package hotime

import (
	"net/http"
	"testing"
)

func TestResolveClientIP_EOPreferred(t *testing.T) {
	req, _ := http.NewRequest("GET", "/", nil)
	req.Header.Set("EO-Connecting-IP", "171.1.2.3")
	req.Header.Set("X-Real-IP", "43.1.2.3")
	req.Header.Set("X-Forwarded-For", "171.1.2.3, 43.1.2.3")
	req.RemoteAddr = "127.0.0.1:12345"

	ip, chain := resolveClientIP(req)
	if ip != "171.1.2.3" {
		t.Fatalf("ip=%q want 171.1.2.3", ip)
	}
	// 去重：171 只出现一次
	if chain != "171.1.2.3,43.1.2.3,127.0.0.1" {
		t.Fatalf("chain=%q", chain)
	}
}

func TestResolveClientIP_SkipLoopbackXReal(t *testing.T) {
	req, _ := http.NewRequest("GET", "/", nil)
	req.Header.Set("X-Real-IP", "127.0.0.1")
	req.Header.Set("X-Forwarded-For", "171.1.2.3, 43.1.2.3")
	req.RemoteAddr = "127.0.0.1:8080"

	ip, chain := resolveClientIP(req)
	if ip != "171.1.2.3" {
		t.Fatalf("ip=%q want 171.1.2.3", ip)
	}
	if chain != "127.0.0.1,171.1.2.3,43.1.2.3" {
		t.Fatalf("chain=%q", chain)
	}
}

func TestResolveClientIP_XFFBeforeMisconfiguredXReal(t *testing.T) {
	// 线上常见：X-Real-IP=CDN，XFF=客户端,CDN
	req, _ := http.NewRequest("GET", "/", nil)
	req.Header.Set("X-Real-IP", "43.1.2.3")
	req.Header.Set("X-Forwarded-For", "171.1.2.3, 43.1.2.3")
	req.RemoteAddr = "127.0.0.1:8080"

	ip, chain := resolveClientIP(req)
	if ip != "171.1.2.3" {
		t.Fatalf("ip=%q want 171.1.2.3", ip)
	}
	if chain != "43.1.2.3,171.1.2.3,127.0.0.1" {
		t.Fatalf("chain=%q", chain)
	}
}

func TestResolveClientIP_XRealWhenNoXFF(t *testing.T) {
	req, _ := http.NewRequest("GET", "/", nil)
	req.Header.Set("X-Real-IP", "203.0.113.9")
	req.RemoteAddr = "10.0.0.1:80"

	ip, chain := resolveClientIP(req)
	if ip != "203.0.113.9" {
		t.Fatalf("ip=%q want 203.0.113.9", ip)
	}
	if chain != "203.0.113.9,10.0.0.1" {
		t.Fatalf("chain=%q", chain)
	}
}

func TestResolveClientIP_DirectRemoteAddr(t *testing.T) {
	req, _ := http.NewRequest("GET", "/", nil)
	req.RemoteAddr = "192.168.1.8:5555"

	ip, chain := resolveClientIP(req)
	if ip != "192.168.1.8" {
		t.Fatalf("ip=%q want 192.168.1.8", ip)
	}
	if chain != "192.168.1.8" {
		t.Fatalf("chain=%q", chain)
	}
	if clientIP(req) != ip {
		t.Fatalf("clientIP mismatch")
	}
}

func TestResolveClientIP_NilReq(t *testing.T) {
	ip, chain := resolveClientIP(nil)
	if ip != "" || chain != "" {
		t.Fatalf("want empty, got %q %q", ip, chain)
	}
}