// Package gcpinfra defines the GCP Resource Manager / Cloud resource structure that
// is used to manage all infrastructure owned by Edge.
// Initial RFC: https://docs.edge-infra.dev/rfc/gcp-infra-structure
package gcpinfra

import (
	"fmt"
	"strings"

	"edge-infra.dev/pkg/lib/gcp/project"
)

// String constants.  These won't change across Instances/Instance Groups,
// so they aren't defaults (see defaults.go)
var (
	// ForemanServiceAccountName is the name used for all Foreman GCP SAs
	ForemanServiceAccountName = "foreman-cnrm-system"
	// ProjectIDPrefix is the string that must begin all GCP Project IDs
	// owned by Edge, per NCR GCP Org requirements.  We think it is as silly
	// as you do.
	ProjectIDPrefix = "ret-edge"
	// InfraFolderName is the folder name that contains the Infra GCP project
	// for an InstanceGroup
	InfraFolderName = "infra"
)

// RootFolder is The root folder that Edge owns, containing all instances
// (dev, stage, test, prod, etc) and Edge infrastructure
type RootFolder struct {
	FolderID       string
	InstanceGroups []InstanceGroup
}

// InstanceGroup contains a group of individual Edge instances, each sharing
// common platform infrastructure, defined in InstanceGroup.Infra
type InstanceGroup struct {
	FolderID  string     `yaml:"folderId"`
	Name      string     `yaml:"name"`
	Instances []Instance `yaml:"instances,omitempty"`
	Infra     Infra      `yaml:"infra,omitempty"`
}

// Infra is the folder + project that owns the billing admin Foreman Service
// Account needed by each Instance to create tenant projects.  Other infrastructure
// shared by instances is also defined here, such as: GCR registries, DNS, etc.
type Infra struct {
	FolderID              string `yaml:"folderId"`
	ProjectID             string `yaml:"projectId,omitempty"`
	ForemanServiceAccount string `yaml:"foremanSvcAct,omitempty"`
}

// Instance is the GCP infra needed for a single Edge instance.  If a
// Namespace is provided, an additional folder will be created that the instance
// is nested in.
type Instance struct {
	// The instance name.
	Name string `yaml:"name"`
	// Abstract logical grouping of instsances, e.g., dev, test, sandbox
	Namespace string `yaml:"namespace,omitempty"`
	// List of tenant projects registered with this instance of Edge
	Tenants []Tenant `yaml:"tenants,omitempty"`
	// The GCP project where the Edge control plane will be deployed
	ForemanProjectID string `yaml:"foremanProjectId,omitempty"`
	// QLIDs that will be given admin privileges on the instance and permissions
	// to manage the instance K8s resources on the platform infrastructure cluster
	Owners []string `yaml:"owners,omitempty"`
}

// Tenant represents a tenant's GCP infra.
type Tenant struct {
	ProjectID string
}

// ForemanProjectID creates + validates a Project ID string for an instance's
// Foreman GCP Project
func ForemanProjectID(name string) (string, error) {
	id := fmt.Sprintf("%s-%s-foreman", ProjectIDPrefix, name)
	err := project.IsValidProjectID(id)
	if err != nil {
		return "", fmt.Errorf("gcpinfra.ForemanProjectID: %w", err)
	}
	return id, nil
}

var ErrMissingPrefix = fmt.Errorf("project ID is missing required prefix %s", ProjectIDPrefix)

// IsValidForemanProjectID validates input project ID strings based on org
// naming requirements (constant prefix) and GCP requirements
func IsValidForemanProjectID(id string) error {
	if !strings.HasPrefix(id, ProjectIDPrefix) {
		return fmt.Errorf("gcpinfra: invalid id %s. error: %w", id, ErrMissingPrefix)
	}
	if err := project.IsValidProjectID(id); err != nil {
		return fmt.Errorf("gcpinfra: project id %s invalid: error: %w", id, err)
	}

	return nil
}