// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package audit_test

import (
	"math/rand"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/zap"

	"storj.io/storj/internal/memory"
	"storj.io/storj/internal/testcontext"
	"storj.io/storj/internal/testplanet"
	"storj.io/storj/pkg/audit"
	"storj.io/storj/pkg/overlay"
	"storj.io/storj/pkg/storage/streams"
	"storj.io/storj/pkg/storj"
	"storj.io/storj/satellite"
)

// TestDisqualificationTooManyFailedAudits does the following:
// * Create a failed audit report for a storagenode
// * Record the audit report several times and check that the node isn't
//	 disqualified until the audit reputation reaches the cut-off value.
func TestDisqualificationTooManyFailedAudits(t *testing.T) {
	var (
		auditDQCutOff         = 0.4
		alpha0        float64 = 1
		beta0         float64
	)

	testplanet.Run(t, testplanet.Config{
		SatelliteCount: 1, StorageNodeCount: 1, Reconfigure: testplanet.Reconfigure{
			Satellite: func(log *zap.Logger, index int, config *satellite.Config) {
				config.Overlay.Node.AuditReputationAlpha0 = alpha0
				config.Overlay.Node.AuditReputationBeta0 = beta0
				config.Overlay.Node.AuditReputationLambda = 1
				config.Overlay.Node.AuditReputationWeight = 1
				config.Overlay.Node.AuditReputationDQ = auditDQCutOff
			},
		},
	}, func(t *testing.T, ctx *testcontext.Context, planet *testplanet.Planet) {
		err := planet.Satellites[0].Audit.Service.Close()
		require.NoError(t, err)

		var (
			sat    = planet.Satellites[0]
			nodeID = planet.StorageNodes[0].ID()
			report = &audit.Report{
				Fails: storj.NodeIDList{nodeID},
			}
		)

		dossier, err := sat.Overlay.Service.Get(ctx, nodeID)
		require.NoError(t, err)

		require.Equal(t, alpha0, dossier.Reputation.AuditReputationAlpha)
		require.Equal(t, beta0, dossier.Reputation.AuditReputationBeta)

		prevReputation := calcReputation(dossier)

		// Report the audit failure until the node gets disqualified due to many
		// failed audits
		iterations := 1
		for ; ; iterations++ {
			_, err := sat.Audit.Service.Reporter.RecordAudits(ctx, report)
			require.NoError(t, err)

			dossier, err := sat.Overlay.Service.Get(ctx, nodeID)
			require.NoError(t, err)

			reputation := calcReputation(dossier)
			require.Truef(t, prevReputation >= reputation,
				"(%d) expected reputation to remain or decrease (previous >= current): %f >= %f",
				iterations, prevReputation, reputation,
			)

			if reputation <= auditDQCutOff || reputation == prevReputation {
				require.NotNilf(t, dossier.Disqualified,
					"Disqualified (%d) - cut-off: %f, prev. reputation: %f, current reputation: %f",
					iterations, auditDQCutOff, prevReputation, reputation,
				)

				require.True(t, time.Now().Sub(*dossier.Disqualified) >= 0,
					"Disqualified should be in the past",
				)

				break
			}

			require.Nil(t, dossier.Disqualified, "Disqualified")
			prevReputation = reputation
		}

		require.True(t, iterations > 1, "the number of iterations must be at least 2")
	})
}

func calcReputation(dossier *overlay.NodeDossier) float64 {
	var (
		alpha = dossier.Reputation.AuditReputationAlpha
		beta  = dossier.Reputation.AuditReputationBeta
	)

	return alpha / (alpha + beta)
}

func TestDisqualifiedNodesGetNoDownload(t *testing.T) {

	// - uploads random data
	// - mark a node as disqualified
	// - check we don't get it when we require order limit

	testplanet.Run(t, testplanet.Config{
		SatelliteCount: 1, StorageNodeCount: 4, UplinkCount: 1,
	}, func(t *testing.T, ctx *testcontext.Context, planet *testplanet.Planet) {
		satellite := planet.Satellites[0]
		upl := planet.Uplinks[0]

		err := satellite.Audit.Service.Close()
		require.NoError(t, err)

		testData := make([]byte, 8*memory.KiB)
		_, err = rand.Read(testData)
		require.NoError(t, err)

		err = upl.Upload(ctx, planet.Satellites[0], "testbucket", "test/path", testData)
		require.NoError(t, err)

		projects, err := satellite.DB.Console().Projects().GetAll(ctx)
		require.NoError(t, err)
		require.Len(t, projects, 1)

		bucketID := []byte(storj.JoinPaths(projects[0].ID.String(), "testbucket"))

		encScheme := upl.GetConfig(satellite).GetEncryptionScheme()
		cipher := encScheme.Cipher
		encryptedAfterBucket, err := streams.EncryptAfterBucket(ctx, "testbucket/test/path", cipher, &storj.Key{})
		require.NoError(t, err)

		lastSegPath := storj.JoinPaths(projects[0].ID.String(), "l", encryptedAfterBucket)
		pointer, err := satellite.Metainfo.Service.Get(ctx, lastSegPath)
		require.NoError(t, err)

		disqualifiedNode := pointer.GetRemote().GetRemotePieces()[0].NodeId
		disqualifyNode(t, ctx, satellite, disqualifiedNode)

		limits, err := satellite.Orders.Service.CreateGetOrderLimits(ctx, upl.Identity.PeerIdentity(), bucketID, pointer)
		require.NoError(t, err)
		assert.Len(t, limits, len(pointer.GetRemote().GetRemotePieces())-1)

		for _, orderLimit := range limits {
			assert.False(t, isDisqualified(t, ctx, satellite, orderLimit.Limit.StorageNodeId))
			assert.NotEqual(t, orderLimit.Limit.StorageNodeId, disqualifiedNode)
		}
	})
}

func TestDisqualifiedNodesGetNoUpload(t *testing.T) {

	// - mark a node as disqualified
	// - check that we have an error if we try to create a segment using all storage nodes

	testplanet.Run(t, testplanet.Config{
		SatelliteCount: 1, StorageNodeCount: 4, UplinkCount: 1,
	}, func(t *testing.T, ctx *testcontext.Context, planet *testplanet.Planet) {
		satellite := planet.Satellites[0]
		disqualifiedNode := planet.StorageNodes[0]

		err := satellite.Audit.Service.Close()
		require.NoError(t, err)

		disqualifyNode(t, ctx, satellite, disqualifiedNode.ID())

		request := overlay.FindStorageNodesRequest{
			MinimumRequiredNodes: 4,
			RequestedCount:       0,
			FreeBandwidth:        0,
			FreeDisk:             0,
			ExcludedNodes:        nil,
			MinimumVersion:       "", // semver or empty
		}
		nodes, err := satellite.Overlay.Service.FindStorageNodes(ctx, request)
		assert.True(t, overlay.ErrNotEnoughNodes.Has(err))

		assert.Len(t, nodes, 3)
		for _, node := range nodes {
			assert.False(t, isDisqualified(t, ctx, satellite, node.Id))
			assert.NotEqual(t, node.Id, disqualifiedNode)
		}

	})
}

func TestDisqualifiedNodeRemainsDisqualified(t *testing.T) {

	// - mark a node as disqualified
	// - give it high uptime and audit rate
	// - check that the node remains disqualified

	testplanet.Run(t, testplanet.Config{
		SatelliteCount: 1, StorageNodeCount: 4, UplinkCount: 1,
	}, func(t *testing.T, ctx *testcontext.Context, planet *testplanet.Planet) {
		satellite := planet.Satellites[0]

		err := satellite.Audit.Service.Close()
		require.NoError(t, err)

		disqualifiedNode := planet.StorageNodes[0]
		disqualifyNode(t, ctx, satellite, disqualifiedNode.ID())

		_, err = satellite.DB.OverlayCache().UpdateUptime(ctx, disqualifiedNode.ID(), true, 0, 1, 0)
		require.NoError(t, err)

		assert.True(t, isDisqualified(t, ctx, satellite, disqualifiedNode.ID()))

		_, err = satellite.DB.OverlayCache().UpdateStats(ctx, &overlay.UpdateRequest{
			NodeID:       disqualifiedNode.ID(),
			IsUp:         true,
			AuditSuccess: true,
			AuditLambda:  0, // forget about history
			AuditWeight:  1,
			AuditDQ:      0, // make sure new reputation scores are larger than the DQ thresholds
			UptimeLambda: 0, // forget about history
			UptimeWeight: 1,
			UptimeDQ:     0, // make sure new reputation scores are larger than the DQ thresholds
		})
		require.NoError(t, err)

		assert.True(t, isDisqualified(t, ctx, satellite, disqualifiedNode.ID()))
	})
}

func isDisqualified(t *testing.T, ctx *testcontext.Context, satellite *satellite.Peer, nodeID storj.NodeID) bool {
	node, err := satellite.Overlay.Service.Get(ctx, nodeID)
	require.NoError(t, err)

	return node.Disqualified != nil
}
func disqualifyNode(t *testing.T, ctx *testcontext.Context, satellite *satellite.Peer, nodeID storj.NodeID) {
	_, err := satellite.DB.OverlayCache().UpdateStats(ctx, &overlay.UpdateRequest{
		NodeID:       nodeID,
		IsUp:         true,
		AuditSuccess: false,
		AuditLambda:  0,
		AuditWeight:  1,
		AuditDQ:      0.5,
		UptimeLambda: 1,
		UptimeWeight: 1,
		UptimeDQ:     0.5,
	})
	require.NoError(t, err)
	assert.True(t, isDisqualified(t, ctx, satellite, nodeID))
}