import React, { useEffect, useMemo, useState } from "react";
import axios from "axios";
import { Button } from "@heroui/react";
import { useTranslation } from "react-i18next";
import AdminUsersTable from "@/components/admin/users/AdminUsersTable";
import AdminUserForm from "@/components/admin/users/AdminUserForm";

type UserItem = {
  id: number;
  name: string;
  email: string;
  is_admin: boolean;
  is_active: boolean;
};

type FormMode = "none" | "create" | "edit";

type PaginatedResponse<T> = {
  data: T[];
};

export default function AdminUsersPage() {
  const { t } = useTranslation("common");
  const [items, setItems] = useState<UserItem[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [refreshKey, setRefreshKey] = useState(0);
  const [query, setQuery] = useState("");

  const [formMode, setFormMode] = useState<FormMode>("none");
  const [editing, setEditing] = useState<UserItem | null>(null);
  const [submitting, setSubmitting] = useState(false);
  const [formError, setFormError] = useState<string | null>(null);

  useEffect(() => {
    let active = true;
    (async () => {
      try {
        setLoading(true);
        setError(null);
        const res = await axios.get<PaginatedResponse<UserItem>>("/api/users", {
          headers: { Accept: "application/json" },
          params: { per_page: 200, query },
          withCredentials: true,
        });
        if (!active) return;
        setItems(res.data.data ?? []);
      } catch (e: any) {
        if (!active) return;
        setError(
          e?.response?.data?.message ??
            (t("admin_users_load_failed") ?? "Nepodařilo se načíst uživatele.")
        );
      } finally {
        if (active) setLoading(false);
      }
    })();
    return () => {
      active = false;
    };
  }, [refreshKey, query, t]);

  const visibleItems = useMemo(() => items, [items]);

  const resetForm = () => {
    setEditing(null);
    setFormError(null);
  };

  const openCreate = () => {
    resetForm();
    setFormMode("create");
  };

  const openEdit = (item: UserItem) => {
    resetForm();
    setEditing(item);
    setFormMode("edit");
  };

  const deactivateUser = async (item: UserItem) => {
    try {
      await axios.delete(`/api/users/${item.id}`, {
        headers: { Accept: "application/json" },
        withCredentials: true,
        withXSRFToken: true,
      });
      setRefreshKey((k) => k + 1);
    } catch (e: any) {
      setError(
        e?.response?.data?.message ??
          (t("admin_users_deactivate_failed") ?? "Nepodařilo se deaktivovat uživatele.")
      );
    }
  };

  const handleSubmit = async (payload: {
    name: string;
    email: string;
    password?: string;
    is_admin: boolean;
    is_active: boolean;
  }) => {
    setFormError(null);

    try {
      setSubmitting(true);
      await axios.get("/sanctum/csrf-cookie", { withCredentials: true });

      if (formMode === "edit" && editing) {
        await axios.put(`/api/users/${editing.id}`, payload, {
          headers: { Accept: "application/json" },
          withCredentials: true,
          withXSRFToken: true,
        });
      } else {
        await axios.post("/api/users", payload, {
          headers: { Accept: "application/json" },
          withCredentials: true,
          withXSRFToken: true,
        });
      }
      setFormMode("none");
      resetForm();
      setRefreshKey((k) => k + 1);
    } catch (e: any) {
      setFormError(
        e?.response?.data?.message ??
          (t("admin_users_save_failed") ?? "Chyba při ukládání uživatele.")
      );
    } finally {
      setSubmitting(false);
    }
  };

  return (
    <div className="space-y-6">
      <div className="flex flex-wrap gap-3 items-center">
        <h1 className="text-xl font-semibold">{t("admin_users_title") ?? "Uživatelé"}</h1>
        <input
          type="text"
          value={query}
          onChange={(e) => setQuery(e.target.value)}
          placeholder={t("admin_users_search") ?? "Hledat jméno nebo email"}
          className="border rounded px-2 py-1 text-sm"
        />
      </div>

      {error && <div className="text-red-600 text-sm">{error}</div>}

      <AdminUsersTable
        items={visibleItems}
        loading={loading}
        onEdit={openEdit}
        onDeactivate={deactivateUser}
      />
      <Button onPress={openCreate}>{t("admin_users_create") ?? "Nový uživatel"}</Button>
      {formMode !== "none" && (
        <Button
          variant="light"
          onPress={() => {
            setFormMode("none");
            resetForm();
          }}
        >
          {t("admin_form_close") ?? "Zavřít formulář"}
        </Button>
      )}
      {formMode !== "none" && (
        <AdminUserForm
          mode={formMode}
          editing={editing}
          submitting={submitting}
          serverError={formError}
          onSubmit={handleSubmit}
          onCancel={() => {
            setFormMode("none");
            resetForm();
          }}
        />
      )}
    </div>
  );
}