package db

import (
	"crypto/rand"
	"fmt"
	"math/big"
	"net/netip"
	"regexp"
	"strconv"
	"sync"
	"testing"
	"time"

	"github.com/google/go-cmp/cmp"
	"github.com/juanfont/headscale/hscontrol/policy"
	"github.com/juanfont/headscale/hscontrol/types"
	"github.com/juanfont/headscale/hscontrol/util"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gopkg.in/check.v1"
	"gorm.io/gorm"
	"tailscale.com/net/tsaddr"
	"tailscale.com/tailcfg"
	"tailscale.com/types/key"
	"tailscale.com/types/ptr"
)

func (s *Suite) TestGetNode(c *check.C) {
	user, err := db.CreateUser(types.User{Name: "test"})
	c.Assert(err, check.IsNil)

	pak, err := db.CreatePreAuthKey(types.UserID(user.ID), false, false, nil, nil)
	c.Assert(err, check.IsNil)

	_, err = db.getNode(types.UserID(user.ID), "testnode")
	c.Assert(err, check.NotNil)

	nodeKey := key.NewNode()
	machineKey := key.NewMachine()

	node := &types.Node{
		ID:             0,
		MachineKey:     machineKey.Public(),
		NodeKey:        nodeKey.Public(),
		Hostname:       "testnode",
		UserID:         user.ID,
		RegisterMethod: util.RegisterMethodAuthKey,
		AuthKeyID:      ptr.To(pak.ID),
	}
	trx := db.DB.Save(node)
	c.Assert(trx.Error, check.IsNil)

	_, err = db.getNode(types.UserID(user.ID), "testnode")
	c.Assert(err, check.IsNil)
}

func (s *Suite) TestGetNodeByID(c *check.C) {
	user, err := db.CreateUser(types.User{Name: "test"})
	c.Assert(err, check.IsNil)

	pak, err := db.CreatePreAuthKey(types.UserID(user.ID), false, false, nil, nil)
	c.Assert(err, check.IsNil)

	_, err = db.GetNodeByID(0)
	c.Assert(err, check.NotNil)

	nodeKey := key.NewNode()
	machineKey := key.NewMachine()

	node := types.Node{
		ID:             0,
		MachineKey:     machineKey.Public(),
		NodeKey:        nodeKey.Public(),
		Hostname:       "testnode",
		UserID:         user.ID,
		RegisterMethod: util.RegisterMethodAuthKey,
		AuthKeyID:      ptr.To(pak.ID),
	}
	trx := db.DB.Save(&node)
	c.Assert(trx.Error, check.IsNil)

	_, err = db.GetNodeByID(0)
	c.Assert(err, check.IsNil)
}

func (s *Suite) TestHardDeleteNode(c *check.C) {
	user, err := db.CreateUser(types.User{Name: "test"})
	c.Assert(err, check.IsNil)

	nodeKey := key.NewNode()
	machineKey := key.NewMachine()

	node := types.Node{
		ID:             0,
		MachineKey:     machineKey.Public(),
		NodeKey:        nodeKey.Public(),
		Hostname:       "testnode3",
		UserID:         user.ID,
		RegisterMethod: util.RegisterMethodAuthKey,
	}
	trx := db.DB.Save(&node)
	c.Assert(trx.Error, check.IsNil)

	err = db.DeleteNode(&node)
	c.Assert(err, check.IsNil)

	_, err = db.getNode(types.UserID(user.ID), "testnode3")
	c.Assert(err, check.NotNil)
}

func (s *Suite) TestListPeers(c *check.C) {
	user, err := db.CreateUser(types.User{Name: "test"})
	c.Assert(err, check.IsNil)

	pak, err := db.CreatePreAuthKey(types.UserID(user.ID), false, false, nil, nil)
	c.Assert(err, check.IsNil)

	_, err = db.GetNodeByID(0)
	c.Assert(err, check.NotNil)

	for index := 0; index <= 10; index++ {
		nodeKey := key.NewNode()
		machineKey := key.NewMachine()

		node := types.Node{
			ID:             types.NodeID(index),
			MachineKey:     machineKey.Public(),
			NodeKey:        nodeKey.Public(),
			Hostname:       "testnode" + strconv.Itoa(index),
			UserID:         user.ID,
			RegisterMethod: util.RegisterMethodAuthKey,
			AuthKeyID:      ptr.To(pak.ID),
		}
		trx := db.DB.Save(&node)
		c.Assert(trx.Error, check.IsNil)
	}

	node0ByID, err := db.GetNodeByID(0)
	c.Assert(err, check.IsNil)

	peersOfNode0, err := db.ListPeers(node0ByID.ID)
	c.Assert(err, check.IsNil)

	c.Assert(len(peersOfNode0), check.Equals, 9)
	c.Assert(peersOfNode0[0].Hostname, check.Equals, "testnode2")
	c.Assert(peersOfNode0[5].Hostname, check.Equals, "testnode7")
	c.Assert(peersOfNode0[8].Hostname, check.Equals, "testnode10")
}

func (s *Suite) TestExpireNode(c *check.C) {
	user, err := db.CreateUser(types.User{Name: "test"})
	c.Assert(err, check.IsNil)

	pak, err := db.CreatePreAuthKey(types.UserID(user.ID), false, false, nil, nil)
	c.Assert(err, check.IsNil)

	_, err = db.getNode(types.UserID(user.ID), "testnode")
	c.Assert(err, check.NotNil)

	nodeKey := key.NewNode()
	machineKey := key.NewMachine()

	node := &types.Node{
		ID:             0,
		MachineKey:     machineKey.Public(),
		NodeKey:        nodeKey.Public(),
		Hostname:       "testnode",
		UserID:         user.ID,
		RegisterMethod: util.RegisterMethodAuthKey,
		AuthKeyID:      ptr.To(pak.ID),
		Expiry:         &time.Time{},
	}
	db.DB.Save(node)

	nodeFromDB, err := db.getNode(types.UserID(user.ID), "testnode")
	c.Assert(err, check.IsNil)
	c.Assert(nodeFromDB, check.NotNil)

	c.Assert(nodeFromDB.IsExpired(), check.Equals, false)

	now := time.Now()
	err = db.NodeSetExpiry(nodeFromDB.ID, now)
	c.Assert(err, check.IsNil)

	nodeFromDB, err = db.getNode(types.UserID(user.ID), "testnode")
	c.Assert(err, check.IsNil)

	c.Assert(nodeFromDB.IsExpired(), check.Equals, true)
}

func (s *Suite) TestSetTags(c *check.C) {
	user, err := db.CreateUser(types.User{Name: "test"})
	c.Assert(err, check.IsNil)

	pak, err := db.CreatePreAuthKey(types.UserID(user.ID), false, false, nil, nil)
	c.Assert(err, check.IsNil)

	_, err = db.getNode(types.UserID(user.ID), "testnode")
	c.Assert(err, check.NotNil)

	nodeKey := key.NewNode()
	machineKey := key.NewMachine()

	node := &types.Node{
		ID:             0,
		MachineKey:     machineKey.Public(),
		NodeKey:        nodeKey.Public(),
		Hostname:       "testnode",
		UserID:         user.ID,
		RegisterMethod: util.RegisterMethodAuthKey,
		AuthKeyID:      ptr.To(pak.ID),
	}

	trx := db.DB.Save(node)
	c.Assert(trx.Error, check.IsNil)

	// assign simple tags
	sTags := []string{"tag:test", "tag:foo"}
	err = db.SetTags(node.ID, sTags)
	c.Assert(err, check.IsNil)
	node, err = db.getNode(types.UserID(user.ID), "testnode")
	c.Assert(err, check.IsNil)
	c.Assert(node.ForcedTags, check.DeepEquals, sTags)

	// assign duplicate tags, expect no errors but no doubles in DB
	eTags := []string{"tag:bar", "tag:test", "tag:unknown", "tag:test"}
	err = db.SetTags(node.ID, eTags)
	c.Assert(err, check.IsNil)
	node, err = db.getNode(types.UserID(user.ID), "testnode")
	c.Assert(err, check.IsNil)
	c.Assert(
		node.ForcedTags,
		check.DeepEquals,
		[]string{"tag:bar", "tag:test", "tag:unknown"},
	)

	// test removing tags
	err = db.SetTags(node.ID, []string{})
	c.Assert(err, check.IsNil)
	node, err = db.getNode(types.UserID(user.ID), "testnode")
	c.Assert(err, check.IsNil)
	c.Assert(node.ForcedTags, check.DeepEquals, []string{})
}

func TestHeadscale_generateGivenName(t *testing.T) {
	type args struct {
		suppliedName string
		randomSuffix bool
	}
	tests := []struct {
		name    string
		args    args
		want    *regexp.Regexp
		wantErr bool
	}{
		{
			name: "simple node name generation",
			args: args{
				suppliedName: "testnode",
				randomSuffix: false,
			},
			want:    regexp.MustCompile("^testnode$"),
			wantErr: false,
		},
		{
			name: "UPPERCASE node name generation",
			args: args{
				suppliedName: "TestNode",
				randomSuffix: false,
			},
			want:    regexp.MustCompile("^testnode$"),
			wantErr: false,
		},
		{
			name: "node name with 53 chars",
			args: args{
				suppliedName: "testmaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaachine",
				randomSuffix: false,
			},
			want:    regexp.MustCompile("^testmaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaachine$"),
			wantErr: false,
		},
		{
			name: "node name with 63 chars",
			args: args{
				suppliedName: "nodeeeeeee12345678901234567890123456789012345678901234567890123",
				randomSuffix: false,
			},
			want:    regexp.MustCompile("^nodeeeeeee12345678901234567890123456789012345678901234567890123$"),
			wantErr: false,
		},
		{
			name: "node name with 64 chars",
			args: args{
				suppliedName: "nodeeeeeee123456789012345678901234567890123456789012345678901234",
				randomSuffix: false,
			},
			want:    nil,
			wantErr: true,
		},
		{
			name: "node name with 73 chars",
			args: args{
				suppliedName: "nodeeeeeee123456789012345678901234567890123456789012345678901234567890123",
				randomSuffix: false,
			},
			want:    nil,
			wantErr: true,
		},
		{
			name: "node name with random suffix",
			args: args{
				suppliedName: "test",
				randomSuffix: true,
			},
			want:    regexp.MustCompile(fmt.Sprintf("^test-[a-z0-9]{%d}$", NodeGivenNameHashLength)),
			wantErr: false,
		},
		{
			name: "node name with 63 chars with random suffix",
			args: args{
				suppliedName: "nodeeee12345678901234567890123456789012345678901234567890123",
				randomSuffix: true,
			},
			want:    regexp.MustCompile(fmt.Sprintf("^nodeeee1234567890123456789012345678901234567890123456-[a-z0-9]{%d}$", NodeGivenNameHashLength)),
			wantErr: false,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := generateGivenName(tt.args.suppliedName, tt.args.randomSuffix)
			if (err != nil) != tt.wantErr {
				t.Errorf(
					"Headscale.GenerateGivenName() error = %v, wantErr %v",
					err,
					tt.wantErr,
				)

				return
			}

			if tt.want != nil && !tt.want.MatchString(got) {
				t.Errorf(
					"Headscale.GenerateGivenName() = %v, does not match %v",
					tt.want,
					got,
				)
			}

			if len(got) > util.LabelHostnameLength {
				t.Errorf(
					"Headscale.GenerateGivenName() = %v is larger than allowed DNS segment %d",
					got,
					util.LabelHostnameLength,
				)
			}
		})
	}
}

func TestAutoApproveRoutes(t *testing.T) {
	tests := []struct {
		name   string
		acl    string
		routes []netip.Prefix
		want   []netip.Prefix
		want2  []netip.Prefix
	}{
		{
			name: "2068-approve-issue-sub-kube",
			acl: `
{
	"groups": {
		"group:k8s": ["test@"]
	},

// 	"acls": [
// 		{"action": "accept", "users": ["*"], "ports": ["*:*"]},
// 	],

	"autoApprovers": {
		"routes": {
			"10.42.0.0/16": ["test@"],
		}
	}
}`,
			routes: []netip.Prefix{netip.MustParsePrefix("10.42.7.0/24")},
			want:   []netip.Prefix{netip.MustParsePrefix("10.42.7.0/24")},
		},
		{
			name: "2068-approve-issue-sub-exit-tag",
			acl: `
{
	"tagOwners": {
		"tag:exit": ["test@"],
	},

	"groups": {
		"group:test": ["test@"]
	},

// 	"acls": [
// 		{"action": "accept", "users": ["*"], "ports": ["*:*"]},
// 	],

	"autoApprovers": {
		"exitNode": ["tag:exit"],
		"routes": {
			"10.10.0.0/16": ["group:test"],
			"10.11.0.0/16": ["test@"],
			"8.11.0.0/24": ["test2@"], // No nodes
		}
	}
}`,
			routes: []netip.Prefix{
				tsaddr.AllIPv4(),
				tsaddr.AllIPv6(),
				netip.MustParsePrefix("10.10.0.0/16"),
				netip.MustParsePrefix("10.11.0.0/24"),

				// Not approved
				netip.MustParsePrefix("8.11.0.0/24"),
			},
			want: []netip.Prefix{
				netip.MustParsePrefix("10.10.0.0/16"),
				netip.MustParsePrefix("10.11.0.0/24"),
			},
			want2: []netip.Prefix{
				tsaddr.AllIPv4(),
				tsaddr.AllIPv6(),
			},
		},
	}

	for _, tt := range tests {
		pmfs := policy.PolicyManagerFuncsForTest([]byte(tt.acl))
		for i, pmf := range pmfs {
			version := i + 1
			t.Run(fmt.Sprintf("%s-policyv%d", tt.name, version), func(t *testing.T) {
				adb, err := newSQLiteTestDB()
				require.NoError(t, err)

				suffix := ""
				if version == 1 {
					suffix = "@"
				}

				user, err := adb.CreateUser(types.User{Name: "test" + suffix})
				require.NoError(t, err)
				_, err = adb.CreateUser(types.User{Name: "test2" + suffix})
				require.NoError(t, err)
				taggedUser, err := adb.CreateUser(types.User{Name: "tagged" + suffix})
				require.NoError(t, err)

				node := types.Node{
					ID:             1,
					MachineKey:     key.NewMachine().Public(),
					NodeKey:        key.NewNode().Public(),
					Hostname:       "testnode",
					UserID:         user.ID,
					RegisterMethod: util.RegisterMethodAuthKey,
					Hostinfo: &tailcfg.Hostinfo{
						RoutableIPs: tt.routes,
					},
					IPv4: ptr.To(netip.MustParseAddr("100.64.0.1")),
				}

				err = adb.DB.Save(&node).Error
				require.NoError(t, err)

				nodeTagged := types.Node{
					ID:             2,
					MachineKey:     key.NewMachine().Public(),
					NodeKey:        key.NewNode().Public(),
					Hostname:       "taggednode",
					UserID:         taggedUser.ID,
					RegisterMethod: util.RegisterMethodAuthKey,
					Hostinfo: &tailcfg.Hostinfo{
						RoutableIPs: tt.routes,
					},
					ForcedTags: []string{"tag:exit"},
					IPv4:       ptr.To(netip.MustParseAddr("100.64.0.2")),
				}

				err = adb.DB.Save(&nodeTagged).Error
				require.NoError(t, err)

				users, err := adb.ListUsers()
				assert.NoError(t, err)

				nodes, err := adb.ListNodes()
				assert.NoError(t, err)

				pm, err := pmf(users, nodes)
				require.NoError(t, err)
				require.NotNil(t, pm)

				changed1 := policy.AutoApproveRoutes(pm, &node)
				assert.True(t, changed1)

				err = adb.DB.Save(&node).Error
				require.NoError(t, err)

				_ = policy.AutoApproveRoutes(pm, &nodeTagged)

				err = adb.DB.Save(&nodeTagged).Error
				require.NoError(t, err)

				node1ByID, err := adb.GetNodeByID(1)
				require.NoError(t, err)

				if diff := cmp.Diff(tt.want, node1ByID.SubnetRoutes(), util.Comparers...); diff != "" {
					t.Errorf("unexpected enabled routes (-want +got):\n%s", diff)
				}

				node2ByID, err := adb.GetNodeByID(2)
				require.NoError(t, err)

				if diff := cmp.Diff(tt.want2, node2ByID.SubnetRoutes(), util.Comparers...); diff != "" {
					t.Errorf("unexpected enabled routes (-want +got):\n%s", diff)
				}
			})
		}
	}
}

func TestEphemeralGarbageCollectorOrder(t *testing.T) {
	want := []types.NodeID{1, 3}
	got := []types.NodeID{}
	var mu sync.Mutex

	e := NewEphemeralGarbageCollector(func(ni types.NodeID) {
		mu.Lock()
		defer mu.Unlock()
		got = append(got, ni)
	})
	go e.Start()

	go e.Schedule(1, 1*time.Second)
	go e.Schedule(2, 2*time.Second)
	go e.Schedule(3, 3*time.Second)
	go e.Schedule(4, 4*time.Second)

	time.Sleep(time.Second)
	go e.Cancel(2)
	go e.Cancel(4)

	time.Sleep(6 * time.Second)

	e.Close()

	mu.Lock()
	defer mu.Unlock()

	if diff := cmp.Diff(want, got); diff != "" {
		t.Errorf("wrong nodes deleted, unexpected result (-want +got):\n%s", diff)
	}
}

func TestEphemeralGarbageCollectorLoads(t *testing.T) {
	var got []types.NodeID
	var mu sync.Mutex

	want := 1000

	e := NewEphemeralGarbageCollector(func(ni types.NodeID) {
		mu.Lock()
		defer mu.Unlock()

		time.Sleep(time.Duration(generateRandomNumber(t, 3)) * time.Millisecond)
		got = append(got, ni)
	})
	go e.Start()

	for i := 0; i < want; i++ {
		go e.Schedule(types.NodeID(i), 1*time.Second)
	}

	time.Sleep(10 * time.Second)

	e.Close()

	mu.Lock()
	defer mu.Unlock()

	if len(got) != want {
		t.Errorf("expected %d, got %d", want, len(got))
	}
}

func generateRandomNumber(t *testing.T, max int64) int64 {
	t.Helper()
	maxB := big.NewInt(max)
	n, err := rand.Int(rand.Reader, maxB)
	if err != nil {
		t.Fatalf("getting random number: %s", err)
	}
	return n.Int64() + 1
}

func TestListEphemeralNodes(t *testing.T) {
	db, err := newSQLiteTestDB()
	if err != nil {
		t.Fatalf("creating db: %s", err)
	}

	user, err := db.CreateUser(types.User{Name: "test"})
	require.NoError(t, err)

	pak, err := db.CreatePreAuthKey(types.UserID(user.ID), false, false, nil, nil)
	require.NoError(t, err)

	pakEph, err := db.CreatePreAuthKey(types.UserID(user.ID), false, true, nil, nil)
	require.NoError(t, err)

	node := types.Node{
		ID:             0,
		MachineKey:     key.NewMachine().Public(),
		NodeKey:        key.NewNode().Public(),
		Hostname:       "test",
		UserID:         user.ID,
		RegisterMethod: util.RegisterMethodAuthKey,
		AuthKeyID:      ptr.To(pak.ID),
	}

	nodeEph := types.Node{
		ID:             0,
		MachineKey:     key.NewMachine().Public(),
		NodeKey:        key.NewNode().Public(),
		Hostname:       "ephemeral",
		UserID:         user.ID,
		RegisterMethod: util.RegisterMethodAuthKey,
		AuthKeyID:      ptr.To(pakEph.ID),
	}

	err = db.DB.Save(&node).Error
	require.NoError(t, err)

	err = db.DB.Save(&nodeEph).Error
	require.NoError(t, err)

	nodes, err := db.ListNodes()
	require.NoError(t, err)

	ephemeralNodes, err := db.ListEphemeralNodes()
	require.NoError(t, err)

	assert.Len(t, nodes, 2)
	assert.Len(t, ephemeralNodes, 1)

	assert.Equal(t, nodeEph.ID, ephemeralNodes[0].ID)
	assert.Equal(t, nodeEph.AuthKeyID, ephemeralNodes[0].AuthKeyID)
	assert.Equal(t, nodeEph.UserID, ephemeralNodes[0].UserID)
	assert.Equal(t, nodeEph.Hostname, ephemeralNodes[0].Hostname)
}

func TestRenameNode(t *testing.T) {
	db, err := newSQLiteTestDB()
	if err != nil {
		t.Fatalf("creating db: %s", err)
	}

	user, err := db.CreateUser(types.User{Name: "test"})
	require.NoError(t, err)

	user2, err := db.CreateUser(types.User{Name: "user2"})
	require.NoError(t, err)

	node := types.Node{
		ID:             0,
		MachineKey:     key.NewMachine().Public(),
		NodeKey:        key.NewNode().Public(),
		Hostname:       "test",
		UserID:         user.ID,
		RegisterMethod: util.RegisterMethodAuthKey,
		Hostinfo:       &tailcfg.Hostinfo{},
	}

	node2 := types.Node{
		ID:             0,
		MachineKey:     key.NewMachine().Public(),
		NodeKey:        key.NewNode().Public(),
		Hostname:       "test",
		UserID:         user2.ID,
		RegisterMethod: util.RegisterMethodAuthKey,
		Hostinfo:       &tailcfg.Hostinfo{},
	}

	err = db.DB.Save(&node).Error
	require.NoError(t, err)

	err = db.DB.Save(&node2).Error
	require.NoError(t, err)

	err = db.DB.Transaction(func(tx *gorm.DB) error {
		_, err := RegisterNode(tx, node, nil, nil)
		if err != nil {
			return err
		}
		_, err = RegisterNode(tx, node2, nil, nil)
		return err
	})
	require.NoError(t, err)

	nodes, err := db.ListNodes()
	require.NoError(t, err)

	assert.Len(t, nodes, 2)

	t.Logf("node1 %s %s", nodes[0].Hostname, nodes[0].GivenName)
	t.Logf("node2 %s %s", nodes[1].Hostname, nodes[1].GivenName)

	assert.Equal(t, nodes[0].Hostname, nodes[0].GivenName)
	assert.NotEqual(t, nodes[1].Hostname, nodes[1].GivenName)
	assert.Equal(t, nodes[0].Hostname, nodes[1].Hostname)
	assert.NotEqual(t, nodes[0].Hostname, nodes[1].GivenName)
	assert.Contains(t, nodes[1].GivenName, nodes[0].Hostname)
	assert.Equal(t, nodes[0].GivenName, nodes[1].Hostname)
	assert.Len(t, nodes[0].Hostname, 4)
	assert.Len(t, nodes[1].Hostname, 4)
	assert.Len(t, nodes[0].GivenName, 4)
	assert.Len(t, nodes[1].GivenName, 13)

	// Nodes can be renamed to a unique name
	err = db.Write(func(tx *gorm.DB) error {
		return RenameNode(tx, nodes[0].ID, "newname")
	})
	require.NoError(t, err)

	nodes, err = db.ListNodes()
	require.NoError(t, err)
	assert.Len(t, nodes, 2)
	assert.Equal(t, "test", nodes[0].Hostname)
	assert.Equal(t, "newname", nodes[0].GivenName)

	// Nodes can reuse name that is no longer used
	err = db.Write(func(tx *gorm.DB) error {
		return RenameNode(tx, nodes[1].ID, "test")
	})
	require.NoError(t, err)

	nodes, err = db.ListNodes()
	require.NoError(t, err)
	assert.Len(t, nodes, 2)
	assert.Equal(t, "test", nodes[0].Hostname)
	assert.Equal(t, "newname", nodes[0].GivenName)
	assert.Equal(t, "test", nodes[1].GivenName)

	// Nodes cannot be renamed to used names
	err = db.Write(func(tx *gorm.DB) error {
		return RenameNode(tx, nodes[0].ID, "test")
	})
	assert.ErrorContains(t, err, "name is not unique")
}