"use client";

import { useState, useEffect } from "react";
import { useRouter } from "next/navigation";
import Link from "next/link";
import { Gift, Trophy, CheckCircle2, Timer, BarChart3, Coins, CircleHelp } from "lucide-react";
import {
  apiVotePoll,
  apiClosePoll,
  apiDrawLottery,
  apiSolveQuestion,
  apiReopenQuestion,
  type PollState,
  type BountyState,
  type LotteryState,
  type QuestionState,
} from "@/lib/api";
import { toast } from "@/lib/toast";
import Avatar from "@/components/Avatar";
import { useAllowComments } from "@/components/CommentsPolicyProvider";

export default function PostInteractPanels({
  postId,
  poll,
  bounty,
  lottery,
  loggedIn,
}: {
  postId: number;
  poll?: PollState | null;
  bounty?: BountyState | null;
  lottery?: LotteryState | null;
  loggedIn: boolean;
}) {
  // 问答 / 已采纳悬赏改在正文下方 AcceptedAnswerCard，此处不再放
  const showBounty = !!bounty && !bounty.accepted_comment_id;
  if (!poll && !showBounty && !lottery) return null;
  return (
    <div className="j13-interact-below space-y-4">
      {poll && <PollPanel postId={postId} state={poll} loggedIn={loggedIn} />}
      {showBounty && <BountyPanel postId={postId} state={bounty!} />}
      {lottery && <LotteryPanel postId={postId} state={lottery} />}
    </div>
  );
}

function formatEndsAt(iso?: string) {
  if (!iso) return "";
  try {
    return new Date(iso).toLocaleString("zh-CN");
  } catch {
    return iso;
  }
}

/** 底栏右侧：进行中显示截止时间，结束后显示结束时间 */
function TypedFootTime({
  endsAt,
  endedAt,
  ended,
}: {
  endsAt?: string;
  endedAt?: string;
  ended?: boolean;
}) {
  if (ended) {
    const t = endedAt || endsAt;
    if (!t) return null;
    return <span className="j13-typed-foot-time">结束时间: {formatEndsAt(t)}</span>;
  }
  if (!endsAt) return null;
  return <span className="j13-typed-foot-time">截止时间: {formatEndsAt(endsAt)}</span>;
}

function pad2(n: number) {
  return String(Math.max(0, n)).padStart(2, "0");
}

function remainParts(endsAtMs: number, now: number) {
  const ms = Math.max(0, endsAtMs - now);
  const totalSec = Math.floor(ms / 1000);
  return {
    days: Math.floor(totalSec / 86400),
    hours: Math.floor((totalSec % 86400) / 3600),
    mins: Math.floor((totalSec % 3600) / 60),
    secs: totalSec % 60,
    expired: ms <= 0,
  };
}

/** 未截止倒计时：最小单位秒，每秒刷新 */
function DeadlineCountdown({
  endsAt,
  activeLabel = "距截止还剩",
  expiredLabel = "已到截止时间",
  expiredHint = "等待处理",
}: {
  endsAt: string;
  activeLabel?: string;
  expiredLabel?: string;
  expiredHint?: string;
}) {
  const endsMs = Date.parse(endsAt);
  const [now, setNow] = useState<number | null>(null);

  useEffect(() => {
    if (!Number.isFinite(endsMs)) return;
    const tick = () => setNow(Date.now());
    tick();
    const id = window.setInterval(tick, 1000);
    return () => window.clearInterval(id);
  }, [endsMs]);

  if (!Number.isFinite(endsMs)) return null;

  if (now === null) {
    return (
      <div className="j13-deadline-countdown" aria-hidden="true">
        <div className="j13-deadline-countdown-label">
          <Timer size={15} strokeWidth={2.25} aria-hidden />
          {activeLabel}
        </div>
        <div className="j13-deadline-countdown-digits">
          {["天", "时", "分", "秒"].map((suf) => (
            <span key={suf} className={`j13-deadline-countdown-unit${suf === "秒" ? " is-sec" : ""}`}>
              <span className="j13-deadline-countdown-num tabular-nums">--</span>
              <span className="j13-deadline-countdown-suf">{suf}</span>
            </span>
          ))}
        </div>
        <p className="j13-deadline-countdown-ends">截止于 {formatEndsAt(endsAt)}</p>
      </div>
    );
  }

  const r = remainParts(endsMs, now);

  return (
    <div
      className={`j13-deadline-countdown${r.expired ? " is-expired" : ""}`}
      role="timer"
      aria-live="polite"
      aria-atomic="true"
    >
      <div className="j13-deadline-countdown-label">
        <Timer size={15} strokeWidth={2.25} aria-hidden />
        {r.expired ? expiredLabel : activeLabel}
      </div>
      {r.expired ? (
        <p className="j13-deadline-countdown-expired">{expiredHint}</p>
      ) : (
        <div
          className="j13-deadline-countdown-digits"
          aria-label={`还剩 ${r.days} 天 ${r.hours} 时 ${r.mins} 分 ${r.secs} 秒`}
        >
          <span className="j13-deadline-countdown-unit">
            <span className="j13-deadline-countdown-num tabular-nums">{pad2(r.days)}</span>
            <span className="j13-deadline-countdown-suf">天</span>
          </span>
          <span className="j13-deadline-countdown-unit">
            <span className="j13-deadline-countdown-num tabular-nums">{pad2(r.hours)}</span>
            <span className="j13-deadline-countdown-suf">时</span>
          </span>
          <span className="j13-deadline-countdown-unit">
            <span className="j13-deadline-countdown-num tabular-nums">{pad2(r.mins)}</span>
            <span className="j13-deadline-countdown-suf">分</span>
          </span>
          <span className="j13-deadline-countdown-unit is-sec">
            <span className="j13-deadline-countdown-num tabular-nums">{pad2(r.secs)}</span>
            <span className="j13-deadline-countdown-suf">秒</span>
          </span>
        </div>
      )}
      <p className="j13-deadline-countdown-ends">截止于 {formatEndsAt(endsAt)}</p>
    </div>
  );
}

/** 正文下方的问答状态卡（未解决 / 仅标记已解决）；有采纳答案时改用 AcceptedAnswerCard */
export function QuestionStatusCard({ postId, state }: { postId: number; state: QuestionState }) {
  const allowComments = useAllowComments();
  const router = useRouter();
  const [busy, setBusy] = useState(false);

  const act = async (fn: () => Promise<{ post?: unknown; error?: string }>, ok: string) => {
    setBusy(true);
    try {
      const res = await fn();
      if (res.post) {
        toast(ok, "ok");
        router.refresh();
      } else toast(res.error || "操作失败", "error");
    } finally {
      setBusy(false);
    }
  };

  const statusBadge = state.solved
    ? { cls: "badge-status badge-status-solved", label: "已解决" }
    : { cls: "badge-status badge-status-unsolved", label: "未解决" };

  const footLeft = state.solved
    ? state.accepted_comment_id
      ? "已采纳答案"
      : "已标记解决"
    : "等待解答";

  return (
    <section className="j13-interact-card j13-typed-card" aria-label={`问答 · ${statusBadge.label}`}>
      <div className="j13-typed-head">
        <div className="j13-typed-head-main">
          <h2 className="j13-typed-title is-question">
            <CircleHelp size={16} strokeWidth={2.25} aria-hidden />
            问答
          </h2>
          <span className={statusBadge.cls}>{statusBadge.label}</span>
        </div>
        {(state.can_solve || state.can_reopen) && (
          <div className="j13-typed-actions">
            {state.can_solve && (
              <button
                type="button"
                className="btn btn-line btn-sm"
                disabled={busy}
                onClick={() => void act(() => apiSolveQuestion(String(postId)), "已标记为已解决")}
              >
                标记已解决
              </button>
            )}
            {state.can_reopen && (
              <button
                type="button"
                className="btn btn-line btn-sm"
                disabled={busy}
                onClick={() => void act(() => apiReopenQuestion(String(postId)), "已重新打开")}
              >
                重新打开
              </button>
            )}
          </div>
        )}
      </div>

      <p className="j13-typed-meta">
        {state.solved
          ? state.accepted_comment_id && allowComments
            ? (
                <>
                  已采纳{" "}
                  <a
                    href={`#comment-${state.accepted_comment_id}`}
                    className="hover:underline"
                    style={{ color: "var(--accent)" }}
                  >
                    #{state.accepted_floor || "?"}
                  </a>
                </>
              )
            : "作者已标记为已解决"
          : allowComments
            ? "可在评论旁采纳答案，或手动标记已解决"
            : "可由作者标记为已解决"}
      </p>

      <div className="j13-typed-foot">
        <span className="j13-typed-foot-status">
          <CheckCircle2 size={14} strokeWidth={2.25} aria-hidden />
          {footLeft}
        </span>
        <TypedFootTime
          ended={state.solved}
          endedAt={state.solved_at || state.accepted_answer?.created_at}
        />
      </div>
    </section>
  );
}

function PollPanel({
  postId,
  state,
  loggedIn,
}: {
  postId: number;
  state: PollState;
  loggedIn: boolean;
}) {
  const router = useRouter();
  const [sel, setSel] = useState<number[]>(state.my_options || []);
  const [busy, setBusy] = useState(false);
  const showResults = state.closed || (state.my_options && state.my_options.length > 0);
  const hasVoted = (state.my_options?.length ?? 0) > 0;

  const toggle = (idx: number) => {
    if (!state.can_vote) return;
    if (state.multi) {
      setSel((prev) =>
        prev.includes(idx) ? prev.filter((x) => x !== idx) : [...prev, idx]
      );
    } else {
      setSel([idx]);
    }
  };

  const vote = async () => {
    if (sel.length === 0) {
      toast("请先选择选项", "error");
      return;
    }
    setBusy(true);
    try {
      const res = await apiVotePoll(String(postId), sel);
      if (res.post) {
        toast("投票成功", "ok");
        router.refresh();
      } else toast(res.error || "投票失败", "error");
    } catch {
      toast("投票失败", "error");
    } finally {
      setBusy(false);
    }
  };

  const close = async () => {
    setBusy(true);
    try {
      const res = await apiClosePoll(String(postId));
      if (res.post) {
        toast("已结束投票", "ok");
        router.refresh();
      } else toast(res.error || "操作失败", "error");
    } finally {
      setBusy(false);
    }
  };

  const statusBadge = state.closed
    ? { cls: "badge-status badge-status-closed", label: "已结束" }
    : { cls: "badge-status badge-status-open", label: "进行中" };

  const footLeft = state.closed
    ? "已结束投票"
    : hasVoted
      ? "你已完成投票"
      : "投票进行中";

  return (
    <section className="j13-interact-card j13-typed-card" aria-label="投票">
      <div className="j13-typed-head">
        <div className="j13-typed-head-main">
          <h2 className="j13-typed-title is-poll">
            <BarChart3 size={16} strokeWidth={2.25} aria-hidden />
            投票
          </h2>
          <span className={statusBadge.cls}>{statusBadge.label}</span>
        </div>
        {state.can_close && (
          <div className="j13-typed-actions">
            <button
              type="button"
              className="btn btn-line btn-sm"
              disabled={busy}
              onClick={() => void close()}
            >
              结束投票
            </button>
          </div>
        )}
      </div>

      <p className="j13-typed-meta">
        {state.multi ? "多选" : "单选"}
        {state.anonymous ? " · 匿名" : " · 实名"}
        {" · "}
        {state.voters} 人参与 · {state.total_votes} 票
      </p>

      {!state.closed && state.ends_at ? (
        <DeadlineCountdown
          endsAt={state.ends_at}
          expiredLabel="已到截止时间"
          expiredHint="投票即将关闭"
        />
      ) : null}

      <ul className="j13-poll-options">
        {state.options.map((o) => {
          const checked = sel.includes(o.index);
          const namedVoters = !state.anonymous && showResults ? o.voters || [] : [];
          return (
            <li key={o.index}>
              <button
                type="button"
                disabled={!state.can_vote || busy}
                onClick={() => toggle(o.index)}
                className={`j13-poll-option${checked ? " is-on" : ""}`}
              >
                {showResults && (
                  <span
                    className="j13-poll-option-bar"
                    style={{ width: `${o.percent}%` }}
                    aria-hidden
                  />
                )}
                <span className="j13-poll-option-row">
                  <span className="j13-poll-option-text">
                    {state.can_vote ? (checked ? "✓ " : "") : ""}
                    {o.text}
                  </span>
                  {showResults && (
                    <span className="j13-poll-option-stat tabular-nums">
                      {o.votes} · {o.percent}%
                    </span>
                  )}
                </span>
              </button>
              {namedVoters.length > 0 && (
                <ul className="j13-poll-voters">
                  {namedVoters.map((v) => (
                    <li key={v.id}>
                      <Link href={`/u/${v.id}`} className="j13-poll-voter">
                        <Avatar name={v.nickname || v.username} src={v.avatar || undefined} size={16} />
                        {v.nickname || v.username}
                      </Link>
                    </li>
                  ))}
                </ul>
              )}
            </li>
          );
        })}
      </ul>

      {(state.can_vote || (!loggedIn && !state.closed)) && (
        <div className="j13-typed-actions-row">
          {state.can_vote && (
            <button
              type="button"
              className="btn btn-primary btn-sm"
              disabled={busy}
              onClick={() => void vote()}
            >
              提交投票
            </button>
          )}
          {!loggedIn && !state.closed && (
            <Link
              href={`/login?redirect=${encodeURIComponent(`/post/${postId}`)}`}
              className="btn btn-line btn-sm"
            >
              登录后投票
            </Link>
          )}
        </div>
      )}

      <div className="j13-typed-foot">
        <span className="j13-typed-foot-status">
          <CheckCircle2 size={14} strokeWidth={2.25} aria-hidden />
          {footLeft}
        </span>
        <TypedFootTime
          ended={state.closed}
          endsAt={state.ends_at}
          endedAt={state.closed_at}
        />
      </div>
    </section>
  );
}

function BountyPanel({ state }: { postId: number; state: BountyState }) {
  const allowComments = useAllowComments();
  const statusBadge = state.accepted_comment_id
    ? { cls: "badge-status badge-status-solved", label: "已采纳" }
    : state.expired || state.refunded
      ? { cls: "badge-status badge-status-closed", label: "已过期" }
      : { cls: "badge-status badge-status-open", label: "进行中" };

  const footLeft = state.accepted_comment_id
    ? "悬赏已完成"
    : state.expired || state.refunded
      ? state.can_accept
        ? "已过期退回 · 仍可采纳支付"
        : "悬赏已过期退回"
      : "悬赏进行中";

  const bodyHint = state.accepted_answer
    ? "悬赏积分已发放给采纳答案"
    : state.accepted_comment_id
      ? null
      : state.expired || state.refunded
        ? state.can_accept
          ? "到期未采纳已自动退回；采纳将从余额扣除，支付后不可撤回"
          : "积分已自动退回发帖人"
        : state.escrowed
          ? "积分已托管，采纳优质回答后发放；到期未采纳自动退回"
          : "悬赏未托管";

  return (
    <section className="j13-interact-card j13-typed-card" aria-label="悬赏">
      <div className="j13-typed-head">
        <div className="j13-typed-head-main">
          <h2 className="j13-typed-title is-bounty">
            <Coins size={16} strokeWidth={2.25} aria-hidden />
            悬赏
          </h2>
          <span className={statusBadge.cls}>{statusBadge.label}</span>
        </div>
      </div>

      <p className="j13-typed-meta">
        <span className="j13-bounty-points tabular-nums">{state.points} 积分</span>
        {bodyHint ? ` · ${bodyHint}` : null}
        {state.can_accept && allowComments ? " · 在评论旁点击「采纳」发放积分" : null}
      </p>

      {!state.accepted_comment_id && state.ends_at ? (
        <DeadlineCountdown
          endsAt={state.ends_at}
          expiredLabel="已到截止时间"
          expiredHint={state.can_accept ? "已自动退回，仍可采纳并支付" : "等待处理"}
        />
      ) : null}

      {allowComments && state.accepted_comment_id > 0 && (
        <p className="j13-typed-meta">
          已采纳{" "}
          <a
            href={`#comment-${state.accepted_comment_id}`}
            className="hover:underline"
            style={{ color: "var(--accent)" }}
          >
            #{state.accepted_floor || "?"}
          </a>
        </p>
      )}

      <div className="j13-typed-foot">
        <span className="j13-typed-foot-status">
          <CheckCircle2 size={14} strokeWidth={2.25} aria-hidden />
          {footLeft}
        </span>
        <TypedFootTime
          ended={!!state.accepted_comment_id || state.expired || state.refunded}
          endsAt={state.ends_at}
          endedAt={state.ends_at}
        />
      </div>
    </section>
  );
}

function LotteryPanel({
  postId,
  state,
}: {
  postId: number;
  state: LotteryState;
}) {
  const router = useRouter();
  const [busy, setBusy] = useState(false);

  const act = async (fn: () => Promise<{ post?: unknown; error?: string }>, ok: string) => {
    setBusy(true);
    try {
      const res = await fn();
      if (res.post) {
        toast(ok, "ok");
        router.refresh();
      } else toast(res.error || "操作失败", "error");
    } finally {
      setBusy(false);
    }
  };

  const prizes = state.prizes?.length ? state.prizes : [];

  const statusBadge = state.drawn
    ? { cls: "badge-status badge-status-closed", label: "已开奖" }
    : { cls: "badge-status badge-status-open", label: "进行中" };

  return (
    <section className="j13-interact-card j13-typed-card" aria-label="抽奖">
      <div className="j13-typed-head">
        <div className="j13-typed-head-main">
          <h2 className="j13-typed-title is-lottery">
            <Gift size={16} strokeWidth={2.25} aria-hidden />
            抽奖
          </h2>
          <span className={statusBadge.cls}>{statusBadge.label}</span>
        </div>
        {state.can_draw && (
          <div className="j13-typed-actions">
            <button
              type="button"
              className="btn btn-primary btn-sm"
              disabled={busy}
              onClick={() => void act(() => apiDrawLottery(String(postId)), "开奖完成")}
            >
              开奖
            </button>
          </div>
        )}
      </div>

      {(state.can_draw || (state.eligible && !state.drawn)) && (
        <p className="j13-typed-meta">
          {state.can_draw ? `已有 ${state.entry_count} 名主评用户入池` : null}
          {state.can_draw && state.eligible && !state.drawn ? " · " : null}
          {state.eligible && !state.drawn ? "你已在奖池中" : null}
        </p>
      )}

      {!state.drawn && state.ends_at ? (
        <DeadlineCountdown
          endsAt={state.ends_at}
          expiredLabel="已到截止时间"
          expiredHint="等待开奖"
        />
      ) : null}

      {prizes.length > 0 && (
        <ul className="j13-lottery-prize-row" aria-label="奖品">
          {prizes.map((prize, i) => (
            <li key={`${prize.name}-${i}`}>
              <div className="j13-lottery-prize-chip" title={`${prize.name} ×${prize.count}`}>
                <Trophy size={13} strokeWidth={2.25} aria-hidden />
                <span className="j13-lottery-prize-chip-text">
                  {prize.name}
                  <span className="j13-lottery-prize-chip-count">×{prize.count}</span>
                </span>
              </div>
            </li>
          ))}
        </ul>
      )}

      {state.drawn && (
        <>
          <p className="j13-lottery-winners-label">中奖名单</p>
          {state.winners.length > 0 ? (
            <ul className="j13-lottery-winner-row">
              {state.winners.map((w) => (
                <li key={`${w.id}-${w.comment_id || 0}`}>
                  <div className="j13-lottery-winner">
                    <Avatar
                      name={w.nickname || w.username}
                      src={w.avatar || undefined}
                      size={36}
                      className="j13-lottery-winner-avatar"
                    />
                    <div className="j13-lottery-winner-body">
                      <Link href={`/u/${w.id}`} className="j13-lottery-winner-name">
                        {w.nickname || w.username}
                      </Link>
                      {w.prize_name ? (
                        <span className="j13-lottery-winner-prize">{w.prize_name}</span>
                      ) : null}
                    </div>
                  </div>
                </li>
              ))}
            </ul>
          ) : (
            <p className="j13-typed-empty">无人回帖，开奖结果为空</p>
          )}
        </>
      )}

      <div className="j13-typed-foot">
        <span className="j13-typed-foot-status">
          <CheckCircle2 size={14} strokeWidth={2.25} aria-hidden />
          {state.drawn ? "开奖完成" : "抽奖进行中"}
        </span>
        {state.ends_at ? (
          <span className="j13-typed-foot-time">截止时间: {formatEndsAt(state.ends_at)}</span>
        ) : null}
      </div>
    </section>
  );
}