import type { ModelMessage } from 'ai';
import { z } from 'zod';
import type { DecideNode } from '../types/flow.js';
import type { ChoiceOption } from '../types/selection.js';
import type { JSONValue, SystemModelMessage } from 'ai';
import type { RunContext } from '../types/run-context.js';
/** Reserved enum member: model declines to pick a listed choice (→ author stay/unmatched). */
export declare const CHOICE_NONE = "__none";
export declare function isConstrainedChoiceEnumSchema(schema: unknown): boolean;
export declare function isChoiceFieldSchema(schema: unknown): schema is z.ZodObject<{
    choice: z.ZodString;
}>;
export declare function buildChoiceEnumSchema(choices: ChoiceOption[]): z.ZodObject<{
    choice: z.ZodEnum<Record<string, string>>;
}>;
export declare function latestUserMessageText(messages: ModelMessage[]): string | undefined;
export declare function matchChoiceFromInput(input: string, choices: ChoiceOption[]): string | undefined;
export declare function resolveStructuredDecide(node: DecideNode, ctx: RunContext, system: string | SystemModelMessage[], providerOptions?: Record<string, Record<string, JSONValue>>): Promise<unknown>;
export type PreparedStructuredDecision = {
    kind: 'immediate';
    value: unknown;
} | {
    kind: 'model';
    schema: z.ZodType;
};
/** Resolve deterministic choice matches and the exact schema used by model-backed decide nodes. */
export declare function prepareStructuredDecide(node: DecideNode, ctx: Pick<RunContext, 'runState'>): PreparedStructuredDecision;