// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0

package consul

import (
	"context"
	"fmt"
	"os"
	"strings"
	"testing"
	"time"

	msgpackrpc "github.com/hashicorp/consul-net-rpc/net-rpc-msgpackrpc"
	"github.com/hashicorp/consul/agent/structs"
	"github.com/hashicorp/consul/sdk/testutil/retry"
	"github.com/hashicorp/consul/testrpc"
	"github.com/hashicorp/go-uuid"
)

func generateUUID() (ret string) {
	var err error
	if ret, err = uuid.GenerateUUID(); err != nil {
		panic(fmt.Sprintf("Unable to generate a UUID, %v", err))
	}
	return ret
}

func TestInitializeSessionTimers(t *testing.T) {
	if testing.Short() {
		t.Skip("too slow for testing.Short")
	}

	t.Parallel()
	dir1, s1 := testServer(t)
	defer os.RemoveAll(dir1)
	defer s1.Shutdown()

	testrpc.WaitForLeader(t, s1.RPC, "dc1")

	state := s1.fsm.State()
	if err := state.EnsureNode(1, &structs.Node{Node: "foo", Address: "127.0.0.1"}); err != nil {
		t.Fatalf("err: %s", err)
	}
	session := &structs.Session{
		ID:   generateUUID(),
		Node: "foo",
		TTL:  "10s",
	}
	if err := state.SessionCreate(100, session); err != nil {
		t.Fatalf("err: %v", err)
	}

	// Reset the session timers
	err := s1.initializeSessionTimers()
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	// Check that we have a timer
	if s1.sessionTimers.Get(session.ID) == nil {
		t.Fatalf("missing session timer")
	}
}

func TestResetSessionTimer_NoTTL(t *testing.T) {
	if testing.Short() {
		t.Skip("too slow for testing.Short")
	}

	t.Parallel()
	dir1, s1 := testServer(t)
	defer os.RemoveAll(dir1)
	defer s1.Shutdown()

	testrpc.WaitForLeader(t, s1.RPC, "dc1")

	// Create a session
	state := s1.fsm.State()
	if err := state.EnsureNode(1, &structs.Node{Node: "foo", Address: "127.0.0.1"}); err != nil {
		t.Fatalf("err: %s", err)
	}
	session := &structs.Session{
		ID:   generateUUID(),
		Node: "foo",
		TTL:  "0000s",
	}
	if err := state.SessionCreate(100, session); err != nil {
		t.Fatalf("err: %v", err)
	}

	// Reset the session timer
	err := s1.resetSessionTimer(session)
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	// Check that we have a timer
	if s1.sessionTimers.Get(session.ID) != nil {
		t.Fatalf("should not have session timer")
	}
}

func TestResetSessionTimer_InvalidTTL(t *testing.T) {
	t.Parallel()
	dir1, s1 := testServer(t)
	defer os.RemoveAll(dir1)
	defer s1.Shutdown()

	// Create a session
	session := &structs.Session{
		ID:   generateUUID(),
		Node: "foo",
		TTL:  "foo",
	}

	// Reset the session timer
	err := s1.resetSessionTimer(session)
	if err == nil || !strings.Contains(err.Error(), "Invalid Session TTL") {
		t.Fatalf("err: %v", err)
	}
}

func TestResetSessionTimerLocked(t *testing.T) {
	if testing.Short() {
		t.Skip("too slow for testing.Short")
	}

	t.Parallel()
	dir1, s1 := testServer(t)
	defer os.RemoveAll(dir1)
	defer s1.Shutdown()

	testrpc.WaitForLeader(t, s1.RPC, "dc1")

	s1.createSessionTimer("foo", 5*time.Millisecond, nil)
	if s1.sessionTimers.Get("foo") == nil {
		t.Fatalf("missing timer")
	}

	retry.Run(t, func(r *retry.R) {
		if s1.sessionTimers.Get("foo") != nil {
			r.Fatal("timer should be gone")
		}
	})
}

func TestResetSessionTimerLocked_Renew(t *testing.T) {
	if testing.Short() {
		t.Skip("too slow for testing.Short")
	}

	dir1, s1 := testServer(t)
	defer os.RemoveAll(dir1)
	defer s1.Shutdown()

	ttl := 100 * time.Millisecond

	retry.Run(t, func(r *retry.R) {
		// create the timer and make verify it was created
		s1.createSessionTimer("foo", ttl, nil)
		if s1.sessionTimers.Get("foo") == nil {
			r.Fatalf("missing timer")
		}

		// wait until it is "expired" but still exists
		// the session will exist until 2*ttl
		time.Sleep(ttl)
		if s1.sessionTimers.Get("foo") == nil {
			r.Fatal("missing timer")
		}
	})

	retry.Run(t, func(r *retry.R) {
		// renew the session which will reset the TTL to 2*ttl
		// since that is the current SessionTTLMultiplier
		s1.createSessionTimer("foo", ttl, nil)
		if s1.sessionTimers.Get("foo") == nil {
			r.Fatal("missing timer")
		}
		renew := time.Now()

		// Ensure invalidation happens after ttl
		for {
			// if timer still exists, sleep and continue
			if s1.sessionTimers.Get("foo") != nil {
				time.Sleep(time.Millisecond)
				continue
			}

			// fail if timer gone before ttl passes
			now := time.Now()
			if now.Sub(renew) < ttl {
				r.Fatalf("early invalidate")
			}
			break
		}
	})
}

func TestInvalidateSession(t *testing.T) {
	if testing.Short() {
		t.Skip("too slow for testing.Short")
	}

	t.Parallel()
	dir1, s1 := testServer(t)
	defer os.RemoveAll(dir1)
	defer s1.Shutdown()

	testrpc.WaitForLeader(t, s1.RPC, "dc1")

	// Create a session
	state := s1.fsm.State()
	if err := state.EnsureNode(1, &structs.Node{Node: "foo", Address: "127.0.0.1"}); err != nil {
		t.Fatalf("err: %s", err)
	}

	session := &structs.Session{
		ID:   generateUUID(),
		Node: "foo",
		TTL:  "10s",
	}
	if err := state.SessionCreate(100, session); err != nil {
		t.Fatalf("err: %v", err)
	}

	// This should cause a destroy
	s1.invalidateSession(session.ID, nil)

	// Check it is gone
	_, sess, err := state.SessionGet(nil, session.ID, nil)
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if sess != nil {
		t.Fatalf("should destroy session")
	}
}

func TestClearSessionTimer(t *testing.T) {
	t.Parallel()
	dir1, s1 := testServer(t)
	defer os.RemoveAll(dir1)
	defer s1.Shutdown()

	s1.createSessionTimer("foo", 5*time.Millisecond, nil)

	err := s1.clearSessionTimer("foo")
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	if s1.sessionTimers.Get("foo") != nil {
		t.Fatalf("timer should be gone")
	}
}

func TestClearAllSessionTimers(t *testing.T) {
	t.Parallel()
	dir1, s1 := testServer(t)
	defer os.RemoveAll(dir1)
	defer s1.Shutdown()

	s1.createSessionTimer("foo", 10*time.Millisecond, nil)
	s1.createSessionTimer("bar", 10*time.Millisecond, nil)
	s1.createSessionTimer("baz", 10*time.Millisecond, nil)

	s1.clearAllSessionTimers()

	// sessionTimers is guarded by the lock
	if s1.sessionTimers.Len() != 0 {
		t.Fatalf("timers should be gone")
	}
}

func TestServer_SessionTTL_Failover(t *testing.T) {
	if testing.Short() {
		t.Skip("too slow for testing.Short")
	}

	t.Parallel()
	dir1, s1 := testServer(t)
	defer os.RemoveAll(dir1)
	defer s1.Shutdown()
	testrpc.WaitForTestAgent(t, s1.RPC, "dc1")

	dir2, s2 := testServerDCBootstrap(t, "dc1", false)
	defer os.RemoveAll(dir2)
	defer s2.Shutdown()

	dir3, s3 := testServerDCBootstrap(t, "dc1", false)
	defer os.RemoveAll(dir3)
	defer s3.Shutdown()
	servers := []*Server{s1, s2, s3}

	// Try to join
	joinLAN(t, s2, s1)
	joinLAN(t, s3, s1)
	retry.Run(t, func(r *retry.R) { r.Check(wantPeers(s1, 3)) })

	// Find the leader
	var leader *Server
	for _, s := range servers {
		// Check that s.sessionTimers is empty
		if s.sessionTimers.Len() != 0 {
			t.Fatalf("should have no sessionTimers")
		}
		// Find the leader too
		if s.IsLeader() {
			leader = s
		}
	}
	if leader == nil {
		t.Fatalf("Should have a leader")
	}

	codec := rpcClient(t, leader)
	defer codec.Close()

	// Register a node
	node := structs.RegisterRequest{
		Datacenter: s1.config.Datacenter,
		Node:       "foo",
		Address:    "127.0.0.1",
	}
	var out struct{}
	if err := s1.RPC(context.Background(), "Catalog.Register", &node, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	// Create a TTL session
	arg := structs.SessionRequest{
		Datacenter: "dc1",
		Op:         structs.SessionCreate,
		Session: structs.Session{
			Node: "foo",
			TTL:  "10s",
		},
	}
	var id1 string
	if err := msgpackrpc.CallWithCodec(codec, "Session.Apply", &arg, &id1); err != nil {
		t.Fatalf("err: %v", err)
	}

	// Check that sessionTimers has the session ID
	if leader.sessionTimers.Get(id1) == nil {
		t.Fatalf("missing session timer")
	}

	// Shutdown the leader!
	leader.Shutdown()

	// sessionTimers should be cleared on leader shutdown
	if leader.sessionTimers.Len() != 0 {
		t.Fatalf("session timers should be empty on the shutdown leader")
	}
	// Find the new leader
	retry.Run(t, func(r *retry.R) {
		leader = nil
		for _, s := range servers {
			if s.IsLeader() {
				leader = s
			}
		}
		if leader == nil {
			r.Fatal("Should have a new leader")
		}

		// Ensure session timer is restored
		if leader.sessionTimers.Get(id1) == nil {
			r.Fatal("missing session timer")
		}
	})
}