package server

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

	"git.codelab.vc/pkg/httpx/internal/clock"
)

func newTestRequest(remoteAddr, xff string) *http.Request {
	r := &http.Request{RemoteAddr: remoteAddr, Header: http.Header{}}
	if xff != "" {
		r.Header.Set("X-Forwarded-For", xff)
	}
	return r
}

// TestLimiterSweepEvictsIdleBuckets verifies that sweep removes fully-refilled
// (idle) buckets while preserving buckets that still hold an active limit, so
// memory is bounded without resetting live clients' allowances.
func TestLimiterSweepEvictsIdleBuckets(t *testing.T) {
	clk := clock.Mock(time.Now())
	o := &rateLimitOptions{rate: 1, burst: 5, clock: clk, maxKeys: 1 << 30}
	lim := &limiter{opts: o}

	// "idle" makes a single request, then time passes so it refills to full.
	lim.allow("idle")
	clk.Advance(10 * time.Second)

	// "active" drains its whole burst at the (advanced) current time.
	for i := 0; i < 6; i++ {
		lim.allow("active")
	}

	lim.sweep()

	if _, ok := lim.buckets.Load("idle"); ok {
		t.Error("fully-refilled idle bucket was not evicted")
	}
	if _, ok := lim.buckets.Load("active"); !ok {
		t.Error("active bucket with a partial limit was wrongly evicted")
	}
}

// TestClientKeyTrustedProxy exercises the X-Forwarded-For walk used behind a
// trusted proxy, independent of the HTTP layer.
func TestClientKeyTrustedProxy(t *testing.T) {
	o := &rateLimitOptions{}
	WithTrustedProxies("192.168.0.0/16")(o)

	r := newTestRequest("192.168.1.10:443", "203.0.113.7, 192.168.1.10")
	if got := o.clientKey(r); got != "203.0.113.7" {
		t.Fatalf("clientKey = %q, want real client 203.0.113.7", got)
	}

	// Untrusted peer: X-Forwarded-For must be ignored entirely.
	r = newTestRequest("203.0.113.7:443", "10.0.0.1")
	if got := o.clientKey(r); got != "203.0.113.7" {
		t.Fatalf("clientKey = %q, want peer 203.0.113.7 (XFF ignored)", got)
	}
}