package netguard

import (
	"context"
	"net"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"
)

func TestIsPublicIP(t *testing.T) {
	cases := map[string]bool{
		"8.8.8.8":         true,
		"1.1.1.1":         true,
		"127.0.0.1":       false,
		"10.0.0.1":        false,
		"172.16.0.1":      false,
		"192.168.1.1":     false,
		"169.254.169.254": false, // cloud metadata
		"100.64.0.1":      false, // CGNAT
		"0.0.0.0":         false,
		"::1":             false,
		"fe80::1":         false,
		"fc00::1":         false,
		"2606:4700::1111": true,
	}
	for s, want := range cases {
		ip := net.ParseIP(s)
		if ip == nil {
			t.Fatalf("bad test IP %q", s)
		}
		if got := IsPublicIP(ip); got != want {
			t.Errorf("IsPublicIP(%q) = %v, want %v", s, got, want)
		}
	}
}

func TestSafeHTTPClientBlocksLoopback(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("ok"))
	}))
	defer srv.Close()

	client := NewSafeHTTPClient(5*time.Second, false)
	_, err := client.Get(srv.URL)
	if err == nil {
		t.Fatal("expected request to loopback server to be blocked")
	}
}

func TestSafeHTTPClientAllowsLoopbackWhenPermitted(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("ok"))
	}))
	defer srv.Close()

	client := NewSafeHTTPClient(5*time.Second, true)
	resp, err := client.Get(srv.URL)
	if err != nil {
		t.Fatalf("expected request to loopback server to succeed: %v", err)
	}
	resp.Body.Close()
}

func TestSafeHTTPClientBlocksRedirectToPrivate(t *testing.T) {
	blocked := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("should never be reached"))
	}))
	defer blocked.Close()

	// A "public-looking" server (still loopback in this test, but with
	// AllowPrivateNetworks=false the initial dial to it would itself be
	// blocked — so instead verify redirect scheme enforcement directly
	// via CheckRedirect using a context that never dials at all).
	client := NewSafeHTTPClient(5*time.Second, false)
	req, _ := http.NewRequestWithContext(context.Background(), http.MethodGet, blocked.URL, nil)
	if err := client.CheckRedirect(req, nil); err != nil {
		t.Fatalf("unexpected error for allowed scheme: %v", err)
	}
	req.URL.Scheme = "file"
	if err := client.CheckRedirect(req, nil); err == nil {
		t.Fatal("expected file:// redirect to be rejected")
	}
}