package teststorage

import (
	"fmt"
	"io/ioutil"
	"os"

	hclog "github.com/hashicorp/go-hclog"
	raftlib "github.com/hashicorp/raft"
	"github.com/hashicorp/vault/physical/raft"
	"github.com/hashicorp/vault/sdk/physical"
	"github.com/hashicorp/vault/vault"
	"github.com/mitchellh/go-testing-interface"
)

// ReusableStorage is a physical backend that can be re-used across
// multiple test clusters in sequence.  It is useful for testing things like
// seal migration, wherein a given physical backend must be re-used as several
// test clusters are sequentially created, tested, and discarded.
type ReusableStorage struct {
	// IsRaft specifies whether the storage is using a raft backend.
	IsRaft bool

	// Setup should be called just before a new TestCluster is created.
	Setup ClusterSetupMutator

	// Cleanup should be called after a TestCluster is no longer
	// needed -- generally in a defer, just before the call to
	// cluster.Cleanup().
	Cleanup func(t testing.T, cluster *vault.TestCluster)
}

// StorageCleanup is a function that should be called once -- at the very end
// of a given unit test, after each of the sequence of clusters have been
// created, tested, and discarded.
type StorageCleanup func()

// MakeReusableStorage makes a physical backend that can be re-used across
// multiple test clusters in sequence.
func MakeReusableStorage(t testing.T, logger hclog.Logger, bundle *vault.PhysicalBackendBundle) (ReusableStorage, StorageCleanup) {
	storage := ReusableStorage{
		IsRaft: false,

		Setup: func(conf *vault.CoreConfig, opts *vault.TestClusterOptions) {
			opts.PhysicalFactory = func(t testing.T, coreIdx int, logger hclog.Logger, conf map[string]interface{}) *vault.PhysicalBackendBundle {
				if coreIdx == 0 {
					// We intentionally do not clone the backend's Cleanup func,
					// because we don't want it to be run until the entire test has
					// been completed.
					return &vault.PhysicalBackendBundle{
						Backend:   bundle.Backend,
						HABackend: bundle.HABackend,
					}
				}
				return nil
			}
		},

		// No-op
		Cleanup: func(t testing.T, cluster *vault.TestCluster) {},
	}

	cleanup := func() {
		if bundle.Cleanup != nil {
			bundle.Cleanup()
		}
	}

	return storage, cleanup
}

// MakeReusableRaftStorage makes a physical raft backend that can be re-used
// across multiple test clusters in sequence.
func MakeReusableRaftStorage(t testing.T, logger hclog.Logger, numCores int, addressProvider raftlib.ServerAddressProvider) (ReusableStorage, StorageCleanup) {
	raftDirs := make([]string, numCores)
	for i := 0; i < numCores; i++ {
		raftDirs[i] = makeRaftDir(t)
	}

	storage := ReusableStorage{
		IsRaft: true,

		Setup: func(conf *vault.CoreConfig, opts *vault.TestClusterOptions) {
			conf.DisablePerformanceStandby = true
			opts.KeepStandbysSealed = true
			opts.PhysicalFactory = func(t testing.T, coreIdx int, logger hclog.Logger, conf map[string]interface{}) *vault.PhysicalBackendBundle {
				return makeReusableRaftBackend(t, coreIdx, logger, raftDirs[coreIdx], addressProvider, false)
			}
		},

		// Close open files being used by raft.
		Cleanup: func(t testing.T, cluster *vault.TestCluster) {
			for i := 0; i < len(cluster.Cores); i++ {
				CloseRaftStorage(t, cluster, i)
			}
		},
	}

	cleanup := func() {
		for _, rd := range raftDirs {
			os.RemoveAll(rd)
		}
	}

	return storage, cleanup
}

// CloseRaftStorage closes open files being used by raft.
func CloseRaftStorage(t testing.T, cluster *vault.TestCluster, idx int) {
	raftStorage := cluster.Cores[idx].UnderlyingRawStorage.(*raft.RaftBackend)
	if err := raftStorage.Close(); err != nil {
		t.Fatal(err)
	}
}

func MakeReusableRaftHAStorage(t testing.T, logger hclog.Logger, numCores int, bundle *vault.PhysicalBackendBundle) (ReusableStorage, StorageCleanup) {
	raftDirs := make([]string, numCores)
	for i := 0; i < numCores; i++ {
		raftDirs[i] = makeRaftDir(t)
	}

	storage := ReusableStorage{
		Setup: func(conf *vault.CoreConfig, opts *vault.TestClusterOptions) {
			opts.KeepStandbysSealed = true
			opts.PhysicalFactory = func(t testing.T, coreIdx int, logger hclog.Logger, conf map[string]interface{}) *vault.PhysicalBackendBundle {
				haBundle := makeReusableRaftBackend(t, coreIdx, logger, raftDirs[coreIdx], nil, true)

				return &vault.PhysicalBackendBundle{
					Backend:   bundle.Backend,
					HABackend: haBundle.HABackend,
				}
			}
		},

		// Close open files being used by raft.
		Cleanup: func(t testing.T, cluster *vault.TestCluster) {
			for _, core := range cluster.Cores {
				raftStorage := core.UnderlyingHAStorage.(*raft.RaftBackend)
				if err := raftStorage.Close(); err != nil {
					t.Fatal(err)
				}
			}
		},
	}

	cleanup := func() {
		if bundle.Cleanup != nil {
			bundle.Cleanup()
		}

		for _, rd := range raftDirs {
			os.RemoveAll(rd)
		}
	}

	return storage, cleanup
}

func makeRaftDir(t testing.T) string {
	raftDir, err := ioutil.TempDir("", "vault-raft-")
	if err != nil {
		t.Fatal(err)
	}
	// t.Logf("raft dir: %s", raftDir)
	return raftDir
}

func makeReusableRaftBackend(t testing.T, coreIdx int, logger hclog.Logger, raftDir string, addressProvider raftlib.ServerAddressProvider, ha bool) *vault.PhysicalBackendBundle {
	nodeID := fmt.Sprintf("core-%d", coreIdx)
	conf := map[string]string{
		"path":                         raftDir,
		"node_id":                      nodeID,
		"performance_multiplier":       "8",
		"autopilot_reconcile_interval": "300ms",
		"autopilot_update_interval":    "100ms",
	}

	backend, err := raft.NewRaftBackend(conf, logger)
	if err != nil {
		t.Fatal(err)
	}

	if addressProvider != nil {
		backend.(*raft.RaftBackend).SetServerAddressProvider(addressProvider)
	}

	bundle := new(vault.PhysicalBackendBundle)

	if ha {
		bundle.HABackend = backend.(physical.HABackend)
	} else {
		bundle.Backend = backend
	}
	return bundle
}
