package gcp

import (
	"fmt"

	"cloud.google.com/go/compute/apiv1/computepb"
	"google.golang.org/protobuf/proto"

	"gitea.home.hrajfrisbee.cz/kacerr/egress-proxies-operator/internal/provider"
)

const (
	defaultNetwork    = "default"
	defaultNetworkTag = "proxy-operator"
	defaultDiskSizeGB = 10
	userDataKey       = "user-data"
)

func withDefaults(cfg provider.GCPConfig) provider.GCPConfig {
	if cfg.Network == "" {
		cfg.Network = defaultNetwork
	}
	if cfg.NetworkTag == "" {
		cfg.NetworkTag = defaultNetworkTag
	}
	if cfg.DiskSizeGB == 0 {
		cfg.DiskSizeGB = defaultDiskSizeGB
	}
	return cfg
}

// buildInsertRequest is pure so the field-by-field unit test needs no fake
// at all — the plan's primary test for this provider.
func buildInsertRequest(cfg provider.GCPConfig, req provider.CreateRequest) *computepb.InsertInstanceRequest {
	inst := &computepb.Instance{
		Name:        proto.String(req.Name),
		MachineType: proto.String(fmt.Sprintf("zones/%s/machineTypes/%s", req.Placement.Zone, req.Placement.MachineType)),
		Disks: []*computepb.AttachedDisk{{
			Boot:       proto.Bool(true),
			AutoDelete: proto.Bool(true),
			InitializeParams: &computepb.AttachedDiskInitializeParams{
				SourceImage: proto.String(req.Placement.Image),
				DiskSizeGb:  proto.Int64(cfg.DiskSizeGB),
			},
		}},
		NetworkInterfaces: []*computepb.NetworkInterface{{
			Network: proto.String("global/networks/" + cfg.Network),
			// An ephemeral external IP: exactly this pair, per the API's
			// contract for one-to-one NAT.
			AccessConfigs: []*computepb.AccessConfig{{
				Name: proto.String("External NAT"),
				Type: proto.String("ONE_TO_ONE_NAT"),
			}},
		}},
		// The GC contract: every resource this operator creates carries
		// these two labels, and orphan GC relies on both.
		Labels: map[string]string{
			provider.LabelManaged: provider.LabelManagedYes,
			provider.LabelUID:     req.UID,
		},
		Tags: &computepb.Tags{Items: []string{cfg.NetworkTag}},
	}
	if req.CloudInit != "" {
		inst.Metadata = &computepb.Metadata{Items: []*computepb.Items{{
			Key:   proto.String(userDataKey),
			Value: proto.String(req.CloudInit),
		}}}
	}
	return &computepb.InsertInstanceRequest{
		Project:          cfg.Project,
		Zone:             req.Placement.Zone,
		InstanceResource: inst,
	}
}