import type { VerbosityLevel } from '../types/index.js';
/**
 * Options for the `pdfToPng` conversion function.
 *
 * All properties are optional. Any unset property falls back to the corresponding
 * value in `PDF_TO_PNG_OPTIONS_DEFAULTS` defined in `src/const.ts`.
 */
export interface PdfToPngOptions {
    /**
     * Scale factor applied to each page viewport before rendering.
     * Values above `1` produce larger, higher-resolution images; values below `1` produce smaller images.
     * Must be a finite positive number. Maximum allowed value is `100`; values above this limit throw
     * immediately to prevent runaway memory allocation (OOM) during canvas creation.
     * Default: `1`.
     */
    viewportScale?: number;
    /**
     * When `true`, pdfjs will not load embedded fonts and substitutes them with built-in fonts.
     * Speeds up rendering but may affect visual fidelity for PDFs with custom fonts.
     * Default: `true`.
     */
    disableFontFace?: boolean;
    /**
     * When `true`, pdfjs attempts to use fonts installed on the host system.
     * Typically combined with `disableFontFace: false` to improve font rendering accuracy.
     * Default: `false`.
     */
    useSystemFonts?: boolean;
    /**
     * When `true`, pdfjs processes XFA (XML Forms Architecture) form data embedded in the PDF.
     * Default: `true`.
     */
    enableXfa?: boolean;
    /**
     * Password for opening password-protected (encrypted) PDFs.
     * Leave `undefined` for unprotected files.
     * Default: `undefined`.
     */
    pdfFilePassword?: string;
    /**
     * Folder path (relative or absolute) where PNG files will be written.
     * Relative paths are resolved against `process.cwd()`.
     * The folder is created recursively if it does not exist.
     * When omitted, no files are written to disk.
     *
     * @remarks
     * **Security (TOCTOU):** The write-containment guard rejects filenames that contain path
     * separators (so the target is always a direct child of this folder), resolves symlinks,
     * checks that the output path stays within this folder, and uses exclusive-create file opens
     * to avoid overwriting pre-existing files or following a pre-planted target symlink at the
     * final filename. To reduce exposure on multi-user or shared systems, ensure this directory
     * is private and not writable by untrusted users.
     */
    outputFolder?: string;
    /**
     * Custom naming function for output PNG files.
     * Receives the 1-based page number and must return a full filename string including the `.png` extension
     * (e.g. `(pageNumber) => \`page_${pageNumber}.png\``).
     * When omitted, names default to `<pdfBasename>_page_<pageNumber>.png`,
     * or `buffer_page_<pageNumber>.png` when the PDF is supplied as an `ArrayBufferLike`.
     * @since 3.14.0
     */
    outputFileMaskFunc?: (pageNumber: number) => string;
    /**
     * 1-based integer page numbers to convert. Non-integer values and values less than or equal to zero throw immediately.
     * Pages above the document page count are silently ignored.
     * When omitted, all pages in the document are processed.
     * @since 3.3.0
     */
    pagesToProcess?: number[];
    /**
     * pdfjs verbosity level. Use the `VerbosityLevel` const for readable values:
     * `VerbosityLevel.ERRORS` (0), `VerbosityLevel.WARNINGS` (1), `VerbosityLevel.INFOS` (5).
     * Default: `VerbosityLevel.ERRORS` (0).
     */
    verbosityLevel?: VerbosityLevel;
    /**
     * When `true`, each `PngPageOutput` will include a `content` property containing the PNG image as a `Buffer`.
     * Set to `false` to skip buffering when only writing files to disk, which reduces memory usage.
     * Default: `true`.
     */
    returnPageContent?: boolean;
    /**
     * When `true`, only page metadata is returned for each page without rendering any PNG image.
     * The returned `PngPageOutput` objects will have `pageNumber`, `name`, `width`, `height`, and
     * `rotation` populated, but `content` will always be `undefined` and `path` will always be `""`.
     * No canvas is created, no rendering is performed, and no files are written to disk even if
     * `outputFolder` is set.
     * This is significantly faster than full rendering and useful for inspecting page dimensions
     * and rotation without generating images.
     * To stay consistent with a real render, this path still rejects pages that could not be
     * rendered at the requested `viewportScale` — both those that floor to `0` px and those whose
     * rendered (floored) canvas area exceeds the internal canvas pixel limit — rather than reporting
     * dimensions for a page that would throw on render.
     * Default: `false`.
     * @since 3.14.0
     */
    returnMetadataOnly?: boolean;
    /**
     * When `true`, selected pages are rendered concurrently through a sliding-window scheduler
     * that keeps up to `concurrencyLimit` pages active. When `false`, pages are processed in
     * a lightly pipelined sequence: results are always returned in page order, but the PNG
     * encoding and disk writes of finished pages may overlap the rendering of the next page
     * (at most three pages in flight), so files may finish writing out of page order and, when
     * a page fails, pages already in flight still complete before the returned promise rejects.
     * Consume output via the resolved `PngPageOutput[]` (ordered) rather than directory-watch order.
     * Peak canvas memory in this mode is up to three live canvases; for strict one-page-at-a-time
     * processing with a single live canvas, set `processPagesInParallel: true` with
     * `concurrencyLimit: 1` (a sliding window of exactly one page).
     * Default: `false`.
     * @since 3.7.0
     */
    processPagesInParallel?: boolean;
    /**
     * Maximum number of pages rendered simultaneously when `processPagesInParallel` is `true`.
     * Must be a positive integer between `1` and `16` (inclusive); values outside that range throw
     * immediately (before any I/O). The upper bound caps peak in-flight canvas memory at roughly
     * `16 × MAX_CANVAS_PIXELS × 4 bytes ≈ 6.4 GiB` so a single conversion cannot exhaust container
     * memory. Higher values increase throughput at the cost of memory. Applies when
     * `processPagesInParallel` or `renderInWorkerThreads` is enabled; in worker-thread mode it
     * sets the worker-pool size.
     * Default: `4`.
     * @since 3.14.0
     */
    concurrencyLimit?: number;
    /**
     * When `true`, pages are rasterized in a pool of Node.js worker threads (pool size =
     * `concurrencyLimit`), giving true multi-core parallelism — unlike `processPagesInParallel`,
     * which interleaves pages on one thread. Each worker loads its own copy of the document, so
     * expect roughly one PDF copy plus one pdf.js instance of memory per worker and a pool
     * startup cost of a few hundred milliseconds per conversion; it pays off on multi-page,
     * render-heavy (e.g. image-heavy) documents and can be slower for small ones.
     * Rendered pixels are identical to single-threaded mode; results are returned in page
     * order; disk writes still happen on the main thread through the same path-security guards.
     * Takes precedence over `processPagesInParallel`. Ignored when `returnMetadataOnly` is `true`
     * (metadata extraction does not render). `outputFileMaskFunc` is fully supported — names are
     * resolved on the main thread before dispatch.
     * Default: `false`.
     * @since 4.2.0
     */
    renderInWorkerThreads?: boolean;
    /**
     * Maximum allowed input PDF size in bytes. Inputs larger than this throw immediately,
     * before any rendering work is started. Applies to both the file path branch (validated via
     * `fs.stat()`) and the buffer / `Uint8Array` branch (validated via `byteLength`). The path
     * branch additionally rejects non-regular files (FIFOs, sockets, character devices such as
     * `/dev/zero`) to prevent unbounded reads. Must be a positive integer.
     * Default: `256 * 1024 * 1024` (256 MiB).
     * @since 4.1.0
     */
    maxInputBytes?: number;
}