// Copyright (c) 2013-2014 Conformal Systems LLC.
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.

package ldb_test

import (
	"bytes"
	"compress/bzip2"
	"encoding/binary"
	"io"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/btcsuite/btcd/chaincfg"
	"github.com/btcsuite/btcd/database"
	"github.com/btcsuite/btcd/txscript"
	"github.com/btcsuite/btcd/wire"
	"github.com/btcsuite/btcutil"
	"golang.org/x/crypto/ripemd160"
)

var network = wire.MainNet

// testDb is used to store db related context for a running test.
// the `cleanUpFunc` *must* be called after each test to maintain db
// consistency across tests.
type testDb struct {
	db          database.Db
	blocks      []*btcutil.Block
	dbName      string
	dbNameVer   string
	cleanUpFunc func()
}

func setUpTestDb(t *testing.T, dbname string) (*testDb, error) {
	// Ignore db remove errors since it means we didn't have an old one.
	dbnamever := dbname + ".ver"
	_ = os.RemoveAll(dbname)
	_ = os.RemoveAll(dbnamever)
	db, err := database.CreateDB("leveldb", dbname)
	if err != nil {
		return nil, err
	}

	testdatafile := filepath.Join("..", "testdata", "blocks1-256.bz2")
	blocks, err := loadBlocks(t, testdatafile)
	if err != nil {
		return nil, err
	}

	cleanUp := func() {
		db.Close()
		os.RemoveAll(dbname)
		os.RemoveAll(dbnamever)
	}

	return &testDb{
		db:          db,
		blocks:      blocks,
		dbName:      dbname,
		dbNameVer:   dbnamever,
		cleanUpFunc: cleanUp,
	}, nil
}

func TestOperational(t *testing.T) {
	testOperationalMode(t)
}

// testAddrIndexOperations ensures that all normal operations concerning
// the optional address index function correctly.
func testAddrIndexOperations(t *testing.T, db database.Db, newestBlock *btcutil.Block, newestSha *wire.ShaHash, newestBlockIdx int64) {
	// Metadata about the current addr index state should be unset.
	sha, height, err := db.FetchAddrIndexTip()
	if err != database.ErrAddrIndexDoesNotExist {
		t.Fatalf("Address index metadata shouldn't be in db, hasn't been built up yet.")
	}

	var zeroHash wire.ShaHash
	if !sha.IsEqual(&zeroHash) {
		t.Fatalf("AddrIndexTip wrong hash got: %s, want %s", sha, &zeroHash)

	}

	if height != -1 {
		t.Fatalf("Addrindex not built up, yet a block index tip has been set to: %d.", height)
	}

	// Test enforcement of constraints for "limit" and "skip"
	var fakeAddr btcutil.Address
	_, err = db.FetchTxsForAddr(fakeAddr, -1, 0)
	if err == nil {
		t.Fatalf("Negative value for skip passed, should return an error")
	}

	_, err = db.FetchTxsForAddr(fakeAddr, 0, -1)
	if err == nil {
		t.Fatalf("Negative value for limit passed, should return an error")
	}

	// Simple test to index outputs(s) of the first tx.
	testIndex := make(database.BlockAddrIndex)
	testTx, err := newestBlock.Tx(0)
	if err != nil {
		t.Fatalf("Block has no transactions, unable to test addr "+
			"indexing, err %v", err)
	}

	// Extract the dest addr from the tx.
	_, testAddrs, _, err := txscript.ExtractPkScriptAddrs(testTx.MsgTx().TxOut[0].PkScript, &chaincfg.MainNetParams)
	if err != nil {
		t.Fatalf("Unable to decode tx output, err %v", err)
	}

	// Extract the hash160 from the output script.
	var hash160Bytes [ripemd160.Size]byte
	testHash160 := testAddrs[0].(*btcutil.AddressPubKey).AddressPubKeyHash().ScriptAddress()
	copy(hash160Bytes[:], testHash160[:])

	// Create a fake index.
	blktxLoc, _ := newestBlock.TxLoc()
	testIndex[hash160Bytes] = []*wire.TxLoc{&blktxLoc[0]}

	// Insert our test addr index into the DB.
	err = db.UpdateAddrIndexForBlock(newestSha, newestBlockIdx, testIndex)
	if err != nil {
		t.Fatalf("UpdateAddrIndexForBlock: failed to index"+
			" addrs for block #%d (%s) "+
			"err %v", newestBlockIdx, newestSha, err)
	}

	// Chain Tip of address should've been updated.
	assertAddrIndexTipIsUpdated(db, t, newestSha, newestBlockIdx)

	// Check index retrieval.
	txReplies, err := db.FetchTxsForAddr(testAddrs[0], 0, 1000)
	if err != nil {
		t.Fatalf("FetchTxsForAddr failed to correctly fetch txs for an "+
			"address, err %v", err)
	}
	// Should have one reply.
	if len(txReplies) != 1 {
		t.Fatalf("Failed to properly index tx by address.")
	}

	// Our test tx and indexed tx should have the same sha.
	indexedTx := txReplies[0]
	if !bytes.Equal(indexedTx.Sha.Bytes(), testTx.Sha().Bytes()) {
		t.Fatalf("Failed to fetch proper indexed tx. Expected sha %v, "+
			"fetched %v", testTx.Sha(), indexedTx.Sha)
	}

	// Shut down DB.
	db.Sync()
	db.Close()

	// Re-Open, tip still should be updated to current height and sha.
	db, err = database.OpenDB("leveldb", "tstdbopmode")
	if err != nil {
		t.Fatalf("Unable to re-open created db, err %v", err)
	}
	assertAddrIndexTipIsUpdated(db, t, newestSha, newestBlockIdx)

	// Delete the entire index.
	err = db.DeleteAddrIndex()
	if err != nil {
		t.Fatalf("Couldn't delete address index, err %v", err)
	}

	// Former index should no longer exist.
	txReplies, err = db.FetchTxsForAddr(testAddrs[0], 0, 1000)
	if err != nil {
		t.Fatalf("Unable to fetch transactions for address: %v", err)
	}
	if len(txReplies) != 0 {
		t.Fatalf("Address index was not successfully deleted. "+
			"Should have 0 tx's indexed, %v were returned.",
			len(txReplies))
	}

	// Tip should be blanked out.
	if _, _, err := db.FetchAddrIndexTip(); err != database.ErrAddrIndexDoesNotExist {
		t.Fatalf("Address index was not fully deleted.")
	}

}

func assertAddrIndexTipIsUpdated(db database.Db, t *testing.T, newestSha *wire.ShaHash, newestBlockIdx int64) {
	// Safe to ignore error, since height will be < 0 in "error" case.
	sha, height, _ := db.FetchAddrIndexTip()
	if newestBlockIdx != height {
		t.Fatalf("Height of address index tip failed to update, "+
			"expected %v, got %v", newestBlockIdx, height)
	}
	if !bytes.Equal(newestSha.Bytes(), sha.Bytes()) {
		t.Fatalf("Sha of address index tip failed to update, "+
			"expected %v, got %v", newestSha, sha)
	}
}

func testOperationalMode(t *testing.T) {
	// simplified basic operation is:
	// 1) fetch block from remote server
	// 2) look up all txin (except coinbase in db)
	// 3) insert block
	// 4) exercise the optional addridex
	testDb, err := setUpTestDb(t, "tstdbopmode")
	if err != nil {
		t.Errorf("Failed to open test database %v", err)
		return
	}
	defer testDb.cleanUpFunc()
	err = nil
out:
	for height := int64(0); height < int64(len(testDb.blocks)); height++ {
		block := testDb.blocks[height]
		mblock := block.MsgBlock()
		var txneededList []*wire.ShaHash
		for _, tx := range mblock.Transactions {
			for _, txin := range tx.TxIn {
				if txin.PreviousOutPoint.Index == uint32(4294967295) {
					continue
				}
				origintxsha := &txin.PreviousOutPoint.Hash
				txneededList = append(txneededList, origintxsha)

				exists, err := testDb.db.ExistsTxSha(origintxsha)
				if err != nil {
					t.Errorf("ExistsTxSha: unexpected error %v ", err)
				}
				if !exists {
					t.Errorf("referenced tx not found %v ", origintxsha)
				}

				_, err = testDb.db.FetchTxBySha(origintxsha)
				if err != nil {
					t.Errorf("referenced tx not found %v err %v ", origintxsha, err)
				}
			}
		}
		txlist := testDb.db.FetchUnSpentTxByShaList(txneededList)
		for _, txe := range txlist {
			if txe.Err != nil {
				t.Errorf("tx list fetch failed %v err %v ", txe.Sha, txe.Err)
				break out
			}
		}

		newheight, err := testDb.db.InsertBlock(block)
		if err != nil {
			t.Errorf("failed to insert block %v err %v", height, err)
			break out
		}
		if newheight != height {
			t.Errorf("height mismatch expect %v returned %v", height, newheight)
			break out
		}

		newSha, blkid, err := testDb.db.NewestSha()
		if err != nil {
			t.Errorf("failed to obtain latest sha %v %v", height, err)
		}

		if blkid != height {
			t.Errorf("height does not match latest block height %v %v %v", blkid, height, err)
		}

		blkSha, _ := block.Sha()
		if *newSha != *blkSha {
			t.Errorf("Newest block sha does not match freshly inserted one %v %v %v ", newSha, blkSha, err)
		}
	}

	// now that the db is populated, do some additional tests
	testFetchHeightRange(t, testDb.db, testDb.blocks)

	// Ensure all operations dealing with the optional address index behave
	// correctly.
	newSha, blkid, err := testDb.db.NewestSha()
	testAddrIndexOperations(t, testDb.db, testDb.blocks[len(testDb.blocks)-1], newSha, blkid)
}

func TestBackout(t *testing.T) {
	testBackout(t)
}

func testBackout(t *testing.T) {
	// simplified basic operation is:
	// 1) fetch block from remote server
	// 2) look up all txin (except coinbase in db)
	// 3) insert block

	testDb, err := setUpTestDb(t, "tstdbbackout")
	if err != nil {
		t.Errorf("Failed to open test database %v", err)
		return
	}
	defer testDb.cleanUpFunc()

	if len(testDb.blocks) < 120 {
		t.Errorf("test data too small")
		return
	}

	err = nil
	for height := int64(0); height < int64(len(testDb.blocks)); height++ {
		if height == 100 {
			t.Logf("Syncing at block height 100")
			testDb.db.Sync()
		}
		if height == 120 {
			t.Logf("Simulating unexpected application quit")
			// Simulate unexpected application quit
			testDb.db.RollbackClose()
			break
		}

		block := testDb.blocks[height]

		newheight, err := testDb.db.InsertBlock(block)
		if err != nil {
			t.Errorf("failed to insert block %v err %v", height, err)
			return
		}
		if newheight != height {
			t.Errorf("height mismatch expect %v returned %v", height, newheight)
			return
		}
	}

	// db was closed at height 120, so no cleanup is possible.

	// reopen db
	testDb.db, err = database.OpenDB("leveldb", testDb.dbName)
	if err != nil {
		t.Errorf("Failed to open test database %v", err)
		return
	}
	defer func() {
		if err := testDb.db.Close(); err != nil {
			t.Errorf("Close: unexpected error: %v", err)
		}
	}()

	sha, err := testDb.blocks[99].Sha()
	if err != nil {
		t.Errorf("failed to get block 99 sha err %v", err)
		return
	}
	if _, err := testDb.db.ExistsSha(sha); err != nil {
		t.Errorf("ExistsSha: unexpected error: %v", err)
	}
	_, err = testDb.db.FetchBlockBySha(sha)
	if err != nil {
		t.Errorf("failed to load block 99 from db %v", err)
		return
	}

	sha, err = testDb.blocks[119].Sha()
	if err != nil {
		t.Errorf("failed to get block 110 sha err %v", err)
		return
	}
	if _, err := testDb.db.ExistsSha(sha); err != nil {
		t.Errorf("ExistsSha: unexpected error: %v", err)
	}
	_, err = testDb.db.FetchBlockBySha(sha)
	if err != nil {
		t.Errorf("loaded block 119 from db")
		return
	}

	block := testDb.blocks[119]
	mblock := block.MsgBlock()
	txsha, err := mblock.Transactions[0].TxSha()
	exists, err := testDb.db.ExistsTxSha(&txsha)
	if err != nil {
		t.Errorf("ExistsTxSha: unexpected error %v ", err)
	}
	if !exists {
		t.Errorf("tx %v not located db\n", txsha)
	}

	_, err = testDb.db.FetchTxBySha(&txsha)
	if err != nil {
		t.Errorf("tx %v not located db\n", txsha)
		return
	}
}

var savedblocks []*btcutil.Block

func loadBlocks(t *testing.T, file string) (blocks []*btcutil.Block, err error) {
	if len(savedblocks) != 0 {
		blocks = savedblocks
		return
	}
	testdatafile := filepath.Join("..", "testdata", "blocks1-256.bz2")
	var dr io.Reader
	var fi io.ReadCloser
	fi, err = os.Open(testdatafile)
	if err != nil {
		t.Errorf("failed to open file %v, err %v", testdatafile, err)
		return
	}
	if strings.HasSuffix(testdatafile, ".bz2") {
		z := bzip2.NewReader(fi)
		dr = z
	} else {
		dr = fi
	}

	defer func() {
		if err := fi.Close(); err != nil {
			t.Errorf("failed to close file %v %v", testdatafile, err)
		}
	}()

	// Set the first block as the genesis block.
	genesis := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	blocks = append(blocks, genesis)

	var block *btcutil.Block
	err = nil
	for height := int64(1); err == nil; height++ {
		var rintbuf uint32
		err = binary.Read(dr, binary.LittleEndian, &rintbuf)
		if err == io.EOF {
			// hit end of file at expected offset: no warning
			height--
			err = nil
			break
		}
		if err != nil {
			t.Errorf("failed to load network type, err %v", err)
			break
		}
		if rintbuf != uint32(network) {
			t.Errorf("Block doesn't match network: %v expects %v",
				rintbuf, network)
			break
		}
		err = binary.Read(dr, binary.LittleEndian, &rintbuf)
		blocklen := rintbuf

		rbytes := make([]byte, blocklen)

		// read block
		dr.Read(rbytes)

		block, err = btcutil.NewBlockFromBytes(rbytes)
		if err != nil {
			t.Errorf("failed to parse block %v", height)
			return
		}
		blocks = append(blocks, block)
	}
	savedblocks = blocks
	return
}

func testFetchHeightRange(t *testing.T, db database.Db, blocks []*btcutil.Block) {

	var testincrement int64 = 50
	var testcnt int64 = 100

	shanames := make([]*wire.ShaHash, len(blocks))

	nBlocks := int64(len(blocks))

	for i := range blocks {
		blockSha, err := blocks[i].Sha()
		if err != nil {
			t.Errorf("FetchHeightRange: unexpected failure computing block sah %v", err)
		}
		shanames[i] = blockSha
	}

	for startheight := int64(0); startheight < nBlocks; startheight += testincrement {
		endheight := startheight + testcnt

		if endheight > nBlocks {
			endheight = database.AllShas
		}

		shalist, err := db.FetchHeightRange(startheight, endheight)
		if err != nil {
			t.Errorf("FetchHeightRange: unexpected failure looking up shas %v", err)
		}

		if endheight == database.AllShas {
			if int64(len(shalist)) != nBlocks-startheight {
				t.Errorf("FetchHeightRange: expected A %v shas, got %v", nBlocks-startheight, len(shalist))
			}
		} else {
			if int64(len(shalist)) != testcnt {
				t.Errorf("FetchHeightRange: expected %v shas, got %v", testcnt, len(shalist))
			}
		}

		for i := range shalist {
			sha0 := *shanames[int64(i)+startheight]
			sha1 := shalist[i]
			if sha0 != sha1 {
				t.Errorf("FetchHeightRange: mismatch sha at %v requested range %v %v: %v %v ", int64(i)+startheight, startheight, endheight, sha0, sha1)
			}
		}
	}

}

func TestLimitAndSkipFetchTxsForAddr(t *testing.T) {
	testDb, err := setUpTestDb(t, "tstdbtxaddr")
	if err != nil {
		t.Errorf("Failed to open test database %v", err)
		return
	}
	defer testDb.cleanUpFunc()

	// Insert a block with some fake test transactions. The block will have
	// 10 copies of a fake transaction involving same address.
	addrString := "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa"
	targetAddr, err := btcutil.DecodeAddress(addrString, &chaincfg.MainNetParams)
	if err != nil {
		t.Fatalf("Unable to decode test address: %v", err)
	}
	outputScript, err := txscript.PayToAddrScript(targetAddr)
	if err != nil {
		t.Fatalf("Unable make test pkScript %v", err)
	}
	fakeTxOut := wire.NewTxOut(10, outputScript)
	var emptyHash wire.ShaHash
	fakeHeader := wire.NewBlockHeader(&emptyHash, &emptyHash, 1, 1)
	msgBlock := wire.NewMsgBlock(fakeHeader)
	for i := 0; i < 10; i++ {
		mtx := wire.NewMsgTx()
		mtx.AddTxOut(fakeTxOut)
		msgBlock.AddTransaction(mtx)
	}

	// Insert the test block into the DB.
	testBlock := btcutil.NewBlock(msgBlock)
	newheight, err := testDb.db.InsertBlock(testBlock)
	if err != nil {
		t.Fatalf("Unable to insert block into db: %v", err)
	}

	// Create and insert an address index for out test addr.
	txLoc, _ := testBlock.TxLoc()
	index := make(database.BlockAddrIndex)
	for i := range testBlock.Transactions() {
		var hash160 [ripemd160.Size]byte
		scriptAddr := targetAddr.ScriptAddress()
		copy(hash160[:], scriptAddr[:])
		index[hash160] = append(index[hash160], &txLoc[i])
	}
	blkSha, _ := testBlock.Sha()
	err = testDb.db.UpdateAddrIndexForBlock(blkSha, newheight, index)
	if err != nil {
		t.Fatalf("UpdateAddrIndexForBlock: failed to index"+
			" addrs for block #%d (%s) "+
			"err %v", newheight, blkSha, err)
		return
	}

	// Try skipping the first 4 results, should get 6 in return.
	txReply, err := testDb.db.FetchTxsForAddr(targetAddr, 4, 100000)
	if err != nil {
		t.Fatalf("Unable to fetch transactions for address: %v", err)
	}
	if len(txReply) != 6 {
		t.Fatalf("Did not correctly skip forward in txs for address reply"+
			" got %v txs, expected %v", len(txReply), 6)
	}

	// Limit the number of results to 3.
	txReply, err = testDb.db.FetchTxsForAddr(targetAddr, 0, 3)
	if err != nil {
		t.Fatalf("Unable to fetch transactions for address: %v", err)
	}
	if len(txReply) != 3 {
		t.Fatalf("Did not correctly limit in txs for address reply"+
			" got %v txs, expected %v", len(txReply), 3)
	}

	// Skip 1, limit 5.
	txReply, err = testDb.db.FetchTxsForAddr(targetAddr, 1, 5)
	if err != nil {
		t.Fatalf("Unable to fetch transactions for address: %v", err)
	}
	if len(txReply) != 5 {
		t.Fatalf("Did not correctly limit in txs for address reply"+
			" got %v txs, expected %v", len(txReply), 5)
	}
}