"use client";

import { useCallback, useEffect, useRef, useState } from "react";
import Link from "next/link";
import {
  Check,
  FileText,
  FolderOpen,
  History,
  Loader2,
  MessagesSquare,
  RotateCcw,
  Trash2,
  X,
} from "lucide-react";
import {
  apiAdminContentCounts,
  apiAdminContentPosts,
  apiAdminContentComments,
  apiAdminSoftDeletePost,
  apiAdminRestorePost,
  apiAdminPurgePost,
  apiAdminSoftDeleteComment,
  apiAdminRestoreComment,
  apiAdminPurgeComment,
  apiAdminApprovePost,
  apiAdminRejectPost,
  apiAdminApproveComment,
  apiAdminRejectComment,
  apiUpdateSiteSettings,
  type AdminContentComment,
  type AdminContentCounts,
  type AdminContentPost,
  type AdminContentStatus,
  type PublicSettings,
} from "@/lib/api";
import { formatRelative } from "@/lib/format";
import { toast } from "@/lib/toast";
import { realtime, RT_MODERATION_CHANGED } from "@/lib/realtime";
import Avatar from "@/components/Avatar";
import ConfirmDialog from "@/components/ConfirmDialog";
import StaffDeletePostModal from "@/components/StaffDeletePostModal";
import DeleteCommentModal from "@/components/DeleteCommentModal";
import CommentEditHistoryModal from "@/components/CommentEditHistoryModal";
import {
  AdminEmpty,
  AdminIconButton,
  AdminPageHeader,
  AdminPager,
  AdminSearchField,
  AdminSegmented,
  AdminSettingRow,
  AdminStatusChip,
  AdminStepper,
  AdminSwitch,
  contentStatusChip,
} from "@/components/admin";

const PAGE_SIZE = 15;

export type ContentKind = "posts" | "comments";

const STATUS_TABS: { key: AdminContentStatus; label: string }[] = [
  { key: "live", label: "全部" },
  { key: "published", label: "已发布" },
  { key: "pending", label: "待审" },
  { key: "rejected", label: "已拒绝" },
  { key: "deleted", label: "已删除" },
];

function excerpt(md: string, max = 120): string {
  const text = md
    .replace(/```[\s\S]*?```/g, " ")
    .replace(/[#>*_`~\-]/g, "")
    .replace(/\[([^\]]+)\]\([^)]+\)/g, "$1")
    .replace(/\s+/g, " ")
    .trim();
  return text.length > max ? `${text.slice(0, max)}…` : text;
}

function isPendingRow(status: string, deleted: boolean) {
  return !deleted && status === "pending";
}

function PendingActions({
  busy,
  onApprove,
  onReject,
}: {
  busy: boolean;
  onApprove: () => void;
  onReject: () => void;
}) {
  return (
    <>
      <button type="button" className="btn btn-sm btn-ok" disabled={busy} onClick={onApprove}>
        {busy ? <Loader2 size={13} className="animate-spin" /> : <Check size={13} />}
        通过
      </button>
      <button type="button" className="btn btn-sm btn-danger" disabled={busy} onClick={onReject}>
        <X size={13} /> 拒绝
      </button>
    </>
  );
}

function emptyCopy(kind: ContentKind, status: AdminContentStatus): { title: string; description?: string } {
  if (status === "pending") {
    return {
      title: kind === "posts" ? "暂无待审帖子" : "暂无待审评论",
      description: "新提交的内容会按时间顺序出现在这里，可通过或拒绝",
    };
  }
  return { title: kind === "posts" ? "暂无帖子" : "暂无评论" };
}

export default function ContentAdmin({
  initialKind,
  initialStatus,
  initialPosts,
  initialPostsTotal,
  initialComments,
  initialCommentsTotal,
  initialCounts,
  initError,
  canConfigureSettings,
  initialSettings,
}: {
  initialKind: ContentKind;
  initialStatus: AdminContentStatus;
  initialPosts: AdminContentPost[];
  initialPostsTotal: number;
  initialComments: AdminContentComment[];
  initialCommentsTotal: number;
  initialCounts: AdminContentCounts;
  initError: string;
  canConfigureSettings: boolean;
  initialSettings: PublicSettings;
}) {
  const [kind, setKind] = useState<ContentKind>(initialKind);
  const [status, setStatus] = useState<AdminContentStatus>(initialStatus);
  const [counts, setCounts] = useState(initialCounts);

  const [posts, setPosts] = useState(initialPosts);
  const [postsTotal, setPostsTotal] = useState(initialPostsTotal);
  const [postsPage, setPostsPage] = useState(1);

  const [comments, setComments] = useState(initialComments);
  const [commentsTotal, setCommentsTotal] = useState(initialCommentsTotal);
  const [commentsPage, setCommentsPage] = useState(1);

  const [keyword, setKeyword] = useState("");
  const [appliedQ, setAppliedQ] = useState("");
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState(initError);
  const loadSeq = useRef(0);
  const [actingKey, setActingKey] = useState<string | null>(null);

  const [trustOn, setTrustOn] = useState(initialSettings.trust_reviewed_publish);
  const [cooldown, setCooldown] = useState(initialSettings.post_cooldown_hours);
  const [savingPolicy, setSavingPolicy] = useState(false);

  const [confirm, setConfirm] = useState<{
    title: string;
    message: string;
    danger?: boolean;
    confirmLabel?: string;
    run: () => Promise<void>;
  } | null>(null);
  const [confirmBusy, setConfirmBusy] = useState(false);
  const [staffDeletePost, setStaffDeletePost] = useState<AdminContentPost | null>(null);
  const [staffDeleteBusy, setStaffDeleteBusy] = useState(false);
  const [staffDeleteComment, setStaffDeleteComment] = useState<AdminContentComment | null>(null);
  const [staffDeleteCommentBusy, setStaffDeleteCommentBusy] = useState(false);
  const [historyCommentId, setHistoryCommentId] = useState<number | null>(null);

  const refreshCounts = useCallback(() => {
    apiAdminContentCounts().then(setCounts).catch(() => {});
  }, []);

  const loadPosts = useCallback(async (page: number, st: AdminContentStatus, q: string) => {
    const seq = ++loadSeq.current;
    setLoading(true);
    try {
      const res = await apiAdminContentPosts(page, st, q);
      if (seq !== loadSeq.current) return;
      setPosts(res.posts);
      setPostsTotal(res.total);
      setPostsPage(page);
      setKind("posts");
      setStatus(st);
      setAppliedQ(q);
      setError("");
    } catch (e) {
      if (seq !== loadSeq.current) return;
      setError(e instanceof Error ? e.message : "获取帖子失败");
    } finally {
      if (seq === loadSeq.current) setLoading(false);
    }
  }, []);

  const loadComments = useCallback(async (page: number, st: AdminContentStatus, q: string) => {
    const seq = ++loadSeq.current;
    setLoading(true);
    try {
      const res = await apiAdminContentComments(page, st, q);
      if (seq !== loadSeq.current) return;
      setComments(res.comments);
      setCommentsTotal(res.total);
      setCommentsPage(page);
      setKind("comments");
      setStatus(st);
      setAppliedQ(q);
      setError("");
    } catch (e) {
      if (seq !== loadSeq.current) return;
      setError(e instanceof Error ? e.message : "获取评论失败");
    } finally {
      if (seq === loadSeq.current) setLoading(false);
    }
  }, []);

  const reload = (page = 1) => {
    if (kind === "posts") void loadPosts(page, status, appliedQ);
    else void loadComments(page, status, appliedQ);
    refreshCounts();
  };

  const reloadAfterItemChange = () => {
    const p = kind === "posts" ? postsPage : commentsPage;
    const len = kind === "posts" ? posts.length : comments.length;
    reload(len <= 1 && p > 1 ? p - 1 : p);
  };

  useEffect(() => {
    refreshCounts();
  }, [refreshCounts]);

  useEffect(() => {
    const off = realtime.on(RT_MODERATION_CHANGED, refreshCounts);
    return off;
  }, [refreshCounts]);

  const switchKind = (k: ContentKind) => {
    if (k === kind) return;
    setError("");
    if (k === "posts") void loadPosts(1, status, appliedQ);
    else void loadComments(1, status, appliedQ);
  };

  const switchStatus = (st: AdminContentStatus) => {
    if (st === status) return;
    setError("");
    if (kind === "posts") void loadPosts(1, st, appliedQ);
    else void loadComments(1, st, appliedQ);
  };

  const applySearch = () => {
    const q = keyword.trim();
    if (kind === "posts") void loadPosts(1, status, q);
    else void loadComments(1, status, q);
  };

  const clearSearch = () => {
    setKeyword("");
    if (kind === "posts") void loadPosts(1, status, "");
    else void loadComments(1, status, "");
  };

  const runAction = (key: string, fn: () => Promise<void>, okMsg: string) => {
    setActingKey(key);
    fn()
      .then(() => {
        toast(okMsg, "ok");
        reloadAfterItemChange();
      })
      .catch((e) => toast(e instanceof Error ? e.message : "操作失败"))
      .finally(() => setActingKey(null));
  };

  const askConfirm = (
    title: string,
    message: string,
    run: () => Promise<void>,
    danger = false,
    confirmLabel?: string
  ) => setConfirm({ title, message, run, danger, confirmLabel });

  const askReject = (kindNow: ContentKind, id: number) => {
    askConfirm(
      kindNow === "posts" ? "拒绝这篇帖子？" : "拒绝这条评论？",
      "拒绝后作者将收到通知，内容不会公开。",
      async () => {
        if (kindNow === "posts") await apiAdminRejectPost(id);
        else await apiAdminRejectComment(id);
        toast("已拒绝，作者将收到通知", "ok");
        reloadAfterItemChange();
      },
      true,
      "确认拒绝"
    );
  };

  const toggleTrust = async () => {
    if (!canConfigureSettings || savingPolicy) return;
    setSavingPolicy(true);
    try {
      const res = await apiUpdateSiteSettings({ trust_reviewed_publish: !trustOn });
      setTrustOn(res.trust_reviewed_publish);
      toast(res.trust_reviewed_publish ? "已开启过审免审" : "已关闭过审免审", "ok");
    } catch (e) {
      toast(e instanceof Error ? e.message : "保存失败");
    } finally {
      setSavingPolicy(false);
    }
  };

  const saveCooldown = async () => {
    if (!canConfigureSettings || savingPolicy) return;
    const n = Math.max(0, Math.min(168, Math.round(Number(cooldown)) || 0));
    setSavingPolicy(true);
    try {
      const res = await apiUpdateSiteSettings({ post_cooldown_hours: n });
      setCooldown(res.post_cooldown_hours);
      toast(
        res.post_cooldown_hours === 0
          ? "已关闭新用户发帖冷静期"
          : `冷静期已设为 ${res.post_cooldown_hours} 小时`,
        "ok"
      );
    } catch (e) {
      toast(e instanceof Error ? e.message : "保存失败");
    } finally {
      setSavingPolicy(false);
    }
  };

  const total = kind === "posts" ? postsTotal : commentsTotal;
  const page = kind === "posts" ? postsPage : commentsPage;

  const statusCount = (st: AdminContentStatus) => {
    if (kind === "posts") {
      if (st === "live") return counts.posts_live;
      if (st === "pending") return counts.posts_pending;
      if (st === "rejected") return counts.posts_rejected;
      if (st === "deleted") return counts.posts_deleted;
      if (st === "published") {
        return Math.max(0, counts.posts_live - counts.posts_pending - counts.posts_rejected);
      }
      return null;
    }
    if (st === "live") return counts.comments_live;
    if (st === "pending") return counts.comments_pending;
    if (st === "rejected") return counts.comments_rejected;
    if (st === "deleted") return counts.comments_deleted;
    if (st === "published") {
      return Math.max(0, counts.comments_live - counts.comments_pending - counts.comments_rejected);
    }
    return null;
  };

  const goPage = (p: number) => {
    if (kind === "posts") void loadPosts(p, status, appliedQ);
    else void loadComments(p, status, appliedQ);
  };

  const empty = emptyCopy(kind, status);

  return (
    <div>
      <AdminPageHeader
        icon={FolderOpen}
        title="内容管理"
        description="审核待发布内容，并处理已发布/已拒绝条目与回收站；策略开关仅超管/站长可改"
      />

      {canConfigureSettings && (
        <div className="flex flex-col gap-3 mb-5">
          <AdminSettingRow
            title="已过审用户后续免审"
            description="开启后，已有过审内容的用户后续发帖与评论将直接公开。默认开启。"
            control={
              <AdminSwitch
                checked={trustOn}
                disabled={savingPolicy}
                onChange={() => void toggleTrust()}
                label="已过审用户后续免审"
              />
            }
          />

          <AdminSettingRow
            title="新用户发帖冷静期"
            description="注册后满该小时数才能发帖；设为 0 表示关闭。上限 168 小时（7 天）。"
            control={
              <div className="flex items-center gap-2.5">
                <AdminStepper
                  value={cooldown}
                  onChange={setCooldown}
                  min={0}
                  max={168}
                  unit="小时"
                  ariaLabel="冷静期小时数"
                  disabled={savingPolicy}
                />
                <button
                  type="button"
                  className="btn btn-line btn-sm"
                  disabled={savingPolicy}
                  onClick={() => void saveCooldown()}
                >
                  保存
                </button>
              </div>
            }
          />
        </div>
      )}

      <div className="panel overflow-hidden">
        <div className="admin-content-toolbar">
          <div className="admin-content-kind" role="tablist" aria-label="内容类型">
            <button
              type="button"
              role="tab"
              aria-selected={kind === "posts"}
              className="admin-content-kind-btn"
              onClick={() => switchKind("posts")}
            >
              <FileText size={14} aria-hidden />
              帖子
              <span className="admin-content-kind-count">{counts.posts_live}</span>
              {counts.posts_pending > 0 ? (
                <span className="admin-status is-warn" title={`${counts.posts_pending} 条待审`}>
                  {counts.posts_pending}
                </span>
              ) : null}
            </button>
            <button
              type="button"
              role="tab"
              aria-selected={kind === "comments"}
              className="admin-content-kind-btn"
              onClick={() => switchKind("comments")}
            >
              <MessagesSquare size={14} aria-hidden />
              评论
              <span className="admin-content-kind-count">{counts.comments_live}</span>
              {counts.comments_pending > 0 ? (
                <span className="admin-status is-warn" title={`${counts.comments_pending} 条待审`}>
                  {counts.comments_pending}
                </span>
              ) : null}
            </button>
          </div>
          <span className="admin-content-split" aria-hidden />
          <div className="admin-content-status">
            <AdminSegmented<AdminContentStatus>
              ariaLabel="状态筛选"
              size="sm"
              value={status}
              onChange={switchStatus}
              options={STATUS_TABS.map((t) => ({
                key: t.key,
                label: t.label,
                count: statusCount(t.key) ?? undefined,
              }))}
            />
          </div>
          <div className="admin-content-search">
            <AdminSearchField
              value={keyword}
              onChange={setKeyword}
              onSubmit={applySearch}
              onClear={clearSearch}
              placeholder={kind === "posts" ? "搜索帖子标题…" : "搜索评论正文…"}
              ariaLabel="搜索内容"
            />
          </div>
        </div>

        {error ? <p className="alert-error m-4">{error}</p> : null}
        {kind === "posts" && posts.length === 0 ? (
          <AdminEmpty icon={<FileText size={22} />} title={empty.title} description={empty.description} />
        ) : kind === "comments" && comments.length === 0 ? (
          <AdminEmpty icon={<MessagesSquare size={22} />} title={empty.title} description={empty.description} />
        ) : kind === "posts" ? (
          posts.map((p, idx) => {
            const key = `p-${p.id}`;
            const busy = actingKey === key;
            const chip = contentStatusChip(p.status, p.deleted);
            const pending = isPendingRow(p.status, p.deleted);
            return (
              <div
                key={p.id}
                className="flex items-start gap-3 px-4 sm:px-5 py-3.5"
                style={idx === 0 ? undefined : { borderTop: "1px solid var(--line)" }}
              >
                <Avatar
                  name={p.user?.nickname || p.user?.username || "?"}
                  src={p.user?.avatar || undefined}
                  size={34}
                />
                <div className="min-w-0 flex-1">
                  <div className="flex items-center gap-2 flex-wrap">
                    <AdminStatusChip tone={chip.tone}>{chip.label}</AdminStatusChip>
                    <span className="meta text-[11.5px]">{p.board?.name}</span>
                    <span className="meta text-[11.5px] tabular-nums">
                      {formatRelative(p.created_at)}
                    </span>
                  </div>
                  {p.deleted ? (
                    <p className="mt-1 text-[14px]" style={{ color: "var(--ink-2)" }}>
                      {p.title}
                    </p>
                  ) : (
                    <Link
                      href={`/post/${p.id}`}
                      className="mt-1 block text-[14px] hover:underline"
                      style={{ color: "var(--ink)" }}
                    >
                      {p.title}
                    </Link>
                  )}
                  <p className="meta text-[12px] mt-0.5">
                    {p.user?.nickname} · {p.comment_count} 评
                  </p>
                </div>
                <div className="flex items-center gap-1.5 shrink-0 flex-wrap justify-end">
                  {pending && (
                    <PendingActions
                      busy={busy}
                      onApprove={() =>
                        runAction(key, () => apiAdminApprovePost(p.id), "已通过审核，内容已公开")
                      }
                      onReject={() => askReject("posts", p.id)}
                    />
                  )}
                  {p.deleted ? (
                    <>
                      <AdminIconButton
                        tip="恢复"
                        ariaLabel="恢复帖子"
                        disabled={busy}
                        onClick={() =>
                          runAction(key, () => apiAdminRestorePost(p.id), "帖子已恢复")
                        }
                      >
                        {busy ? (
                          <Loader2 size={14} className="animate-spin" />
                        ) : (
                          <RotateCcw size={14} />
                        )}
                      </AdminIconButton>
                      <AdminIconButton
                        tip="清除"
                        ariaLabel="彻底删除帖子"
                        tone="danger"
                        disabled={busy}
                        onClick={() =>
                          askConfirm(
                            "彻底删除帖子",
                            `「${p.title}」将从数据库永久删除，且其下评论一并清除，不可撤销。`,
                            () =>
                              apiAdminPurgePost(p.id).then(() => {
                                toast("帖子已彻底删除", "ok");
                                reloadAfterItemChange();
                              }),
                            true
                          )
                        }
                      >
                        <Trash2 size={14} />
                      </AdminIconButton>
                    </>
                  ) : (
                    <AdminIconButton
                      tip="删除"
                      ariaLabel="删除帖子"
                      disabled={busy}
                      onClick={() => setStaffDeletePost(p)}
                    >
                      <Trash2 size={14} />
                    </AdminIconButton>
                  )}
                </div>
              </div>
            );
          })
        ) : (
          comments.map((c, idx) => {
            const key = `c-${c.id}`;
            const busy = actingKey === key;
            const chip = contentStatusChip(c.status, c.deleted);
            const pending = isPendingRow(c.status, c.deleted);
            return (
              <div
                key={c.id}
                className="flex items-start gap-3 px-4 sm:px-5 py-3.5"
                style={idx === 0 ? undefined : { borderTop: "1px solid var(--line)" }}
              >
                <Avatar
                  name={c.user?.nickname || c.user?.username || "?"}
                  src={c.user?.avatar || undefined}
                  size={34}
                />
                <div className="min-w-0 flex-1">
                  <div className="flex items-center gap-2 flex-wrap">
                    <AdminStatusChip tone={chip.tone}>{chip.label}</AdminStatusChip>
                    <span className="meta text-[11.5px]">{c.board?.name}</span>
                    <span className="meta text-[11.5px] tabular-nums">
                      {formatRelative(c.created_at)}
                    </span>
                  </div>
                  <p className="mt-1 text-[13.5px] leading-relaxed" style={{ color: "var(--ink)" }}>
                    {excerpt(c.content)}
                  </p>
                  <p className="meta text-[12px] mt-0.5">
                    {c.user?.nickname} ·{" "}
                    {c.deleted ? (
                      c.post_title
                    ) : (
                      <Link
                        href={`/post/${c.post_id}`}
                        className="hover:underline"
                        style={{ color: "var(--accent)" }}
                      >
                        {c.post_title || `帖子 #${c.post_id}`}
                      </Link>
                    )}
                  </p>
                </div>
                <div className="flex items-center gap-1.5 shrink-0 flex-wrap justify-end">
                  {pending && (
                    <PendingActions
                      busy={busy}
                      onApprove={() =>
                        runAction(key, () => apiAdminApproveComment(c.id), "已通过审核，内容已公开")
                      }
                      onReject={() => askReject("comments", c.id)}
                    />
                  )}
                  <AdminIconButton
                    tip="历史"
                    ariaLabel="查看编辑历史"
                    onClick={() => setHistoryCommentId(c.id)}
                  >
                    <History size={14} />
                  </AdminIconButton>
                  {c.deleted ? (
                    <>
                      <AdminIconButton
                        tip="恢复"
                        ariaLabel="恢复评论"
                        disabled={busy}
                        onClick={() =>
                          runAction(key, () => apiAdminRestoreComment(c.id), "评论已恢复")
                        }
                      >
                        {busy ? (
                          <Loader2 size={14} className="animate-spin" />
                        ) : (
                          <RotateCcw size={14} />
                        )}
                      </AdminIconButton>
                      <AdminIconButton
                        tip="清除"
                        ariaLabel="彻底删除评论"
                        tone="danger"
                        disabled={busy}
                        onClick={() =>
                          askConfirm(
                            "彻底删除评论",
                            "该评论将永久删除且不可恢复。",
                            () =>
                              apiAdminPurgeComment(c.id).then(() => {
                                toast("评论已彻底删除", "ok");
                                reloadAfterItemChange();
                              }),
                            true
                          )
                        }
                      >
                        <Trash2 size={14} />
                      </AdminIconButton>
                    </>
                  ) : (
                    <AdminIconButton
                      tip="删除"
                      ariaLabel="删除评论"
                      disabled={busy}
                      onClick={() => setStaffDeleteComment(c)}
                    >
                      <Trash2 size={14} />
                    </AdminIconButton>
                  )}
                </div>
              </div>
            );
          })
        )}

        <AdminPager
          page={page}
          total={total}
          pageSize={PAGE_SIZE}
          loading={loading}
          onChange={goPage}
        />
      </div>

      <ConfirmDialog
        open={!!confirm}
        title={confirm?.title || ""}
        message={confirm?.message || ""}
        danger={confirm?.danger}
        busy={confirmBusy}
        confirmLabel={confirm?.confirmLabel || (confirm?.danger ? "确认删除" : "确定")}
        onCancel={() => !confirmBusy && setConfirm(null)}
        onConfirm={() => {
          if (!confirm) return;
          setConfirmBusy(true);
          confirm
            .run()
            .catch((e) => toast(e instanceof Error ? e.message : "操作失败"))
            .finally(() => {
              setConfirmBusy(false);
              setConfirm(null);
            });
        }}
      />

      <StaffDeletePostModal
        open={!!staffDeletePost}
        title={staffDeletePost?.title}
        busy={staffDeleteBusy}
        onClose={() => !staffDeleteBusy && setStaffDeletePost(null)}
        onConfirm={(opts) => {
          if (!staffDeletePost) return;
          setStaffDeleteBusy(true);
          apiAdminSoftDeletePost(staffDeletePost.id, opts)
            .then(() => {
              toast("已移入回收站", "ok");
              setStaffDeletePost(null);
              reloadAfterItemChange();
            })
            .catch((e) => toast(e instanceof Error ? e.message : "操作失败"))
            .finally(() => setStaffDeleteBusy(false));
        }}
      />

      <DeleteCommentModal
        open={!!staffDeleteComment}
        mode="staff"
        busy={staffDeleteCommentBusy}
        onClose={() => !staffDeleteCommentBusy && setStaffDeleteComment(null)}
        onConfirm={(opts) => {
          if (!staffDeleteComment) return;
          setStaffDeleteCommentBusy(true);
          apiAdminSoftDeleteComment(staffDeleteComment.id, opts)
            .then(() => {
              toast("已移入回收站", "ok");
              setStaffDeleteComment(null);
              reloadAfterItemChange();
            })
            .catch((e) => toast(e instanceof Error ? e.message : "操作失败"))
            .finally(() => setStaffDeleteCommentBusy(false));
        }}
      />

      <CommentEditHistoryModal
        open={historyCommentId != null}
        commentId={historyCommentId}
        onClose={() => setHistoryCommentId(null)}
      />
    </div>
  );
}