package httpapi

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestClientIP(t *testing.T) {
	cases := []struct {
		name       string
		remoteAddr string
		headers    map[string]string
		want       string
		wantErr    bool
	}{
		{name: "ipv4", remoteAddr: "90.156.213.5:51234", want: "90.156.213.5"},
		{name: "ipv4 mapped in ipv6", remoteAddr: "[::ffff:90.156.213.5]:51234", want: "90.156.213.5"},
		{name: "ipv6", remoteAddr: "[2001:db8::7]:443", want: "2001:db8::7"},
		// A client-supplied header must never change the answer.
		{name: "forwarded for is ignored", remoteAddr: "90.156.213.5:1",
			headers: map[string]string{"X-Forwarded-For": "1.2.3.4", "X-Real-IP": "5.6.7.8"}, want: "90.156.213.5"},
		{name: "no port", remoteAddr: "90.156.213.5", wantErr: true},
		{name: "not an address", remoteAddr: "host:80", wantErr: true},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			r := httptest.NewRequest(http.MethodGet, "/", nil)
			r.RemoteAddr = tc.remoteAddr
			for k, v := range tc.headers {
				r.Header.Set(k, v)
			}
			got, err := clientIP(r)
			if tc.wantErr {
				if err == nil {
					t.Fatalf("expected an error, got %q", got)
				}
				return
			}
			if err != nil || got != tc.want {
				t.Fatalf("clientIP = %q, %v; want %q", got, err, tc.want)
			}
		})
	}
}

// The route is open (no token), answers a known validator with the address
// control-api sees, and refuses unknown validators and a forged header.
func TestObservedIPEndpoint(t *testing.T) {
	fc, d, _, _ := newConfigTestHarness(t)
	if err := d.RegisterValidator(context.Background(), "validator-1", "host-1", "port-1", "v0.1"); err != nil {
		t.Fatal(err)
	}

	req, _ := http.NewRequest(http.MethodGet, fc.base+"/api/v1/agents/validator-1/observed-ip", nil)
	req.Header.Set("X-Forwarded-For", "8.8.8.8")
	resp, err := fc.client.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("status = %d, want 200", resp.StatusCode)
	}
	var got observedIPResponse
	if err := json.NewDecoder(resp.Body).Decode(&got); err != nil {
		t.Fatal(err)
	}
	// httptest connects from loopback; the forged header must not leak through.
	if got.IP != "127.0.0.1" || got.Source != "remote_addr" {
		t.Fatalf("response = %+v, want 127.0.0.1 / remote_addr", got)
	}

	if resp, _ := fc.do(http.MethodGet, "/api/v1/agents/no-such-validator/observed-ip", nil); resp.StatusCode != http.StatusNotFound {
		t.Fatalf("unknown validator: status = %d, want 404", resp.StatusCode)
	}
}