"use client";

import { useEffect, useState } from "react";
import { useRouter } from "next/navigation";
import Link from "next/link";
import {
  confirmEndingDetection,
  decideInvitation,
  decideLobbyCall,
  enterPossession,
  exitPossession,
  getFullLobby,
  getPossessionStatus,
  listEndingDetections,
  listPendingAdjudication,
  listPendingInvitations,
  listPendingLobbyCalls,
  rejectEndingDetection,
  sayToLobby,
  type EndingDetectionLog,
  type LobbyFullSnapshot,
  type LobbyPresenceState,
  type PendingInvitation,
  type PendingLobbyCall,
  type PossessionStatus,
} from "../../lib/api";

const USER_ID = "seed-user-primary";

const PRESENCE_LABELS: Record<LobbyPresenceState, string> = {
  BUILDING: "建置中",
  SLEEPING: "睡眠中",
  BUSY: "忙碌中",
  SEMI_BUSY: "略忙",
  IDLE: "空閒",
  IN_SOLO_ROOM: "單獨聊天中",
  IN_GROUP_ROOM: "多人房中",
};

const UNAVAILABLE_STATES: LobbyPresenceState[] = ["BUILDING", "SLEEPING", "IN_SOLO_ROOM", "IN_GROUP_ROOM"];

// T19-P2：大廳頁完整版——取代 T19-P1 的最小快照（在場名單＋房間清單），改用 T4 正式聚合端點
// 一次取得作品分組、角色狀態、各進行中房間未讀數，並提供大廳對話式呼叫（T5）輸入框：答應者開房
// 後直接導向該房，全部婉拒或找代答時把角色台詞就地顯示在輸入框上方（不跳轉）。
export function LobbyView() {
  const router = useRouter();
  const [snapshot, setSnapshot] = useState<LobbyFullSnapshot | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [text, setText] = useState("");
  const [pending, setPending] = useState(false);
  const [lobbyMessage, setLobbyMessage] = useState<string | null>(null);
  const [pendingAdjudicationByWork, setPendingAdjudicationByWork] = useState<Record<string, number>>({});
  const [endingDetectionsByWork, setEndingDetectionsByWork] = useState<Record<string, EndingDetectionLog[]>>({});
  const [possession, setPossession] = useState<PossessionStatus | null>(null);
  const [pendingInvitations, setPendingInvitations] = useState<PendingInvitation[]>([]);
  const [pendingCalls, setPendingCalls] = useState<PendingLobbyCall[]>([]);

  async function refresh() {
    try {
      const [lobby, possessionStatus] = await Promise.all([getFullLobby(USER_ID), getPossessionStatus(USER_ID)]);
      setSnapshot(lobby);
      setPossession(possessionStatus);
      setError(null);
    } catch {
      setError("大廳查詢失敗，請確認 api 服務是否已啟動");
    }
  }

  useEffect(() => {
    void refresh();
  }, []);

  // T19-P5：套用中時查詢待決邀請與待決大廳呼叫——沿用她的身分決定接受／婉拒，不讓人格系統代答。
  useEffect(() => {
    if (!possession?.possessingCharacterId) {
      setPendingInvitations([]);
      setPendingCalls([]);
      return;
    }
    let cancelled = false;
    void Promise.all([listPendingInvitations(USER_ID), listPendingLobbyCalls(USER_ID)]).then(([invitations, calls]) => {
      if (cancelled) return;
      setPendingInvitations(invitations);
      setPendingCalls(calls);
    });
    return () => {
      cancelled = true;
    };
  }, [possession]);

  async function handleEnterPossession(characterId: string) {
    if (pending) return;
    setPending(true);
    setError(null);
    try {
      await enterPossession(USER_ID, characterId);
      await refresh();
    } catch (err) {
      setError(err instanceof Error ? err.message : "套用失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  async function handleExitPossession() {
    if (pending) return;
    setPending(true);
    setError(null);
    try {
      await exitPossession(USER_ID);
      await refresh();
    } catch (err) {
      setError(err instanceof Error ? err.message : "退出套用失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  async function handleDecideInvitation(invitationId: string, accept: boolean) {
    if (pending) return;
    setPending(true);
    setError(null);
    try {
      await decideInvitation(invitationId, accept);
      const invitations = await listPendingInvitations(USER_ID);
      setPendingInvitations(invitations);
      await refresh();
    } catch (err) {
      setError(err instanceof Error ? err.message : "邀請決定失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  async function handleDecideCall(pendingCallId: string, accept: boolean) {
    if (pending) return;
    setPending(true);
    setError(null);
    try {
      const decision = await decideLobbyCall(pendingCallId, accept);
      const calls = await listPendingLobbyCalls(USER_ID);
      setPendingCalls(calls);
      if (decision.roomId) {
        router.push(`/room/${decision.roomId}`);
        return;
      }
    } catch (err) {
      setError(err instanceof Error ? err.message : "呼叫決定失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  // T19-P4：作品卡片標題列的「有待裁決項目」提示與結局偵測待確認清單——依目前大廳snapshot 內的
  // 作品清單批次查詢，snapshot 每次刷新（匯入、裁決、確認結局後）都會連動重新取得。
  useEffect(() => {
    if (!snapshot) return;
    const workIds = snapshot.works.map((w) => w.id);
    let cancelled = false;
    void Promise.all(
      workIds.map(async (workId) => {
        const [adjudication, endings] = await Promise.all([listPendingAdjudication(workId), listEndingDetections(workId)]);
        return { workId, pendingCount: adjudication.length, endings };
      }),
    ).then((results) => {
      if (cancelled) return;
      setPendingAdjudicationByWork(Object.fromEntries(results.map((r) => [r.workId, r.pendingCount])));
      setEndingDetectionsByWork(Object.fromEntries(results.map((r) => [r.workId, r.endings])));
    });
    return () => {
      cancelled = true;
    };
  }, [snapshot]);

  async function handleConfirmEnding(logId: string) {
    if (pending) return;
    setPending(true);
    setError(null);
    try {
      await confirmEndingDetection(logId);
      await refresh();
    } catch (err) {
      setError(err instanceof Error ? err.message : "結局確認失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  async function handleRejectEnding(logId: string) {
    if (pending) return;
    setPending(true);
    setError(null);
    try {
      await rejectEndingDetection(logId);
      await refresh();
    } catch (err) {
      setError(err instanceof Error ? err.message : "結局拒絕失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  async function handleSay() {
    const trimmed = text.trim();
    if (!trimmed || pending || possession?.possessingCharacterId) return;
    setPending(true);
    setError(null);
    setLobbyMessage(null);
    try {
      const result = await sayToLobby(USER_ID, trimmed);
      setText("");
      if (result.roomId) {
        router.push(`/room/${result.roomId}`);
        return;
      }
      if (result.message) {
        setLobbyMessage(result.message);
      }
      await refresh();
    } catch {
      setError("大廳呼叫失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  if (error) {
    return (
      <p className="text-xs" style={{ color: "var(--accent)" }}>
        {error}
      </p>
    );
  }

  if (!snapshot) {
    return (
      <p className="text-xs" style={{ color: "var(--ink-soft)" }}>
        載入中……
      </p>
    );
  }

  const workGroups = snapshot.works.map((work) => ({
    work,
    characters: snapshot.characters.filter((c) => c.workId === work.id),
  }));
  const unassigned = snapshot.characters.filter((c) => c.workId === null);
  const possessedCharacterId = possession?.possessingCharacterId ?? null;
  const possessedCharacterName = possessedCharacterId
    ? snapshot.characters.find((c) => c.id === possessedCharacterId)?.formalName ?? possessedCharacterId
    : null;

  return (
    <div className="flex flex-col gap-4">
      {possessedCharacterId && (
        <section
          className="flex flex-col gap-2 rounded-2xl border-2 p-3"
          style={{ borderColor: "var(--accent-bright)", background: "var(--chip-bg)" }}
        >
          <div className="flex items-center justify-between">
            <p className="text-sm font-bold" style={{ color: "var(--accent)" }}>
              你現在是「{possessedCharacterName}」
            </p>
            <button
              type="button"
              onClick={() => void handleExitPossession()}
              disabled={pending}
              className="rounded-full border px-3 py-1 text-xs font-bold disabled:opacity-50"
              style={{ borderColor: "var(--accent)", color: "var(--accent)" }}
            >
              退出套用
            </button>
          </div>
          <p className="text-[11px]" style={{ color: "var(--ink-soft)" }}>
            她的自走已暫停；請到她所在的房間以她的身分發話，或在下方決定她收到的邀請與呼叫。
          </p>

          {pendingCalls.map((call) => (
            <div key={call.id} className="flex flex-col gap-1 rounded-xl border p-2 text-[11px]" style={{ borderColor: "var(--line)" }}>
              <p style={{ color: "var(--ink)" }}>有人喊了你：「{call.text}」</p>
              <div className="flex gap-2">
                <button
                  type="button"
                  onClick={() => void handleDecideCall(call.id, true)}
                  disabled={pending}
                  className="rounded-full px-3 py-1 font-bold text-white disabled:opacity-50"
                  style={{ background: "var(--accent-bright)" }}
                >
                  接受
                </button>
                <button
                  type="button"
                  onClick={() => void handleDecideCall(call.id, false)}
                  disabled={pending}
                  className="rounded-full border px-3 py-1 disabled:opacity-50"
                  style={{ borderColor: "var(--line)", color: "var(--ink-soft)" }}
                >
                  婉拒
                </button>
              </div>
            </div>
          ))}

          {pendingInvitations.map((invitation) => (
            <div key={invitation.id} className="flex flex-col gap-1 rounded-xl border p-2 text-[11px]" style={{ borderColor: "var(--line)" }}>
              <p style={{ color: "var(--ink)" }}>
                {(invitation.invitedByCharacterId &&
                  snapshot.characters.find((c) => c.id === invitation.invitedByCharacterId)?.formalName) ??
                  "有人"}
                邀請你到房間裡聊聊
              </p>
              <div className="flex gap-2">
                <button
                  type="button"
                  onClick={() => void handleDecideInvitation(invitation.id, true)}
                  disabled={pending}
                  className="rounded-full px-3 py-1 font-bold text-white disabled:opacity-50"
                  style={{ background: "var(--accent-bright)" }}
                >
                  接受
                </button>
                <button
                  type="button"
                  onClick={() => void handleDecideInvitation(invitation.id, false)}
                  disabled={pending}
                  className="rounded-full border px-3 py-1 disabled:opacity-50"
                  style={{ borderColor: "var(--line)", color: "var(--ink-soft)" }}
                >
                  婉拒
                </button>
              </div>
            </div>
          ))}
        </section>
      )}

      <section className="flex flex-col gap-2 rounded-2xl border p-3" style={{ borderColor: "var(--line)" }}>
        <h2 className="text-sm font-bold" style={{ color: "var(--ink)" }}>
          進行中房間（{snapshot.activeRooms.length}）
        </h2>
        {snapshot.activeRooms.length === 0 ? (
          <p className="text-xs" style={{ color: "var(--ink-soft)" }}>
            目前沒有進行中的房間。
          </p>
        ) : (
          <ul className="flex flex-col gap-2">
            {snapshot.activeRooms.map((room) => (
              <li key={room.id}>
                <button
                  type="button"
                  onClick={() => router.push(`/room/${room.id}`)}
                  className="flex w-full flex-col gap-1 rounded-xl border px-3 py-2 text-left text-xs"
                  style={{ borderColor: "var(--line)", color: "var(--ink)" }}
                >
                  <span className="flex items-center justify-between">
                    <span style={{ color: "var(--ink-soft)" }}>{room.mode}</span>
                    {room.unreadCount > 0 && (
                      <span
                        className="rounded-full px-2 py-0.5 text-[10px] font-bold text-white"
                        style={{ background: "var(--accent-bright)" }}
                      >
                        {room.unreadCount}
                      </span>
                    )}
                  </span>
                  <span>
                    {room.memberCharacterIds
                      .map((id) => snapshot.characters.find((c) => c.id === id)?.formalName ?? id)
                      .join("、") || "（無人在場）"}
                  </span>
                  {room.topicSeed && <span style={{ color: "var(--ink-soft)" }}>話題：{room.topicSeed}</span>}
                </button>
              </li>
            ))}
          </ul>
        )}
      </section>

      {workGroups.map(({ work, characters }) => {
        if (characters.length === 0) return null;
        const pendingCount = pendingAdjudicationByWork[work.id] ?? 0;
        const endings = endingDetectionsByWork[work.id] ?? [];
        return (
          <section key={work.id} className="flex flex-col gap-2 rounded-2xl border p-3" style={{ borderColor: "var(--line)" }}>
            <div className="flex flex-wrap items-center justify-between gap-2">
              <h2 className="flex items-center gap-2 text-sm font-bold" style={{ color: "var(--ink)" }}>
                {work.title}
                {work.inEpilogue && (
                  <span className="rounded-full px-2 py-0.5 text-[10px]" style={{ background: "var(--chip-bg)", color: "var(--accent)" }}>
                    後日談
                  </span>
                )}
              </h2>
              <div className="flex items-center gap-2 text-[10px]">
                {pendingCount > 0 && (
                  <Link
                    href="/canon-review"
                    className="rounded-full px-2 py-0.5 font-bold text-white"
                    style={{ background: "var(--accent)" }}
                  >
                    有 {pendingCount} 項待裁決
                  </Link>
                )}
                <Link
                  href={`/canon-import?workId=${work.id}`}
                  className="rounded-full border px-2 py-0.5"
                  style={{ borderColor: "var(--line)", color: "var(--ink-soft)" }}
                >
                  匯入章節
                </Link>
              </div>
            </div>

            <div className="flex flex-wrap gap-2 text-xs">
              {characters.map((character) => (
                <span
                  key={character.id}
                  className="flex items-center gap-1 rounded-full border px-2 py-1"
                  style={{
                    borderColor: "var(--line)",
                    color: UNAVAILABLE_STATES.includes(character.presenceState) ? "var(--ink-soft)" : "var(--ink)",
                  }}
                >
                  {character.formalName}
                  <span style={{ color: "var(--ink-soft)" }}>／{PRESENCE_LABELS[character.presenceState]}</span>
                  {character.id === possessedCharacterId ? (
                    <span className="rounded-full px-1.5 py-0.5 text-[9px] font-bold text-white" style={{ background: "var(--accent)" }}>
                      套用中
                    </span>
                  ) : (
                    !possessedCharacterId && (
                      <button
                        type="button"
                        onClick={() => void handleEnterPossession(character.id)}
                        disabled={pending}
                        className="rounded-full border px-1.5 py-0.5 text-[9px] disabled:opacity-50"
                        style={{ borderColor: "var(--line)", color: "var(--ink-soft)" }}
                      >
                        套用
                      </button>
                    )
                  )}
                </span>
              ))}
            </div>

            {endings.length > 0 && (
              <div className="flex flex-col gap-2">
                {endings.map((ending) => (
                  <div key={ending.id} className="flex flex-col gap-1 rounded-xl border p-2 text-[11px]" style={{ borderColor: "var(--line)" }}>
                    <p style={{ color: "var(--ink)" }}>偵測到可能的結局章節，是否切入後日談？</p>
                    <p style={{ color: "var(--ink-soft)" }}>判定理由：{ending.evidence}</p>
                    <div className="flex gap-2">
                      <button
                        type="button"
                        onClick={() => void handleConfirmEnding(ending.id)}
                        disabled={pending}
                        className="rounded-full px-3 py-1 font-bold text-white disabled:opacity-50"
                        style={{ background: "var(--accent-bright)" }}
                      >
                        確認．切入後日談
                      </button>
                      <button
                        type="button"
                        onClick={() => void handleRejectEnding(ending.id)}
                        disabled={pending}
                        className="rounded-full border px-3 py-1 disabled:opacity-50"
                        style={{ borderColor: "var(--line)", color: "var(--ink-soft)" }}
                      >
                        拒絕
                      </button>
                    </div>
                  </div>
                ))}
              </div>
            )}

            {work.milestones.length > 0 && (
              <div className="flex flex-col gap-1 text-[11px]" style={{ color: "var(--ink-soft)" }}>
                {work.milestones.map((milestone, index) => (
                  <p key={`${milestone.characterId}-${index}`}>
                    ．{characters.find((c) => c.id === milestone.characterId)?.formalName ?? milestone.characterId}
                    ：{milestone.label}
                  </p>
                ))}
              </div>
            )}
          </section>
        );
      })}

      {unassigned.length > 0 && (
        <section className="flex flex-col gap-2 rounded-2xl border p-3" style={{ borderColor: "var(--line)" }}>
          <h2 className="text-sm font-bold" style={{ color: "var(--ink)" }}>
            未分組角色
          </h2>
          <div className="flex flex-wrap gap-2 text-xs">
            {unassigned.map((character) => (
              <span
                key={character.id}
                className="flex items-center gap-1 rounded-full border px-2 py-1"
                style={{ borderColor: "var(--line)", color: "var(--ink)" }}
              >
                {character.formalName}
                <span style={{ color: "var(--ink-soft)" }}>／{PRESENCE_LABELS[character.presenceState]}</span>
                {character.id === possessedCharacterId ? (
                  <span className="rounded-full px-1.5 py-0.5 text-[9px] font-bold text-white" style={{ background: "var(--accent)" }}>
                    套用中
                  </span>
                ) : (
                  !possessedCharacterId && (
                    <button
                      type="button"
                      onClick={() => void handleEnterPossession(character.id)}
                      disabled={pending}
                      className="rounded-full border px-1.5 py-0.5 text-[9px] disabled:opacity-50"
                      style={{ borderColor: "var(--line)", color: "var(--ink-soft)" }}
                    >
                      套用
                    </button>
                  )
                )}
              </span>
            ))}
          </div>
        </section>
      )}

      {lobbyMessage && (
        <p className="rounded-xl border px-3 py-2 text-xs" style={{ borderColor: "var(--line)", color: "var(--ink)" }}>
          {lobbyMessage}
        </p>
      )}

      {possessedCharacterId ? (
        <p className="rounded-full border px-3 py-2 text-center text-xs" style={{ borderColor: "var(--line)", color: "var(--ink-soft)" }}>
          套用中無法以自己的身分喊人，請先退出套用。
        </p>
      ) : (
        <div className="flex items-center gap-2">
          <input
            value={text}
            onChange={(event) => setText(event.target.value)}
            onKeyDown={(event) => {
              if (event.key === "Enter") void handleSay();
            }}
            placeholder="喊一下誰的名字……"
            className="flex-1 rounded-full border bg-transparent px-3 py-2 text-sm outline-none"
            style={{ borderColor: "var(--line)", color: "var(--ink)" }}
            disabled={pending}
          />
          <button
            type="button"
            onClick={() => void handleSay()}
            disabled={pending || !text.trim()}
            className="rounded-full px-4 py-2 text-sm font-bold text-white disabled:opacity-50"
            style={{ background: "var(--accent-bright)" }}
          >
            送出
          </button>
        </div>
      )}
    </div>
  );
}