fable/val Public Public: anyone can read this; nobody can change it.

/**

 * The arena: this game's one live match, served the way `engine/arena.ts`

 * serves any match — ticking only while somebody is connected, one playing

 * seat an address, a positionless view for whoever has no seat, and every

 * snapshot built for one viewer from what they can see.

 *

 * What is this game's own is here: taking a seat replaces a bot in the

 * emptiest team (same body, same credits, same position, so joining

 * mid-round hands you a live player rather than a lobby), the commands a

 * client may send, the shape of the snapshot, and the kill feed read off the

 * match a tick at a time.

 */

import { agentById, sightBlocked } from "./abilities.ts";

import { runBots } from "./bots.ts";

import { recordResult } from "./db.ts";

import { makeArena, type Command, type Why } from "./engine/arena.ts";

import { fallsBetween, marksOf, trimFeed, type Fall, type Mark } from "./killfeed.ts";

import type { Point } from "./map.ts";

import { buyAbility, buyShield, buyWeapon, newMatch, pickAgent, setInput, speedOf, tick, visible } from "./match.ts";

import type { MatchState, Player } from "./state.ts";

import { isWeaponId, WEAPONS } from "./weapons.ts";

export { broadcastEvery, TICK, type Command, type Seat, type Why } from "./engine/arena.ts";

const state: MatchState = newMatch();

let lastResult: string | null = null;

// The kill feed is read off the match a tick at a time; the rules keep no

// list of their own, and this is a view, not a rule.

let marks: Mark[] = marksOf(state.players);

let feed: Fall[] = [];

const round2 = (n: number): number => Math.round(n * 10) / 10;

/** Sit in the emptiest team, on a bot's seat, keeping its body as it stands. */

function sit(state: MatchState): Player | null {

  const humans = { red: 0, blue: 0 };

  for (const player of state.players) if (!player.bot) humans[player.team] += 1;

  const wanted = humans.red <= humans.blue ? "red" : "blue";

  const seat = state.players.find((p) => p.bot && p.team === wanted) ?? state.players.find((p) => p.bot);

  if (!seat) return null;

  seat.bot = false;

  seat.think = 0;

  seat.input = { mx: 0, my: 0, angle: seat.angle, fire: false, use: false, reload: false, cast: null };

  return seat;

}

/** The seat goes back to a bot, mid-round and all. */

function stand(_state: MatchState, player: Player): void {

  player.bot = true;

  player.think = 0;

  player.input.fire = false;

  player.input.use = false;

}

const num = (value: unknown): number | undefined =>

  typeof value === "number" && Number.isFinite(value) ? value : undefined;

/** Everything a client may ask for, validated here and nowhere else. */

function runCommand(state: MatchState, player: Player, message: Command): void {

  switch (message.t) {

    case "i":

      setInput(player, {

        mx: num(message.mx),

        my: num(message.my),

        angle: num(message.a),

        fire: typeof message.f === "boolean" ? message.f : undefined,

        use: typeof message.u === "boolean" ? message.u : undefined,

        reload: typeof message.r === "boolean" ? message.r : undefined,

        cast: message.c === "c" || message.c === "q" || message.c === "e" || message.c === "x" ? message.c : undefined,

      });

      break;

    case "buy": {

      const what = String(message.what ?? "");

      if (isWeaponId(what)) buyWeapon(state, player, what);

      else if (what === "light" || what === "heavy") buyShield(state, player, what);

      else if (what === "c" || what === "q") buyAbility(state, player, what);

      break;

    }

    case "agent":

      if (typeof message.id === "string") pickAgent(state, player, message.id);

      break;

  }

}

// Names and a gun, never a position: the feed says what happened, not

// where, so it can never be read as a call-out.

const feedFor = (state: MatchState) =>

  feed.map((f) => ({

    k: f.killer,

    v: f.victim,

    w: f.weapon ? WEAPONS[f.weapon].name : null,

    h: f.headshot,

    t: round2(Math.max(0, state.now - f.at)),

  }));

/** The public state everyone already sees on the page itself. */

function spectatorShape(state: MatchState, _why: Why) {

  return {

    phase: state.phase,

    clock: round2(Math.max(0, state.clock)),

    round: state.round,

    score: state.score,

    attackers: state.attackers,

    result: state.result,

    last: state.last,

    events: state.events.slice(0, 5).map((e) => e.text),

    feed: feedFor(state),

  };

}

/** The snapshot for one seat: `seen` is exactly who the arena says they may see. */

function snapshotShape(state: MatchState, me: Player, seen: Player[]) {

  const agent = agentById(me.agent);

  const canSee = (point: Point): boolean => !sightBlocked(me, point, state.zones);

  return {

    phase: state.phase,

    clock: round2(Math.max(0, state.clock)),

    round: state.round,

    score: state.score,

    attackers: state.attackers,

    result: state.result,

    last: state.last,

    me: {

      id: me.id,

      side: me.side,

      team: me.team,

      agent: me.agent,

      alive: me.alive,

      x: round2(me.x),

      y: round2(me.y),

      angle: round2(me.angle),

      hp: Math.round(me.hp),

      armour: Math.round(me.armour),

      credits: me.credits,

      weapon: me.weapon,

      ammo: me.ammo,

      reloading: me.reloadIn > 0,

      charges: me.charges,

      cooldown: { c: round2(me.cooldown.c), q: round2(me.cooldown.q), e: round2(me.cooldown.e), x: 0 },

      ult: me.ult,

      ultNeeds: agent.abilities.x.points,

      blind: round2(me.blind),

      spike: me.spike,

      planting: round2(me.planting),

      // How fast the server is about to move you, in units a second, and not

      // the reasons behind it: the browser's prediction runs at this number

      // and re-derives nothing. A rule that holds you still — planting,

      // defusing, a decided round — arrives as a zero. To a tenth, like every

      // other number here: rounded to a whole unit instead, a hasted walk

      // (337.5) is drawn a half-unit a second fast and clipped back by the

      // cap every frame, which measured 0.2 points of per-frame spread. A

      // tenth is a no-op for feel and costs at most two bytes.

      speed: round2(speedOf(state, me)),

      bot: me.bot,

    },

    players: seen.map((p) => ({

      id: p.id,

      name: p.name,

      agent: p.agent,

      x: round2(p.x),

      y: round2(p.y),

      angle: round2(p.angle),

      hp: Math.round(p.hp),

      armour: Math.round(p.armour),

      alive: p.alive,

      mate: p.side === me.side,

      spike: p.spike,

      blind: p.blind > 0,

      revealed: p.revealed > 0,

    })),

    zones: state.zones

      .filter((z) => (z.kind === "trip" ? z.side === me.side : true))

      .map((z) => ({ k: z.kind, x: round2(z.x), y: round2(z.y), r: z.r, f: round2(z.fuse), l: round2(z.life) })),

    spike: {

      planted: state.spike.planted,

      carried: state.spike.carried !== null,

      fuse: round2(state.spike.fuse),

      defuse: round2(state.spike.defuse),

      checkpoint: state.spike.checkpoint,

      // A loose spike is the attackers' business until it is armed.

      x: state.spike.planted || me.side === "atk" ? round2(state.spike.x) : null,

      y: state.spike.planted || me.side === "atk" ? round2(state.spike.y) : null,

    },

    orbs: state.orbs.filter((o) => !o.taken).map((o) => ({ x: o.x, y: o.y })),

    shots: state.shots.filter((s) => canSee({ x: s.x1, y: s.y1 }) || canSee({ x: s.x2, y: s.y2 })),

    // The scoreboard — ten names, agents and tallies — was almost half of

    // every snapshot and changes a few times a round, so the arena sends it

    // only when it differs from what the seat last received.

    board: state.players.map((p) => ({

      id: p.id,

      name: p.name,

      team: p.team,

      side: p.side,

      agent: p.agent,

      bot: p.bot,

      alive: p.alive,

      kills: p.kills,

      deaths: p.deaths,

      damage: Math.round(p.damageDone),

      credits: p.team === me.team ? p.credits : null,

      ult: p.ult,

      ultNeeds: agentById(p.agent).abilities.x.points,

    })),

    events: state.events.slice(0, 5).map((e) => e.text),

    feed: feedFor(state),

  };

}

/**

 * Who fell on this tick. A shot that landed this tick and started where the

 * killer stands is what tells a gun kill from an ability kill — the position

 * is used here and goes no further.

 */

function readFalls(state: MatchState): void {

  const after = marksOf(state.players);

  const shooters = new Set<string>();

  for (const shot of state.shots) {

    if (!shot.hit || shot.age > 0) continue;

    for (const player of state.players)

      if (Math.hypot(player.x - shot.x1, player.y - shot.y1) < 2) shooters.add(player.id);

  }

  const falls = fallsBetween(marks, after, {

    at: state.now,

    events: state.events.slice(0, 6).map((e) => e.text),

    shooters,

  });

  marks = after;

  if (falls.length) feed = [...feed, ...falls];

  feed = trimFeed(feed, state.now);

}

/** One tick of this game: the bots, the rules, the feed, and the record. */

function step(state: MatchState, dt: number): void {

  runBots(state, dt);

  tick(state, dt);

  readFalls(state);

  if (state.result && state.result !== lastResult) {

    lastResult = state.result;

    recordResult(state.result, state.score.red, state.score.blue, state.round);

  }

  if (state.result === null) lastResult = null;

}

const arena = makeArena<MatchState, Player>({

  state,

  players: (s) => s.players,

  step,

  sit,

  stand,

  visible,

  snapshot: snapshotShape,

  sticky: "board",

  spectatorSnapshot: spectatorShape,

  command: runCommand,

});

export const {

  match,

  findPlayer,

  addressCapped,

  takeSeat,

  attach,

  release,

  releaseAddress,

  seatCount,

  watch,

  unwatch,

  spectatorSnapshot,

  command,

  snapshot,

  snapshotForSeat,

  attendance,

  beat,

  advance,

} = arena;

export const startArena = arena.start;

export const stopArena = arena.stop;