import { type FootballSpec } from "./geometry.ts";
/** The sports whose markings have a history here. The IFAF's surface is 2021's and has none. */
export type EraSport = "nfl" | "cfl" | "nhl" | "nba" | "mlb";
/** The sports with a history, in the order a menu lists them. */
export declare const ERA_SPORTS: readonly EraSport[];
/**
 * The season whose rules are "today's", and the one a drawing without a `year` shows: the data were last checked in 2026. A
 * change scheduled for a later season is `planned` and is drawn only when that season is asked for.
 */
export declare const ERA_CURRENT = 2026;
/** Where a change was read. */
export interface EraSource {
    id: string;
    /** The page: the article's title for Wikipedia, else the page's own. */
    title: string;
    /** Who publishes it. */
    by: string;
    /** For Wikipedia (CC BY-SA 4.0): the revision of the article, so that the figure can be checked. */
    revision?: number;
    url: string;
    /** What was taken from it. */
    note?: string;
}
/** Every page a change was read from, by id. Wikipedia is cited by revision, for facts only. */
export declare const ERA_SOURCES: Readonly<Record<string, EraSource>>;
/** One state of a marking, from a season on. */
export interface EraSpan<T> {
    /** The first season it was in force, or `null` for "from the start" (the state the earliest season of the sport had). */
    from: number | null;
    value: T;
    /** What it was, in a sentence. */
    what: string;
    /** The same in Japanese. */
    ja: string;
    /** Keys of `ERA_SOURCES`; at least one. */
    sources: string[];
    /** A rule announced for a season that has not been played yet. It is drawn only when that season is asked for. */
    planned?: boolean;
    /** The source gives this state but not its measure (the box's size): drawn as the nearest figure that is cited. */
    approx?: boolean;
}
/** The NHL rink's markings in a season. Lengths are feet. */
export interface NhlRules {
    /** The centre red line across the middle of the ice. */
    centreLine: boolean;
    /** The goal line's distance from the end boards. */
    goalLine: number;
    /** The blue line's distance from the end boards. */
    blueLine: number;
    /** The goaltender's trapezoid behind the net, or none. */
    trapezoid: {
        atGoalLine: number;
        atBoards: number;
    } | null;
    /** The gap between the two hash marks beside an end-zone face-off circle (Rule 1.9). */
    hashApart: number;
    /** The centre red line judges the offside pass: a pass from inside a team's own defensive zone across both its blue line and the centre line, to a team-mate who has not touched it, stops play. Data only: the lines are drawn the same. */
    twoLinePass: boolean;
}
/** The NBA court's markings in a season. Lengths are feet. */
export interface NbaRules {
    /** The width of the free-throw lane. */
    keyWidth: number;
    /** The three-point arc's radius from the basket (the corners stay at 22 feet), or none. */
    threePoint: {
        radius: number;
    } | null;
    /** The restricted area (the no-charge arc) under each basket. */
    restrictedArea: boolean;
}
/** A football field's markings in a season: the NFL's or the CFL's. Lengths are feet. */
export interface FootballRules {
    /** Goal line to goal line. */
    length: number;
    /** The depth of each end zone. */
    endZone: number;
    /** The hash marks' distance from each sideline, or `null` before there were hash marks. */
    hash: number | null;
    /** Where the goal posts stand. */
    posts: "goal-line" | "end-line";
    /** Two poles joined by a crossbar (`h`), or one curved support behind the crossbar (`slingshot`). */
    postShape: "h" | "slingshot";
}
/** The baseball field's markings in a season. Lengths are feet, the mound's height inches. */
export interface MlbRules {
    /** The side of first, second and third base, in feet (home plate is not a base of this size). */
    baseSize: number;
    /**
     * Where the pitcher throws from: a chalked box whose front edge is `distance` from the back point of home plate, with its
     * `width` and `depth`, or (from 1893) the rubber, whose front edge is `distance` from it.
     */
    pitcher: {
        kind: "box" | "plate";
        distance: number;
        width: number;
        depth: number;
    };
    /** The batter's boxes, or none (there were none before 1874). */
    battersBox: {
        width: number;
        length: number;
        gap: number;
    } | null;
    /** The shape of home plate. */
    plateShape: "circle" | "square" | "diamond" | "pentagon";
    /** Where it lies: `centred` on the foul lines' meeting, `behind` it, or (since 1877) `front`, its back point on it, in fair ground. */
    platePlacement: "centred" | "behind" | "front";
    /** The mound's greatest height above home plate, in inches, or `null` when the sources give none. */
    moundHeight: number | null;
}
/** The rules of a sport in a season. */
export interface EraRulesOf {
    nhl: NhlRules;
    nba: NbaRules;
    nfl: FootballRules;
    cfl: FootballRules;
    mlb: MlbRules;
}
/** A change in the markings: one span of one marking that started in some season. */
export interface EraChange {
    /** `nhl.trapezoid.2005`. */
    id: string;
    sport: EraSport;
    /** The marking's name: a key of the sport's rules. */
    feature: string;
    /** The first season, or `null` for the state the sport started with. */
    from: number | null;
    value: unknown;
    what: string;
    ja: string;
    sources: string[];
    planned: boolean;
    approx: boolean;
}
/**
 * Every change of a sport's markings, in season order: what moved, from which season, in a sentence in English and in Japanese,
 * and the sources that say so. The state a sport started with is not a change and is left out (see `eraStates`).
 * @example
 * ```ts
 * import { eraChanges } from "@johnmorrisdotca/kyogijo-stadiums/eras";
 * const nhl = eraChanges("nhl");
 * console.log(nhl.length, nhl[0].id, nhl[0].from);
 * // 12 nhl.centreLine.1943 1943
 * ```
 */
export declare function eraChanges(sport: EraSport): EraChange[];
/** The state each marking of a sport started with: the spans that begin "from the start". */
export declare function eraStates(sport: EraSport): EraChange[];
/** The seasons a sport's history is drawn for: from the league's first to today's, or to a planned season when one is announced. */
export declare function eraRange(sport: EraSport): {
    from: number;
    to: number;
};
/**
 * The name of a season as the sport writes it: `1979–80` for the NHL and the NBA, which play across the new year, and `1974` for
 * the NFL, the CFL and baseball. The year is the one the season starts in.
 * @example
 * ```ts
 * import { seasonLabel } from "@johnmorrisdotca/kyogijo-stadiums/eras";
 * console.log(seasonLabel("nba", 1979), seasonLabel("nhl", 1999), seasonLabel("nfl", 1974));
 * // 1979–80 1999–00 1974
 * ```
 */
export declare function seasonLabel(sport: EraSport, year: number): string;
/** The markings in force in a season, with what differs from today's and what is not known. */
export interface EraRules<S extends EraSport = EraSport> {
    sport: S;
    /** The season asked for (the year it starts in); today's when none was. */
    year: number;
    /** Its name: `1979–80`. */
    season: string;
    /** The markings. Every one is in feet, except the mound's height in inches. */
    rules: EraRulesOf[S];
    /** The states in force that are not today's, each as the change that began it (a marking in `gaps` is not listed). */
    differences: EraChange[];
    /** Markings that no source covers for this season: they keep the nearest cited state. */
    gaps: string[];
    /** Markings whose state is cited but whose measure is not: drawn at the nearest cited figure. */
    approx: string[];
    /** True when a marking is one that is announced for this season and has not been played yet. */
    planned: boolean;
}
/**
 * The markings of a sport's surface in a season: what the rule books and the leagues had painted on it then. Without a year it is
 * today's (`ERA_CURRENT`). A season is named by the year it starts in (`1979` is the 1979–80 season). `differences` lists what is
 * not as it is today, `gaps` the markings that no source covers for the season, and `approx` those whose measure is not cited.
 * @example
 * ```ts
 * import { rulesFor } from "@johnmorrisdotca/kyogijo-stadiums/eras";
 * const nba = rulesFor("nba", 1995);
 * console.log(nba.season, nba.rules.threePoint, nba.rules.restrictedArea, nba.differences.length);
 * // 1995–96 { radius: 22 } false 2
 * ```
 */
export declare function rulesFor<S extends EraSport>(sport: S, year?: number): EraRules<S>;
/**
 * A football field's spec in a season: the NFL's or the CFL's as `FOOTBALL` has it today, with the length, the end zones, the
 * hash marks and the goal posts of that season. The IFAF's has no history and is returned as it is.
 * @example
 * ```ts
 * import { footballIn } from "@johnmorrisdotca/kyogijo-stadiums/eras";
 * console.log(footballIn("cfl", 1985).endZone / 3, footballIn("cfl", 1986).endZone / 3, footballIn("nfl", 1960).hash / 3);
 * // 25 20 20
 * ```
 */
export declare function footballIn(sport: "nfl" | "cfl" | "ifaf", year?: number): FootballSpec;