/*
Copyright IBM Corp. All Rights Reserved.

SPDX-License-Identifier: Apache-2.0
*/

package rwsetutil

import (
	"crypto/sha256"
	"fmt"
	"testing"

	"github.com/golang/protobuf/proto"
	"github.com/hyperledger/fabric-protos-go/ledger/rwset/kvrwset"
	"github.com/hyperledger/fabric/core/ledger/internal/version"
	"github.com/stretchr/testify/require"
)

var (
	testHashFunc = func(data []byte) ([]byte, error) {
		h := sha256.New()
		if _, err := h.Write(data); err != nil {
			return nil, err
		}
		return h.Sum(nil), nil
	}
)

func TestQueryResultHelper_NoResults(t *testing.T) {
	helper, _ := NewRangeQueryResultsHelper(true, 3, testHashFunc)
	r, h, err := helper.Done()
	require.NoError(t, err)
	require.Nil(t, h)
	require.Nil(t, r)
}

func TestQueryResultHelper_HashNotEnabled(t *testing.T) {
	kvReads := buildTestKVReads(t, 5)
	r, h := buildTestResults(t, false, 3, kvReads)
	require.Nil(t, h)
	require.Equal(t, kvReads, r)
}

func TestQueryResultHelper_ResultsNoMoreThanMaxDegree(t *testing.T) {
	maxDegree := 3
	numResults := 3
	kvReads := buildTestKVReads(t, numResults)
	r, h := buildTestResults(t, true, maxDegree, kvReads)
	require.Nil(t, h)
	require.Equal(t, kvReads, r)
}

func TestQueryResultHelper_Hash_OneLevel(t *testing.T) {
	maxDegree := 3
	kvReads := buildTestKVReads(t, 9)
	r, h := buildTestResults(t, true, maxDegree, kvReads)
	level1_1 := computeTestHashKVReads(t, kvReads[0:4])
	level1_2 := computeTestHashKVReads(t, kvReads[4:8])
	level1_3 := computeTestHashKVReads(t, kvReads[8:])
	require.Nil(t, r)
	require.Equal(t, &kvrwset.QueryReadsMerkleSummary{
		MaxDegree:      uint32(maxDegree),
		MaxLevel:       1,
		MaxLevelHashes: hashesToBytes([]Hash{level1_1, level1_2, level1_3})}, h)

}

func TestQueryResultHelper_Hash_TwoLevel(t *testing.T) {
	maxDegree := 3
	kvReads := buildTestKVReads(t, 25)
	r, h := buildTestResults(t, true, maxDegree, kvReads)
	level1_1 := computeTestHashKVReads(t, kvReads[0:4])
	level1_2 := computeTestHashKVReads(t, kvReads[4:8])
	level1_3 := computeTestHashKVReads(t, kvReads[8:12])
	level1_4 := computeTestHashKVReads(t, kvReads[12:16])
	level1_5 := computeTestHashKVReads(t, kvReads[16:20])
	level1_6 := computeTestHashKVReads(t, kvReads[20:24])
	level1_7 := computeTestHashKVReads(t, kvReads[24:])

	level2_1 := computeTestCombinedHash(t, level1_1, level1_2, level1_3, level1_4)
	level2_2 := computeTestCombinedHash(t, level1_5, level1_6, level1_7)
	require.Nil(t, r)
	require.Equal(t, &kvrwset.QueryReadsMerkleSummary{
		MaxDegree:      uint32(maxDegree),
		MaxLevel:       2,
		MaxLevelHashes: hashesToBytes([]Hash{level2_1, level2_2})}, h)

}

func TestQueryResultHelper_Hash_ThreeLevel(t *testing.T) {
	maxDegree := 3
	kvReads := buildTestKVReads(t, 65)
	r, h := buildTestResults(t, true, maxDegree, kvReads)
	level1_1 := computeTestHashKVReads(t, kvReads[0:4])
	level1_2 := computeTestHashKVReads(t, kvReads[4:8])
	level1_3 := computeTestHashKVReads(t, kvReads[8:12])
	level1_4 := computeTestHashKVReads(t, kvReads[12:16])
	level1_5 := computeTestHashKVReads(t, kvReads[16:20])
	level1_6 := computeTestHashKVReads(t, kvReads[20:24])
	level1_7 := computeTestHashKVReads(t, kvReads[24:28])
	level1_8 := computeTestHashKVReads(t, kvReads[28:32])
	level1_9 := computeTestHashKVReads(t, kvReads[32:36])
	level1_10 := computeTestHashKVReads(t, kvReads[36:40])
	level1_11 := computeTestHashKVReads(t, kvReads[40:44])
	level1_12 := computeTestHashKVReads(t, kvReads[44:48])
	level1_13 := computeTestHashKVReads(t, kvReads[48:52])
	level1_14 := computeTestHashKVReads(t, kvReads[52:56])
	level1_15 := computeTestHashKVReads(t, kvReads[56:60])
	level1_16 := computeTestHashKVReads(t, kvReads[60:64])
	level1_17 := computeTestHashKVReads(t, kvReads[64:])

	level2_1 := computeTestCombinedHash(t, level1_1, level1_2, level1_3, level1_4)
	level2_2 := computeTestCombinedHash(t, level1_5, level1_6, level1_7, level1_8)
	level2_3 := computeTestCombinedHash(t, level1_9, level1_10, level1_11, level1_12)
	level2_4 := computeTestCombinedHash(t, level1_13, level1_14, level1_15, level1_16)

	level3_1 := computeTestCombinedHash(t, level2_1, level2_2, level2_3, level2_4)
	level3_2 := level1_17
	require.Nil(t, r)
	require.Equal(t, &kvrwset.QueryReadsMerkleSummary{
		MaxDegree:      uint32(maxDegree),
		MaxLevel:       3,
		MaxLevelHashes: hashesToBytes([]Hash{level3_1, level3_2})}, h)

}

func TestQueryResultHelper_Hash_MaxLevelIncrementNeededInDone(t *testing.T) {
	maxDegree := 2
	kvReads := buildTestKVReads(t, 24)
	r, h := buildTestResults(t, true, maxDegree, kvReads)
	level1_1 := computeTestHashKVReads(t, kvReads[0:3])
	level1_2 := computeTestHashKVReads(t, kvReads[3:6])
	level1_3 := computeTestHashKVReads(t, kvReads[6:9])
	level1_4 := computeTestHashKVReads(t, kvReads[9:12])
	level1_5 := computeTestHashKVReads(t, kvReads[12:15])
	level1_6 := computeTestHashKVReads(t, kvReads[15:18])
	level1_7 := computeTestHashKVReads(t, kvReads[18:21])
	level1_8 := computeTestHashKVReads(t, kvReads[21:24])

	level2_1 := computeTestCombinedHash(t, level1_1, level1_2, level1_3)
	level2_2 := computeTestCombinedHash(t, level1_4, level1_5, level1_6)
	level2_3 := computeTestCombinedHash(t, level1_7, level1_8)

	level3_1 := computeTestCombinedHash(t, level2_1, level2_2, level2_3)

	require.Nil(t, r)
	require.Equal(t, &kvrwset.QueryReadsMerkleSummary{
		MaxDegree:      uint32(maxDegree),
		MaxLevel:       3,
		MaxLevelHashes: hashesToBytes([]Hash{level3_1})}, h)

}

func TestQueryResultHelper_Hash_FirstLevelSkipNeededInDone(t *testing.T) {
	maxDegree := 2
	kvReads := buildTestKVReads(t, 45)
	r, h := buildTestResults(t, true, maxDegree, kvReads)
	level1_1 := computeTestHashKVReads(t, kvReads[0:3])
	level1_2 := computeTestHashKVReads(t, kvReads[3:6])
	level1_3 := computeTestHashKVReads(t, kvReads[6:9])
	level1_4 := computeTestHashKVReads(t, kvReads[9:12])
	level1_5 := computeTestHashKVReads(t, kvReads[12:15])
	level1_6 := computeTestHashKVReads(t, kvReads[15:18])
	level1_7 := computeTestHashKVReads(t, kvReads[18:21])
	level1_8 := computeTestHashKVReads(t, kvReads[21:24])
	level1_9 := computeTestHashKVReads(t, kvReads[24:27])
	level1_10 := computeTestHashKVReads(t, kvReads[27:30])
	level1_11 := computeTestHashKVReads(t, kvReads[30:33])
	level1_12 := computeTestHashKVReads(t, kvReads[33:36])
	level1_13 := computeTestHashKVReads(t, kvReads[36:39])
	level1_14 := computeTestHashKVReads(t, kvReads[39:42])
	level1_15 := computeTestHashKVReads(t, kvReads[42:45])

	level2_1 := computeTestCombinedHash(t, level1_1, level1_2, level1_3)
	level2_2 := computeTestCombinedHash(t, level1_4, level1_5, level1_6)
	level2_3 := computeTestCombinedHash(t, level1_7, level1_8, level1_9)
	level2_4 := computeTestCombinedHash(t, level1_10, level1_11, level1_12)
	level2_5 := computeTestCombinedHash(t, level1_13, level1_14, level1_15)

	level3_1 := computeTestCombinedHash(t, level2_1, level2_2, level2_3)
	level3_2 := computeTestCombinedHash(t, level2_4, level2_5)

	require.Nil(t, r)
	require.Equal(t, &kvrwset.QueryReadsMerkleSummary{
		MaxDegree:      uint32(maxDegree),
		MaxLevel:       3,
		MaxLevelHashes: hashesToBytes([]Hash{level3_1, level3_2})}, h)

}

func buildTestResults(t *testing.T, enableHashing bool, maxDegree int, kvReads []*kvrwset.KVRead) ([]*kvrwset.KVRead, *kvrwset.QueryReadsMerkleSummary) {
	helper, _ := NewRangeQueryResultsHelper(enableHashing, uint32(maxDegree), testHashFunc)
	for _, kvRead := range kvReads {
		require.NoError(t, helper.AddResult(kvRead))
	}
	r, h, err := helper.Done()
	require.NoError(t, err)
	return r, h
}

func buildTestKVReads(t *testing.T, num int) []*kvrwset.KVRead {
	kvreads := []*kvrwset.KVRead{}
	for i := 0; i < num; i++ {
		kvreads = append(kvreads, NewKVRead(fmt.Sprintf("key_%d", i), version.NewHeight(1, uint64(i))))
	}
	return kvreads
}

func computeTestHashKVReads(t *testing.T, kvReads []*kvrwset.KVRead) Hash {
	queryReads := &kvrwset.QueryReads{}
	queryReads.KvReads = kvReads
	b, err := proto.Marshal(queryReads)
	require.NoError(t, err)
	h, err := testHashFunc(b)
	require.NoError(t, err)
	return h
}

func computeTestCombinedHash(t *testing.T, hashes ...Hash) Hash {
	h, err := computeCombinedHash(hashes, testHashFunc)
	require.NoError(t, err)
	return h
}
