package httpapi

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

	"evobgp/internal/store"
)

func TestOperationLimitsSharedCapacityAndWindows(t *testing.T) {
	l := newOperationLimiter()
	l.maxActive = 2
	l.maxTenantActive = 1
	l.rates = [3]int{1, 2, 2}
	now := time.Now()
	a, _ := l.acquire("a", lookupOperation, now)
	if a == nil {
		t.Fatal("first denied")
	}
	if r, _ := l.acquire("a", cdnPreviewOperation, now); r != nil {
		t.Fatal("tenant concurrency bypass")
	}
	b, _ := l.acquire("b", revisionPreviewOperation, now)
	if b == nil {
		t.Fatal("other tenant denied")
	}
	if r, _ := l.acquire("c", lookupOperation, now); r != nil {
		t.Fatal("global concurrency bypass")
	}
	a()
	a()
	b()
	if l.active != 0 {
		t.Fatal("release not idempotent")
	}
	if r, retry := l.acquire("a", lookupOperation, now.Add(time.Second)); r != nil || retry != 59 {
		t.Fatalf("rate bypass/retry admitted=%t seconds=%d", r != nil, retry)
	}
	c, _ := l.acquire("a", cdnPreviewOperation, now.Add(time.Second))
	if c == nil {
		t.Fatal("independent operation denied")
	}
	c()
	d, _ := l.acquire("a", lookupOperation, now.Add(time.Minute))
	if d == nil {
		t.Fatal("expired window not reset")
	}
	d()
}

func TestOperationTenantMapBoundWithoutActiveEviction(t *testing.T) {
	l := newOperationLimiter()
	l.maxTenants = 1
	now := time.Now()
	a, _ := l.acquire("a", lookupOperation, now)
	if r, _ := l.acquire("b", lookupOperation, now.Add(2*time.Minute)); r != nil {
		t.Fatal("active entry evicted")
	}
	a()
	b, _ := l.acquire("b", lookupOperation, now.Add(3*time.Minute))
	if b == nil || len(l.tenants) != 1 {
		t.Fatal("idle expiry did not free bounded state")
	}
	b()
}

func TestOperationConcurrentAdmissionBound(t *testing.T) {
	l := newOperationLimiter()
	l.maxActive = 4
	l.maxTenantActive = 4
	l.rates = [3]int{100, 100, 100}
	results := make(chan func(), 32)
	var wg sync.WaitGroup
	for range 32 {
		wg.Add(1)
		go func() { defer wg.Done(); r, _ := l.acquire("tenant", lookupOperation, time.Now()); results <- r }()
	}
	wg.Wait()
	close(results)
	accepted := 0
	for r := range results {
		if r != nil {
			accepted++
			r()
		}
	}
	if accepted != 4 || l.active != 0 {
		t.Fatalf("accepted=%d active=%d", accepted, l.active)
	}
}

type waitingRevisionStore struct {
	store.Backend
	entered chan struct{}
	unblock chan struct{}
}

func (s waitingRevisionStore) GetRevision(tenant, id string) (*store.Revision, error) {
	s.entered <- struct{}{}
	<-s.unblock
	return s.Backend.GetRevision(tenant, id)
}

func TestRevisionQuotaHeldUntilWorkReturns(t *testing.T) {
	t.Setenv("EVOBGP_API_EXPENSIVE_TENANT_CONCURRENT", "1")
	t.Setenv("EVOBGP_API_REVISION_PREVIEW_PER_MINUTE", "30")
	m := store.NewMemory()
	m.SeedDemo()
	tenant, _, _, revision, _ := m.DemoIDs()
	entered := make(chan struct{}, 2)
	unblock := make(chan struct{})
	s := &Server{store: waitingRevisionStore{Backend: m, entered: entered, unblock: unblock}}
	request := func() *http.Request {
		r := httptest.NewRequest(http.MethodGet, "/v1/revisions/"+revision+"/preview", nil)
		r.SetPathValue("revision_id", revision)
		return r.WithContext(context.WithValue(r.Context(), authCtxKey, Auth{TenantID: tenant, Role: "operator"}))
	}
	ctx, cancel := context.WithCancel(request().Context())
	defer cancel()
	first := httptest.NewRecorder()
	done := make(chan struct{})
	go func() { defer close(done); s.handleRevisionPreview(first, request().WithContext(ctx)) }()
	<-entered
	cancel() // Backend deliberately ignores cancellation: capacity stays reserved.
	second := httptest.NewRecorder()
	s.handleRevisionPreview(second, request())
	if second.Code != http.StatusTooManyRequests || second.Header().Get("Retry-After") == "" {
		close(unblock)
		<-done
		t.Fatalf("quota: %d %s", second.Code, second.Body.String())
	}
	close(unblock)
	<-done
	third := httptest.NewRecorder()
	s.handleRevisionPreview(third, request())
	if third.Code != http.StatusOK {
		t.Fatalf("release failed: %d %s", third.Code, third.Body.String())
	}
}