package httpmw_test

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

	"github.com/stretchr/testify/require"

	"github.com/coder/coder/v2/coderd/httpmw"
)

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

	tests := []struct {
		Name    string
		Handler http.HandlerFunc

		expectStatus       int
		expectCacheControl string
		expectPragma       string
		assert             func(t *testing.T, res *httptest.ResponseRecorder)
	}{
		{
			// The POST /oauth2/tokens shape.
			Name: "OK",
			Handler: func(rw http.ResponseWriter, _ *http.Request) {
				rw.WriteHeader(http.StatusOK)
				_, _ = rw.Write([]byte(`{"access_token":"secret"}`))
			},
			expectStatus:       http.StatusOK,
			expectCacheControl: "no-store",
			expectPragma:       "no-cache",
		},
		{
			// The DELETE /oauth2/clients/{client_id} shape: headers on a
			// response with no body.
			Name: "NoContent",
			Handler: func(rw http.ResponseWriter, _ *http.Request) {
				rw.WriteHeader(http.StatusNoContent)
			},
			expectStatus:       http.StatusNoContent,
			expectCacheControl: "no-store",
			expectPragma:       "no-cache",
		},
		{
			// The POST /oauth2/authorize shape: http.Redirect writes its own
			// headers without clearing the map.
			Name: "Redirect",
			Handler: func(rw http.ResponseWriter, r *http.Request) {
				http.Redirect(rw, r, "https://example.com/callback?code=abc", http.StatusFound)
			},
			expectStatus:       http.StatusFound,
			expectCacheControl: "no-store",
			expectPragma:       "no-cache",
			assert: func(t *testing.T, res *httptest.ResponseRecorder) {
				require.Equal(t, "https://example.com/callback?code=abc", res.Header().Get("Location"))
			},
		},
		{
			// The revoke.go and registration.go shape: a bare WriteHeader,
			// never httpapi.Write.
			Name: "BareWriteHeaderError",
			Handler: func(rw http.ResponseWriter, _ *http.Request) {
				rw.WriteHeader(http.StatusBadRequest)
			},
			expectStatus:       http.StatusBadRequest,
			expectCacheControl: "no-store",
			expectPragma:       "no-cache",
		},
		{
			// The headers are advisory: a handler that writes its own
			// Cache-Control wins, and Pragma survives alongside it.
			Name: "HandlerOverwrites",
			Handler: func(rw http.ResponseWriter, _ *http.Request) {
				rw.Header().Set("Cache-Control", "private")
				rw.WriteHeader(http.StatusOK)
			},
			expectStatus:       http.StatusOK,
			expectCacheControl: "private",
			expectPragma:       "no-cache",
		},
	}

	for _, tt := range tests {
		t.Run(tt.Name, func(t *testing.T) {
			t.Parallel()

			req := httptest.NewRequest(http.MethodGet, "/", nil)
			res := httptest.NewRecorder()
			httpmw.NoStore(tt.Handler).ServeHTTP(res, req)

			require.Equal(t, tt.expectStatus, res.Code)
			require.Equal(t, tt.expectCacheControl, res.Header().Get("Cache-Control"))
			require.Equal(t, tt.expectPragma, res.Header().Get("Pragma"))
			if tt.assert != nil {
				tt.assert(t, res)
			}
		})
	}
}