package roaring

import (
	"math"
	"math/rand"
	"testing"

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

// bitmapContainer's numberOfRuns() function should be correct against the runContainer equivalent
func TestBitmapContainerNumberOfRuns024(t *testing.T) {
	seed := int64(42)
	rand.Seed(seed)

	trials := []trial{
		{n: 1000, percentFill: .1, ntrial: 10},
	}

	for _, tr := range trials {
		for j := 0; j < tr.ntrial; j++ {
			ma := make(map[int]bool)

			n := tr.n
			a := []uint16{}

			draw := int(float64(n) * tr.percentFill)
			for i := 0; i < draw; i++ {
				r0 := rand.Intn(n)
				a = append(a, uint16(r0))
				ma[r0] = true
			}

			// RunContainer compute this automatically
			rc := newRunContainer16FromVals(false, a...)
			rcNr := rc.numberOfRuns()

			// vs bitmapContainer
			bc := newBitmapContainer()
			for k := range ma {
				bc.iadd(uint16(k))
			}

			bcNr := bc.numberOfRuns()
			assert.Equal(t, rcNr, bcNr)
		}
	}
}

// bitmap containers get cardinality in range, miss the last index, issue #183
func TestBitmapcontainerAndCardinality(t *testing.T) {
	for r := 0; r <= 65535; r++ {
		c1 := newRunContainer16Range(0, uint16(r))
		c2 := newBitmapContainerwithRange(0, r)

		assert.Equal(t, r+1, c1.andCardinality(c2))
	}
}

func TestIssue181(t *testing.T) {
	t.Run("Initial issue 181", func(t *testing.T) {
		a := New()
		var x uint32

		// adding 1M integers
		for i := 1; i <= 1000000; i++ {
			x += uint32(rand.Intn(10) + 1)
			a.Add(x)
		}
		b := New()
		for i := 1; i <= int(x); i++ {
			b.Add(uint32(i))
		}

		assert.Equal(t, b.AndCardinality(a), a.AndCardinality(b))
		assert.Equal(t, b.AndCardinality(a), And(a, b).GetCardinality())
	})

	t.Run("Second version of issue 181", func(t *testing.T) {
		a := New()
		var x uint32

		// adding 1M integers
		for i := 1; i <= 1000000; i++ {
			x += uint32(rand.Intn(10) + 1)
			a.Add(x)
		}
		b := New()
		b.AddRange(1, uint64(x))

		assert.Equal(t, b.AndCardinality(a), a.AndCardinality(b))
		assert.Equal(t, b.AndCardinality(a), And(a, b).GetCardinality())
	})
}

// RunReverseIterator16 unit tests for cur, next, hasNext, and remove should pass
func TestBitmapContainerReverseIterator(t *testing.T) {
	t.Run("reverse iterator on the empty container", func(t *testing.T) {
		bc := newBitmapContainer()
		it := bc.getReverseIterator()

		assert.False(t, it.hasNext())
		assert.Panics(t, func() { it.next() })
	})

	t.Run("reverse iterator on the container with range(0,0)", func(t *testing.T) {
		bc := newBitmapContainerwithRange(0, 0)
		it := bc.getReverseIterator()

		assert.True(t, it.hasNext())
		assert.EqualValues(t, 0, it.next())
	})

	t.Run("reverse iterator on the container with range(4,4)", func(t *testing.T) {
		bc := newBitmapContainerwithRange(4, 4)
		it := bc.getReverseIterator()

		assert.True(t, it.hasNext())
		assert.EqualValues(t, 4, it.next())
	})

	t.Run("reverse iterator on the container with range(4,9)", func(t *testing.T) {
		bc := newBitmapContainerwithRange(4, 9)
		it := bc.getReverseIterator()

		assert.True(t, it.hasNext())

		for i := 9; i >= 4; i-- {
			assert.EqualValues(t, i, it.next())

			if i > 4 {
				assert.True(t, it.hasNext())
			} else if i == 4 {
				assert.False(t, it.hasNext())
			}
		}

		assert.False(t, it.hasNext())
		assert.Panics(t, func() { it.next() })
	})

	t.Run("reverse iterator on the container with values", func(t *testing.T) {
		values := []uint16{0, 2, 15, 16, 31, 32, 33, 9999, MaxUint16}
		bc := newBitmapContainer()

		for n := 0; n < len(values); n++ {
			bc.iadd(values[n])
		}

		it := bc.getReverseIterator()
		n := len(values)

		assert.True(t, it.hasNext())

		for it.hasNext() {
			n--
			assert.Equal(t, values[n], it.next())
		}

		assert.Equal(t, 0, n)
	})
}

func TestBitmapNextSet(t *testing.T) {
	testSize := 5000
	bc := newBitmapContainer()

	for i := 0; i < testSize; i++ {
		bc.iadd(uint16(i))
	}

	m := 0

	for n := 0; m < testSize; n, m = bc.NextSetBit(uint(n)+1), m+1 {
		assert.Equal(t, m, n)
	}

	assert.Equal(t, 5000, m)
}

func TestBitmapPrevSet(t *testing.T) {
	testSize := 5000
	bc := newBitmapContainer()

	for i := 0; i < testSize; i++ {
		bc.iadd(uint16(i))
	}

	m := testSize - 1

	for n := testSize - 1; n > 0; n, m = bc.PrevSetBit(n-1), m-1 {
		assert.Equal(t, m, n)
	}

	assert.Equal(t, 0, m)
}

func TestBitmapIteratorPeekNext(t *testing.T) {
	testContainerIteratorPeekNext(t, newBitmapContainer())
}

func TestBitmapIteratorAdvance(t *testing.T) {
	testContainerIteratorAdvance(t, newBitmapContainer())
}

// go test -bench BenchmarkShortIteratorAdvance -run -
func BenchmarkShortIteratorAdvanceBitmap(b *testing.B) {
	benchmarkContainerIteratorAdvance(b, newBitmapContainer())
}

// go test -bench BenchmarkShortIteratorNext -run -
func BenchmarkShortIteratorNextBitmap(b *testing.B) {
	benchmarkContainerIteratorNext(b, newBitmapContainer())
}

func TestBitmapOffset(t *testing.T) {
	nums := []uint16{10, 60, 70, 100, 1000}
	expected := make([]int, len(nums))
	offtest := uint16(65000)
	v := container(newBitmapContainer())
	for i, n := range nums {
		v.iadd(n)
		expected[i] = int(n) + int(offtest)
	}
	l, h := v.addOffset(offtest)

	var w0card, w1card int
	wout := make([]int, len(nums))

	if l != nil {
		w0card = l.getCardinality()

		for i := 0; i < w0card; i++ {
			wout[i] = l.selectInt(uint16(i))
		}
	}

	if h != nil {
		w1card = h.getCardinality()

		for i := 0; i < w1card; i++ {
			wout[i+w0card] = h.selectInt(uint16(i)) + 65536
		}
	}

	assert.Equal(t, v.getCardinality(), w0card+w1card)
	for i, x := range wout {
		assert.Equal(t, expected[i], x)
	}
}

func TestBitmapContainerResetTo(t *testing.T) {
	array := newArrayContainer()
	for i := 0; i < 1000; i++ {
		array.iadd(uint16(i*1000 + i + 50))
	}

	bitmap := newBitmapContainer()
	for i := 0; i < 10000; i++ {
		bitmap.iadd(uint16(i*1000 + i + 50))
	}

	run := newRunContainer16()
	for i := 0; i < 10; i++ {
		start := i*1000 + i + 50
		run.iaddRange(start, start+100+i)
	}

	makeDirty := func() *bitmapContainer {
		ret := newBitmapContainer()
		for i := 0; i < maxCapacity; i += 42 {
			ret.iadd(uint16(i))
		}
		return ret
	}

	t.Run("to array container", func(t *testing.T) {
		clean := newBitmapContainer()
		clean.resetTo(array)
		assert.True(t, clean.toArrayContainer().equals(array))

		dirty := makeDirty()
		dirty.resetTo(array)
		assert.True(t, dirty.toArrayContainer().equals(array))
	})

	t.Run("to bitmap container", func(t *testing.T) {
		clean := newBitmapContainer()
		clean.resetTo(bitmap)
		assert.True(t, clean.equals(bitmap))

		dirty := makeDirty()
		dirty.resetTo(bitmap)
		assert.True(t, dirty.equals(bitmap))
	})

	t.Run("to run container", func(t *testing.T) {
		clean := newBitmapContainer()
		clean.resetTo(run)
		assert.EqualValues(t, clean.cardinality, run.getCardinality())
		assert.True(t, clean.toEfficientContainer().equals(run))

		dirty := makeDirty()
		dirty.resetTo(run)
		assert.EqualValues(t, dirty.cardinality, run.getCardinality())
		assert.True(t, dirty.toEfficientContainer().equals(run))
	})
}

func TestBitmapContainerIAndNot(t *testing.T) {
	var bc container
	bc = newBitmapContainer()
	for i := 0; i < arrayDefaultMaxSize; i++ {
		bc.iadd(uint16(i * 3))
	}
	bc.iadd(math.MaxUint16)

	var rc container
	rc = newRunContainer16Range(0, 1)
	for i := 0; i < arrayDefaultMaxSize-3; i++ {
		rc = rc.iaddRange(i*3, i*3+1)
	}
	rc.iaddRange(math.MaxUint16-3, math.MaxUint16+1)

	bc = bc.iandNot(rc)

	require.ElementsMatch(t, []uint16{12279, 12282, 12285}, bc.(*arrayContainer).content)
	require.Equal(t, 3, bc.getCardinality())
}

func TestPreviousNexts(t *testing.T) {
	bc := newBitmapContainer()
	bc.iadd(10)
	bc.iadd(12)
	bc.iadd(13)
	bc.iaddRange(50, 60)
	// Crosses the 64 division mod boundary
	bc.iadd(100)
	// Another 64 division mod boundary
	bc.iadd(129)

	t.Run("Next value", func(t *testing.T) {
		assert.Equal(t, 10, bc.nextValue(uint16(0)))
		assert.Equal(t, 10, bc.nextValue(uint16(5)))
		assert.Equal(t, 10, bc.nextValue(uint16(10)))
		assert.Equal(t, 12, bc.nextValue(uint16(11)))
		assert.Equal(t, 12, bc.nextValue(uint16(12)))
		assert.Equal(t, 13, bc.nextValue(uint16(13)))
		assert.Equal(t, 50, bc.nextValue(uint16(14)))
		assert.Equal(t, 55, bc.nextValue(uint16(55)))
		assert.Equal(t, 100, bc.nextValue(uint16(61)))
		assert.Equal(t, 100, bc.nextValue(uint16(100)))
		assert.Equal(t, 129, bc.nextValue(uint16(101)))
		assert.Equal(t, 129, bc.nextValue(uint16(129)))
		assert.Equal(t, -1, bc.nextValue(uint16(130)))
	})

	t.Run("Previous value", func(t *testing.T) {
		assert.Equal(t, -1, bc.previousValue(uint16(0)))
		assert.Equal(t, -1, bc.previousValue(uint16(1)))
		assert.Equal(t, -1, bc.previousValue(uint16(2)))
		assert.Equal(t, -1, bc.previousValue(uint16(5)))
		assert.Equal(t, 10, bc.previousValue(uint16(10)))
		assert.Equal(t, 10, bc.previousValue(uint16(11)))
		assert.Equal(t, 12, bc.previousValue(uint16(12)))
		assert.Equal(t, 13, bc.previousValue(uint16(13)))
		assert.Equal(t, 13, bc.previousValue(uint16(14)))
		assert.Equal(t, 55, bc.previousValue(uint16(55)))
		assert.Equal(t, 59, bc.previousValue(uint16(61)))
		assert.Equal(t, 100, bc.previousValue(uint16(101)))
	})

	t.Run("Next Absent value", func(t *testing.T) {
		assert.Equal(t, 0, bc.nextAbsentValue(uint16(0)))
		assert.Equal(t, 5, bc.nextAbsentValue(uint16(5)))
		assert.Equal(t, 11, bc.nextAbsentValue(uint16(11)))
		assert.Equal(t, 14, bc.nextAbsentValue(uint16(12)))
		assert.Equal(t, 14, bc.nextAbsentValue(uint16(13)))
		assert.Equal(t, 14, bc.nextAbsentValue(uint16(14)))
		assert.Equal(t, 49, bc.nextAbsentValue(uint16(49)))
		assert.Equal(t, 60, bc.nextAbsentValue(uint16(50)))
		assert.Equal(t, 60, bc.nextAbsentValue(uint16(60)))
		assert.Equal(t, 101, bc.nextAbsentValue(uint16(100)))
		assert.Equal(t, 101, bc.nextAbsentValue(uint16(101)))
		assert.Equal(t, 130, bc.nextAbsentValue(uint16(129)))
	})

	t.Run("Previous Absent value", func(t *testing.T) {
		assert.Equal(t, 0, bc.previousAbsentValue(uint16(0)))
		assert.Equal(t, 1, bc.previousAbsentValue(uint16(1)))
		assert.Equal(t, 2, bc.previousAbsentValue(uint16(2)))
		assert.Equal(t, 5, bc.previousAbsentValue(uint16(5)))
		assert.Equal(t, 9, bc.previousAbsentValue(uint16(10)))
		assert.Equal(t, 11, bc.previousAbsentValue(uint16(11)))
		assert.Equal(t, 11, bc.previousAbsentValue(uint16(12)))
		assert.Equal(t, 11, bc.previousAbsentValue(uint16(13)))
		assert.Equal(t, 49, bc.previousAbsentValue(uint16(50)))
		assert.Equal(t, 49, bc.previousAbsentValue(uint16(51)))
		assert.Equal(t, 99, bc.previousAbsentValue(uint16(100)))
		assert.Equal(t, 128, bc.previousAbsentValue(uint16(129)))
		assert.Equal(t, 130, bc.previousAbsentValue(uint16(130)))
	})
}

func TestNextAbsent(t *testing.T) {
	bc := newBitmapContainer()
	for i := 0; i < 1<<16; i++ {
		bc.iadd(uint16(i))
	}
	v := bc.nextAbsentValue((1 << 16) - 1)
	assert.Equal(t, v, 65536)
}

func TestBitMapContainerValidate(t *testing.T) {
	bc := newBitmapContainer()

	for i := 0; i < arrayDefaultMaxSize-1; i++ {
		bc.iadd(uint16(i * 3))
	}
	// bitmap containers should have size arrayDefaultMaxSize or larger
	assert.Error(t, bc.validate())
	bc.iadd(math.MaxUint16)

	assert.NoError(t, bc.validate())

	// Break the max cardinality invariant
	bc.cardinality = maxCapacity + 1

	assert.Error(t, bc.validate())

	// violate cardinality underlying container size invariant
	bc = newBitmapContainer()
	for i := 0; i < arrayDefaultMaxSize+1; i++ {
		bc.iadd(uint16(i * 3))
	}
	assert.NoError(t, bc.validate())
	bc.cardinality += 1
	assert.Error(t, bc.validate())

	// check that underlying packed slice doesn't exceed maxCapacity
	bc = newBitmapContainer()
	orginalSize := (1 << 16) / 64
	for i := 0; i < orginalSize; i++ {
		bc.cardinality += 1
		bc.bitmap[i] = uint64(1)
	}

	appendSize := ((1 << 16) - orginalSize) + 1
	for i := 0; i < appendSize; i++ {
		bc.cardinality += 1
		bc.bitmap = append(bc.bitmap, uint64(1))
	}

	assert.Error(t, bc.validate())
}

func TestBitmapcontainerNextHasMany(t *testing.T) {
	t.Run("Empty Bitmap", func(t *testing.T) {
		bc := newBitmapContainer()
		iterator := newBitmapContainerManyIterator(bc)
		high := uint64(1024)
		buf := []uint64{}
		result := iterator.nextMany64(high, buf)
		assert.Equal(t, 0, result)
	})

	t.Run("512 in iterator and buf size 512", func(t *testing.T) {
		bc := newBitmapContainer()
		bc.iaddRange(0, 512)
		iterator := newBitmapContainerManyIterator(bc)
		high := uint64(1024)
		buf := make([]uint64, 512)
		result := iterator.nextMany64(high, buf)
		assert.Equal(t, 512, result)
	})

	t.Run("512 in iterator and buf size 256", func(t *testing.T) {
		bc := newBitmapContainer()
		bc.iaddRange(0, 512)
		iterator := newBitmapContainerManyIterator(bc)
		high := uint64(1024)
		buf := make([]uint64, 256)
		result := iterator.nextMany64(high, buf)
		assert.Equal(t, 256, result)
	})
}

func TestBitmapcontainerOrArrayCardinality(t *testing.T) {
	t.Run("Empty Bitmap and Empty Array", func(t *testing.T) {
		array := newArrayContainer()
		bc := newBitmapContainer()
		result := bc.orArrayCardinality(array)

		assert.Equal(t, 0, result)
	})

	t.Run("Populated Bitmap with Empty Array", func(t *testing.T) {
		bc := newBitmapContainer()
		bc.iaddRange(0, 1024)
		array := newArrayContainer()

		result := bc.orArrayCardinality(array)

		assert.Equal(t, 1024, result)
	})

	t.Run("Populated Bitmap with Empty Run Container", func(t *testing.T) {
		bc := newBitmapContainer()
		bc.iaddRange(0, 1024)

		runC := newRunContainer16()

		result := runC.orBitmapContainerCardinality(bc)

		assert.Equal(t, 1024, result)

		other := newBitmapContainerFromRun(runC)
		result = bc.orBitmapCardinality(other)

		assert.Equal(t, 1024, result)
	})

	t.Run("Populated Bitmap with Empty Bitmap", func(t *testing.T) {
		bc := newBitmapContainer()
		bc.iaddRange(0, 1024)

		other := newBitmapContainer()

		result := bc.orBitmapCardinality(other)

		assert.Equal(t, 1024, result)
	})
}