package registries

import (
	"encoding/json"
	"net/http"
	"strconv"

	httperror "github.com/portainer/libhttp/error"
	"github.com/portainer/libhttp/request"
	"github.com/portainer/portainer/api"
)

// request on /api/registries/:id/v2
func (handler *Handler) proxyRequestsToRegistryAPI(w http.ResponseWriter, r *http.Request) *httperror.HandlerError {
	registryID, err := request.RetrieveNumericRouteVariableValue(r, "id")
	if err != nil {
		return &httperror.HandlerError{http.StatusBadRequest, "Invalid registry identifier route variable", err}
	}

	registry, err := handler.RegistryService.Registry(portainer.RegistryID(registryID))
	if err == portainer.ErrObjectNotFound {
		return &httperror.HandlerError{http.StatusNotFound, "Unable to find a registry with the specified identifier inside the database", err}
	} else if err != nil {
		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to find a registry with the specified identifier inside the database", err}
	}

	err = handler.requestBouncer.RegistryAccess(r, registry)
	if err != nil {
		return &httperror.HandlerError{http.StatusForbidden, "Permission denied to access registry", portainer.ErrEndpointAccessDenied}
	}

	extension, err := handler.ExtensionService.Extension(portainer.RegistryManagementExtension)
	if err == portainer.ErrObjectNotFound {
		return &httperror.HandlerError{http.StatusNotFound, "Registry management extension is not enabled", err}
	} else if err != nil {
		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to find a extension with the specified identifier inside the database", err}
	}

	var proxy http.Handler
	proxy = handler.ProxyManager.GetExtensionProxy(portainer.RegistryManagementExtension)
	if proxy == nil {
		proxy, err = handler.ProxyManager.CreateExtensionProxy(portainer.RegistryManagementExtension)
		if err != nil {
			return &httperror.HandlerError{http.StatusInternalServerError, "Unable to create extension proxy for registry manager", err}
		}
	}

	managementConfiguration := registry.ManagementConfiguration
	if managementConfiguration == nil {
		managementConfiguration = createDefaultManagementConfiguration(registry)
	}

	encodedConfiguration, err := json.Marshal(managementConfiguration)
	if err != nil {
		return &httperror.HandlerError{http.StatusInternalServerError, "Unable to encode management configuration", err}
	}

	id := strconv.Itoa(int(registryID))
	r.Header.Set("X-RegistryManagement-Key", id)
	r.Header.Set("X-RegistryManagement-URI", registry.URL)
	r.Header.Set("X-RegistryManagement-Config", string(encodedConfiguration))
	r.Header.Set("X-PortainerExtension-License", extension.License.LicenseKey)

	http.StripPrefix("/registries/"+id, proxy).ServeHTTP(w, r)
	return nil
}

func createDefaultManagementConfiguration(registry *portainer.Registry) *portainer.RegistryManagementConfiguration {
	config := &portainer.RegistryManagementConfiguration{
		Type: registry.Type,
		TLSConfig: portainer.TLSConfiguration{
			TLS: false,
		},
	}

	if registry.Authentication {
		config.Authentication = true
		config.Username = registry.Username
		config.Password = registry.Password
	}

	return config
}