package service

import (
	"axolotl/models"
	"axolotl/store"
)

// NodeService is the single entry point for all node operations.
// All data-model integrity rules are enforced here; callers cannot produce
// invalid state by interacting with this interface alone.
type NodeService interface {
	// Query
	GetByID(id string) (*models.Node, error)
	List(filter ListFilter) ([]*models.Node, error)

	// Lifecycle
	Add(input AddInput) (*models.Node, error)
	Update(id string, input UpdateInput) (*models.Node, error)
	Delete(id string) error

	// User management
	AddUser(name string) (*models.Node, error)
	ListUsers() ([]*models.Node, error)
}

// AddInput describes a new node to create.
type AddInput struct {
	Title    string
	Content  string
	DueDate  string
	Type     string // default: "issue"
	Status   string // default: "open" when Type is "issue"
	Priority string
	// Namespace is a namespace name or node ID. Defaults to the current user.
	Namespace string
	// Assignee is a username or node ID.
	Assignee string
	// Tags are arbitrary user-defined labels (not system properties).
	Tags []string
	// Rels are additional typed edges (e.g. blocks, subtask, related).
	Rels []RelInput
}

// UpdateInput describes changes to apply to an existing node.
// Nil pointer fields mean "no change".
type UpdateInput struct {
	Title   *string
	Content *string
	DueDate *string // nil = no change; pointer to "" = clear due date
	// Status "done" is rejected when the node has open blockers.
	Status   *string
	Priority *string
	Type     *string
	// Namespace replaces the current namespace.
	Namespace *string
	// Assignee replaces the current assignee.
	Assignee   *string
	AddTags    []string
	RemoveTags []string
	AddRels    []RelInput
	RemoveRels []RelInput
}

// ListFilter specifies which nodes to return. Empty fields are ignored.
type ListFilter struct {
	Tags     []string
	Status   string
	Priority string
	Type     string
	// Namespace filters by namespace name or node ID.
	Namespace string
	// Assignee filters by username or node ID.
	Assignee string
	// Mention filters to nodes that mention the given username or node ID.
	Mention string
	// Rels are additional relation filters (e.g. blocks:someID).
	Rels []RelInput
}

// RelInput is a typed, directed edge with a target that may be a name or node ID.
type RelInput struct {
	Type   models.RelType
	Target string // name or node ID; the service resolves names
}

func InitNodeService(path string) error {
	return store.InitSQLiteStore(path)
}

func GetNodeService(cfg Config) (NodeService, error) {
	st, err := store.FindAndOpenSQLiteStore()
	if err != nil {
		return nil, err
	}
	return &nodeServiceImpl{store: st, userID: cfg.GetUser()}, nil
}