// Copyright 2019 The NATS Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package server

import (
	"context"
	"fmt"
	"net/url"
	"os"
	"strings"
	"testing"
	"time"
)

type captureLeafNodeRandomIPLogger struct {
	DummyLogger
	ch  chan struct{}
	ips [3]int
}

func (c *captureLeafNodeRandomIPLogger) Debugf(format string, v ...interface{}) {
	msg := fmt.Sprintf(format, v...)
	if strings.Contains(msg, "hostname_to_resolve") {
		ippos := strings.Index(msg, "127.0.0.")
		if ippos != -1 {
			n := int(msg[ippos+8] - '1')
			c.ips[n]++
			for _, v := range c.ips {
				if v < 2 {
					return
				}
			}
			// All IPs got at least some hit, we are done.
			c.ch <- struct{}{}
		}
	}
}

func TestLeafNodeRandomIP(t *testing.T) {
	u, err := url.Parse("nats://hostname_to_resolve:1234")
	if err != nil {
		t.Fatalf("Error parsing: %v", err)
	}

	resolver := &myDummyDNSResolver{ips: []string{"127.0.0.1", "127.0.0.2", "127.0.0.3"}}

	o := DefaultOptions()
	o.Host = "127.0.0.1"
	o.Port = -1
	o.LeafNode.Port = 0
	o.LeafNode.Remotes = []*RemoteLeafOpts{{URL: u}}
	o.LeafNode.ReconnectInterval = 50 * time.Millisecond
	o.LeafNode.resolver = resolver
	o.LeafNode.dialTimeout = 15 * time.Millisecond
	s := RunServer(o)
	defer s.Shutdown()

	l := &captureLeafNodeRandomIPLogger{ch: make(chan struct{})}
	s.SetLogger(l, true, true)

	select {
	case <-l.ch:
	case <-time.After(3 * time.Second):
		t.Fatalf("Does not seem to have used random IPs")
	}
}

type testLoopbackResolver struct{}

func (r *testLoopbackResolver) LookupHost(ctx context.Context, host string) ([]string, error) {
	return []string{"127.0.0.1"}, nil
}

func TestLeafNodeTLSWithCerts(t *testing.T) {
	conf1 := createConfFile(t, []byte(`
		port: -1
		leaf {
			listen: "127.0.0.1:-1"
			tls {
				ca_file: "../test/configs/certs/tlsauth/ca.pem"
				cert_file: "../test/configs/certs/tlsauth/server.pem"
				key_file:  "../test/configs/certs/tlsauth/server-key.pem"
				timeout: 2
			}
		}
	`))
	defer os.Remove(conf1)
	s1, o1 := RunServerWithConfig(conf1)
	defer s1.Shutdown()

	u, err := url.Parse(fmt.Sprintf("nats://localhost:%d", o1.LeafNode.Port))
	if err != nil {
		t.Fatalf("Error parsing url: %v", err)
	}
	conf2 := createConfFile(t, []byte(fmt.Sprintf(`
		port: -1
		leaf {
			remotes [
				{
					url: "%s"
					tls {
						ca_file: "../test/configs/certs/tlsauth/ca.pem"
						cert_file: "../test/configs/certs/tlsauth/client.pem"
						key_file:  "../test/configs/certs/tlsauth/client-key.pem"
						timeout: 2
					}
				}
			]
		}
	`, u.String())))
	defer os.Remove(conf2)
	o2, err := ProcessConfigFile(conf2)
	if err != nil {
		t.Fatalf("Error processing config file: %v", err)
	}
	o2.NoLog, o2.NoSigs = true, true
	o2.LeafNode.resolver = &testLoopbackResolver{}
	s2 := RunServer(o2)
	defer s2.Shutdown()

	checkFor(t, 3*time.Second, 10*time.Millisecond, func() error {
		if nln := s1.NumLeafNodes(); nln != 1 {
			return fmt.Errorf("Number of leaf nodes is %d", nln)
		}
		return nil
	})
}

func TestLeafNodeTLSRemoteWithNoCerts(t *testing.T) {
	conf1 := createConfFile(t, []byte(`
		port: -1
		leaf {
			listen: "127.0.0.1:-1"
			tls {
				ca_file: "../test/configs/certs/tlsauth/ca.pem"
				cert_file: "../test/configs/certs/tlsauth/server.pem"
				key_file:  "../test/configs/certs/tlsauth/server-key.pem"
				timeout: 2
			}
		}
	`))
	defer os.Remove(conf1)
	s1, o1 := RunServerWithConfig(conf1)
	defer s1.Shutdown()

	u, err := url.Parse(fmt.Sprintf("nats://localhost:%d", o1.LeafNode.Port))
	if err != nil {
		t.Fatalf("Error parsing url: %v", err)
	}
	conf2 := createConfFile(t, []byte(fmt.Sprintf(`
		port: -1
		leaf {
			remotes [
				{
					url: "%s"
					tls {
						ca_file: "../test/configs/certs/tlsauth/ca.pem"
						timeout: 5
					}
				}
			]
		}
	`, u.String())))
	defer os.Remove(conf2)
	o2, err := ProcessConfigFile(conf2)
	if err != nil {
		t.Fatalf("Error processing config file: %v", err)
	}

	if len(o2.LeafNode.Remotes) == 0 {
		t.Fatal("Expected at least a single leaf remote")
	}

	var (
		got      float64 = o2.LeafNode.Remotes[0].TLSTimeout
		expected float64 = 5
	)
	if got != expected {
		t.Fatalf("Expected %v, got: %v", expected, got)
	}
	o2.NoLog, o2.NoSigs = true, true
	o2.LeafNode.resolver = &testLoopbackResolver{}
	s2 := RunServer(o2)
	defer s2.Shutdown()

	checkFor(t, 3*time.Second, 10*time.Millisecond, func() error {
		if nln := s1.NumLeafNodes(); nln != 1 {
			return fmt.Errorf("Number of leaf nodes is %d", nln)
		}
		return nil
	})

	// Here we only process options without starting the server
	// and without a root CA for the remote.
	conf3 := createConfFile(t, []byte(fmt.Sprintf(`
		port: -1
		leaf {
			remotes [
				{
					url: "%s"
					tls {
						timeout: 10
					}
				}
			]
		}
	`, u.String())))
	defer os.Remove(conf3)
	o3, err := ProcessConfigFile(conf3)
	if err != nil {
		t.Fatalf("Error processing config file: %v", err)
	}

	if len(o3.LeafNode.Remotes) == 0 {
		t.Fatal("Expected at least a single leaf remote")
	}
	got = o3.LeafNode.Remotes[0].TLSTimeout
	expected = 10
	if got != expected {
		t.Fatalf("Expected %v, got: %v", expected, got)
	}

	// Here we only process options without starting the server
	// and check the default for leafnode remotes.
	conf4 := createConfFile(t, []byte(fmt.Sprintf(`
		port: -1
		leaf {
			remotes [
				{
					url: "%s"
					tls {
						ca_file: "../test/configs/certs/tlsauth/ca.pem"
					}
				}
			]
		}
	`, u.String())))
	defer os.Remove(conf4)
	o4, err := ProcessConfigFile(conf4)
	if err != nil {
		t.Fatalf("Error processing config file: %v", err)
	}

	if len(o4.LeafNode.Remotes) == 0 {
		t.Fatal("Expected at least a single leaf remote")
	}
	got = o4.LeafNode.Remotes[0].TLSTimeout
	expected = float64(DEFAULT_LEAF_TLS_TIMEOUT)
	if int(got) != int(expected) {
		t.Fatalf("Expected %v, got: %v", expected, got)
	}
}