graph

type BaseNode struct {
	ID          string                 `json:"id"`
	Type        NodeType               `json:"type"`
	Name        string                 `json:"name,omitempty"`
	Description string                 `json:"description,omitempty"`
	Metadata    map[string]interface{} `json:"metadata,omitempty"`
}

type Edge struct {
	// ID is a unique identifier for this edge.
	ID string `json:"id,omitempty"`

	// From is the ID of the source node.
	From string `json:"from"`

	// To is the ID of the target node.
	To string `json:"to"`

	// Condition is an optional expression that must evaluate to true for this edge to be traversed.
	// If empty, the edge is always traversable.
	// The expression syntax is implementation-specific.
	Condition string `json:"condition,omitempty"`

	// Label provides a human-readable description of this edge.
	Label string `json:"label,omitempty"`

	// Metadata stores additional edge-specific data.
	Metadata map[string]interface{} `json:"metadata,omitempty"`
}

type ExecutorNode struct {
	BaseNode
	// ExecutorType specifies what kind of executor this is (e.g., "llm", "tool", "python").
	ExecutorType string `json:"executor_type"`

	// Config contains executor-specific configuration.
	// The structure depends on the ExecutorType.
	Config map[string]interface{} `json:"config"`

	// InputMapping defines how to map state values to executor inputs.
	InputMapping map[string]string `json:"input_mapping,omitempty"`

	// OutputMapping defines how to map executor outputs back to state.
	OutputMapping map[string]string `json:"output_mapping,omitempty"`
}

type Graph struct {
	// ID is a unique identifier for this graph.
	ID string `json:"id"`

	// Name is a human-readable name for the graph.
	Name string `json:"name,omitempty"`

	// Description provides context about what this graph does.
	Description string `json:"description,omitempty"`

	// Nodes is a map of node ID to node instance.
	// Using a map allows O(1) lookups by ID.
	Nodes map[string]Node `json:"nodes"`

	// Edges defines the connections between nodes.
	Edges []*Edge `json:"edges"`

	// EntryNode is the ID of the node where execution begins.
	EntryNode string `json:"entry_node"`

	// Metadata stores additional graph-level data.
	Metadata map[string]interface{} `json:"metadata,omitempty"`

	// Version is the schema version of this graph definition.
	Version string `json:"version,omitempty"`
}

type Node interface {
	// GetID returns the unique identifier for this node.
	GetID() string

	// GetType returns the type of this node.
	GetType() NodeType

	// Execute runs the node's logic with the given context and state.
	// It returns the updated state and any error that occurred.
	// Implementations should be provided in the main dago repository, not here.
	Execute(ctx context.Context, state state.State) (state.State, error)

	// Validate checks if the node configuration is valid.
	Validate() error
}

type NodeType string

type Route struct {
	// Condition is an expression evaluated against the state.
	// The expression syntax is implementation-specific (e.g., JSONPath, simple comparisons).
	Condition string `json:"condition"`

	// Target is the ID of the node to route to if the condition is true.
	Target string `json:"target"`

	// Description provides human-readable context for this route.
	Description string `json:"description,omitempty"`
}

type RouterNode struct {
	BaseNode
	// Routes defines the routing logic.
	// Each route has a condition and target node ID.
	Routes []Route `json:"routes"`

	// DefaultRoute is the fallback route if no conditions match.
	DefaultRoute string `json:"default_route,omitempty"`
}

type ValidationError struct {
	Field   string
	Message string
}