import { useGameMeta } from "../state/gameMeta.tsx";
import { formatRemaining } from "../../shared/time.ts";
import type { RowEvent } from "./EventRow.tsx";
import { Meter, URGENCY_COLOR } from "./Meter.tsx";

/**
 * The thesis of the page: this app is a clock, so the first thing you see is
 * the event closest to expiring, at a size nothing else competes with.
 *
 * The two behind it are listed under it, small. A reader asked for the three
 * next deadlines and he was right that one is too few — finishing the headline
 * event used to leave the panel pointing at something with no context — but
 * three equal panels is a stat grid, and the reader arrives with one question.
 * So the shape is one answer and two follow-ups, not three answers.
 */
export function NextUp({
  rows,
  focused,
  onOpen,
}: {
  /**
   * The soonest-expiring events the reader has neither finished nor ignored,
   * closest first. A panel headed "next to expire" is a list of deadlines they
   * still have to meet, so events they already ticked off do not belong in it
   * however visible they have chosen to keep them elsewhere.
   */
  rows: RowEvent[];
  /** Name of the game being focused on, when the page is narrowed to one. */
  focused: string | null;
  onOpen: (id: string) => void;
}) {
  const gameMeta = useGameMeta();
  const [lead, ...rest] = rows;

  if (lead === undefined) {
    return (
      <section className="border-b border-hairline px-4 py-8">
        <p className="eyebrow">Nothing running</p>
        <p className="mt-2 max-w-sm text-sm text-muted">
          {focused === null
            ? "Nothing live and unfinished in the games you have switched on. Turn a game back on below, or check again after the next patch."
            : `Nothing live and unfinished in ${focused}. Move to the next game, or show all of them.`}
        </p>
      </section>
    );
  }

  const { event, clock } = lead;
  const game = gameMeta(event.game);
  const heat = URGENCY_COLOR[clock.urgency];
  const known = clock.msRemaining !== null;

  return (
    <section className="relative overflow-hidden border-b border-hairline px-4 pb-6 pt-5">
      {/* A wash of the urgency colour, so the panel itself changes temperature
          as the deadline closes in. */}
      <div
        aria-hidden
        className="pointer-events-none absolute inset-x-0 -top-24 h-48 opacity-[0.16] blur-2xl"
        style={{ background: `radial-gradient(60% 100% at 50% 100%, ${heat}, transparent)` }}
      />

      <div className="relative">
        <p className="eyebrow">Next to expire</p>

        {/* The one thing on the page a reader is most likely to tap, and it was
            the only clickable text here that did not answer the cursor — the
            queued rows under it brighten, the row list brightens, and this sat
            inert and read as a heading rather than a way in. */}
        <button
          type="button"
          onClick={() => onOpen(event.id)}
          className="group mt-2 block max-w-full text-left"
        >
          <h1 className="font-display text-[1.75rem] font-semibold leading-[1.15] tracking-tight transition-colors duration-150 group-hover:text-ink-strong">
            {event.title}
          </h1>
          <p className="mt-1 text-sm" style={{ color: game.hue }}>
            {game.name}
          </p>
        </button>

        <div className="mt-5 flex items-end justify-between gap-4">
          <p
            className="tnum font-display text-[2.75rem] font-bold leading-none tracking-tight"
            style={{ color: known ? heat : "var(--color-faint)" }}
          >
            {known ? formatRemaining(clock.msRemaining ?? 0) : "unknown"}
          </p>
          <p className="pb-1 text-right text-xs leading-tight text-muted">
            {known ? "left" : "no end date"}
            <br />
            {known ? "to finish it" : "announced"}
          </p>
        </div>

        <div className="mt-4">
          <Meter
            progress={clock.progress}
            urgency={clock.urgency}
            label={`${event.title} time remaining`}
          />
        </div>

        {rest.length > 0 && (
          <div className="mt-5 border-t border-hairline pt-3">
            <p className="eyebrow">Then</p>
            <ul className="mt-1.5">
              {rest.map((row) => (
                <QueuedRow key={row.event.id} row={row} onOpen={onOpen} />
              ))}
            </ul>
          </div>
        )}
      </div>
    </section>
  );
}

/**
 * A deadline waiting behind the headline.
 *
 * Deliberately a different object from an `EventRow`: no meter, no summary, no
 * badges. Its whole job is "what is after this one, and how long have I got" —
 * anything more turns the panel into a second copy of the list it sits above.
 */
function QueuedRow({
  row,
  onOpen,
}: {
  row: RowEvent;
  onOpen: (id: string) => void;
}) {
  const gameMeta = useGameMeta();
  const { event, clock } = row;
  const game = gameMeta(event.game);
  const known = clock.msRemaining !== null;

  return (
    <li>
      <button
        type="button"
        onClick={() => onOpen(event.id)}
        className="group flex w-full items-baseline gap-2.5 py-1.5 text-left"
      >
        <span
          aria-hidden
          className="size-1.5 shrink-0 translate-y-[-1px] rounded-full"
          style={{ background: game.hue }}
        />
        <span className="min-w-0 flex-1 truncate text-[0.8125rem] leading-snug text-muted transition-colors duration-150 group-hover:text-ink">
          <span className="sr-only">{game.name}: </span>
          {event.title}
        </span>
        <span
          className="tnum shrink-0 font-display text-xs font-semibold"
          style={{
            color: known ? URGENCY_COLOR[clock.urgency] : "var(--color-faint)",
          }}
        >
          {known ? formatRemaining(clock.msRemaining ?? 0) : "no end date"}
        </span>
      </button>
    </li>
  );
}