package middleware //nolint:testpackage // tests internal CORS behavior

import (
	"log/slog"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/stretchr/testify/assert"

	"sneak.berlin/go/upaas/internal/config"
)

//nolint:gosec // test credentials
func newCORSTestMiddleware(corsOrigins string) *Middleware {
	return &Middleware{
		log: slog.Default(),
		params: &Params{
			Config: &config.Config{
				CORSOrigins:   corsOrigins,
				SessionSecret: "test-secret-32-bytes-long-enough",
			},
		},
	}
}

// assertNoCORSHeaders runs a request with the given Origin header through
// CORS middleware configured with corsOrigins and asserts that no
// Access-Control-Allow-Origin header is set.
func assertNoCORSHeaders(t *testing.T, corsOrigins, origin, msg string) {
	t.Helper()

	m := newCORSTestMiddleware(corsOrigins)
	handler := m.CORS()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))

	req := httptest.NewRequestWithContext(t.Context(), http.MethodGet, "/", nil)
	req.Header.Set("Origin", origin)

	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)

	assert.Empty(t, rec.Header().Get("Access-Control-Allow-Origin"), msg)
}

func TestCORS_NoOriginsConfigured_NoCORSHeaders(t *testing.T) {
	t.Parallel()

	assertNoCORSHeaders(t, "", "https://evil.com",
		"expected no CORS headers when no origins configured")
}

func TestCORS_OriginsConfigured_AllowsMatchingOrigin(t *testing.T) {
	t.Parallel()

	m := newCORSTestMiddleware("https://app.example.com,https://other.example.com")
	handler := m.CORS()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))

	req := httptest.NewRequestWithContext(t.Context(), http.MethodGet, "/", nil)
	req.Header.Set("Origin", "https://app.example.com")

	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)

	assert.Equal(t, "https://app.example.com",
		rec.Header().Get("Access-Control-Allow-Origin"))
	assert.Equal(t, "true",
		rec.Header().Get("Access-Control-Allow-Credentials"))
}

func TestCORS_OriginsConfigured_RejectsNonMatchingOrigin(t *testing.T) {
	t.Parallel()

	assertNoCORSHeaders(t, "https://app.example.com", "https://evil.com",
		"expected no CORS headers for non-matching origin")
}