// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
)

// The config file used by the vkube command.
type vkubeConfig struct {
	// The GCE project name.
	Project string `json:"project"`
	// The GCE zone.
	Zone string `json:"zone"`
	// The name of the Kubernetes cluster.
	Cluster string `json:"cluster"`

	ClusterAgent clusterAgentConfig `json:"clusterAgent"`
	PodAgent     podAgentConfig     `json:"podAgent"`
}

type clusterAgentConfig struct {
	// The Kubernetes namespace of the cluster agent. An empty
	// value is equivalent to "default".
	Namespace string `json:"namespace"`
	// The name of the docker image for the cluster agent.
	Image string `json:"image"`
	// The amount of CPU to reserve for the cluster agent.
	CPU string `json:"cpu"`
	// The amount of memory to reserve for the cluster agent.
	Memory string `json:"memory"`
	// The blessing name of the cluster agent.
	Blessing string `json:"blessing"`
	// The blessing pattern of the cluster agent admin, i.e. who's
	// allowed to create and delete secrets.
	Admin string `json:"admin"`
	// The external IP address of the cluster agent. An empty value
	// means that an ephemeral address will be used.
	// TODO(rthellend): This doesn't currently work.
	// https://github.com/kubernetes/kubernetes/issues/10323
	// https://github.com/kubernetes/kubernetes/pull/13005
	ExternalIP string `json:"externalIP"`
	// The name of the Persistent Disk of the cluster agent. An
	// value means that the cluster agent won't use a persistent
	// disk.
	PersistentDisk string `json:"persistentDisk"`
}

type podAgentConfig struct {
	// The name of the docker image for the pod agent.
	Image string `json:"image"`
}

// readConfig reads a config file.
func readConfig(fileName string) (*vkubeConfig, error) {
	data, err := ioutil.ReadFile(fileName)
	if err != nil {
		return nil, err
	}
	var config vkubeConfig
	if err := json.Unmarshal(data, &config); err != nil {
		return nil, fmt.Errorf("json.Unmarshal: %v", err)
	}
	if config.ClusterAgent.Namespace == "" {
		config.ClusterAgent.Namespace = "default"
	}
	return &config, nil
}