// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package trie

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/davecgh/go-spew/spew"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/ethdb"
)

func init() {
	spew.Config.Indent = "    "
	spew.Config.DisableMethods = true
}

// Used for testing
func newEmpty() *Trie {
	db, _ := ethdb.NewMemDatabase()
	trie, _ := New(common.Hash{}, db)
	return trie
}

func TestEmptyTrie(t *testing.T) {
	var trie Trie
	res := trie.Hash()
	exp := emptyRoot
	if res != common.Hash(exp) {
		t.Errorf("expected %x got %x", exp, res)
	}
}

func TestNull(t *testing.T) {
	var trie Trie
	key := make([]byte, 32)
	value := common.FromHex("0x823140710bf13990e4500136726d8b55")
	trie.Update(key, value)
	value = trie.Get(key)
}

func TestMissingRoot(t *testing.T) {
	db, _ := ethdb.NewMemDatabase()
	trie, err := New(common.HexToHash("0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33"), db)
	if trie != nil {
		t.Error("New returned non-nil trie for invalid root")
	}
	if err != ErrMissingRoot {
		t.Error("New returned wrong error: %v", err)
	}
}

func TestInsert(t *testing.T) {
	trie := newEmpty()

	updateString(trie, "doe", "reindeer")
	updateString(trie, "dog", "puppy")
	updateString(trie, "dogglesworth", "cat")

	exp := common.HexToHash("8aad789dff2f538bca5d8ea56e8abe10f4c7ba3a5dea95fea4cd6e7c3a1168d3")
	root := trie.Hash()
	if root != exp {
		t.Errorf("exp %x got %x", exp, root)
	}

	trie = newEmpty()
	updateString(trie, "A", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")

	exp = common.HexToHash("d23786fb4a010da3ce639d66d5e904a11dbc02746d1ce25029e53290cabf28ab")
	root, err := trie.Commit()
	if err != nil {
		t.Fatalf("commit error: %v", err)
	}
	if root != exp {
		t.Errorf("exp %x got %x", exp, root)
	}
}

func TestGet(t *testing.T) {
	trie := newEmpty()
	updateString(trie, "doe", "reindeer")
	updateString(trie, "dog", "puppy")
	updateString(trie, "dogglesworth", "cat")

	for i := 0; i < 2; i++ {
		res := getString(trie, "dog")
		if !bytes.Equal(res, []byte("puppy")) {
			t.Errorf("expected puppy got %x", res)
		}

		unknown := getString(trie, "unknown")
		if unknown != nil {
			t.Errorf("expected nil got %x", unknown)
		}

		if i == 1 {
			return
		}
		trie.Commit()
	}
}

func TestDelete(t *testing.T) {
	trie := newEmpty()
	vals := []struct{ k, v string }{
		{"do", "verb"},
		{"ether", "wookiedoo"},
		{"horse", "stallion"},
		{"shaman", "horse"},
		{"doge", "coin"},
		{"ether", ""},
		{"dog", "puppy"},
		{"shaman", ""},
	}
	for _, val := range vals {
		if val.v != "" {
			updateString(trie, val.k, val.v)
		} else {
			deleteString(trie, val.k)
		}
	}

	hash := trie.Hash()
	exp := common.HexToHash("5991bb8c6514148a29db676a14ac506cd2cd5775ace63c30a4fe457715e9ac84")
	if hash != exp {
		t.Errorf("expected %x got %x", exp, hash)
	}
}

func TestEmptyValues(t *testing.T) {
	trie := newEmpty()

	vals := []struct{ k, v string }{
		{"do", "verb"},
		{"ether", "wookiedoo"},
		{"horse", "stallion"},
		{"shaman", "horse"},
		{"doge", "coin"},
		{"ether", ""},
		{"dog", "puppy"},
		{"shaman", ""},
	}
	for _, val := range vals {
		updateString(trie, val.k, val.v)
	}

	hash := trie.Hash()
	exp := common.HexToHash("5991bb8c6514148a29db676a14ac506cd2cd5775ace63c30a4fe457715e9ac84")
	if hash != exp {
		t.Errorf("expected %x got %x", exp, hash)
	}
}

func TestReplication(t *testing.T) {
	trie := newEmpty()
	vals := []struct{ k, v string }{
		{"do", "verb"},
		{"ether", "wookiedoo"},
		{"horse", "stallion"},
		{"shaman", "horse"},
		{"doge", "coin"},
		{"dog", "puppy"},
		{"somethingveryoddindeedthis is", "myothernodedata"},
	}
	for _, val := range vals {
		updateString(trie, val.k, val.v)
	}
	exp, err := trie.Commit()
	if err != nil {
		t.Fatalf("commit error: %v", err)
	}

	// create a new trie on top of the database and check that lookups work.
	trie2, err := New(exp, trie.db)
	if err != nil {
		t.Fatalf("can't recreate trie at %x: %v", exp, err)
	}
	for _, kv := range vals {
		if string(getString(trie2, kv.k)) != kv.v {
			t.Errorf("trie2 doesn't have %q => %q", kv.k, kv.v)
		}
	}
	hash, err := trie2.Commit()
	if err != nil {
		t.Fatalf("commit error: %v", err)
	}
	if hash != exp {
		t.Errorf("root failure. expected %x got %x", exp, hash)
	}

	// perform some insertions on the new trie.
	vals2 := []struct{ k, v string }{
		{"do", "verb"},
		{"ether", "wookiedoo"},
		{"horse", "stallion"},
		// {"shaman", "horse"},
		// {"doge", "coin"},
		// {"ether", ""},
		// {"dog", "puppy"},
		// {"somethingveryoddindeedthis is", "myothernodedata"},
		// {"shaman", ""},
	}
	for _, val := range vals2 {
		updateString(trie2, val.k, val.v)
	}
	if trie2.Hash() != exp {
		t.Errorf("root failure. expected %x got %x", exp, hash)
	}
}

func paranoiaCheck(t1 *Trie) (bool, *Trie) {
	t2 := new(Trie)
	it := NewIterator(t1)
	for it.Next() {
		t2.Update(it.Key, it.Value)
	}
	return t2.Hash() == t1.Hash(), t2
}

func TestParanoia(t *testing.T) {
	t.Skip()
	trie := newEmpty()

	vals := []struct{ k, v string }{
		{"do", "verb"},
		{"ether", "wookiedoo"},
		{"horse", "stallion"},
		{"shaman", "horse"},
		{"doge", "coin"},
		{"ether", ""},
		{"dog", "puppy"},
		{"shaman", ""},
		{"somethingveryoddindeedthis is", "myothernodedata"},
	}
	for _, val := range vals {
		updateString(trie, val.k, val.v)
	}
	trie.Commit()

	ok, t2 := paranoiaCheck(trie)
	if !ok {
		t.Errorf("trie paranoia check failed %x %x", trie.Hash(), t2.Hash())
	}
}

// Not an actual test
func TestOutput(t *testing.T) {
	t.Skip()

	base := "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
	trie := newEmpty()
	for i := 0; i < 50; i++ {
		updateString(trie, fmt.Sprintf("%s%d", base, i), "valueeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee")
	}
	fmt.Println("############################## FULL ################################")
	fmt.Println(trie.root)

	trie.Commit()
	fmt.Println("############################## SMALL ################################")
	trie2, _ := New(trie.Hash(), trie.db)
	getString(trie2, base+"20")
	fmt.Println(trie2.root)
}

func TestLargeValue(t *testing.T) {
	trie := newEmpty()
	trie.Update([]byte("key1"), []byte{99, 99, 99, 99})
	trie.Update([]byte("key2"), bytes.Repeat([]byte{1}, 32))
	trie.Hash()

}

type kv struct {
	k, v []byte
	t    bool
}

func TestLargeData(t *testing.T) {
	trie := newEmpty()
	vals := make(map[string]*kv)

	for i := byte(0); i < 255; i++ {
		value := &kv{common.LeftPadBytes([]byte{i}, 32), []byte{i}, false}
		value2 := &kv{common.LeftPadBytes([]byte{10, i}, 32), []byte{i}, false}
		trie.Update(value.k, value.v)
		trie.Update(value2.k, value2.v)
		vals[string(value.k)] = value
		vals[string(value2.k)] = value2
	}

	it := NewIterator(trie)
	for it.Next() {
		vals[string(it.Key)].t = true
	}

	var untouched []*kv
	for _, value := range vals {
		if !value.t {
			untouched = append(untouched, value)
		}
	}

	if len(untouched) > 0 {
		t.Errorf("Missed %d nodes", len(untouched))
		for _, value := range untouched {
			t.Error(value)
		}
	}
}

func BenchmarkGet(b *testing.B)      { benchGet(b, false) }
func BenchmarkGetDB(b *testing.B)    { benchGet(b, true) }
func BenchmarkUpdateBE(b *testing.B) { benchUpdate(b, binary.BigEndian) }
func BenchmarkUpdateLE(b *testing.B) { benchUpdate(b, binary.LittleEndian) }
func BenchmarkHashBE(b *testing.B)   { benchHash(b, binary.BigEndian) }
func BenchmarkHashLE(b *testing.B)   { benchHash(b, binary.LittleEndian) }

const benchElemCount = 20000

func benchGet(b *testing.B, commit bool) {
	trie := new(Trie)
	if commit {
		dir, tmpdb := tempDB()
		defer os.RemoveAll(dir)
		trie, _ = New(common.Hash{}, tmpdb)
	}
	k := make([]byte, 32)
	for i := 0; i < benchElemCount; i++ {
		binary.LittleEndian.PutUint64(k, uint64(i))
		trie.Update(k, k)
	}
	binary.LittleEndian.PutUint64(k, benchElemCount/2)
	if commit {
		trie.Commit()
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		trie.Get(k)
	}
}

func benchUpdate(b *testing.B, e binary.ByteOrder) *Trie {
	trie := newEmpty()
	k := make([]byte, 32)
	for i := 0; i < b.N; i++ {
		e.PutUint64(k, uint64(i))
		trie.Update(k, k)
	}
	return trie
}

func benchHash(b *testing.B, e binary.ByteOrder) {
	trie := newEmpty()
	k := make([]byte, 32)
	for i := 0; i < benchElemCount; i++ {
		e.PutUint64(k, uint64(i))
		trie.Update(k, k)
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		trie.Hash()
	}
}

func tempDB() (string, Database) {
	dir, err := ioutil.TempDir("", "trie-bench")
	if err != nil {
		panic(fmt.Sprintf("can't create temporary directory: %v", err))
	}
	db, err := ethdb.NewLDBDatabase(dir, 300*1024)
	if err != nil {
		panic(fmt.Sprintf("can't create temporary database: %v", err))
	}
	return dir, db
}

func getString(trie *Trie, k string) []byte {
	return trie.Get([]byte(k))
}

func updateString(trie *Trie, k, v string) {
	trie.Update([]byte(k), []byte(v))
}

func deleteString(trie *Trie, k string) {
	trie.Delete([]byte(k))
}