package ratelimit

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

func TestLimiterAllowsUpToMax(t *testing.T) {
	l := New(3, time.Minute)
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.RemoteAddr = "1.2.3.4:1234"

	for i := 0; i < 3; i++ {
		if !l.Allow(req) {
			t.Fatalf("request %d rejected, want allowed", i+1)
		}
	}
	if l.Allow(req) {
		t.Fatal("4th request allowed, want rejected")
	}
}

func TestLimiterSeparatesIPs(t *testing.T) {
	l := New(2, time.Minute)
	reqA := httptest.NewRequest(http.MethodGet, "/", nil)
	reqA.RemoteAddr = "1.1.1.1:1"
	reqB := httptest.NewRequest(http.MethodGet, "/", nil)
	reqB.RemoteAddr = "2.2.2.2:2"

	l.Allow(reqA)
	l.Allow(reqA)
	if l.Allow(reqA) {
		t.Fatal("IP A over limit, want rejected")
	}
	if !l.Allow(reqB) {
		t.Fatal("IP B should have its own budget")
	}
}

func TestLimiterWindowResets(t *testing.T) {
	l := New(1, 50*time.Millisecond)
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.RemoteAddr = "9.9.9.9:9"

	if !l.Allow(req) {
		t.Fatal("first request rejected")
	}
	if l.Allow(req) {
		t.Fatal("second request within window allowed, want rejected")
	}
	time.Sleep(60 * time.Millisecond)
	if !l.Allow(req) {
		t.Fatal("request after window reset rejected")
	}
}

func TestClientIPPrefersForwarded(t *testing.T) {
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.RemoteAddr = "10.0.0.5:1234"
	req.Header.Set("X-Forwarded-For", "203.0.113.9, 10.0.0.1")
	if got := ClientIP(req); got != "203.0.113.9" {
		t.Fatalf("ClientIP = %q, want 203.0.113.9", got)
	}
}