package fn_operations

import "time"

// EntityStatus represents the lifecycle state of an entity.
type EntityStatus string

const (
	StatusActive    EntityStatus = "active"
	StatusStale     EntityStatus = "stale"
	StatusCorrupted EntityStatus = "corrupted"
	StatusArchived  EntityStatus = "archived"
)

// RelationStatus represents the lifecycle state of a relation.
type RelationStatus string

const (
	RelDesigned    RelationStatus = "designed"
	RelImplemented RelationStatus = "implemented"
	RelTested      RelationStatus = "tested"
	RelRunning     RelationStatus = "running"
	RelDeprecated  RelationStatus = "deprecated"
)

// Direction represents the directionality of a relation.
type Direction string

const (
	DirUnidirectional Direction = "unidirectional"
	DirBidirectional  Direction = "bidirectional"
	DirInverse        Direction = "inverse"
)

// Entity is a concrete instance of a registry type within a project context.
type Entity struct {
	ID          string            `json:"id"`
	Name        string            `json:"name"`
	TypeRef     string            `json:"type_ref"`
	Status      EntityStatus      `json:"status"`
	Description string            `json:"description"`
	Domain      string            `json:"domain"`
	Tags        []string          `json:"tags"`
	Source      string            `json:"source"`
	Metadata    map[string]any    `json:"metadata"`
	Notes       string            `json:"notes"`
	CreatedAt   time.Time         `json:"created_at"`
	UpdatedAt   time.Time         `json:"updated_at"`
}

// Relation describes how one entity connects to or transforms into another.
type Relation struct {
	ID          string         `json:"id"`
	Name        string         `json:"name"`
	FromEntity  string         `json:"from_entity"`
	ToEntity    string         `json:"to_entity"`
	Via         string         `json:"via"`
	Description string         `json:"description"`
	Purity      string         `json:"purity"`
	Direction   Direction      `json:"direction"`
	Weight      *float64       `json:"weight"`
	Status      RelationStatus `json:"status"`
	StartedAt   *time.Time     `json:"started_at"`
	EndedAt     *time.Time     `json:"ended_at"`
	Order       *int           `json:"order"`
	Tags        []string       `json:"tags"`
	Notes       string         `json:"notes"`
	CreatedAt   time.Time      `json:"created_at"`
	UpdatedAt   time.Time      `json:"updated_at"`
}

// RelationInput represents one input entity in a multi-input relation.
type RelationInput struct {
	ID         string `json:"id"`
	RelationID string `json:"relation_id"`
	EntityID   string `json:"entity_id"`
	Role       string `json:"role"`
	Order      *int   `json:"order"`
}

// TypeSnapshot is an immutable copy of a registry type at point of use.
type TypeSnapshot struct {
	ID          string    `json:"id"`
	Version     string    `json:"version"`
	Lang        string    `json:"lang"`
	Algebraic   string    `json:"algebraic"`
	Definition  string    `json:"definition"`
	Description string    `json:"description"`
	SnappedAt   time.Time `json:"snapped_at"`
}