package wheel

import (
	"math"
	"testing"

	"chatapp3-golang/internal/model"
)

func TestPickRewardDistribution1000000Draws(t *testing.T) {
	const (
		draws                  = 1000000
		maxAllowedDriftPercent = 1.0
	)

	rewards := []model.WheelRewardConfig{
		{ID: 1, Enabled: true, RewardType: rewardTypeResource, ResourceName: "Coral Crown", Probability: 3000},
		{ID: 2, Enabled: true, RewardType: rewardTypeResource, ResourceName: "Aurora Wing", Probability: 2200},
		{ID: 3, Enabled: true, RewardType: rewardTypeResource, ResourceName: "Moon Card", Probability: 1500},
		{ID: 4, Enabled: true, RewardType: rewardTypeResource, ResourceName: "Snow Pet", Probability: 1200},
		{ID: 5, Enabled: true, RewardType: rewardTypeResource, ResourceName: "Love Banner", Probability: 900},
		{ID: 6, Enabled: true, RewardType: rewardTypeResource, ResourceName: "Emerald Ring", Probability: 600},
		{ID: 7, Enabled: true, RewardType: rewardTypeResource, ResourceName: "Royal Chest", Probability: 400},
		{ID: 8, Enabled: true, RewardType: rewardTypeGold, ResourceName: "Gold", Probability: 200},
	}

	counts := make(map[int64]int, len(rewards))
	for index := 0; index < draws; index++ {
		reward, err := pickReward(rewards)
		if err != nil {
			t.Fatalf("pickReward() error = %v", err)
		}
		counts[reward.ID]++
	}

	for _, reward := range rewards {
		expectedPercent := float64(reward.Probability) / probabilityTotal * 100
		actualPercent := float64(counts[reward.ID]) / draws * 100
		driftPercent := math.Abs(actualPercent - expectedPercent)
		t.Logf(
			"reward=%s configured=%.2f%% actual=%.2f%% drift=%.2f%% hits=%d/%d",
			reward.ResourceName,
			expectedPercent,
			actualPercent,
			driftPercent,
			counts[reward.ID],
			draws,
		)
		if driftPercent > maxAllowedDriftPercent {
			t.Fatalf(
				"reward %s probability drift %.2f%% exceeds %.2f%%",
				reward.ResourceName,
				driftPercent,
				maxAllowedDriftPercent,
			)
		}
	}
}