import { type ContentTypeMimeType, type Maybe } from '@dereekb/util';
import { type ICalendarIcsString, type ICalendarMethod } from './icalendar';
import { type ICalendarComponent, type ICalendarContentLine } from './icalendar.component';
import { type ICalendar, type ICalendarSerializeConfig } from './icalendar.model';
/**
 * Returns the number of octets the given string occupies when encoded as UTF-8.
 *
 * Computed from the code points directly rather than through a platform encoder, so the serializer stays
 * free of any Node or browser API.
 *
 * @param input - The string to measure.
 * @returns The UTF-8 octet length.
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function utf8OctetLength(input: string): number;
/**
 * Splits a line into the smallest units a fold is allowed to fall between.
 *
 * An atom is a single code point, except that a backslash and the character it escapes form one atom.
 * Iterating by code point (rather than by UTF-16 index) is what keeps a surrogate pair — an emoji — intact;
 * keeping escape pairs together is defensive, since unfolding restores the octet stream and a split escape is
 * technically legal, but real-world parsers choke on it.
 *
 * @param line - The assembled, already-escaped content line.
 * @returns The atoms of the line, in order.
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function iCalendarLineAtoms(line: string): readonly string[];
/**
 * Folds a single assembled content line into physical lines of at most 75 octets each.
 *
 * The returned values carry no fold prefix and no line break; see {@link iCalendarFoldedLineString}.
 *
 * A continuation line's leading space counts toward the 75-octet limit, so every line after the first has a
 * payload budget of 74 octets.
 *
 * @param line - The assembled, already-escaped content line.
 * @returns The physical line payloads, in order. Always at least one.
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function foldICalendarLine(line: string): readonly string[];
/**
 * Folds a single assembled content line and joins the result with CRLF-prefixed continuations.
 *
 * The result does NOT carry a trailing line break.
 *
 * @param line - The assembled, already-escaped content line.
 * @returns The folded line.
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function iCalendarFoldedLineString(line: string): string;
/**
 * Assembles a content line into its unfolded ICS representation.
 *
 * I.E. `DTSTART;TZID=America/Denver:20260315T090000`. Both the parameters and the value are expected to have
 * been encoded already; this only joins them with the structural delimiters.
 *
 * @param line - The content line to assemble.
 * @returns The unfolded line.
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function iCalendarContentLineToUnfoldedString(line: ICalendarContentLine): string;
/**
 * Serializes a component tree as an RFC 5545 ICS document.
 *
 * THE ONLY ICS-AWARE STEP. Everything specific to the text serialization — BEGIN/END wrappers, the `:` and
 * `;` delimiters, 75-octet folding and CRLF line endings — lives here and nowhere else, so an alternate
 * serialization of the same data model (jCal, xCal) replaces this function alone.
 *
 * @param component - The component tree to serialize.
 * @returns The ICS document, CRLF-terminated including after the final line.
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function iCalendarComponentToIcsString(component: ICalendarComponent): ICalendarIcsString;
/**
 * Serializes a calendar as an RFC 5545 ICS document.
 *
 * @param calendar - The calendar to serialize.
 * @param config - Optional serialization config, notably the DTSTAMP source.
 * @returns The ICS document, CRLF-terminated including after the final line.
 *
 * @example
 * ```ts
 * iCalendarToIcsString({ name: 'My Feed', events: [] }, { now: new Date('2026-03-15T14:00:00Z') });
 * ```
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function iCalendarToIcsString(calendar: ICalendar, config?: Maybe<ICalendarSerializeConfig>): ICalendarIcsString;
/**
 * Reverses the 75-octet folding of an ICS document, yielding the logical content lines.
 *
 * Useful for validating or re-parsing emitted output.
 *
 * @param ics - The ICS document to unfold.
 * @returns The logical content lines, with the trailing empty line removed.
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function unfoldIcsString(ics: ICalendarIcsString): readonly string[];
/**
 * Builds the Content-Type value an iTIP payload's MIME part must carry.
 *
 * The METHOD is duplicated here deliberately: RFC 6047 2.4 requires the `method` parameter to agree with
 * the METHOD property in the body, and a receiving client decides whether to treat the part as an
 * invitation from the PART TYPE, before it parses anything. The same bytes typed
 * `application/octet-stream` are a paperclip.
 *
 * @param method - The iTIP method the payload carries.
 * @returns The full Content-Type value, e.g. `text/calendar; method=REQUEST; charset=utf-8`.
 *
 * @example
 * ```ts
 * iCalendarITipContentType('REQUEST'); // 'text/calendar; method=REQUEST; charset=utf-8'
 * ```
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function iCalendarITipContentType(method: ICalendarMethod): ContentTypeMimeType;