package scraper

import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"testing"
)

// newDetectServer serves a robots.txt that allows /api/ plus the given
// version paths. Returns the server's fqdn (host:port).
func newDetectServer(t *testing.T, versionPaths ...string) string {
	t.Helper()
	mux := http.NewServeMux()
	mux.HandleFunc("/robots.txt", func(w http.ResponseWriter, r *http.Request) {
		_, _ = fmt.Fprintln(w, "User-agent: *")
		_, _ = fmt.Fprintln(w, "Allow: /")
	})
	for _, p := range versionPaths {
		p := p
		mux.HandleFunc(p, func(w http.ResponseWriter, r *http.Request) {
			w.Header().Set("Content-Type", "application/json")
			_, _ = fmt.Fprintln(w, `{"version":"16.0.5"}`)
		})
	}
	srv := httptest.NewServer(mux)
	t.Cleanup(srv.Close)
	return srv.Listener.Addr().String()
}

func TestDetectForgejo(t *testing.T) {
	// Forgejo serves BOTH endpoints; the Forgejo-native one must win.
	fqdn := newDetectServer(t, "/api/forgejo/v1/version", "/api/v1/version")

	typ, version, err := detectAt("http://" + fqdn)
	if err != nil {
		t.Fatalf("detect: %v", err)
	}
	if typ != TypeForgejo {
		t.Errorf("expected TypeForgejo, got %q", typ)
	}
	if version != "16.0.5" {
		t.Errorf("expected version 16.0.5, got %q", version)
	}
}

func TestDetectGitea(t *testing.T) {
	// Gitea serves only the shared /api/v1/version endpoint.
	fqdn := newDetectServer(t, "/api/v1/version")

	typ, version, err := detectAt("http://" + fqdn)
	if err != nil {
		t.Fatalf("detect: %v", err)
	}
	if typ != TypeGitea {
		t.Errorf("expected TypeGitea, got %q", typ)
	}
	if version != "16.0.5" {
		t.Errorf("expected version 16.0.5, got %q", version)
	}
}

func TestDetectUnknown(t *testing.T) {
	// A server that serves robots but no version endpoint.
	fqdn := newDetectServer(t)

	typ, version, err := detectAt("http://" + fqdn)
	if err != nil {
		t.Fatalf("detect: %v", err)
	}
	if typ != TypeUnknown {
		t.Errorf("expected TypeUnknown, got %q", typ)
	}
	if version != "" {
		t.Errorf("expected empty version, got %q", version)
	}
}

func TestDetectHonorsRobotsDisallow(t *testing.T) {
	mux := http.NewServeMux()
	mux.HandleFunc("/robots.txt", func(w http.ResponseWriter, r *http.Request) {
		_, _ = fmt.Fprintln(w, "User-agent: *")
		_, _ = fmt.Fprintln(w, "Disallow: /api/")
	})
	mux.HandleFunc("/api/forgejo/v1/version", func(w http.ResponseWriter, r *http.Request) {
		_, _ = fmt.Fprintln(w, `{"version":"16.0.5"}`)
	})
	srv := httptest.NewServer(mux)
	t.Cleanup(srv.Close)
	fqdn := srv.Listener.Addr().String()

	typ, version, err := detectAt("http://" + fqdn)
	if err != nil {
		t.Fatalf("detect: %v", err)
	}
	if typ != TypeUnknown {
		t.Errorf("expected TypeUnknown when /api/ is disallowed, got %q", typ)
	}
	if version != "" {
		t.Errorf("expected empty version when disallowed, got %q", version)
	}
}