package pmap

import (
	"fmt"
	"testing"
)

func hash(k Key) uint32 {
	//u := uint(k.(int))*6364136223846793005 + 1
	//return uint32(u >> 32)
	u := uint(k) //u := uint(k.(int))
	return uint32(u + u>>32)
}

// FIXME: collisions can cause allocations during Get

func TestPmap(t *testing.T) {
	p := New(hash)
	const numElems = 100
	for i := range iter(numElems) {
		p = p.Set(i, i)
	}
	if p.Len() != numElems {
		t.Fatalf("Len() = %v, want %v", p.Len(), numElems)
	}
	for i := range iter(numElems) {
		v, ok := p.Get(i)
		if v != i || !ok {
			t.Errorf("Get(%d) = %v %v, want %v %v", i, v, ok, i, true)
		}
	}
	fmt.Print(p.(pmap).stats())
}

func BenchmarkGet(b *testing.B) {
	b.Run("size=10", func(b *testing.B) { benchmarkGet(b, 10) })
	b.Run("size=100", func(b *testing.B) { benchmarkGet(b, 100) })
	b.Run("size=1000", func(b *testing.B) { benchmarkGet(b, 1000) })
	b.Run("size=10000", func(b *testing.B) { benchmarkGet(b, 10000) })
	//b.Run("size=100000", func(b *testing.B) { benchmarkGet(b, 100000) })
	//b.Run("size=1000000", func(b *testing.B) { benchmarkGet(b, 1000000) })
}

func BenchmarkGetAbsent(b *testing.B) {
	b.Run("size=10", func(b *testing.B) { benchmarkGetAbsent(b, 10) })
	b.Run("size=100", func(b *testing.B) { benchmarkGetAbsent(b, 100) })
	b.Run("size=1000", func(b *testing.B) { benchmarkGetAbsent(b, 1000) })
	b.Run("size=10000", func(b *testing.B) { benchmarkGetAbsent(b, 10000) })
}

func benchmarkGet(b *testing.B, numElems int) {
	p := New(hash)
	for i := range iter(numElems) {
		p = p.Set(i, i)
	}
	if p.Len() != numElems {
		b.Fatalf("Len() = %v, want %v", p.Len(), numElems)
	}
	b.ResetTimer()
	i := 0
	for range iter(b.N) {
		v, ok := p.Get(i)
		if v != i || !ok {
			b.Errorf("Get(%d) = %v %v, want %v %v", i, v, ok, i, true)
		}
		i++
		if i >= numElems {
			i = 0
		}
	}
}

func benchmarkGetAbsent(b *testing.B, numElems int) {
	p := New(hash)
	for i := range iter(numElems) {
		p = p.Set(i-numElems, i)
	}
	if p.Len() != numElems {
		b.Fatalf("Len() = %v, want %v", p.Len(), numElems)
	}
	b.ResetTimer()
	i := 0
	for range iter(b.N) {
		v, ok := p.Get(i)
		if ok {
			b.Errorf("Get(%d) = %v %v, want %v %v", i, v, ok, 0, false)
		}
		i++
	}
}

func iter(n int) []struct{} {
	return make([]struct{}, n)
}

func BenchmarkHmapGet_baseline(b *testing.B) {
	b.Run("size=10", func(b *testing.B) { benchmarkHmapGet(b, 10) })
	b.Run("size=100", func(b *testing.B) { benchmarkHmapGet(b, 100) })
	b.Run("size=1000", func(b *testing.B) { benchmarkHmapGet(b, 1000) })
	b.Run("size=10000", func(b *testing.B) { benchmarkHmapGet(b, 10000) })
	b.Run("size=100000", func(b *testing.B) { benchmarkHmapGet(b, 100000) })
	b.Run("size=1000000", func(b *testing.B) { benchmarkHmapGet(b, 1000000) })
}

func benchmarkHmapGet(b *testing.B, numElems int) {
	h := make(map[int]int)
	for i := range iter(numElems) {
		h[i] = i
	}
	if len(h) != numElems {
		b.Fatalf("Len() = %v, want %v", len(h), numElems)
	}
	b.ResetTimer()
	i := 0
	for range iter(b.N) {
		v, ok := h[i]
		if v != i || !ok {
			b.Errorf("h[%d] = %v %v, want %v %v", i, v, ok, i, true)
		}
		i++
		if i >= numElems {
			i = 0
		}
	}
}

func BenchmarkSet(b *testing.B) {
	b.Run("size=10", func(b *testing.B) { benchmarkSet(b, 10) })
	b.Run("size=100", func(b *testing.B) { benchmarkSet(b, 100) })
	b.Run("size=1000", func(b *testing.B) { benchmarkSet(b, 1000) })
	b.Run("size=10000", func(b *testing.B) { benchmarkSet(b, 10000) })
	if !testing.Short() {
		b.Run("size=100000", func(b *testing.B) { benchmarkSet(b, 100000) })
	}
}

func benchmarkSet(b *testing.B, numElems int) {
	p := New(hash)
	for i := range iter(numElems) {
		p = p.Set(i, i)
	}
	if p.Len() != numElems {
		b.Fatalf("Len() = %v, want %v", p.Len(), numElems)
	}
	b.ResetTimer()
	for i := range iter(b.N) {
		k := i + numElems
		_ = p.Set(k, k)
	}
}

func BenchmarkHmapSet_baseline(b *testing.B) {
	b.Run("size=10", func(b *testing.B) { benchmarkHmapSet(b, 10) })
	b.Run("size=100", func(b *testing.B) { benchmarkHmapSet(b, 100) })
	b.Run("size=1000", func(b *testing.B) { benchmarkHmapSet(b, 1000) })
	b.Run("size=10000", func(b *testing.B) { benchmarkHmapSet(b, 10000) })
	if !testing.Short() {
		b.Run("size=100000", func(b *testing.B) { benchmarkHmapSet(b, 100000) })
	}
}

func benchmarkHmapSet(b *testing.B, numElems int) {
	h := make(map[int]int)
	for i := range iter(numElems) {
		h[i] = i
	}
	if len(h) != numElems {
		b.Fatalf("Len() = %v, want %v", len(h), numElems)
	}
	b.ResetTimer()
	for i := range iter(b.N) {
		k := i + numElems
		h[k] = k
		delete(h, k)
	}
}

func TestBitmap(t *testing.T) {
	n := node{bitmap: 0xff0a}
	const x = -1
	want := []int{x, 0, x, 1, x, x, x, x, 2, 3, 4, 5, 6, 7, 8, 9}
	for i, j := range want {
		if j == x {
			continue
		}
		m := bitmask(uint32(i))
		if got := n.index(m); got != j {
			t.Errorf("got %v, want %v", got, j)
		}
	}
}