package channeldb

import (
	"io/ioutil"
	"os"
	"path/filepath"
	"testing"

	"github.com/btcsuite/btcutil"
	"github.com/lightningnetwork/lnd/lnwire"
)

func TestOpenWithCreate(t *testing.T) {
	t.Parallel()

	// First, create a temporary directory to be used for the duration of
	// this test.
	tempDirName, err := ioutil.TempDir("", "channeldb")
	if err != nil {
		t.Fatalf("unable to create temp dir: %v", err)
	}
	defer os.RemoveAll(tempDirName)

	// Next, open thereby creating channeldb for the first time.
	dbPath := filepath.Join(tempDirName, "cdb")
	cdb, err := Open(dbPath)
	if err != nil {
		t.Fatalf("unable to create channeldb: %v", err)
	}
	if err := cdb.Close(); err != nil {
		t.Fatalf("unable to close channeldb: %v", err)
	}

	// The path should have been successfully created.
	if !fileExists(dbPath) {
		t.Fatalf("channeldb failed to create data directory")
	}
}

// TestWipe tests that the database wipe operation completes successfully
// and that the buckets are deleted. It also checks that attempts to fetch
// information while the buckets are not set return the correct errors.
func TestWipe(t *testing.T) {
	t.Parallel()

	// First, create a temporary directory to be used for the duration of
	// this test.
	tempDirName, err := ioutil.TempDir("", "channeldb")
	if err != nil {
		t.Fatalf("unable to create temp dir: %v", err)
	}
	defer os.RemoveAll(tempDirName)

	// Next, open thereby creating channeldb for the first time.
	dbPath := filepath.Join(tempDirName, "cdb")
	cdb, err := Open(dbPath)
	if err != nil {
		t.Fatalf("unable to create channeldb: %v", err)
	}
	defer cdb.Close()

	if err := cdb.Wipe(); err != nil {
		t.Fatalf("unable to wipe channeldb: %v", err)
	}
	// Check correct errors are returned
	_, err = cdb.FetchAllOpenChannels()
	if err != ErrNoActiveChannels {
		t.Fatalf("fetching open channels: expected '%v' instead got '%v'",
			ErrNoActiveChannels, err)
	}
	_, err = cdb.FetchClosedChannels(false)
	if err != ErrNoClosedChannels {
		t.Fatalf("fetching closed channels: expected '%v' instead got '%v'",
			ErrNoClosedChannels, err)
	}
}

// TestFetchClosedChannelForID tests that we are able to properly retrieve a
// ChannelCloseSummary from the DB given a ChannelID.
func TestFetchClosedChannelForID(t *testing.T) {
	t.Parallel()

	const numChans = 101

	cdb, cleanUp, err := makeTestDB()
	if err != nil {
		t.Fatalf("unable to make test database: %v", err)
	}
	defer cleanUp()

	// Create the test channel state, that we will mutate the index of the
	// funding point.
	state, err := createTestChannelState(cdb)
	if err != nil {
		t.Fatalf("unable to create channel state: %v", err)
	}

	// Now run through the number of channels, and modify the outpoint index
	// to create new channel IDs.
	for i := uint32(0); i < numChans; i++ {
		// Save the open channel to disk.
		state.FundingOutpoint.Index = i
		if err := state.FullSync(); err != nil {
			t.Fatalf("unable to save and serialize channel "+
				"state: %v", err)
		}

		// Close the channel. To make sure we retrieve the correct
		// summary later, we make them differ in the SettledBalance.
		closeSummary := &ChannelCloseSummary{
			ChanPoint:      state.FundingOutpoint,
			RemotePub:      state.IdentityPub,
			SettledBalance: btcutil.Amount(500 + i),
		}
		if err := state.CloseChannel(closeSummary); err != nil {
			t.Fatalf("unable to close channel: %v", err)
		}
	}

	// Now run though them all again and make sure we are able to retrieve
	// summaries from the DB.
	for i := uint32(0); i < numChans; i++ {
		state.FundingOutpoint.Index = i

		// We calculate the ChannelID and use it to fetch the summary.
		cid := lnwire.NewChanIDFromOutPoint(&state.FundingOutpoint)
		fetchedSummary, err := cdb.FetchClosedChannelForID(cid)
		if err != nil {
			t.Fatalf("unable to fetch close summary: %v", err)
		}

		// Make sure we retrieved the correct one by checking the
		// SettledBalance.
		if fetchedSummary.SettledBalance != btcutil.Amount(500+i) {
			t.Fatalf("summaries don't match: expected %v got %v",
				btcutil.Amount(500+i),
				fetchedSummary.SettledBalance)
		}
	}

	// As a final test we make sure that we get ErrClosedChannelNotFound
	// for a ChannelID we didn't add to the DB.
	state.FundingOutpoint.Index++
	cid := lnwire.NewChanIDFromOutPoint(&state.FundingOutpoint)
	_, err = cdb.FetchClosedChannelForID(cid)
	if err != ErrClosedChannelNotFound {
		t.Fatalf("expected ErrClosedChannelNotFound, instead got: %v", err)
	}
}