package backendclient_test

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

	"scrabble/gateway/internal/backendclient"
	"scrabble/gateway/internal/ratelimit"
)

// TestReportRateLimited verifies the rejection report reaches the backend's
// internal endpoint with the agreed JSON shape and no user identity.
func TestReportRateLimited(t *testing.T) {
	var got struct {
		WindowSeconds int                   `json:"window_seconds"`
		Entries       []ratelimit.Rejection `json:"entries"`
	}
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost || r.URL.Path != "/api/v1/internal/ratelimit/report" {
			t.Errorf("call = %s %s, want POST /api/v1/internal/ratelimit/report", r.Method, r.URL.Path)
		}
		if uid := r.Header.Get("X-User-ID"); uid != "" {
			t.Errorf("X-User-ID = %q, want empty", uid)
		}
		if err := json.NewDecoder(r.Body).Decode(&got); err != nil {
			t.Errorf("decode report: %v", err)
		}
	}))
	defer srv.Close()

	c, err := backendclient.New(srv.URL, "localhost:9090", 2*time.Second)
	if err != nil {
		t.Fatalf("backendclient: %v", err)
	}
	defer func() { _ = c.Close() }()

	entries := []ratelimit.Rejection{{Class: "user", Key: "u-1", Rejected: 5}}
	if err := c.ReportRateLimited(context.Background(), 30, entries); err != nil {
		t.Fatalf("ReportRateLimited: %v", err)
	}
	if got.WindowSeconds != 30 || len(got.Entries) != 1 || got.Entries[0] != entries[0] {
		t.Fatalf("backend received %+v, want window 30 + %+v", got, entries[0])
	}
}