/**
 * 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.
 *
 * **XML-entity attacks are not applicable here.** Unlike `WordProcessor`
 * (mammoth/@xmldom/xmldom) and `ExcelProcessor` (exceljs/saxes), this
 * processor never hands slide XML to a DOM or SAX parser at all — extraction
 * is a single regex (`TEXT_ELEMENT_REGEX`, below) run over the raw decoded
 * bytes. There is no DOCTYPE/ENTITY resolution path for a payload to reach,
 * so there is nothing for a `.pptx`-specific XXE or billion-laughs test to
 * falsify; one is deliberately not written (see
 * `test/continuous-test-suite-office-security.ts`'s header).
 *
 * @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 the speaker notes for one slide.
     *
     * Speaker notes live in a separate `ppt/notesSlides/notesSlideN.xml` part
     * whose number is NOT tied to the slide number — the link is declared in the
     * slide's own relationships file (`ppt/slides/_rels/slideN.xml.rels`) via a
     * relationship of type `.../notesSlide`. We resolve that target, then pull the
     * `<a:t>` runs from the notes part. Returns null when the slide has no notes.
     *
     * @param zip - The opened PPTX archive
     * @param slideNumber - 1-indexed slide number
     * @returns The notes text (runs joined by a space), or null when absent
     */
    private static extractNotesForSlide;
    /**
     * 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>;
}