobotsWithoutABaseOmitsTheSitemapLine(t *testing.T) {
	h := crawlerHandler(t, content.Settings{}, nil)
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/robots.txt", nil))
	if got := rec.Body.String(); strings.Contains(got, "Sitemap:") {
		t.Errorf("a relative sitemap reference is not something a crawler accepts:\n%s", got)
	}
}