package ffiwrapper

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"io/ioutil"
	"math/rand"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"testing"
	"time"

	logging "github.com/ipfs/go-log"
	"github.com/stretchr/testify/require"
	"golang.org/x/xerrors"

	ffi "github.com/filecoin-project/filecoin-ffi"
	paramfetch "github.com/filecoin-project/go-paramfetch"
	"github.com/filecoin-project/specs-actors/actors/abi"
	"github.com/filecoin-project/specs-storage/storage"

	"github.com/filecoin-project/sector-storage/ffiwrapper/basicfs"
	"github.com/filecoin-project/sector-storage/stores"
)

func init() {
	logging.SetLogLevel("*", "DEBUG") //nolint: errcheck
}

var sealProofType = abi.RegisteredSealProof_StackedDrg2KiBV1
var sectorSize, _ = sealProofType.SectorSize()

var sealRand = abi.SealRandomness{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2}

type seal struct {
	id     abi.SectorID
	cids   storage.SectorCids
	pi     abi.PieceInfo
	ticket abi.SealRandomness
}

func data(sn abi.SectorNumber, dlen abi.UnpaddedPieceSize) io.Reader {
	return io.MultiReader(
		io.LimitReader(rand.New(rand.NewSource(42+int64(sn))), int64(123)),
		io.LimitReader(rand.New(rand.NewSource(42+int64(sn))), int64(dlen-123)),
	)
}

func (s *seal) precommit(t *testing.T, sb *Sealer, id abi.SectorID, done func()) {
	defer done()
	dlen := abi.PaddedPieceSize(sectorSize).Unpadded()

	var err error
	r := data(id.Number, dlen)
	s.pi, err = sb.AddPiece(context.TODO(), id, []abi.UnpaddedPieceSize{}, dlen, r)
	if err != nil {
		t.Fatalf("%+v", err)
	}

	s.ticket = sealRand

	p1, err := sb.SealPreCommit1(context.TODO(), id, s.ticket, []abi.PieceInfo{s.pi})
	if err != nil {
		t.Fatalf("%+v", err)
	}
	cids, err := sb.SealPreCommit2(context.TODO(), id, p1)
	if err != nil {
		t.Fatalf("%+v", err)
	}
	s.cids = cids
}

func (s *seal) commit(t *testing.T, sb *Sealer, done func()) {
	defer done()
	seed := abi.InteractiveSealRandomness{0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9, 8, 7, 6, 45, 3, 2, 1, 0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9}

	pc1, err := sb.SealCommit1(context.TODO(), s.id, s.ticket, seed, []abi.PieceInfo{s.pi}, s.cids)
	if err != nil {
		t.Fatalf("%+v", err)
	}
	proof, err := sb.SealCommit2(context.TODO(), s.id, pc1)
	if err != nil {
		t.Fatalf("%+v", err)
	}

	ok, err := ProofVerifier.VerifySeal(abi.SealVerifyInfo{
		SectorID:              s.id,
		SealedCID:             s.cids.Sealed,
		SealProof:             sealProofType,
		Proof:                 proof,
		Randomness:            s.ticket,
		InteractiveRandomness: seed,
		UnsealedCID:           s.cids.Unsealed,
	})
	if err != nil {
		t.Fatalf("%+v", err)
	}

	if !ok {
		t.Fatal("proof failed to validate")
	}
}

func (s *seal) unseal(t *testing.T, sb *Sealer, sp *basicfs.Provider, si abi.SectorID, done func()) {
	defer done()

	var b bytes.Buffer
	err := sb.ReadPiece(context.TODO(), &b, si, 0, 1016)
	if err != nil {
		t.Fatal(err)
	}

	expect, _ := ioutil.ReadAll(data(si.Number, 1016))
	if !bytes.Equal(b.Bytes(), expect) {
		t.Fatal("read wrong bytes")
	}

	p, sd, err := sp.AcquireSector(context.TODO(), si, stores.FTUnsealed, stores.FTNone, false)
	if err != nil {
		t.Fatal(err)
	}
	if err := os.Remove(p.Unsealed); err != nil {
		t.Fatal(err)
	}
	sd()

	err = sb.ReadPiece(context.TODO(), &b, si, 0, 1016)
	if err == nil {
		t.Fatal("HOW?!")
	}
	log.Info("this is what we expect: ", err)

	if err := sb.UnsealPiece(context.TODO(), si, 0, 1016, sealRand, s.cids.Unsealed); err != nil {
		t.Fatal(err)
	}

	b.Reset()
	err = sb.ReadPiece(context.TODO(), &b, si, 0, 1016)
	if err != nil {
		t.Fatal(err)
	}

	expect, _ = ioutil.ReadAll(data(si.Number, 1016))
	require.Equal(t, expect, b.Bytes())

	b.Reset()
	err = sb.ReadPiece(context.TODO(), &b, si, 0, 2032)
	if err != nil {
		t.Fatal(err)
	}

	expect = append(expect, bytes.Repeat([]byte{0}, 1016)...)
	if !bytes.Equal(b.Bytes(), expect) {
		t.Fatal("read wrong bytes")
	}
}

func post(t *testing.T, sealer *Sealer, seals ...seal) time.Time {
	/*randomness := abi.PoStRandomness{0, 9, 2, 7, 6, 5, 4, 3, 2, 1, 0, 9, 8, 7, 6, 45, 3, 2, 1, 0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9, 7}

	sis := make([]abi.SectorInfo, len(seals))
	for i, s := range seals {
		sis[i] = abi.SectorInfo{
			RegisteredProof: sealProofType,
			SectorNumber:    s.id.Number,
			SealedCID:       s.cids.Sealed,
		}
	}

	candidates, err := sealer.GenerateEPostCandidates(context.TODO(), seals[0].id.Miner, sis, randomness, []abi.SectorNumber{})
	if err != nil {
		t.Fatalf("%+v", err)
	}*/

	fmt.Println("skipping post")

	genCandidates := time.Now()

	/*if len(candidates) != 1 {
		t.Fatal("expected 1 candidate")
	}

	candidatesPrime := make([]abi.PoStCandidate, len(candidates))
	for idx := range candidatesPrime {
		candidatesPrime[idx] = candidates[idx].Candidate
	}

	proofs, err := sealer.ComputeElectionPoSt(context.TODO(), seals[0].id.Miner, sis, randomness, candidatesPrime)
	if err != nil {
		t.Fatalf("%+v", err)
	}

	ePoStChallengeCount := ElectionPostChallengeCount(uint64(len(sis)), 0)

	ok, err := ProofVerifier.VerifyElectionPost(context.TODO(), abi.PoStVerifyInfo{
		Randomness:      randomness,
		Candidates:      candidatesPrime,
		Proofs:          proofs,
		EligibleSectors: sis,
		Prover:          seals[0].id.Miner,
		ChallengeCount:  ePoStChallengeCount,
	})
	if err != nil {
		t.Fatalf("%+v", err)
	}
	if !ok {
		t.Fatal("bad post")
	}
	*/
	return genCandidates
}

func getGrothParamFileAndVerifyingKeys(s abi.SectorSize) {
	dat, err := ioutil.ReadFile("../parameters.json")
	if err != nil {
		panic(err)
	}

	err = paramfetch.GetParams(dat, uint64(s))
	if err != nil {
		panic(xerrors.Errorf("failed to acquire Groth parameters for 2KiB sectors: %w", err))
	}
}

// TestDownloadParams exists only so that developers and CI can pre-download
// Groth parameters and verifying keys before running the tests which rely on
// those parameters and keys. To do this, run the following command:
//
// go test -run=^TestDownloadParams
//
func TestDownloadParams(t *testing.T) {
	defer requireFDsClosed(t, openFDs(t))

	getGrothParamFileAndVerifyingKeys(sectorSize)
}

func TestSealAndVerify(t *testing.T) {
	defer requireFDsClosed(t, openFDs(t))

	if runtime.NumCPU() < 10 && os.Getenv("CI") == "" { // don't bother on slow hardware
		t.Skip("this is slow")
	}
	_ = os.Setenv("RUST_LOG", "info")

	getGrothParamFileAndVerifyingKeys(sectorSize)

	cdir, err := ioutil.TempDir("", "sbtest-c-")
	if err != nil {
		t.Fatal(err)
	}
	miner := abi.ActorID(123)

	cfg := &Config{
		SealProofType: sealProofType,
	}

	sp := &basicfs.Provider{
		Root: cdir,
	}
	sb, err := New(sp, cfg)
	if err != nil {
		t.Fatalf("%+v", err)
	}
	cleanup := func() {
		if t.Failed() {
			fmt.Printf("not removing %s\n", cdir)
			return
		}
		if err := os.RemoveAll(cdir); err != nil {
			t.Error(err)
		}
	}
	defer cleanup()

	si := abi.SectorID{Miner: miner, Number: 1}

	s := seal{id: si}

	start := time.Now()

	s.precommit(t, sb, si, func() {})

	precommit := time.Now()

	s.commit(t, sb, func() {})

	commit := time.Now()

	genCandidiates := post(t, sb, s)

	epost := time.Now()

	post(t, sb, s)

	if err := sb.FinalizeSector(context.TODO(), si, nil); err != nil {
		t.Fatalf("%+v", err)
	}

	s.unseal(t, sb, sp, si, func() {})

	fmt.Printf("PreCommit: %s\n", precommit.Sub(start).String())
	fmt.Printf("Commit: %s\n", commit.Sub(precommit).String())
	fmt.Printf("GenCandidates: %s\n", genCandidiates.Sub(commit).String())
	fmt.Printf("EPoSt: %s\n", epost.Sub(genCandidiates).String())
}

func TestSealPoStNoCommit(t *testing.T) {
	defer requireFDsClosed(t, openFDs(t))

	if runtime.NumCPU() < 10 && os.Getenv("CI") == "" { // don't bother on slow hardware
		t.Skip("this is slow")
	}
	_ = os.Setenv("RUST_LOG", "info")

	getGrothParamFileAndVerifyingKeys(sectorSize)

	dir, err := ioutil.TempDir("", "sbtest")
	if err != nil {
		t.Fatal(err)
	}

	miner := abi.ActorID(123)

	cfg := &Config{
		SealProofType: sealProofType,
	}
	sp := &basicfs.Provider{
		Root: dir,
	}
	sb, err := New(sp, cfg)
	if err != nil {
		t.Fatalf("%+v", err)
	}

	cleanup := func() {
		if t.Failed() {
			fmt.Printf("not removing %s\n", dir)
			return
		}
		if err := os.RemoveAll(dir); err != nil {
			t.Error(err)
		}
	}
	defer cleanup()

	si := abi.SectorID{Miner: miner, Number: 1}

	s := seal{id: si}

	start := time.Now()

	s.precommit(t, sb, si, func() {})

	precommit := time.Now()

	if err := sb.FinalizeSector(context.TODO(), si, nil); err != nil {
		t.Fatal(err)
	}

	genCandidiates := post(t, sb, s)

	epost := time.Now()

	fmt.Printf("PreCommit: %s\n", precommit.Sub(start).String())
	fmt.Printf("GenCandidates: %s\n", genCandidiates.Sub(precommit).String())
	fmt.Printf("EPoSt: %s\n", epost.Sub(genCandidiates).String())
}

func TestSealAndVerify2(t *testing.T) {
	defer requireFDsClosed(t, openFDs(t))

	if runtime.NumCPU() < 10 && os.Getenv("CI") == "" { // don't bother on slow hardware
		t.Skip("this is slow")
	}
	_ = os.Setenv("RUST_LOG", "trace")

	getGrothParamFileAndVerifyingKeys(sectorSize)

	dir, err := ioutil.TempDir("", "sbtest")
	if err != nil {
		t.Fatal(err)
	}

	miner := abi.ActorID(123)

	cfg := &Config{
		SealProofType: sealProofType,
	}
	sp := &basicfs.Provider{
		Root: dir,
	}
	sb, err := New(sp, cfg)
	if err != nil {
		t.Fatalf("%+v", err)
	}

	cleanup := func() {
		if err := os.RemoveAll(dir); err != nil {
			t.Error(err)
		}
	}

	defer cleanup()

	var wg sync.WaitGroup

	si1 := abi.SectorID{Miner: miner, Number: 1}
	si2 := abi.SectorID{Miner: miner, Number: 2}

	s1 := seal{id: si1}
	s2 := seal{id: si2}

	wg.Add(2)
	go s1.precommit(t, sb, si1, wg.Done) //nolint: staticcheck
	time.Sleep(100 * time.Millisecond)
	go s2.precommit(t, sb, si2, wg.Done) //nolint: staticcheck
	wg.Wait()

	wg.Add(2)
	go s1.commit(t, sb, wg.Done) //nolint: staticcheck
	go s2.commit(t, sb, wg.Done) //nolint: staticcheck
	wg.Wait()

	post(t, sb, s1, s2)
}

func BenchmarkWriteWithAlignment(b *testing.B) {
	bt := abi.UnpaddedPieceSize(2 * 127 * 1024 * 1024)
	b.SetBytes(int64(bt))

	for i := 0; i < b.N; i++ {
		b.StopTimer()
		rf, w, _ := ToReadableFile(bytes.NewReader(bytes.Repeat([]byte{0xff, 0}, int(bt/2))), int64(bt))
		tf, _ := ioutil.TempFile("/tmp/", "scrb-")
		b.StartTimer()

		ffi.WriteWithAlignment(abi.RegisteredSealProof_StackedDrg2KiBV1, rf, bt, tf, nil)
		w()
	}
}

func openFDs(t *testing.T) int {
	dent, err := ioutil.ReadDir("/proc/self/fd")
	require.NoError(t, err)

	var skip int
	for _, info := range dent {
		l, err := os.Readlink(filepath.Join("/proc/self/fd", info.Name()))
		if err != nil {
			continue
		}

		if strings.HasPrefix(l, "/dev/nvidia") {
			skip++
		}

		if strings.HasPrefix(l, "/var/tmp/filecoin-proof-parameters/") {
			skip++
		}
	}

	return len(dent) - skip
}

func requireFDsClosed(t *testing.T, start int) {
	openNow := openFDs(t)

	if start != openNow {
		dent, err := ioutil.ReadDir("/proc/self/fd")
		require.NoError(t, err)

		for _, info := range dent {
			l, err := os.Readlink(filepath.Join("/proc/self/fd", info.Name()))
			if err != nil {
				fmt.Printf("FD err %s\n", err)
				continue
			}

			fmt.Printf("FD %s -> %s\n", info.Name(), l)
		}
	}

	log.Infow("open FDs", "start", start, "now", openNow)
	require.Equal(t, start, openNow, "FDs shouldn't leak")
}