package roaring

// to run just these tests: go test -run TestSerialization*

import (
	"bytes"
	"encoding/binary"
	"encoding/gob"
	"fmt"
	"os"
	"path/filepath"
	"runtime"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestSerializationOfEmptyBitmap(t *testing.T) {
	rb := NewBitmap()

	buf := &bytes.Buffer{}
	_, err := rb.WriteTo(buf)

	require.NoError(t, err)
	assert.EqualValues(t, buf.Len(), rb.GetSerializedSizeInBytes())

	newrb := NewBitmap()
	_, err = newrb.ReadFrom(buf)

	require.NoError(t, err)
	assert.True(t, rb.Equals(newrb))
}

func TestBase64_036(t *testing.T) {
	rb := BitmapOf(1, 2, 3, 4, 5, 100, 1000)

	bstr, _ := rb.ToBase64()
	assert.NotEmpty(t, bstr)

	newrb := NewBitmap()

	_, err := newrb.FromBase64(bstr)

	require.NoError(t, err)
	assert.True(t, rb.Equals(newrb))
}

func TestSerializationBasic037(t *testing.T) {
	rb := BitmapOf(1, 2, 3, 4, 5, 100, 1000)

	buf := &bytes.Buffer{}
	_, err := rb.WriteTo(buf)

	require.NoError(t, err)
	assert.EqualValues(t, buf.Len(), rb.GetSerializedSizeInBytes())

	newrb := NewBitmap()
	_, err = newrb.ReadFrom(buf)

	require.NoError(t, err)
	assert.True(t, rb.Equals(newrb))
}

func TestSerializationToFile038(t *testing.T) {
	rb := BitmapOf(1, 2, 3, 4, 5, 100, 1000)
	fname := filepath.Join(t.TempDir(), "myfile.bin")
	fout, err := os.OpenFile(fname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0660)
	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}

	var l int64
	l, err = rb.WriteTo(fout)
	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}

	assert.EqualValues(t, l, rb.GetSerializedSizeInBytes())

	fout.Close()

	newrb := NewBitmap()
	fin, err := os.Open(fname)
	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}

	defer fin.Close()

	_, _ = newrb.ReadFrom(fin)
	assert.True(t, rb.Equals(newrb))
}

func TestSerializationReadRunsFromFile039(t *testing.T) {
	fn := "testdata/bitmapwithruns.bin"

	by, err := os.ReadFile(fn)
	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}

	newrb := NewBitmap()
	_, err = newrb.ReadFrom(bytes.NewBuffer(by))

	require.NoError(t, err)
}

func TestSerializationBasic4WriteAndReadFile040(t *testing.T) {
	fname := "testdata/all3.classic"

	rb := NewBitmap()
	for k := uint32(0); k < 100000; k += 1000 {
		rb.Add(k)
	}
	for k := uint32(100000); k < 200000; k++ {
		rb.Add(3 * k)
	}
	for k := uint32(700000); k < 800000; k++ {
		rb.Add(k)
	}

	rb.highlowcontainer.runOptimize()
	fout, err := os.Create(fname)
	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}

	var l int64

	l, err = rb.WriteTo(fout)

	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}
	assert.EqualValues(t, l, rb.GetSerializedSizeInBytes())

	fout.Close()
	fin, err := os.Open(fname)
	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}

	defer fin.Close()

	newrb := NewBitmap()
	_, err = newrb.ReadFrom(fin)

	require.NoError(t, err)
	assert.True(t, rb.Equals(newrb))
}

func TestSerializationFromJava051(t *testing.T) {
	fname := "testdata/bitmapwithoutruns.bin"
	newrb := NewBitmap()
	fin, err := os.Open(fname)
	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}

	defer func() {
		fin.Close()
	}()

	_, _ = newrb.ReadFrom(fin)
	t.Log(newrb.GetCardinality())
	rb := NewBitmap()
	for k := uint32(0); k < 100000; k += 1000 {
		rb.Add(k)
	}
	for k := uint32(100000); k < 200000; k++ {
		rb.Add(3 * k)
	}
	for k := uint32(700000); k < 800000; k++ {
		rb.Add(k)
	}

	assert.True(t, rb.Equals(newrb))
}

func TestSerializationFromJavaWithRuns052(t *testing.T) {
	fname := "testdata/bitmapwithruns.bin"

	newrb := NewBitmap()
	fin, err := os.Open(fname)
	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}

	defer func() {
		fin.Close()
	}()
	_, _ = newrb.ReadFrom(fin)
	rb := NewBitmap()

	for k := uint32(0); k < 100000; k += 1000 {
		rb.Add(k)
	}
	for k := uint32(100000); k < 200000; k++ {
		rb.Add(3 * k)
	}
	for k := uint32(700000); k < 800000; k++ {
		rb.Add(k)
	}

	assert.True(t, rb.Equals(newrb))
}

func TestSerializationBasic2_041(t *testing.T) {
	rb := BitmapOf(1, 2, 3, 4, 5, 100, 1000, 10000, 100000, 1000000)
	buf := &bytes.Buffer{}
	sz := rb.GetSerializedSizeInBytes()
	ub := BoundSerializedSizeInBytes(rb.GetCardinality(), 1000001)

	assert.False(t, sz > ub+10)

	l := int(rb.GetSerializedSizeInBytes())
	_, err := rb.WriteTo(buf)

	require.NoError(t, err)
	assert.Equal(t, l, buf.Len())

	newrb := NewBitmap()
	_, err = newrb.ReadFrom(buf)

	require.NoError(t, err)
	assert.True(t, rb.Equals(newrb))
}

func TestFromUnsafeBytes(t *testing.T) {
	rb := BitmapOf(1, 2, 3, 4, 5, 100, 1000, 10000, 100000, 1000000)
	buf := &bytes.Buffer{}
	_, err := rb.WriteTo(buf)
	require.NoError(t, err)
	b := buf.Bytes()
	rb2 := NewBitmap()
	_, err2 := rb2.FromUnsafeBytes(b)
	require.NoError(t, err2)
	assert.True(t, rb.Equals(rb2))
}

// roaringarray.writeTo and .readFrom should serialize and unserialize when containing all 3 container types
func TestSerializationBasic3_042(t *testing.T) {
	rb := BitmapOf(1, 2, 3, 4, 5, 100, 1000, 10000, 100000, 1000000)
	for i := 5000000; i < 5000000+2*(1<<16); i++ {
		rb.AddInt(i)
	}

	// confirm all three types present
	var bc, ac, rc bool
	for _, v := range rb.highlowcontainer.containers {
		switch cn := v.(type) {
		case *bitmapContainer:
			bc = true
		case *arrayContainer:
			ac = true
		case *runContainer16:
			rc = true
		default:
			t.Fatalf("Unrecognized container implementation: %T", cn)
		}
	}

	assert.True(t, bc, "no bitmapContainer found, change your test input so we test all three!")
	assert.True(t, ac, "no arrayContainer found, change your test input so we test all three!")
	assert.True(t, rc, "no runContainer16 found, change your test input so we test all three!")

	var buf bytes.Buffer
	_, err := rb.WriteTo(&buf)

	require.NoError(t, err)
	assert.EqualValues(t, buf.Len(), rb.GetSerializedSizeInBytes())

	newrb := NewBitmap()
	_, err = newrb.ReadFrom(&buf)

	require.NoError(t, err)
	assert.Equal(t, rb.GetCardinality(), newrb.GetCardinality())
	assert.True(t, newrb.Equals(rb))
}

func TestGobcoding043(t *testing.T) {
	rb := BitmapOf(1, 2, 3, 4, 5, 100, 1000)

	buf := new(bytes.Buffer)
	encoder := gob.NewEncoder(buf)
	err := encoder.Encode(rb)

	require.NoError(t, err)

	var b Bitmap
	decoder := gob.NewDecoder(buf)
	err = decoder.Decode(&b)

	require.NoError(t, err)
	assert.True(t, b.Equals(rb))
}

func TestByteSliceAsUint16Slice(t *testing.T) {
	t.Run("valid slice", func(t *testing.T) {
		expectedSize := 2
		slice := make([]byte, 4)
		binary.LittleEndian.PutUint16(slice, 42)
		binary.LittleEndian.PutUint16(slice[2:], 43)

		uint16Slice := byteSliceAsUint16Slice(slice)

		assert.Equal(t, expectedSize, len(uint16Slice))
		assert.Equal(t, expectedSize, cap(uint16Slice))
		assert.False(t, uint16Slice[0] != 42 || uint16Slice[1] != 43)
	})

	t.Run("inlined", func(t *testing.T) {
		first, second := singleSliceInArray()
		t.Logf("received %v %v", first, second[0])
		if !first.Equals(second[0]) {
			t.Errorf("inline fail %v %v", first, second[0])
		}
	})

	t.Run("empty slice", func(t *testing.T) {
		slice := make([]byte, 0, 0)
		uint16Slice := byteSliceAsUint16Slice(slice)

		assert.Equal(t, 0, len(uint16Slice))
		assert.Equal(t, 0, cap(uint16Slice))
	})

	t.Run("invalid slice size", func(t *testing.T) {
		slice := make([]byte, 1, 1)

		assert.Panics(t, func() {
			byteSliceAsUint16Slice(slice)
		})
	})
}

func singleSliceInArray() (*Bitmap, []*Bitmap) {
	firstSlice := singleSlice()
	containerSlice := make([]*Bitmap, 0)
	secondContainer := singleSlice()
	containerSlice = append(containerSlice, secondContainer)
	return firstSlice, containerSlice
}

func singleSlice() *Bitmap {
	slice := make([]byte, 2)
	return &Bitmap{highlowcontainer: roaringArray{keys: []uint16{0}, containers: []container{&arrayContainer{byteSliceAsUint16Slice(slice)}}}}
}

func TestByteSliceAsUint64Slice(t *testing.T) {
	t.Run("valid slice", func(t *testing.T) {
		expectedSize := 2
		slice := make([]byte, 16)
		binary.LittleEndian.PutUint64(slice, 42)
		binary.LittleEndian.PutUint64(slice[8:], 43)

		uint64Slice := byteSliceAsUint64Slice(slice)

		assert.Equal(t, expectedSize, len(uint64Slice))
		assert.Equal(t, expectedSize, cap(uint64Slice))
		assert.False(t, uint64Slice[0] != 42 || uint64Slice[1] != 43)
	})

	t.Run("empty slice", func(t *testing.T) {
		slice := make([]byte, 0, 0)
		uint64Slice := byteSliceAsUint64Slice(slice)

		assert.Equal(t, 0, len(uint64Slice))
		assert.Equal(t, 0, cap(uint64Slice))
	})

	t.Run("invalid slice size", func(t *testing.T) {
		slice := make([]byte, 1, 1)

		assert.Panics(t, func() {
			byteSliceAsUint64Slice(slice)
		})
	})
}

func TestByteSliceAsInterval16Slice(t *testing.T) {
	t.Run("valid slice", func(t *testing.T) {
		expectedSize := 2
		slice := make([]byte, 8)
		binary.LittleEndian.PutUint16(slice, 10)
		binary.LittleEndian.PutUint16(slice[2:], 2)
		binary.LittleEndian.PutUint16(slice[4:], 20)
		binary.LittleEndian.PutUint16(slice[6:], 2)

		intervalSlice := byteSliceAsInterval16Slice(slice)

		assert.Equal(t, expectedSize, len(intervalSlice))
		assert.Equal(t, expectedSize, cap(intervalSlice))

		i1 := newInterval16Range(10, 12)
		i2 := newInterval16Range(20, 22)

		assert.False(t, intervalSlice[0] != i1 || intervalSlice[1] != i2)
	})

	t.Run("empty slice", func(t *testing.T) {
		slice := make([]byte, 0, 0)
		intervalSlice := byteSliceAsInterval16Slice(slice)

		assert.Equal(t, 0, len(intervalSlice))
		assert.Equal(t, 0, cap(intervalSlice))
	})

	t.Run("invalid slice length", func(t *testing.T) {
		slice := make([]byte, 1, 1)

		assert.Panics(t, func() {
			byteSliceAsInterval16Slice(slice)
		})
	})
}

func TestBitmap_FromBuffer(t *testing.T) {
	t.Run("empty bitmap", func(t *testing.T) {
		rb := NewBitmap()

		buf := &bytes.Buffer{}
		_, err := rb.WriteTo(buf)

		require.NoError(t, err)
		assert.EqualValues(t, buf.Len(), rb.GetSerializedSizeInBytes())

		newRb := NewBitmap()
		newRb.FromBuffer(buf.Bytes())

		require.NoError(t, err)
		assert.True(t, rb.Equals(newRb))
	})

	t.Run("basic bitmap of 7 elements", func(t *testing.T) {
		rb := BitmapOf(1, 2, 3, 4, 5, 100, 1000)

		buf := &bytes.Buffer{}
		_, err := rb.WriteTo(buf)

		require.NoError(t, err)

		newRb := NewBitmap()
		_, err = newRb.FromBuffer(buf.Bytes())

		require.NoError(t, err)
		assert.True(t, rb.Equals(newRb))
	})

	t.Run("bitmap with runs", func(t *testing.T) {
		file := "testdata/bitmapwithruns.bin"

		buf, err := os.ReadFile(file)
		if err != nil {
			fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
			return
		}

		rb := NewBitmap()
		_, err = rb.FromBuffer(buf)

		require.NoError(t, err)
		assert.EqualValues(t, 3, rb.Stats().RunContainers)
		assert.EqualValues(t, 11, rb.Stats().Containers)
	})

	t.Run("bitmap without runs", func(t *testing.T) {
		fn := "testdata/bitmapwithruns.bin"
		buf, err := os.ReadFile(fn)

		if err != nil {
			fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
			return
		}

		rb := NewBitmap()
		_, err = rb.FromBuffer(buf)

		require.NoError(t, err)
	})

	// all3.classic somehow created by other tests.
	t.Run("all3.classic bitmap", func(t *testing.T) {
		file := "testdata/all3.classic"
		buf, err := os.ReadFile(file)

		if err != nil {
			fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
			return
		}

		rb := NewBitmap()
		_, err = rb.FromBuffer(buf)

		require.NoError(t, err)
	})

	t.Run("testdata/bitmapwithruns.bin bitmap Ops", func(t *testing.T) {
		file := "testdata/bitmapwithruns.bin"
		buf, err := os.ReadFile(file)

		if err != nil {
			fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
			return
		}

		empt := NewBitmap()

		rb1 := NewBitmap()
		_, err = rb1.FromBuffer(buf)

		require.NoError(t, err)

		rb2 := NewBitmap()
		_, err = rb2.FromBuffer(buf)

		require.NoError(t, err)

		rbor := Or(rb1, rb2)
		rbfastor := FastOr(rb1, rb2)
		rband := And(rb1, rb2)
		rbxor := Xor(rb1, rb2)
		rbandnot := AndNot(rb1, rb2)

		assert.True(t, rbor.Equals(rb1))
		assert.True(t, rbfastor.Equals(rbor))
		assert.True(t, rband.Equals(rb1))
		assert.True(t, rbxor.Equals(empt))
		assert.True(t, rbandnot.Equals(empt))
	})

	t.Run("marking all containers as requiring COW", func(t *testing.T) {
		file := "testdata/bitmapwithruns.bin"
		buf, err := os.ReadFile(file)

		if err != nil {
			fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
			return
		}

		rb := NewBitmap()
		_, err = rb.FromBuffer(buf)

		require.NoError(t, err)

		for i, cow := range rb.highlowcontainer.needCopyOnWrite {
			assert.Truef(t, cow, "Container at pos %d was not marked as needs-copy-on-write", i)
		}
	})
}

func TestSerializationCrashers(t *testing.T) {
	crashers, err := filepath.Glob("testdata/crash*")

	if err != nil {
		fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
		return
	}

	for _, crasher := range crashers {
		data, err := os.ReadFile(crasher)
		if err != nil {
			fmt.Fprintf(os.Stderr, "\n\nIMPORTANT: For testing file IO, the roaring library requires disk access.\nWe omit some tests for now.\n\n")
			return
		}

		// take a copy in case the stream is modified during unpacking attempt
		orig := make([]byte, len(data))
		copy(orig, data)

		_, err = NewBitmap().FromBuffer(data)
		assert.Error(t, err)

		// reset for next one
		copy(data, orig)
		_, err = NewBitmap().ReadFrom(bytes.NewReader(data))

		assert.Error(t, err)
	}
}

func TestIssue396(t *testing.T) {
	id := uint64(100000)
	bitmap := NewBitmap()
	for i := uint64(0); i < id; i++ {
		if i%2 == 0 {
			bitmap.Add(uint32(i))
		}
	}
	bitmapBytes, err := bitmap.MarshalBinary()
	require.Nil(t, err)

	bitmapUnmarshalled := NewBitmap()
	err = bitmapUnmarshalled.UnmarshalBinary(bitmapBytes)
	require.Nil(t, err)
	assert.True(t, bitmap.Equals(bitmapUnmarshalled))
	bitmapUnmarshalled = bitmapUnmarshalled.Clone()
	assert.True(t, bitmap.Equals(bitmapUnmarshalled))
}

func TestBitmapFromBufferCOW(t *testing.T) {
	rbbogus := NewBitmap()
	rbbogus.Add(100)
	rbbogus.Add(100000)
	rb1 := NewBitmap()
	rb1.Add(1)
	buf1 := &bytes.Buffer{}
	rb1.WriteTo(buf1)
	rb2 := NewBitmap()
	rb2.Add(1000000)
	buf2 := &bytes.Buffer{}
	rb2.WriteTo(buf2)
	newRb1 := NewBitmap()
	newRb1.FromBuffer(buf1.Bytes())
	newRb2 := NewBitmap()
	newRb2.FromBuffer(buf2.Bytes())
	rbor1 := Or(newRb1, newRb2)
	rbor2 := rbor1
	rbor3 := Or(newRb1, newRb2)
	rbor1.CloneCopyOnWriteContainers()
	rbor2.CloneCopyOnWriteContainers()
	rbor3.CloneCopyOnWriteContainers()
	buf1.Reset()
	buf2.Reset()
	rbbogus.WriteTo(buf1)
	rbbogus.WriteTo(buf2)
	rbexpected := NewBitmap()
	rbexpected.Add(1)
	rbexpected.Add(1000000)

	assert.True(t, rbexpected.Equals(rbor2))
	assert.True(t, rbexpected.Equals(rbor3))
}

func TestHoldReference(t *testing.T) {
	t.Run("Test Hold Reference", func(t *testing.T) {
		rb := New()
		buf := &bytes.Buffer{}

		for i := uint32(0); i < 650; i++ {
			rb.Add(i)
		}

		_, err := rb.WriteTo(buf)
		require.NoError(t, err)

		nb := New()
		data := buf.Bytes()
		_, err = nb.ReadFrom(bytes.NewReader(data))

		require.NoError(t, err)

		buf = nil
		rb = nil
		data = nil

		runtime.GC()

		iterator := nb.Iterator()
		i := uint32(0)

		for iterator.HasNext() {
			v := iterator.Next()

			if v != i {
				return
			}

			assert.Equal(t, i, v)
			i++
		}
	})
}

func BenchmarkUnserializeReadFrom(b *testing.B) {
	for _, size := range []uint32{650, 6500, 65000, 650000, 6500000} {
		rb := New()
		buf := &bytes.Buffer{}

		for i := uint32(0); i < size; i++ {
			rb.Add(i)
		}

		_, err := rb.WriteTo(buf)

		if err != nil {
			b.Fatalf("Unexpected error occurs: %v", err)
		}

		b.Run(fmt.Sprintf("ReadFrom-%d", size), func(b *testing.B) {
			b.ReportAllocs()
			b.StartTimer()

			for n := 0; n < b.N; n++ {
				reader := bytes.NewReader(buf.Bytes())
				nb := New()

				if _, err := nb.ReadFrom(reader); err != nil {
					b.Fatalf("Unexpected error occurs: %v", err)
				}
			}

			b.StopTimer()
		})
	}
}

func BenchmarkUnserializeFromBuffer(b *testing.B) {
	for _, size := range []uint32{650, 6500, 65000, 650000, 6500000} {
		rb := New()
		buf := &bytes.Buffer{}

		for i := uint32(0); i < size; i++ {
			rb.Add(i)
		}

		_, err := rb.WriteTo(buf)

		if err != nil {
			b.Fatalf("Unexpected error occurs: %v", err)
		}

		b.Run(fmt.Sprintf("FromBuffer-%d", size), func(b *testing.B) {
			b.ReportAllocs()
			b.StartTimer()

			for n := 0; n < b.N; n++ {
				nb := New()

				if _, err := nb.FromBuffer(buf.Bytes()); err != nil {
					b.Fatalf("Unexpected error occurs: %v", err)
				}
			}

			b.StopTimer()
		})
	}
}