"use client";

import { Clock3, MoonStar } from "lucide-react";
import { useCurrentSubject } from "@/lib/current-subject";
import type { RectificationEntrySummary } from "@/lib/rectification-entry";

/**
 * The empty state is split across two slots on purpose.
 *
 * `StarterGreeting` sits in the conversation area, bottom-aligned, so it lands
 * directly above the composer. `StarterEntries` sits inside `.composer-wrap`,
 * below the composer. The composer itself never moves: it keeps the one DOM
 * position it has in a live session, so nothing remounts when the first message
 * arrives and an in-flight draft, focus or queued card survives the transition.
 *
 * Before this, the empty state was a bordered hero card plus two 132px product
 * cards, and the composer sat under roughly 800px of content — the primary
 * action was the last thing on the page.
 */

export type StarterGreetingProps = {
  readonly starterGreeting: { readonly text: string };
  /* Today's trend, one quiet line under the greeting. `null` hides it (no natal
     minute). Before the card is ready the caller passes the static sentence,
     never a placeholder or a spinner. */
  readonly dailyTrend?: string | null;
  readonly dailyTrendSettled?: boolean;
};

/* One line. The salutation/question pair it replaces asked the user's question
   for them; the composer placeholder asks now. The optional sub-line is today's
   trend, moved up from the fine print under the entry pills where it was glued
   to an unrelated rectification hint with a middle dot. */
export function StarterGreeting({ starterGreeting, dailyTrend = null, dailyTrendSettled = true }: StarterGreetingProps) {
  return (
    <section className="starter-greeting-block" aria-labelledby="starter-heading">
      <h1 id="starter-heading">{starterGreeting.text}</h1>
      {dailyTrend ? (
        <p className="starter-greeting-sub" role={dailyTrendSettled ? undefined : "status"}>
          {dailyTrend}
        </p>
      ) : null}
    </section>
  );
}

/* The line under the pills only appears when there is something to do about
   it: a non-self subject cannot start a rectification. A resumable case says
   nothing here any more (2026-09-30, product: 「这个提示可以去掉」); the case
   is still in the history list. */
export function rectificationEntryHint(rectificationForSelf: boolean): string | null {
  if (!rectificationForSelf) return "生时校正暂时只支持本人。";
  return null;
}

export type StarterEntriesProps = {
  readonly natalMinuteAvailable: boolean;
  readonly dailyStarlanguageQuestion: string;
  readonly productEntrypointsDisabled: boolean;
  readonly startDailyStarlanguageConsultation: () => void;
  readonly rectificationCardLabel: string;
  readonly rectificationLoading: boolean;
  readonly rectificationMutationPending: boolean;
  readonly openRectificationFromHomepage: () => void;
  /** Still passed by the page; the hint no longer reads it (2026-09-30). */
  readonly rectificationEntrySummary: RectificationEntrySummary | null;
  readonly rectificationError: string;
  readonly rectificationSurfaceOpen: boolean;
  readonly rectificationErrorMessage: string;
};

export function StarterEntries({
  natalMinuteAvailable,
  dailyStarlanguageQuestion,
  productEntrypointsDisabled,
  startDailyStarlanguageConsultation,
  rectificationCardLabel,
  rectificationLoading,
  rectificationMutationPending,
  openRectificationFromHomepage,
  rectificationError,
  rectificationSurfaceOpen,
  rectificationErrorMessage,
}: StarterEntriesProps) {
  const subjectId = useCurrentSubject();
  const rectificationForSelf = subjectId === "self";
  const dailyLabel = natalMinuteAvailable ? "今日星语" : "每日运势";
  const rectificationHint = rectificationEntryHint(rectificationForSelf);

  return (
    <div className="starter-entries">
      <div className="starter-entry-row">
        <button
          className="starter-entry"
          type="button"
          aria-label={natalMinuteAvailable ? dailyStarlanguageQuestion : "查看今日运势"}
          disabled={productEntrypointsDisabled}
          onClick={startDailyStarlanguageConsultation}
        >
          <MoonStar aria-hidden="true" />
          <span>{dailyLabel}</span>
        </button>
        <button
          className="starter-entry"
          type="button"
          aria-label={rectificationCardLabel}
          data-opening={rectificationLoading ? "true" : undefined}
          disabled={productEntrypointsDisabled || rectificationLoading || rectificationMutationPending || !rectificationForSelf}
          onClick={() => void openRectificationFromHomepage()}
        >
          <Clock3 aria-hidden="true" />
          <span>生时校正</span>
        </button>
      </div>
      {rectificationHint && <p className="starter-entry-hint">{rectificationHint}</p>}
      {!natalMinuteAvailable && (
        <p className="starter-entry-boundary">出生时间不足以支持的判断我会说明，不会补造具体分钟。</p>
      )}
      {rectificationError && !rectificationSurfaceOpen && (
        <p className="form-error rectification-entry-error" role="alert">
          {rectificationErrorMessage}
        </p>
      )}
    </div>
  );
}