import { ModelMessage, UIMessage } from '../../types.js';
/**
 * Convert UIMessages or ModelMessages to ModelMessages
 */
export declare function convertMessagesToModelMessages(messages: Array<UIMessage | ModelMessage>): Array<ModelMessage>;
/**
 * Convert a UIMessage to ModelMessage(s)
 *
 * Walks the parts array IN ORDER to preserve the interleaving of text,
 * tool calls, and tool results. This is critical for multi-round tool
 * flows where the model generates text, calls a tool, gets the result,
 * then generates more text and calls another tool.
 *
 * The output preserves the sequential structure:
 *   text1 → toolCall1 → toolResult1 → text2 → toolCall2 → toolResult2
 * becomes:
 *   assistant: {content: "text1", toolCalls: [toolCall1]}
 *   tool: toolResult1
 *   assistant: {content: "text2", toolCalls: [toolCall2]}
 *   tool: toolResult2
 *
 * @param uiMessage - The UIMessage to convert
 * @returns An array of ModelMessages preserving part ordering
 */
export declare function uiMessageToModelMessages(uiMessage: UIMessage): Array<ModelMessage>;
/**
 * Convert a ModelMessage to UIMessage
 *
 * This conversion creates a parts-based structure:
 * - content field → TextPart
 * - toolCalls array → ToolCallPart[]
 * - role="tool" messages should be converted separately and merged
 *
 * @param modelMessage - The ModelMessage to convert
 * @param id - Optional ID for the UIMessage (generated if not provided)
 * @returns A UIMessage with parts
 */
export declare function modelMessageToUIMessage(modelMessage: ModelMessage, id?: string): UIMessage;
/**
 * Convert an array of ModelMessages to UIMessages
 *
 * This handles merging tool result messages with their corresponding assistant messages
 *
 * @param modelMessages - Array of ModelMessages to convert
 * @returns Array of UIMessages
 */
export declare function modelMessagesToUIMessages(modelMessages: Array<ModelMessage>): Array<UIMessage>;
/**
 * Normalize a message (UIMessage or ModelMessage) to a UIMessage
 * Ensures the message has an ID and createdAt timestamp
 *
 * @param message - Either a UIMessage or ModelMessage
 * @param generateId - Function to generate a message ID if needed
 * @returns A UIMessage with guaranteed id and createdAt
 */
export declare function normalizeToUIMessage(message: UIMessage | ModelMessage, generateId: () => string): UIMessage;
/**
 * Generate a unique message ID
 */
export declare function generateMessageId(): string;