/**
 * A minimal OPC/xlsx container, written by hand.
 *
 * An `.xlsx` file is a zip of XML parts, so this needs no dependency at all -
 * which is the point. The workbook has to be produced inside a Cloudflare
 * Worker (#355), where `fs` and Node streams do not exist and bundle size is a
 * budget, and every xlsx library on npm is both larger than this file and
 * built for Node.
 *
 * Entries are written with the **stored** method rather than deflated. Excel
 * accepts stored entries, and it keeps writing SYNCHRONOUS: the only
 * compressor available in a Worker is `CompressionStream`, which is async, and
 * an async writer would infect every caller including ApertureX's synchronous
 * `SourceStore` seam (ADR 0100). Reading is a different matter and is async,
 * because Excel re-saves deflated.
 *
 * Timestamps are fixed rather than current, so identical input produces
 * identical bytes. `export rtm` already holds that line - "the output carries
 * no timestamp, so identical inputs produce identical bytes and CI can diff
 * it" - and a workbook that differs on every run could not be reviewed.
 */
/** How a sheet appears in Excel's tab strip. */
export type SheetState = 'visible' | 'hidden' | 'veryHidden';
/**
 * A cell's ROLE, not its appearance (#416).
 *
 * The set is closed on purpose, and named for roles so that it stays closed:
 * a caller asking for a fourth should be asking for a fourth ROLE — "this
 * cell is stale", "this cell is derived" — and the test for admitting one is
 * whether it can be named without reference to how it looks. A request for
 * `blue`, or for a shade matching a client's deck, is the request that turns
 * a style vocabulary into a styling engine, and refusing it is the closed
 * set doing its job.
 *
 * Three will be wrong eventually. It should be wrong LOUDLY, by someone
 * filing for a role, rather than quietly by callers approximating a missing
 * role with the nearest available one — which is how `muted` would come to
 * mean two things.
 *
 * Named rather than given as colours for a second reason: the styles part is
 * then a CONSTANT, so "identical inputs produce identical bytes" stays
 * trivially true instead of becoming something a reviewer has to re-derive.
 */
export type CellStyle = 'header' | 'muted' | 'emphasis';
export interface WorkbookSheet {
    readonly name: string;
    /** Defaults to visible. `veryHidden` cannot be unhidden from Excel's UI. */
    readonly state?: SheetState;
    /** Rows of cells. Every value is written as an inline string. */
    readonly rows: readonly (readonly string[])[];
    /** Rows to keep on screen when scrolling, usually 1 for a header. */
    readonly frozenRows?: number;
    /**
     * Applied to every row BELOW the first, by column index. Row 1 takes
     * `headerStyle` instead, so a header band is not overwritten by the column
     * role beneath it.
     */
    readonly columnStyles?: readonly (CellStyle | undefined)[];
    /** Applied to row 1 only. */
    readonly headerStyle?: CellStyle;
    /** Column widths in characters, by column index. */
    readonly columnWidths?: readonly number[];
}
/**
 * XML text escaping.
 *
 * Control characters are dropped rather than escaped: XML 1.0 cannot represent
 * most of them at all, and a NUL reaching a spreadsheet is the failure mode
 * that silently defeats every text tool downstream.
 */
export declare const escapeXml: (value: string) => string;
/** `0 -> A`, `26 -> AA`, the spreadsheet column alphabet. */
export declare const columnName: (index: number) => string;
/**
 * Excel forbids these in a sheet name, and caps it at 31 characters. A name
 * that collides after truncation would produce a workbook Excel refuses to
 * open, so callers keep their names short and distinct rather than relying on
 * repair here.
 */
export declare const sheetNameIsLegal: (name: string) => boolean;
/**
 * The workbook, as bytes. Synchronous, dependency-free, and deterministic:
 * the same sheets always produce the same bytes.
 */
export declare const writeXlsx: (sheets: readonly WorkbookSheet[]) => Uint8Array;