package network

import (
	"bytes"
	"encoding/json"
	"net/http"
	"net/url"

	"github.com/Azure/azure-sdk-for-go/services/network/mgmt/2018-08-01/network"
	"github.com/pkg/errors"
	"github.com/virtual-kubelet/virtual-kubelet/providers/azure/client/api"
)

const (
	subnetPath = "subscriptions/{{.subscriptionId}}/resourcegroups/{{.resourceGroupName}}/providers/Microsoft.Network/virtualNetworks/{{.vnetName}}/subnets/{{.subnetName}}"
	subnetAction   = "Microsoft.Network/virtualNetworks/subnets/action"
)

var (
	delegationName = "aciDelegation"
	serviceName    = "Microsoft.ContainerInstance/containerGroups"
)

// NewSubnetWithContainerInstanceDelegation creates the subnet instance with ACI delegation
func NewSubnetWithContainerInstanceDelegation(name, addressPrefix string) *network.Subnet {
	subnet := network.Subnet{
		Name: &name,
		SubnetPropertiesFormat: &network.SubnetPropertiesFormat{
			AddressPrefix: &addressPrefix,
			Delegations: &[]network.Delegation{
				network.Delegation{
					Name: &delegationName,
					ServiceDelegationPropertiesFormat: &network.ServiceDelegationPropertiesFormat{
						ServiceName: &serviceName,
						Actions:     &[]string{subnetAction},
					},
				},
			},
		},
	}

	return &subnet
}

// GetSubnet gets the subnet from the specified resourcegroup/vnet
func (c *Client) GetSubnet(resourceGroup, vnet, name string) (*network.Subnet, error) {
	urlParams := url.Values{
		"api-version": []string{apiVersion},
	}

	// Create the url.
	uri := api.ResolveRelative(baseURI, subnetPath)
	uri += "?" + url.Values(urlParams).Encode()

	req, err := http.NewRequest("GET", uri, nil)
	if err != nil {
		return nil, errors.Wrap(err, "creating subnet get uri request failed")
	}

	if err := api.ExpandURL(req.URL, map[string]string{
		"subscriptionId":    c.auth.SubscriptionID,
		"resourceGroupName": resourceGroup,
		"subnetName":        name,
		"vnetName":          vnet,
	}); err != nil {
		return nil, errors.Wrap(err, "expanding URL with parameters failed")
	}

	// Send the request.
	resp, err := c.hc.Do(req)
	if err != nil {
		return nil, errors.Wrap(err, "sending subnet get request failed")
	}
	defer resp.Body.Close()

	// 200 (OK) is a success response.
	if err := api.CheckResponse(resp); err != nil {
		return nil, err
	}

	var subnet network.Subnet
	if err := json.NewDecoder(resp.Body).Decode(&subnet); err != nil {
		return nil, err
	}
	return &subnet, nil
}

// CreateOrUpdateSubnet creates a new or updates an existing subnet in the defined resourcegroup/vnet
func (c *Client) CreateOrUpdateSubnet(resourceGroup, vnet string, s *network.Subnet) (*network.Subnet, error) {
	urlParams := url.Values{
		"api-version": []string{apiVersion},
	}

	// Create the url.
	uri := api.ResolveRelative(baseURI, subnetPath)
	uri += "?" + url.Values(urlParams).Encode()

	// Create the request.
	b, err := json.Marshal(s)
	if err != nil {
		return nil, errors.Wrap(err, "marshallig networking profile failed")
	}

	req, err := http.NewRequest("PUT", uri, bytes.NewReader(b))
	if err != nil {
		return nil, errors.New("creating subnet create uri request failed")
	}

	// Add the parameters to the url.
	if err := api.ExpandURL(req.URL, map[string]string{
		"subscriptionId":    c.auth.SubscriptionID,
		"resourceGroupName": resourceGroup,
		"subnetName":        *s.Name,
		"vnetName":          vnet,
	}); err != nil {
		return nil, errors.Wrap(err, "expanding URL with parameters failed")
	}

	// Send the request.
	resp, err := c.hc.Do(req)
	if err != nil {
		return nil, errors.Wrap(err, "sending create subnet request failed")
	}
	defer resp.Body.Close()

	// 200 (OK) is a success response.
	if err := api.CheckResponse(resp); err != nil {
		return nil, err
	}

	var subnet network.Subnet
	if err := json.NewDecoder(resp.Body).Decode(&subnet); err != nil {
		return nil, err
	}
	return &subnet, nil
}