package handler

import (
	"testing"

	"kefu-sys/server/internal/model"
)

func TestPickLeastLoadedPrefersFewerSessions(t *testing.T) {
	a := model.User{ID: 1}
	b := model.User{ID: 2}
	c := model.User{ID: 3}
	candidates := []model.User{a, b, c}
	counts := map[uint]int64{1: 3, 2: 1, 3: 1}
	got := pickLeastLoadedAgent(candidates, counts)
	if got == nil || got.ID != 2 {
		t.Fatalf("期望 id=2（平局取更小 id），got=%v", got)
	}
}

func TestPickRoundRobinAdvances(t *testing.T) {
	candidates := []model.User{{ID: 10}, {ID: 20}, {ID: 30}}
	last := uint(10)
	got := pickRoundRobinAgent(candidates, &last)
	if got == nil || got.ID != 20 {
		t.Fatalf("期望下一位 20，got=%v", got)
	}
	last = 30
	got = pickRoundRobinAgent(candidates, &last)
	if got == nil || got.ID != 10 {
		t.Fatalf("期望绕回 10，got=%v", got)
	}
	got = pickRoundRobinAgent(candidates, nil)
	if got == nil || got.ID != 10 {
		t.Fatalf("无游标时期望第一位 10，got=%v", got)
	}
}

func TestNormalizeAssignStrategy(t *testing.T) {
	if normalizeAssignStrategy("round_robin") != assignStrategyRoundRobin {
		t.Fatal("round_robin")
	}
	if normalizeAssignStrategy("") != assignStrategyLeastLoad {
		t.Fatal("default least_load")
	}
	if normalizeAssignStrategy("unknown") != assignStrategyLeastLoad {
		t.Fatal("unknown -> least_load")
	}
}