/**
 * n8n expression classifier. n8n stores an expression as a string value that
 * begins with `=` and interpolates `{{ … }}` blocks of JS. We lower them into
 * the three tiers the Pikku graph input mapper supports:
 *
 *  - literal   → a plain value
 *  - ref       → ref(nodeId, path)                 (pure single reference)
 *  - template  → template('… $0 …', [ref, …])      (literal text + pure refs)
 *  - transform → not declaratively expressible; needs a generated function
 *                (the original expression is preserved verbatim)
 */
export interface RefPart {
    nodeId: string;
    path?: string;
}
export type ClassifiedExpression = {
    kind: 'literal';
    value: unknown;
} | {
    kind: 'ref';
    nodeId: string;
    path?: string;
} | {
    kind: 'template';
    parts: string[];
    refs: RefPart[];
} | {
    kind: 'transform';
    expression: string;
};
export interface ExprContext {
    /** nodeId of the immediate predecessor — what `$json` refers to. */
    predecessorNodeId?: string;
    /** All graph-node predecessors in order — the input streams of a join node. */
    predecessorNodeIds?: string[];
    /** Map from original n8n node NAME to sanitized graph nodeId. */
    nameToNodeId: Record<string, string>;
    /**
     * Sanitized nodeIds of trigger nodes. A trigger is not a graph node — its data
     * is the graph's implicit `trigger` input — so any reference to one lowers to
     * `ref('trigger', …)`, the only form the generated ref map accepts for it.
     */
    triggerNodeIds?: Set<string>;
    /**
     * Rewrite map for references at non-graph nodes (dropped No Op passthroughs) →
     * their terminal data source (`'trigger'` or a graph nodeId). See Topology.
     */
    refRewrite?: Record<string, string>;
    /**
     * Per graph nodeId: n8n output-field name → addon output key. A ref whose
     * leading path segment is a node's n8n output-field name is remapped onto the
     * addon key (e.g. dateTime `formattedDate` → `result`). See native-map.
     */
    outputAliasByNodeId?: Record<string, Record<string, string>>;
}
/**
 * Classify a single n8n parameter value.
 */
export declare function classifyExpression(value: unknown, ctx: ExprContext): ClassifiedExpression;