package middleware_test

import (
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/gin-gonic/gin"

	"github.com/wangjia/pay/internal/middleware"
)

func newTestEngine(rl *middleware.IPRateLimiter) *gin.Engine {
	gin.SetMode(gin.TestMode)
	r := gin.New()
	r.GET("/x", rl.Gin(), func(c *gin.Context) { c.Status(http.StatusOK) })
	return r
}

// burst(=RequestsPerMin)个请求应放行,第 burst+1 个应 429。
func TestIPRateLimiterBurstThenBlocks(t *testing.T) {
	rl := middleware.NewIPRateLimiter(3)
	r := newTestEngine(rl)

	for i := 0; i < 3; i++ {
		w := httptest.NewRecorder()
		r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/x", nil))
		if w.Code != http.StatusOK {
			t.Fatalf("第 %d 次(burst 内)应 200, got %d", i+1, w.Code)
		}
	}
	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/x", nil))
	if w.Code != http.StatusTooManyRequests {
		t.Fatalf("第 4 次(超 burst)应 429, got %d", w.Code)
	}
}

// 不同 IP 各自独立计桶,互不影响。
func TestIPRateLimiterPerIPIsolated(t *testing.T) {
	rl := middleware.NewIPRateLimiter(1)
	r := newTestEngine(rl)

	req1 := httptest.NewRequest(http.MethodGet, "/x", nil)
	req1.RemoteAddr = "10.0.0.1:1234"
	w1 := httptest.NewRecorder()
	r.ServeHTTP(w1, req1)
	if w1.Code != http.StatusOK {
		t.Fatalf("IP1 第 1 次应 200, got %d", w1.Code)
	}

	req2 := httptest.NewRequest(http.MethodGet, "/x", nil)
	req2.RemoteAddr = "10.0.0.2:1234"
	w2 := httptest.NewRecorder()
	r.ServeHTTP(w2, req2)
	if w2.Code != http.StatusOK {
		t.Fatalf("IP2(独立桶)第 1 次应 200, got %d", w2.Code)
	}

	// IP1 burst=1 已耗尽,第 2 次应 429。
	req3 := httptest.NewRequest(http.MethodGet, "/x", nil)
	req3.RemoteAddr = "10.0.0.1:1234"
	w3 := httptest.NewRecorder()
	r.ServeHTTP(w3, req3)
	if w3.Code != http.StatusTooManyRequests {
		t.Fatalf("IP1 第 2 次(超 burst)应 429, got %d", w3.Code)
	}
}

// perMinute<=0 兜底成默认 30/min(config.RateLimitConfig 零值语义:"零值=默认开")。
func TestNewIPRateLimiterZeroDefaultsTo30(t *testing.T) {
	rl := middleware.NewIPRateLimiter(0)
	r := newTestEngine(rl)

	for i := 0; i < 30; i++ {
		w := httptest.NewRecorder()
		r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/x", nil))
		if w.Code != http.StatusOK {
			t.Fatalf("零值兜底 30/min:第 %d 次应 200, got %d", i+1, w.Code)
		}
	}
	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/x", nil))
	if w.Code != http.StatusTooManyRequests {
		t.Fatalf("第 31 次(超默认 30/min)应 429, got %d", w.Code)
	}
}