package deliver

import (
	"strconv"
	"testing"
)

func TestConsistentHashPicker(t *testing.T) {
	var nodes []*PickNode
	var hits = make(map[string]int, 10)
	for i := 0; i < 10; i++ {
		node := &PickNode{
			Key:    "node-" + strconv.Itoa(i),
			Weight: 10,
		}
		if i < 5 {
			node.Weight = 5 // 遵循 weight 进行负载均衡
		}
		nodes = append(nodes, node)
		hits[node.Key] = 0
	}
	picker := NewConsistentHashPicker(nodes, DefaultReplicas, DefaultSalt)
	picker.Init()

	for i := 0; i < 100000; i++ {
		node1, ok1 := picker.Pick(strconv.Itoa(i))
		node2, ok2 := picker.Pick(strconv.Itoa(i))
		if !ok1 || !ok2 {
			t.Error("pick non node")
		}
		if node1 != node2 {
			t.Error("pick same key not same node")
		}
		hits[node1.Key]++
	}

	for nodeKey, hit := range hits {
		if hit == 0 {
			t.Errorf("node %s not picked", nodeKey)
		}
	}

	node1, same1, ok1 := picker.PickOffset("100", 1)
	node2, same2, ok2 := picker.PickOffset("100", 1)
	if !ok1 || !ok2 {
		t.Error("pick non node")
	}
	if node1 != node2 || same1 != same2 {
		t.Error("pick same key not same node")
	}
}