/**
 * PowerPoint (PPTX) Processing Utility
 *
 * Extracts text content from PowerPoint (.pptx) files by treating them
 * as ZIP archives and parsing the slide XML files within.
 *
 * PPTX files are ZIP archives containing:
 * - ppt/slides/slide1.xml, slide2.xml, ... — slide content
 * - ppt/slideMasters/ — master slide templates
 * - ppt/slideLayouts/ — slide layout definitions
 *
 * Text is extracted from `<a:t>` elements in the slide XML files.
 * Slides are sorted by number and presented in reading order.
 *
 * Uses `adm-zip` (already a project dependency) for ZIP extraction.
 *
 * @module processors/document/PptxProcessor
 *
 * @example
 * ```typescript
 * import { PptxProcessor } from "./PptxProcessor.js";
 *
 * const text = await PptxProcessor.extractText(buffer);
 * if (text) {
 *   console.log("Extracted text:", text);
 * }
 * ```
 */
/**
 * Static utility class for extracting text from PPTX files.
 *
 * Designed as a static class (not extending BaseFileProcessor) because
 * PPTX processing is straightforward ZIP+XML extraction and does not
 * need the full download/validate/process pipeline of BaseFileProcessor.
 */
export declare class PptxProcessor {
    /**
     * Extract all text content from a PPTX buffer.
     *
     * @param content - Raw PPTX file buffer
     * @returns Formatted text content with slide headers, or null if no text found
     * @throws Error if the buffer is not a valid ZIP/PPTX file
     */
    static extractText(content: Buffer): Promise<string | null>;
    /**
     * Extract text strings from a slide XML document.
     * Finds all `<a:t>` elements and returns their text content.
     *
     * @param xml - Raw XML string from a slide file
     * @returns Array of text strings found in the slide
     */
    private static extractTextFromXml;
    /**
     * Extract text from specific slides in a PPTX file.
     *
     * Called by the `extract_file_content` tool for targeted slide access.
     *
     * @param content - Raw PPTX file buffer
     * @param slideNumbers - Array of 1-indexed slide numbers to extract
     * @returns Formatted text from the requested slides
     */
    static extractSlides(content: Buffer, slideNumbers: number[]): Promise<string>;
}