import { useCallback, useEffect, useRef, useState } from "react";
import { useConfirm } from "../../shared/ui/ConfirmDialog";
import { Edit2, Info, Plus, RefreshCw, Trash2, X } from "lucide-react";
import type { PageResult } from "../../shared/api/types";
import { ipEntryApi, type IpEntryApi } from "./ipEntryApi";
import type {
  IpEntryCreateRequest,
  IpEntrySummary,
  IpEntryUpdateRequest,
} from "./ipEntryTypes";
import {
  B,
  DANGER,
  N,
  PBG,
  W,
  type ApiResultState,
  describeError,
  initialResult,
  LabeledInput,
  ModalFooter,
  ModalShell,
  smallButton,
} from "./directoryUi";

const EMPTY_IP_PAGE: PageResult<IpEntrySummary> = {
  items: [],
  page: 1,
  pageSize: 20,
  total: 0,
  totalPages: 0,
};

interface IpEntryForm {
  ipValue: string;
  remark: string;
}

interface IpEntryEditState {
  mode: "create" | "edit";
  target: IpEntrySummary | null;
  form: IpEntryForm;
  rowVersion: number;
}

function buildIpEntryForm(
  mode: "create" | "edit",
  target: IpEntrySummary | null,
): IpEntryForm {
  if (mode === "edit" && target) {
    return { ipValue: target.ipValue, remark: target.remark };
  }
  return { ipValue: "", remark: "" };
}

/** IP地址池维护：全局唯一IP池（精确IP或CIDR网段），供机构维护中为部门分配。 */
export function IpEntryMaintenancePanel({
  api = ipEntryApi,
}: {
  api?: IpEntryApi;
}) {
  const { confirm: confirmDialog, dialog: confirmDialogNode } = useConfirm();
  const [keyword, setKeyword] = useState("");
  const [page, setPage] = useState(1);
  const pageSize = 20;
  const [retry, setRetry] = useState(0);

  const [data, setData] = useState<PageResult<IpEntrySummary>>(EMPTY_IP_PAGE);
  const [listStatus, setListStatus] = useState<"loading" | "success" | "error">(
    "loading",
  );
  const [listError, setListError] = useState<string | null>(null);

  const [editState, setEditState] = useState<IpEntryEditState | null>(null);
  const [mutation, setMutation] = useState<ApiResultState>(initialResult);

  // 列表：搜索防抖 + 分页（与 RoleMaintenancePanel 相同的竞态防护模式）
  const listVersion = useRef(0);
  useEffect(() => {
    const controller = new AbortController();
    const current = ++listVersion.current;
    const timer = window.setTimeout(async () => {
      setListStatus("loading");
      setListError(null);
      try {
        const result = await api.getIpEntries(
          {
            keyword: keyword.trim() || undefined,
            page,
            pageSize,
          },
          controller.signal,
        );
        if (controller.signal.aborted || current !== listVersion.current) {
          return;
        }
        setData(result);
        setListStatus("success");
      } catch (loadError) {
        if (controller.signal.aborted || current !== listVersion.current) {
          return;
        }
        setListError(describeError(loadError));
        setListStatus("error");
      }
    }, keyword.trim() ? 300 : 0);
    return () => {
      window.clearTimeout(timer);
      controller.abort();
    };
  }, [api, keyword, page, retry]);

  const refresh = useCallback(() => setRetry((v) => v + 1), []);

  const openCreate = () => {
    setEditState({
      mode: "create",
      target: null,
      form: buildIpEntryForm("create", null),
      rowVersion: 0,
    });
    setMutation(initialResult);
  };

  const openEdit = (entry: IpEntrySummary) => {
    setEditState({
      mode: "edit",
      target: entry,
      form: buildIpEntryForm("edit", entry),
      rowVersion: entry.rowVersion,
    });
    setMutation(initialResult);
  };

  const closeEditor = () => {
    setEditState(null);
    setMutation(initialResult);
  };

  const handleSubmit = async () => {
    if (!editState) return;
    const form = editState.form;
    if (!form.ipValue.trim()) {
      setMutation({ submitting: false, error: "IP地址或网段不能为空" });
      return;
    }
    setMutation({ submitting: true, error: null });
    try {
      if (editState.mode === "create") {
        const payload: IpEntryCreateRequest = {
          ipValue: form.ipValue.trim(),
          remark: form.remark.trim() || null,
        };
        await api.create(payload);
      } else if (editState.target) {
        const payload: IpEntryUpdateRequest = {
          ipValue: form.ipValue.trim(),
          remark: form.remark.trim() || null,
          rowVersion: editState.rowVersion,
        };
        await api.update(editState.target.id, payload);
      }
      closeEditor();
      refresh();
    } catch (error) {
      setMutation({ submitting: false, error: describeError(error) });
    }
  };

  const handleDelete = async (entry: IpEntrySummary) => {
    if (!(await confirmDialog({ message: `确认删除IP「${entry.ipValue}」？`, danger: true }))) return;
    setMutation({ submitting: true, error: null });
    try {
      await api.delete(entry.id, entry.rowVersion);
      setMutation(initialResult);
      refresh();
    } catch (error) {
      setMutation({ submitting: false, error: describeError(error) });
    }
  };

  return (
    <div className="w-full h-full flex flex-col overflow-hidden">
      {confirmDialogNode}
      <div
        className="flex-shrink-0 flex items-center justify-between gap-3 px-6 py-3 border-b"
        style={{ background: W, borderColor: "rgba(var(--dms-bright-rgb),0.15)" }}
      >
        <div className="flex items-center gap-2 flex-1 max-w-md">
          <input
            value={keyword}
            onChange={(e) => {
              setKeyword(e.target.value);
              setPage(1);
            }}
            placeholder="按IP或备注筛选"
            className="flex-1 px-3 py-1.5 text-base border rounded-sm outline-none"
            style={{ borderColor: "rgba(var(--dms-bright-rgb),0.4)", color: N }}
          />
          {keyword && (
            <button
              type="button"
              onClick={() => setKeyword("")}
              className="text-base font-bold opacity-60 hover:opacity-100"
              style={{ color: N }}
            >
              <X size={14} />
            </button>
          )}
        </div>
        <div className="flex items-center gap-1.5">
          {smallButton(false, {
            label: "刷新",
            icon: <RefreshCw size={12} />,
            onClick: refresh,
          })}
          {smallButton(true, {
            label: "新建IP",
            icon: <Plus size={12} />,
            onClick: openCreate,
          })}
        </div>
      </div>

      <div
        className="flex-shrink-0 flex items-center gap-1.5 px-6 py-2 text-base font-bold border-b"
        style={{
          color: N,
          background: "rgba(var(--dms-bright-rgb),0.05)",
          borderColor: "rgba(var(--dms-bright-rgb),0.15)",
        }}
      >
        <Info size={12} />
        全局IP池：维护精确IP或CIDR网段；在「机构管理」中为部门分配后，该部门用户仅可从分配的IP登录（ADMIN不受限制）。
      </div>

      <div
        className="flex-1 min-h-0 overflow-auto px-6 py-4"
        style={{ background: PBG }}
      >
        {listStatus === "loading" && (
          <div
            className="text-base font-bold text-center py-8"
            style={{ color: N }}
          >
            正在加载IP条目…
          </div>
        )}
        {listStatus === "error" && (
          <div
            className="text-base font-bold text-center py-8"
            style={{ color: DANGER }}
          >
            {listError ?? "加载失败"}
          </div>
        )}
        {listStatus === "success" && data.items.length === 0 && (
          <div
            className="text-base font-bold text-center py-8"
            style={{ color: N }}
          >
            暂无IP条目，点击右上角"新建IP"开始维护。
          </div>
        )}
        {data.items.length > 0 && (
          <table
            className="w-full text-base"
            style={{ background: W, borderCollapse: "collapse" }}
          >
            <thead>
              <tr style={{ background: PBG }}>
                {["IP地址/网段", "备注", "操作"].map((h) => (
                  <th
                    key={h}
                    className="text-left px-3 py-2 text-base font-black border"
                    style={{
                      color: N,
                      borderColor: "rgba(var(--dms-bright-rgb),0.2)",
                    }}
                  >
                    {h}
                  </th>
                ))}
              </tr>
            </thead>
            <tbody>
              {data.items.map((entry) => (
                <tr
                  key={entry.id}
                  className="border-t transition-colors hover:bg-[rgba(var(--dms-bright-rgb),0.18)]"
                  style={{ borderColor: "rgba(var(--dms-bright-rgb),0.12)" }}
                >
                  <td className="px-3 py-2 font-black" style={{ color: N }}>
                    {entry.ipValue}
                  </td>
                  <td className="px-3 py-2" style={{ color: N }}>
                    {entry.remark || "—"}
                  </td>
                  <td className="px-3 py-2">
                    <div className="flex items-center gap-1.5">
                      {smallButton(false, {
                        label: "编辑",
                        icon: <Edit2 size={12} />,
                        onClick: () => openEdit(entry),
                      })}
                      {smallButton(false, {
                        label: "删除",
                        icon: <Trash2 size={12} />,
                        onClick: () => handleDelete(entry),
                        danger: true,
                      })}
                    </div>
                  </td>
                </tr>
              ))}
            </tbody>
          </table>
        )}
      </div>

      <div
        className="flex-shrink-0 flex items-center justify-between px-6 py-2 border-t text-base font-bold"
        style={{
          color: N,
          background: W,
          borderColor: "rgba(var(--dms-bright-rgb),0.15)",
        }}
      >
        <span>
          共 {data.total} 条 · 第 {data.page} / {Math.max(data.totalPages, 1)}{" "}
          页
        </span>
        <div className="flex items-center gap-1.5">
          <button
            type="button"
            onClick={() => setPage((p) => Math.max(1, p - 1))}
            disabled={data.page <= 1}
            className="px-2.5 py-1 text-base font-bold rounded-sm disabled:opacity-40"
            style={{ border: `1px solid ${B}`, color: N, background: W }}
          >
            上一页
          </button>
          <button
            type="button"
            onClick={() =>
              setPage((p) => Math.min(Math.max(data.totalPages, 1), p + 1))
            }
            disabled={data.page >= data.totalPages}
            className="px-2.5 py-1 text-base font-bold rounded-sm disabled:opacity-40"
            style={{ border: `1px solid ${B}`, color: N, background: W }}
          >
            下一页
          </button>
        </div>
      </div>

      {mutation.error && (
        <div
          className="flex-shrink-0 px-6 py-2 text-base font-bold border-t"
          style={{
            color: DANGER,
            background: "rgba(192,57,43,0.05)",
            borderColor: "rgba(192,57,43,0.2)",
          }}
        >
          {mutation.error}
        </div>
      )}

      {editState && (
        <IpEntryEditorModal
          mode={editState.mode}
          target={editState.target}
          form={editState.form}
          onChange={(patch) =>
            setEditState((current) =>
              current
                ? { ...current, form: { ...current.form, ...patch } }
                : current,
            )
          }
          onClose={closeEditor}
          onSubmit={handleSubmit}
          submitting={mutation.submitting}
        />
      )}
    </div>
  );
}

function IpEntryEditorModal({
  mode,
  target,
  form,
  onChange,
  onClose,
  onSubmit,
  submitting,
}: {
  mode: "create" | "edit";
  target: IpEntrySummary | null;
  form: IpEntryForm;
  onChange: (patch: Partial<IpEntryForm>) => void;
  onClose: () => void;
  onSubmit: () => void;
  submitting: boolean;
}) {
  const title =
    mode === "create" ? "新建IP条目" : `编辑IP条目：${target?.ipValue ?? ""}`;
  return (
    <ModalShell title={title} onClose={onClose}>
      <div className="space-y-3">
        <LabeledInput
          label="IP地址/网段"
          value={form.ipValue}
          onChange={(v) => onChange({ ipValue: v })}
          placeholder="如：192.168.1.5 或 10.0.0.0/24"
        />
        <div
          className="text-base font-bold px-2 py-1.5 rounded-sm"
          style={{ color: N, background: "rgba(var(--dms-bright-rgb),0.05)" }}
        >
          支持精确IP（IPv4/IPv6）或无主机位的CIDR网段；输入会被自动规范化，
          网段不允许携带主机位（如 10.0.0.1/24 将被拒绝）。
        </div>
        <LabeledInput
          label="备注"
          value={form.remark}
          onChange={(v) => onChange({ remark: v })}
          placeholder="选填，如：总部办公网段"
        />
      </div>
      <ModalFooter
        onClose={onClose}
        onSubmit={onSubmit}
        submitting={submitting}
        submitLabel={mode === "create" ? "创建" : "保存"}
      />
    </ModalShell>
  );
}