package service

import (
	"os"
	"testing"

	"github.com/topfans/backend/pkg/logger"
)

// TestMain 初始化全局 logger（避免 CalculateLikeBetRevenue 内部 logger.Logger.Debug 触发 nil panic）
func TestMain(m *testing.M) {
	_ = logger.Init(logger.Config{
		ServiceName: "task-service-test",
		Environment: "test",
		LogLevel:    "error", // 测试环境只输出错误日志
	})
	os.Exit(m.Run())
}

// TestCalculateLikeBetRevenue_TableDriven 表驱动测试
// 公式：R2 = (1 + (N - i)) × R3，其中 R3=1，封顶 100
//   - N = totalLikes（藏品下架时的总点赞数）
//   - i = betOrder（第几位押注者，1=第一个点赞）
func TestCalculateLikeBetRevenue_TableDriven(t *testing.T) {
	tests := []struct {
		name       string
		totalLikes int
		betOrder   int
		want       int64
	}{
		// 边界
		{"zero_likes", 0, 1, 0},
		{"zero_bet_order", 10, 0, 0},
		{"negative_bet_order", 10, -1, 0},

		// N=1：第一个（且唯一）点赞者拿 1 水晶
		{"n1_bet1", 1, 1, 1},

		// N=2：第一个拿 2，第二个拿 1
		{"n2_bet1", 2, 1, 2},
		{"n2_bet2", 2, 2, 1},

		// N=10：单调递减 10,9,8,...,1
		{"n10_bet1", 10, 1, 10},
		{"n10_bet5", 10, 5, 6},
		{"n10_bet10", 10, 10, 1},

		// N=30：第 1 个 = 30，...，封顶应该发生在第 1 个（=30）附近
		// 注：公式 (1 + N - i) * 1，第一个点赞 = 1+N-1 = N = 30，未超过 100
		{"n30_bet1", 30, 1, 30},
		{"n30_bet30", 30, 30, 1},

		// N=50：第 1 个 = 50，未到封顶
		{"n50_bet1", 50, 1, 50},
		{"n50_bet2", 50, 2, 49},

		// N=100：第 1 个 = 100，正好到封顶
		{"n100_bet1", 100, 1, 100},

		// N=101：第 1 个 = 101，应被封顶到 100
		{"n101_bet1_cap", 101, 1, 100},
		// 封顶附近
		{"n150_bet51", 150, 51, 100}, // 1+(150-51) = 100，正好
		{"n150_bet1", 150, 1, 100},   // 1+(150-1)=150，封顶到 100

		// 大数
		{"n1000_bet1_cap", 1000, 1, 100},
		{"n1000_bet950", 1000, 950, 51}, // 1+(1000-950)=51，未到封顶
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := CalculateLikeBetRevenue(tt.totalLikes, tt.betOrder)
			if got != tt.want {
				t.Errorf("CalculateLikeBetRevenue(%d, %d) = %d, want %d",
					tt.totalLikes, tt.betOrder, got, tt.want)
			}
		})
	}
}

// TestCalculateLikeBetRevenue_MonotonicDecreasing 单调递减：
// 同一个 totalLikes 下，betOrder 越大，金额越小（或封顶后持平）
func TestCalculateLikeBetRevenue_MonotonicDecreasing(t *testing.T) {
	const totalLikes = 50
	prev := int64(999999)
	for i := 1; i <= totalLikes; i++ {
		got := CalculateLikeBetRevenue(totalLikes, i)
		if got > prev {
			t.Errorf("betOrder=%d: got %d > prev %d (must be non-increasing)",
				i, got, prev)
		}
		prev = got
	}
}

// TestCalculateLikeBetRevenue_NeverExceedCap 封顶验证：任何 (N, i) 都 <= 100
func TestCalculateLikeBetRevenue_NeverExceedCap(t *testing.T) {
	for n := 1; n <= 1000; n += 37 {
		for i := 1; i <= n; i += 13 {
			got := CalculateLikeBetRevenue(n, i)
			if got > 100 {
				t.Errorf("CalculateLikeBetRevenue(%d, %d) = %d > 100 (cap)",
					n, i, got)
			}
		}
	}
}