package kit

import (
	"context"
	"fmt"
	"io/ioutil"
	"os"
	"testing"
	"time"

	"github.com/filecoin-project/go-fil-markets/storagemarket"
	"github.com/filecoin-project/go-state-types/abi"
	"github.com/filecoin-project/lotus/api"
	"github.com/filecoin-project/lotus/build"
	"github.com/filecoin-project/lotus/chain/types"
	sealing "github.com/filecoin-project/lotus/extern/storage-sealing"
	"github.com/ipfs/go-cid"
	files "github.com/ipfs/go-ipfs-files"
	ipld "github.com/ipfs/go-ipld-format"
	dag "github.com/ipfs/go-merkledag"
	dstest "github.com/ipfs/go-merkledag/test"
	unixfile "github.com/ipfs/go-unixfs/file"
	"github.com/ipld/go-car"
	"github.com/stretchr/testify/require"
	"golang.org/x/sync/errgroup"
)

type DealHarness struct {
	t      *testing.T
	client *TestFullNode
	miner  *TestMiner
}

type MakeFullDealParams struct {
	Rseed      int
	FastRet    bool
	StartEpoch abi.ChainEpoch

	// SuspendUntilCryptoeconStable suspends deal-making, until cryptoecon
	// parameters are stabilised. This affects projected collateral, and tests
	// will fail in network version 13 and higher if deals are started too soon
	// after network birth.
	//
	// The reason is that the formula for collateral calculation takes
	// circulating supply into account:
	//
	//   [portion of power this deal will be] * [~1% of tokens].
	//
	// In the first epochs after genesis, the total circulating supply is
	// changing dramatically in percentual terms. Therefore, if the deal is
	// proposed too soon, by the time it gets published on chain, the quoted
	// provider collateral will no longer be valid.
	//
	// The observation is that deals fail with:
	//
	//   GasEstimateMessageGas error: estimating gas used: message execution
	//   failed: exit 16, reason: Provider collateral out of bounds. (RetCode=16)
	//
	// Enabling this will suspend deal-making until the network has reached a
	// height of 300.
	SuspendUntilCryptoeconStable bool
}

// NewDealHarness creates a test harness that contains testing utilities for deals.
func NewDealHarness(t *testing.T, client *TestFullNode, miner *TestMiner) *DealHarness {
	return &DealHarness{
		t:      t,
		client: client,
		miner:  miner,
	}
}

// MakeOnlineDeal makes an online deal, generating a random file with the
// supplied seed, and setting the specified fast retrieval flag and start epoch
// on the storage deal. It returns when the deal is sealed.
//
// TODO: convert input parameters to struct, and add size as an input param.
func (dh *DealHarness) MakeOnlineDeal(ctx context.Context, params MakeFullDealParams) (deal *cid.Cid, res *api.ImportRes, path string) {
	res, path = dh.client.CreateImportFile(ctx, params.Rseed, 0)

	dh.t.Logf("FILE CID: %s", res.Root)

	if params.SuspendUntilCryptoeconStable {
		dh.t.Logf("deal-making suspending until cryptecon parameters have stabilised")
		ts := dh.client.WaitTillChain(ctx, HeightAtLeast(300))
		dh.t.Logf("deal-making continuing; current height is %d", ts.Height())
	}

	deal = dh.StartDeal(ctx, res.Root, params.FastRet, params.StartEpoch)

	// TODO: this sleep is only necessary because deals don't immediately get logged in the dealstore, we should fix this
	time.Sleep(time.Second)
	dh.WaitDealSealed(ctx, deal, false, false, nil)

	return deal, res, path
}

// StartDeal starts a storage deal between the client and the miner.
func (dh *DealHarness) StartDeal(ctx context.Context, fcid cid.Cid, fastRet bool, startEpoch abi.ChainEpoch) *cid.Cid {
	maddr, err := dh.miner.ActorAddress(ctx)
	require.NoError(dh.t, err)

	addr, err := dh.client.WalletDefaultAddress(ctx)
	require.NoError(dh.t, err)

	deal, err := dh.client.ClientStartDeal(ctx, &api.StartDealParams{
		Data: &storagemarket.DataRef{
			TransferType: storagemarket.TTGraphsync,
			Root:         fcid,
		},
		Wallet:            addr,
		Miner:             maddr,
		EpochPrice:        types.NewInt(1000000),
		DealStartEpoch:    startEpoch,
		MinBlocksDuration: uint64(build.MinDealDuration),
		FastRetrieval:     fastRet,
	})
	require.NoError(dh.t, err)

	return deal
}

// WaitDealSealed waits until the deal is sealed.
func (dh *DealHarness) WaitDealSealed(ctx context.Context, deal *cid.Cid, noseal, noSealStart bool, cb func()) {
loop:
	for {
		di, err := dh.client.ClientGetDealInfo(ctx, *deal)
		require.NoError(dh.t, err)

		switch di.State {
		case storagemarket.StorageDealAwaitingPreCommit, storagemarket.StorageDealSealing:
			if noseal {
				return
			}
			if !noSealStart {
				dh.StartSealingWaiting(ctx)
			}
		case storagemarket.StorageDealProposalRejected:
			dh.t.Fatal("deal rejected")
		case storagemarket.StorageDealFailing:
			dh.t.Fatal("deal failed")
		case storagemarket.StorageDealError:
			dh.t.Fatal("deal errored", di.Message)
		case storagemarket.StorageDealActive:
			dh.t.Log("COMPLETE", di)
			break loop
		}

		mds, err := dh.miner.MarketListIncompleteDeals(ctx)
		require.NoError(dh.t, err)

		var minerState storagemarket.StorageDealStatus
		for _, md := range mds {
			if md.DealID == di.DealID {
				minerState = md.State
				break
			}
		}

		dh.t.Logf("Deal %d state: client:%s provider:%s\n", di.DealID, storagemarket.DealStates[di.State], storagemarket.DealStates[minerState])
		time.Sleep(time.Second / 2)
		if cb != nil {
			cb()
		}
	}
}

// WaitDealPublished waits until the deal is published.
func (dh *DealHarness) WaitDealPublished(ctx context.Context, deal *cid.Cid) {
	subCtx, cancel := context.WithCancel(ctx)
	defer cancel()

	updates, err := dh.miner.MarketGetDealUpdates(subCtx)
	require.NoError(dh.t, err)

	for {
		select {
		case <-ctx.Done():
			dh.t.Fatal("context timeout")
		case di := <-updates:
			if deal.Equals(di.ProposalCid) {
				switch di.State {
				case storagemarket.StorageDealProposalRejected:
					dh.t.Fatal("deal rejected")
				case storagemarket.StorageDealFailing:
					dh.t.Fatal("deal failed")
				case storagemarket.StorageDealError:
					dh.t.Fatal("deal errored", di.Message)
				case storagemarket.StorageDealFinalizing, storagemarket.StorageDealAwaitingPreCommit, storagemarket.StorageDealSealing, storagemarket.StorageDealActive:
					dh.t.Log("COMPLETE", di)
					return
				}
				dh.t.Log("Deal state: ", storagemarket.DealStates[di.State])
			}
		}
	}
}

func (dh *DealHarness) StartSealingWaiting(ctx context.Context) {
	snums, err := dh.miner.SectorsList(ctx)
	require.NoError(dh.t, err)

	for _, snum := range snums {
		si, err := dh.miner.SectorsStatus(ctx, snum, false)
		require.NoError(dh.t, err)

		dh.t.Logf("Sector state: %s", si.State)
		if si.State == api.SectorState(sealing.WaitDeals) {
			require.NoError(dh.t, dh.miner.SectorStartSealing(ctx, snum))
		}

		dh.miner.FlushSealingBatches(ctx)
	}
}

func (dh *DealHarness) PerformRetrieval(ctx context.Context, deal *cid.Cid, root cid.Cid, carExport bool) (path string) {
	// perform retrieval.
	info, err := dh.client.ClientGetDealInfo(ctx, *deal)
	require.NoError(dh.t, err)

	offers, err := dh.client.ClientFindData(ctx, root, &info.PieceCID)
	require.NoError(dh.t, err)
	require.NotEmpty(dh.t, offers, "no offers")

	carFile, err := ioutil.TempFile(dh.t.TempDir(), "ret-car")
	require.NoError(dh.t, err)

	defer carFile.Close() //nolint:errcheck

	caddr, err := dh.client.WalletDefaultAddress(ctx)
	require.NoError(dh.t, err)

	ref := &api.FileRef{
		Path:  carFile.Name(),
		IsCAR: carExport,
	}

	updates, err := dh.client.ClientRetrieveWithEvents(ctx, offers[0].Order(caddr), ref)
	require.NoError(dh.t, err)

	for update := range updates {
		require.Emptyf(dh.t, update.Err, "retrieval failed: %s", update.Err)
	}

	ret := carFile.Name()
	if carExport {
		actualFile := dh.ExtractFileFromCAR(ctx, carFile)
		ret = actualFile.Name()
		_ = actualFile.Close() //nolint:errcheck
	}

	return ret
}

func (dh *DealHarness) ExtractFileFromCAR(ctx context.Context, file *os.File) (out *os.File) {
	bserv := dstest.Bserv()
	ch, err := car.LoadCar(bserv.Blockstore(), file)
	require.NoError(dh.t, err)

	b, err := bserv.GetBlock(ctx, ch.Roots[0])
	require.NoError(dh.t, err)

	nd, err := ipld.Decode(b)
	require.NoError(dh.t, err)

	dserv := dag.NewDAGService(bserv)
	fil, err := unixfile.NewUnixfsFile(ctx, dserv, nd)
	require.NoError(dh.t, err)

	tmpfile, err := ioutil.TempFile(dh.t.TempDir(), "file-in-car")
	require.NoError(dh.t, err)

	defer tmpfile.Close() //nolint:errcheck

	err = files.WriteTo(fil, tmpfile.Name())
	require.NoError(dh.t, err)

	return tmpfile
}

type RunConcurrentDealsOpts struct {
	N             int
	FastRetrieval bool
	CarExport     bool
	StartEpoch    abi.ChainEpoch
}

func (dh *DealHarness) RunConcurrentDeals(opts RunConcurrentDealsOpts) {
	errgrp, _ := errgroup.WithContext(context.Background())
	for i := 0; i < opts.N; i++ {
		i := i
		errgrp.Go(func() (err error) {
			defer func() {
				// This is necessary because golang can't deal with test
				// failures being reported from children goroutines ¯\_(ツ)_/¯
				if r := recover(); r != nil {
					err = fmt.Errorf("deal failed: %s", r)
				}
			}()
			deal, res, inPath := dh.MakeOnlineDeal(context.Background(), MakeFullDealParams{
				Rseed:      5 + i,
				FastRet:    opts.FastRetrieval,
				StartEpoch: opts.StartEpoch,
			})
			outPath := dh.PerformRetrieval(context.Background(), deal, res.Root, opts.CarExport)
			AssertFilesEqual(dh.t, inPath, outPath)
			return nil
		})
	}
	require.NoError(dh.t, errgrp.Wait())
}