// Copyright 2016 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 state

import (
	"bytes"
	"testing"

	"github.com/ethereum/go-ethereum/common"
)

// Tests that the node iterator indeed walks over the entire database contents.
func TestNodeIteratorCoverage(t *testing.T) {
	// Create some arbitrary test state to iterate
	db, sdb, root, _ := makeTestState()
	sdb.TrieDB().Commit(root, false, nil)

	state, err := New(root, sdb, nil)
	if err != nil {
		t.Fatalf("failed to create state trie at %x: %v", root, err)
	}
	// Gather all the node hashes found by the iterator
	hashes := make(map[common.Hash]struct{})
	for it := NewNodeIterator(state); it.Next(); {
		if it.Hash != (common.Hash{}) {
			hashes[it.Hash] = struct{}{}
		}
	}
	// Cross check the iterated hashes and the database/nodepool content
	for hash := range hashes {
		if _, err = sdb.TrieDB().Node(hash); err != nil {
			_, err = sdb.ContractCode(common.Hash{}, hash)
		}
		if err != nil {
			t.Errorf("failed to retrieve reported node %x", hash)
		}
	}
	for _, hash := range sdb.TrieDB().Nodes() {
		if _, ok := hashes[hash]; !ok {
			t.Errorf("state entry not reported %x", hash)
		}
	}
	it := db.NewIterator(nil, nil)
	for it.Next() {
		key := it.Key()
		if bytes.HasPrefix(key, []byte("secure-key-")) {
			continue
		}
		if _, ok := hashes[common.BytesToHash(key)]; !ok {
			t.Errorf("state entry not reported %x", key)
		}
	}
	it.Release()
}