package cuckoo_test

import (
	"bytes"
	"encoding/binary"
	"testing"

	"github.com/stretchr/testify/assert"

	"git.maximhutz.com/tools/go-cuckoo"
)

func offsetHash(seed uint32) cuckoo.Hash[uint32] {
	return func(x uint32) uint64 {
		v := uint64(x) ^ uint64(seed)
		v = (v ^ (v >> 30)) * 0xbf58476d1ce4e5b9
		v = (v ^ (v >> 27)) * 0x94d049bb133111eb
		return v ^ (v >> 31)
	}
}

func FuzzInsertLookup(f *testing.F) {
	f.Fuzz(func(t *testing.T, data []byte, seedA, seedB uint32) {
		assert := assert.New(t)

		table := cuckoo.NewCustomTable[uint32, uint32](
			offsetHash(seedA),
			offsetHash(seedB),
			func(a, b uint32) bool { return a == b },
		)

		if seedA == seedB {
			return
		}

		r := bytes.NewReader(data)
		var key, value uint32
		for binary.Read(r, binary.LittleEndian, &key) == nil &&
			binary.Read(r, binary.LittleEndian, &value) == nil {

			err := table.Put(key, value)
			assert.NoError(err)

			found, err := table.Get(key)
			assert.NoError(err)
			assert.Equal(value, found)
		}
	})
}