//go:build linux
// +build linux

package nomad09upgrade

import (
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	getter "github.com/hashicorp/go-getter"
	"github.com/hashicorp/nomad/e2e/e2eutil"
	"github.com/hashicorp/nomad/e2e/execagent"
	"github.com/hashicorp/nomad/e2e/framework"
	"github.com/hashicorp/nomad/helper/discover"
	"github.com/hashicorp/nomad/helper/testlog"
	"github.com/hashicorp/nomad/helper/uuid"
	"github.com/hashicorp/nomad/testutil"
	"github.com/stretchr/testify/require"
)

func init() {
	framework.AddSuites(&framework.TestSuite{
		Component:   "nomad09upgrade",
		CanRunLocal: true,
		Cases: []framework.TestCase{
			&UpgradePathTC{},
		},
	})
}

var (
	nomadVersions = [...]string{
		"0.8.7",
		"0.8.6",
		"0.8.5",
		"0.8.4",
		"0.8.3",
		"0.8.2",
		"0.8.1",
		"0.8.0",
	}
)

type UpgradePathTC struct {
	framework.TC

	binDir string
	bin    string
}

type upgradeAgents struct {
	origAgent   *execagent.NomadAgent
	targetAgent *execagent.NomadAgent
}

func (tc *UpgradePathTC) newNomadServer(t *testing.T, ver string) (*upgradeAgents, error) {
	binPath := filepath.Join(tc.binDir, ver, "nomad")
	srv, err := execagent.NewMixedAgent(binPath)
	if err != nil {
		return nil, err
	}

	w := testlog.NewWriter(t)
	srv.Cmd.Stdout = w
	srv.Cmd.Stderr = w

	// Target should copy everything but the binary to target
	target, err := execagent.NewMixedAgent(tc.bin)
	if err != nil {
		return nil, err
	}
	target.Cmd.Stdout = w
	target.Cmd.Stderr = w

	agents := &upgradeAgents{
		origAgent:   srv,
		targetAgent: target,
	}
	return agents, nil
}

// BeforeAll downloads all of the desired nomad versions to test against
func (tc *UpgradePathTC) BeforeAll(f *framework.F) {
	// Upgrade tests currently fail because the nomad binary isn't found by
	// discover.NomadExecutable().  Ensure that nomad binary is available
	// and discoverable and enable this test
	f.T().Skip("upgrade tests are expected to fail.  TODO: Fix")

	bin, err := discover.NomadExecutable()
	f.NoError(err)
	tc.bin = bin
	dir, err := ioutil.TempDir("", "")
	f.NoError(err)

	tc.binDir = dir
	for _, ver := range nomadVersions {
		verBin := filepath.Join(tc.binDir, ver)
		f.NoError(os.Mkdir(verBin, 0755))
		f.NoError(
			getter.Get(verBin, fmt.Sprintf(
				"https://releases.hashicorp.com/nomad/%s/nomad_%s_linux_amd64.zip",
				ver, ver,
			)))
		f.T().Logf("downloaded nomad version %s to %s", ver, verBin)
	}
}

// AfterAll cleans up the downloaded nomad binaries
func (tc *UpgradePathTC) AfterAll(f *framework.F) {
	os.RemoveAll(tc.binDir)
}

func (tc *UpgradePathTC) TestRawExecTaskUpgrade(f *framework.F) {
	for _, ver := range nomadVersions {
		ver := ver
		f.T().Run(ver, func(t *testing.T) {
			t.Parallel()
			tc.testUpgradeForJob(t, ver, "nomad09upgrade/rawexec.nomad")
		})
	}
}

func (tc *UpgradePathTC) TestExecTaskUpgrade(f *framework.F) {
	for _, ver := range nomadVersions {
		ver := ver
		f.T().Run(ver, func(t *testing.T) {
			t.Parallel()
			tc.testUpgradeForJob(t, ver, "nomad09upgrade/exec.nomad")
		})
	}
}

func (tc *UpgradePathTC) TestDockerTaskUpgrade(f *framework.F) {
	for _, ver := range nomadVersions {
		ver := ver
		f.T().Run(ver, func(t *testing.T) {
			t.Parallel()
			tc.testUpgradeForJob(t, ver, "nomad09upgrade/docker.nomad")
		})
	}
}

func (tc *UpgradePathTC) testUpgradeForJob(t *testing.T, ver string, jobfile string) {
	require := require.New(t)
	// Start a nomad agent for the given version
	agents, err := tc.newNomadServer(t, ver)
	require.NoError(err)
	t.Logf("launching v%s nomad agent", ver)
	require.NoError(agents.origAgent.Start())

	// Wait for the agent to be ready
	client, err := agents.origAgent.Client()
	require.NoError(err)
	e2eutil.WaitForNodesReady(t, client, 1)

	// Register a sleep job
	jobID := "sleep-" + uuid.Generate()[:8]
	t.Logf("registering exec job with id %s", jobID)
	e2eutil.RegisterAndWaitForAllocs(t, client, jobfile, jobID, "")
	allocs, _, err := client.Jobs().Allocations(jobID, false, nil)
	require.NoError(err)
	require.Len(allocs, 1)

	// Wait for sleep job to transition to running
	id := allocs[0].ID
	e2eutil.WaitForAllocRunning(t, client, id)

	// Stop the agent, leaving the sleep job running
	require.NoError(agents.origAgent.Stop())

	// Start a nomad agent with the to be tested nomad binary
	t.Logf("launching test nomad agent")
	require.NoError(agents.targetAgent.Start())

	// Wait for the agent to be ready
	e2eutil.WaitForNodesReady(t, client, 1)

	// Make sure the same allocation still exists
	alloc, _, err := client.Allocations().Info(id, nil)
	require.NoError(err)
	// Pull stats from the allocation, testing that new code can interface with
	// the old stats driver apis
	testutil.WaitForResult(func() (bool, error) {
		stats, err := client.Allocations().Stats(alloc, nil)
		if err != nil {
			return false, err
		}

		return stats.ResourceUsage.MemoryStats.RSS > 0, fmt.Errorf("RSS for task should be greater than 0")
	}, func(err error) {
		require.NoError(err)
	})

	// Deregister the job. This tests that the new code can properly tear down
	// upgraded allocs
	_, _, err = client.Jobs().Deregister(alloc.JobID, true, nil)
	require.NoError(err)
	testutil.WaitForResult(func() (bool, error) {
		j, _, _ := client.Jobs().Info(jobID, nil)
		if j == nil {
			return true, nil
		}
		time.Sleep(time.Millisecond * 100)
		return false, fmt.Errorf("job with id %q should be purged", jobID)
	}, func(err error) {
		require.NoError(err)
	})

	// Check that the task dir mounts have been removed
	testutil.WaitForResult(func() (bool, error) {
		defer client.System().GarbageCollect()
		time.Sleep(time.Millisecond * 100)
		data, err := ioutil.ReadFile("/proc/mounts")
		if err != nil {
			return false, err
		}

		return !strings.Contains(string(data), id), fmt.Errorf("taskdir mounts should be cleaned up, but found mount for id %q:\n%s", id, string(data))
	}, func(err error) {
		require.NoError(err)
	})

	// Cleanup
	agents.targetAgent.Stop()
	agents.targetAgent.Destroy()
}