package cushion

import (
	"fmt"
	"regexp"
	"strconv"
	"strings"

	"edge-infra.dev/pkg/edge/apis/meta"
	"edge-infra.dev/pkg/edge/datasync/couchdb"
)

var (
	couchdbValidName = regexp.MustCompile(`^[a-z][a-z0-9_$()+/-]*$`)
)

const (
	OperationCreate = "CREATE"
	OperationDelete = "DELETE"
)

// Request is a data-sync pubsub message
type Request struct {
	// todo - need to filter on tenant_id, maybe just need a subscription per banner
	// TenantID is the BSL organization the message is meant for. Right now assumed child org
	TenantID string `json:"tenant_id"`
	// DBName is the name of the CouchDB the data should go into. Services integrated with data-sync
	// will use the same name when reading from store CouchDB instance.
	DBName string `json:"db_name"`
	// EntityID is a unique ID specific to the entity in the message. Will be used as docID in CouchDB.
	EntityID string `json:"entity_id"`
	// Deleted is a flag to determine if the entity should be deleted
	Deleted bool `json:"deleted"` // todo - wire up
	// Provider is the name of the data provider associated with a database
	Provider string `json:"provider"`
	// SiteID is unique id representing the store to replicate to
	SiteID string `json:"site_id"`
	// TouchpointID is unique id representing the touchpoint to replicate to
	TouchpointID string `json:"touchpoint_id"`

	// EnterpriseUnitID is the bsl unit id, can also be found in the store bsl info configmap
	EnterpriseUnitID string `json:"enterprise_unit_id"`

	// todo - want to replace deleted with this on next round
	// Operation string `json:"operation"`

	// ParentID is not used right now as we're assuming all messages are coming from child orgs
	ParentID string `json:"parent_id"`
	// EntityType is not used right now, maybe useful to add contextual information in logs
	EntityType string `json:"entity_type"`
	// Version represents the version the entity, not sure what it's purpose is
	Version string `json:"version"`

	// Credentials use for deleting database by ps users
	Credentials string `json:"credentials"`
}

// Validate checks if the request is valid
// DBName if error is nil, CouchDB database name is correct
// TODO add regex validation for other fields in another PR
func (r *Request) Validate() error {
	// commenting out till we are able to get to the point where we can make changes we want
	// if r.Operation == "" {
	// 	return fmt.Errorf("operation must not be empty")
	// }

	// switch r.Operation {
	// case OperationCreate:
	// case OperationDelete:
	// default:
	// 	return fmt.Errorf("unsupported Operation %q", r.Operation)
	// }

	if r.TenantID == "" {
		return fmt.Errorf("tenant_id message attribute must not be empty")
	}

	if r.DBName == "" {
		return fmt.Errorf("db_name message attribute must not be empty")
	}
	r.DBName = normalizeDBName(r.DBName) // backward compatibility
	if !couchdbValidName.MatchString(r.DBName) {
		return fmt.Errorf("db name: %s not matching regex: ^[a-z][a-z0-9_$()+/-]*$", r.DBName)
	}

	if r.EntityID == "" {
		return fmt.Errorf("entity_id message attribute must not be empty")
	}
	return nil
}

func (r *Request) FromAttributes(attrs map[string]string) error {
	// could look into using reflect to do this a little more intelligently

	// r.Operation = attrs["operation"]
	r.TenantID = attrs["tenant_id"]
	r.DBName = attrs["db_name"]
	r.EntityID = attrs["entity_id"]

	deletedStr := attrs["deleted"]
	if deletedStr == "" {
		r.Deleted = false
	} else {
		var err error
		r.Deleted, err = strconv.ParseBool(deletedStr)
		if err != nil {
			return err
		}
	}

	r.ParentID = attrs["parent_id"]
	r.EntityType = attrs["entity_type"]
	r.Version = attrs["version"]
	r.Provider = attrs["provider"]
	r.SiteID = attrs["site_id"]
	r.TouchpointID = attrs["touchpoint_id"]
	r.EnterpriseUnitID = attrs["enterprise_unit_id"] // can we just bind this to site id?

	return r.Validate()
}

// K8sDBName returns the name of the k8s CouchDBDatabase resource
func (r *Request) K8sDBName() string {
	return K8sDBName(r.DBName)
}

// normalizeDBName couchdb db names are lowercase
// Note: This only exists for backward compatibility
func normalizeDBName(dbname string) string {
	return strings.ToLower(dbname)
}

// K8sDBName normalize and avoid name collision for k8s resources
func K8sDBName(name string) string {
	return fmt.Sprintf("%s-%s", couchdb.CouchDBName, meta.Hash(normalizeDBName(name)))
}