Crussell/backend/mw/ratelimit_dev_test.go

//go:build test && dev

package mw

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

	"crussell/clock"
	"github.com/stretchr/testify/assert"
)

// ============================================================
// Dev Stub Behavioral Tests
// ============================================================

// TestDevRateLimiter_AllowAlwaysTrue verifies the dev stub never throttles.
func TestDevRateLimiter_AllowAlwaysTrue(t *testing.T) {
	rl := NewRateLimiter(10, time.Minute)

	if !rl.Allow("any-key") {
		t.Error("expected Allow to return true for dev stub")
	}
	if !rl.Allow("another-key") {
		t.Error("expected Allow to return true for dev stub (different key)")
	}
	// Even an empty key should pass
	if !rl.Allow("") {
		t.Error("expected Allow to return true for empty key in dev stub")
	}
}

// TestDevProgressiveRateLimiter_CheckAlwaysZero verifies the dev stub never delays.
func TestDevProgressiveRateLimiter_CheckAlwaysZero(t *testing.T) {
	prl := NewProgressiveRateLimiter()

	for i := 0; i < 200; i++ {
		delay := prl.Check("10.0.0.1")
		if delay != 0 {
			t.Errorf("expected 0 delay for dev stub (request %d), got %d", i+1, delay)
		}
	}

	// Different IP also returns 0
	if delay := prl.Check("10.0.0.2"); delay != 0 {
		t.Errorf("expected 0 delay for different IP in dev stub, got %d", delay)
	}
}

func TestProgressiveRateLimiter_CleanupRemovesStaleEntries(t *testing.T) {
	prl := NewProgressiveRateLimiter()

	prl.mu.Lock()
	prl.requests["stale-ip"] = &ipProgressiveState{
		timestamps: []time.Time{clock.Now().Add(-120 * time.Second)},
	}
	prl.mu.Unlock()

	prl.Cleanup()

	prl.mu.RLock()
	_, exists := prl.requests["stale-ip"]
	prl.mu.RUnlock()
	if exists {
		t.Error("expected stale IP to be cleaned up")
	}
}

func TestRateLimiter_Cleanup(t *testing.T) {
	rl := NewRateLimiter(10, time.Minute)

	rl.mu.Lock()
	rl.requests["stale-key"] = []time.Time{clock.Now().Add(-5 * time.Minute)}
	rl.requests["fresh-key"] = []time.Time{clock.Now()}
	rl.mu.Unlock()

	rl.Cleanup()

	rl.mu.RLock()
	_, staleExists := rl.requests["stale-key"]
	_, freshExists := rl.requests["fresh-key"]
	rl.mu.RUnlock()

	if staleExists {
		t.Error("expected stale-key to be removed")
	}
	if !freshExists {
		t.Error("expected fresh-key to be preserved")
	}
}

func TestRateLimiter_Cleanup_EmptyMap(t *testing.T) {
	rl := NewRateLimiter(10, time.Minute)

	rl.mu.Lock()
	rl.requests = make(map[string][]time.Time)
	rl.mu.Unlock()

	rl.Cleanup()

	rl.mu.RLock()
	count := len(rl.requests)
	rl.mu.RUnlock()
	if count != 0 {
		t.Errorf("expected empty map, got %d entries", count)
	}
}

func TestCleanupAllRateLimiters(t *testing.T) {
	registeredLimitersMu.Lock()
	saved := registeredLimiters
	registeredLimitersMu.Unlock()
	defer func() {
		registeredLimitersMu.Lock()
		registeredLimiters = saved
		registeredLimitersMu.Unlock()
	}()

	rl1 := NewRateLimiter(10, time.Minute)
	rl2 := NewRateLimiter(20, time.Minute)

	rl1.mu.Lock()
	rl1.requests["rl1-stale"] = []time.Time{clock.Now().Add(-5 * time.Minute)}
	rl1.mu.Unlock()

	rl2.mu.Lock()
	rl2.requests["rl2-stale"] = []time.Time{clock.Now().Add(-5 * time.Minute)}
	rl2.mu.Unlock()

	_, err := CleanupAllRateLimiters(context.Background())
	if err != nil {
		t.Errorf("expected nil error, got %v", err)
	}

	rl1.mu.RLock()
	_, rl1Stale := rl1.requests["rl1-stale"]
	rl1.mu.RUnlock()

	rl2.mu.RLock()
	_, rl2Stale := rl2.requests["rl2-stale"]
	rl2.mu.RUnlock()

	if rl1Stale {
		t.Error("expected rl1-stale to be removed")
	}
	if rl2Stale {
		t.Error("expected rl2-stale to be removed")
	}
}

func TestCleanupAllRateLimiters_Empty(t *testing.T) {
	registeredLimitersMu.Lock()
	saved := registeredLimiters
	registeredLimiters = nil
	registeredLimitersMu.Unlock()
	defer func() {
		registeredLimitersMu.Lock()
		registeredLimiters = saved
		registeredLimitersMu.Unlock()
	}()

	_, err := CleanupAllRateLimiters(context.Background())
	if err != nil {
		t.Errorf("expected nil error, got %v", err)
	}
}

func TestCleanupProgressiveRateLimiter(t *testing.T) {
	globalProgressiveLimiter.mu.Lock()
	saved := globalProgressiveLimiter.requests
	globalProgressiveLimiter.requests = map[string]*ipProgressiveState{
		"global-stale": {timestamps: []time.Time{clock.Now().Add(-120 * time.Second)}},
	}
	globalProgressiveLimiter.mu.Unlock()
	defer func() {
		globalProgressiveLimiter.mu.Lock()
		globalProgressiveLimiter.requests = saved
		globalProgressiveLimiter.mu.Unlock()
	}()

	_, err := CleanupProgressiveRateLimiter(context.Background())
	if err != nil {
		t.Errorf("expected nil error, got %v", err)
	}

	globalProgressiveLimiter.mu.RLock()
	_, exists := globalProgressiveLimiter.requests["global-stale"]
	globalProgressiveLimiter.mu.RUnlock()
	if exists {
		t.Error("expected global-stale to be removed")
	}
}

// ============================================================
// Dev Stub Middleware Pass-Through Tests
// ============================================================

// TestProgressiveRateLimit_PassThrough verifies the dev stub middleware
// passes through to the next handler without rate limiting.
func TestProgressiveRateLimit_PassThrough(t *testing.T) {
	handler := ProgressiveRateLimit(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte("ok"))
	}))

	req := httptest.NewRequest("GET", "/", nil)
	w := httptest.NewRecorder()
	handler.ServeHTTP(w, req)

	assert.Equal(t, http.StatusOK, w.Code)
	assert.Equal(t, "ok", w.Body.String())
}

// TestRateLimit_PassThrough verifies the dev stub middleware
// passes through to the next handler without rate limiting.
func TestRateLimit_PassThrough(t *testing.T) {
	handler := RateLimit(10, time.Minute)(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte("ok"))
	}))

	req := httptest.NewRequest("GET", "/", nil)
	w := httptest.NewRecorder()
	handler.ServeHTTP(w, req)

	assert.Equal(t, http.StatusOK, w.Code)
	assert.Equal(t, "ok", w.Body.String())
}