package ipranger

import (
	"context"
	"fmt"
	"time"

	"google.golang.org/api/compute/v1"
)

type gcpSubnetSvc struct {
	compute *compute.Service
	svc     *compute.SubnetworksService
}

func newGCPSubnetService(ctx context.Context) (*gcpSubnetSvc, error) {
	computeSvc, err := compute.NewService(ctx)
	if err != nil {
		return nil, err
	}
	return &gcpSubnetSvc{
		compute: computeSvc,
		svc:     compute.NewSubnetworksService(computeSvc),
	}, nil
}

func (g *gcpSubnetSvc) List(project string) (computeSubnetAggregatedList, error) {
	list, err := g.svc.AggregatedList(project).Do()
	if err != nil {
		return nil, err
	}
	return list.Items, nil
}

func (g *gcpSubnetSvc) Create(project, ipRange, region, name string) (*compute.Subnetwork, error) {
	toCreate := &compute.Subnetwork{
		IpCidrRange: ipRange,
		Name:        name,
		Network:     defaultNetwork(project),
	}

	// create the subnet
	op, err := g.svc.Insert(project, region, toCreate).Do()
	if err != nil {
		return nil, err
	}
	ctx, cancel := context.WithTimeout(context.Background(), time.Second*30)
	defer cancel()
	for {
		if op.Status == "DONE" {
			break
		}
		op, err = g.compute.RegionOperations.Get(project, region, op.Name).Do()
		if err != nil {
			return nil, err
		}
		select {
		case <-ctx.Done():
			if err := ctx.Err(); err != nil {
				return nil, err
			}
			break
		case <-time.After(5 * time.Second):
			continue
		}
	}

	// get the newly created subnet
	newSubnet, err := g.svc.Get(project, region, name).Do()
	if err != nil {
		return nil, err
	}
	return newSubnet, nil
}

func defaultNetwork(project string) string {
	return fmt.Sprintf("projects/%s/global/networks/default", project)
}