// deleteGroups ensures the given groups are deleted, by retrying
// until a timeout or all groups cannot be found anymore.
// This should be used to make sure tests leave no groups around.
func (s *ServerTests) deleteGroups(c *C, groups []ec2.SecurityGroup) {
	testAttempt := aws.AttemptStrategy{
		Total: 2 * time.Minute,
		Delay: 5 * time.Second,
	}
	for a := testAttempt.Start(); a.Next(); {
		deleted := 0
		c.Logf("deleting groups %v", groups)
		for _, group := range groups {
			_, err := s.ec2.DeleteSecurityGroup(group)
			if err == nil || errorCode(err) == "InvalidGroup.NotFound" {
				c.Logf("group %v deleted", group)
				deleted++
				continue
			}
			if err != nil {
				c.Logf("retrying; DeleteSecurityGroup returned: %v", err)
			}
		}
		if deleted == len(groups) {
			c.Logf("all groups deleted")
			return
		}
	}
	c.Fatalf("timeout while waiting %v groups to get deleted!", groups)
}

func (S) TestAttemptTiming(c *C) {
	testAttempt := aws.AttemptStrategy{
		Total: 0.25e9,
		Delay: 0.1e9,
	}
	want := []time.Duration{0, 0.1e9, 0.2e9, 0.2e9}
	got := make([]time.Duration, 0, len(want)) // avoid allocation when testing timing
	t0 := time.Now()
	for a := testAttempt.Start(); a.Next(); {
		got = append(got, time.Now().Sub(t0))
	}
	got = append(got, time.Now().Sub(t0))
	c.Assert(got, HasLen, len(want))
	const margin = 0.01e9
	for i, got := range want {
		lo := want[i] - margin
		hi := want[i] + margin
		if got < lo || got > hi {
			c.Errorf("attempt %d want %g got %g", i, want[i].Seconds(), got.Seconds())
		}
	}
}

func terminateInstances(c *C, e *ec2.EC2, ids []string) {
	_, err := e.TerminateInstances(ids)
	c.Assert(err, IsNil, Commentf("%v INSTANCES LEFT RUNNING!!!", ids))
	// We need to wait until the instances are really off, because
	// entities that depend on them won't be deleted (i.e. groups,
	// NICs, subnets, etc.)
	testAttempt := aws.AttemptStrategy{
		Total: 10 * time.Minute,
		Delay: 5 * time.Second,
	}
	f := ec2.NewFilter()
	f.Add("instance-state-name", "terminated")
	idsLeft := make(map[string]bool)
	for _, id := range ids {
		idsLeft[id] = true
	}
	for a := testAttempt.Start(); a.Next(); {
		c.Logf("waiting for %v to get terminated", ids)
		resp, err := e.Instances(ids, f)
		if err != nil {
			c.Fatalf("not waiting for %v to terminate: %v", ids, err)
		}
		for _, r := range resp.Reservations {
			for _, inst := range r.Instances {
				delete(idsLeft, inst.InstanceId)
			}
		}
		ids = []string{}
		for id, _ := range idsLeft {
			ids = append(ids, id)
		}
		if len(ids) == 0 {
			c.Logf("all instances terminated.")
			return
		}
	}
	c.Fatalf("%v INSTANCES LEFT RUNNING!!!", ids)
}

func (S) TestAttemptNextHasNext(c *C) {
	a := aws.AttemptStrategy{}.Start()
	c.Assert(a.Next(), Equals, true)
	c.Assert(a.Next(), Equals, false)

	a = aws.AttemptStrategy{}.Start()
	c.Assert(a.Next(), Equals, true)
	c.Assert(a.HasNext(), Equals, false)
	c.Assert(a.Next(), Equals, false)

	a = aws.AttemptStrategy{Total: 2e8}.Start()
	c.Assert(a.Next(), Equals, true)
	c.Assert(a.HasNext(), Equals, true)
	time.Sleep(2e8)
	c.Assert(a.HasNext(), Equals, true)
	c.Assert(a.Next(), Equals, true)
	c.Assert(a.Next(), Equals, false)

	a = aws.AttemptStrategy{Total: 1e8, Min: 2}.Start()
	time.Sleep(1e8)
	c.Assert(a.Next(), Equals, true)
	c.Assert(a.HasNext(), Equals, true)
	c.Assert(a.Next(), Equals, true)
	c.Assert(a.HasNext(), Equals, false)
	c.Assert(a.Next(), Equals, false)
}

func (s *AmazonServerSuite) TestRunInstancesVPC(c *C) {
	vpcResp, err := s.ec2.CreateVPC("10.6.0.0/16", "")
	c.Assert(err, IsNil)
	vpcId := vpcResp.VPC.Id
	defer s.deleteVPCs(c, []string{vpcId})

	subResp := s.createSubnet(c, vpcId, "10.6.1.0/24", "")
	subId := subResp.Subnet.Id
	defer s.deleteSubnets(c, []string{subId})

	groupResp, err := s.ec2.CreateSecurityGroupVPC(
		vpcId,
		sessionName("testgroup1 vpc"),
		"testgroup description vpc",
	)
	c.Assert(err, IsNil)
	group := groupResp.SecurityGroup

	defer s.deleteGroups(c, []ec2.SecurityGroup{group})

	// Run a single instance with a new network interface.
	ips := []ec2.PrivateIP{
		{Address: "10.6.1.10", IsPrimary: true},
		{Address: "10.6.1.20", IsPrimary: false},
	}
	instResp, err := s.ec2.RunInstances(&ec2.RunInstances{
		MinCount:     1,
		ImageId:      imageId,
		InstanceType: "t1.micro",
		NetworkInterfaces: []ec2.RunNetworkInterface{{
			DeviceIndex:         0,
			SubnetId:            subId,
			PrivateIPs:          ips,
			SecurityGroupIds:    []string{group.Id},
			DeleteOnTermination: true,
		}},
	})
	c.Assert(err, IsNil)
	inst := &instResp.Instances[0]

	defer terminateInstances(c, s.ec2, []string{inst.InstanceId})

	// Now list the network interfaces and find ours.
	testAttempt := aws.AttemptStrategy{
		Total: 5 * time.Minute,
		Delay: 5 * time.Second,
	}
	f := ec2.NewFilter()
	f.Add("subnet-id", subId)
	var newNIC *ec2.NetworkInterface
	for a := testAttempt.Start(); a.Next(); {
		c.Logf("waiting for NIC to become available")
		listNICs, err := s.ec2.NetworkInterfaces(nil, f)
		if err != nil {
			c.Logf("retrying; NetworkInterfaces returned: %v", err)
			continue
		}
		for _, iface := range listNICs.Interfaces {
			c.Logf("found NIC %v", iface)
			if iface.Attachment.InstanceId == inst.InstanceId {
				c.Logf("instance %v new NIC appeared", inst.InstanceId)
				newNIC = &iface
				break
			}
		}
		if newNIC != nil {
			break
		}
	}
	if newNIC == nil {
		c.Fatalf("timeout while waiting for NIC to appear.")
	}
	c.Check(newNIC.Id, Matches, `^eni-[0-9a-f]+$`)
	c.Check(newNIC.SubnetId, Equals, subId)
	c.Check(newNIC.VPCId, Equals, vpcId)
	c.Check(newNIC.Status, Matches, `^(attaching|in-use)$`)
	c.Check(newNIC.PrivateIPAddress, Equals, ips[0].Address)
	c.Check(newNIC.PrivateIPs, DeepEquals, ips)
	c.Check(newNIC.Groups, HasLen, 1)
	c.Check(newNIC.Groups[0].Id, Equals, group.Id)
	c.Check(newNIC.Attachment.Status, Matches, `^(attaching|attached)$`)
	c.Check(newNIC.Attachment.DeviceIndex, Equals, 0)
	c.Check(newNIC.Attachment.DeleteOnTermination, Equals, true)
}