import { useState } from "react";
import { useQuery } from "@tanstack/react-query";
import { motion } from "framer-motion";
import { useAuth } from "../context/AuthContext";
import { useAlert } from "../context/AlertContext";
import Forbidden from "../components/Forbidden";
import Pagination from "../components/Pagination";
import FormField from "../components/FormField";
import FormModal from "../components/FormModal";
import AdminDatePicker from "../components/AdminDatePicker";
import { czechPlural } from "../utils/formatters";
import apiFetch from "../utils/api";
import { useApiMutation } from "../lib/queries/mutations";
import { ENTITY_TYPE_LABELS } from "../lib/entityTypeLabels";

const API_BASE = "/api/admin";

const ACTION_LABELS: Record<string, string> = {
  create: "Vytvoření",
  update: "Úprava",
  delete: "Smazání",
  login: "Přihlášení",
  login_failed: "Neúspěšné přihlášení",
  logout: "Odhlášení",
  view: "Zobrazení",
  activate: "Aktivace",
  deactivate: "Deaktivace",
  password_change: "Změna hesla",
  permission_change: "Změna oprávnění",
  access_denied: "Přístup odepřen",
};

const ACTION_BADGE_CLASS: Record<string, string> = {
  create: "admin-badge-success",
  update: "admin-badge-info",
  delete: "admin-badge-danger",
  login: "admin-badge-secondary",
  login_failed: "admin-badge-danger",
  logout: "admin-badge-secondary",
  view: "admin-badge-info",
  activate: "admin-badge-success",
  deactivate: "admin-badge-warning",
  password_change: "admin-badge-info",
  permission_change: "admin-badge-warning",
  access_denied: "admin-badge-danger",
};

const ACTION_OPTIONS = Object.entries(ACTION_LABELS).map(([value, label]) => ({
  value,
  label,
}));
const ENTITY_OPTIONS = Object.entries(ENTITY_TYPE_LABELS).map(
  ([value, label]) => ({ value, label }),
);

interface AuditLogEntry {
  id: number;
  created_at: string;
  username: string | null;
  action: string;
  entity_type: string | null;
  description: string | null;
  user_ip: string | null;
}

interface Filters {
  search: string;
  action: string;
  entity_type: string;
  date_from: string;
  date_to: string;
}

export default function AuditLog() {
  const { hasPermission } = useAuth();
  const alert = useAlert();
  const [filters, setFilters] = useState<Filters>({
    search: "",
    action: "",
    entity_type: "",
    date_from: "",
    date_to: "",
  });
  const [page, setPage] = useState(1);
  const [perPage, setPerPage] = useState(50);
  const [showCleanup, setShowCleanup] = useState(false);
  const [cleanupDays, setCleanupDays] = useState(90);

  const { data: logsData, isPending } = useQuery({
    queryKey: [
      "audit-log",
      {
        search: filters.search,
        action: filters.action,
        entityType: filters.entity_type,
        dateFrom: filters.date_from,
        dateTo: filters.date_to,
        page,
        perPage,
      },
    ],
    queryFn: async () => {
      const params = new URLSearchParams({
        page: String(page),
        per_page: String(perPage),
      });
      if (filters.search) params.set("search", filters.search);
      if (filters.action) params.set("action", filters.action);
      if (filters.entity_type) params.set("entity_type", filters.entity_type);
      if (filters.date_from) params.set("date_from", filters.date_from);
      if (filters.date_to) params.set("date_to", filters.date_to);

      const response = await apiFetch(
        `${API_BASE}/audit-log?${params.toString()}`,
      );
      if (response.status === 401) throw new Error("Unauthorized");
      const result = await response.json();
      if (!result.success)
        throw new Error(result.error || "Nepodařilo se načíst audit log");
      return {
        data: Array.isArray(result.data) ? result.data : [],
        pagination: {
          total: result.pagination?.total ?? 0,
          page: result.pagination?.page ?? 1,
          per_page: result.pagination?.limit ?? perPage,
          total_pages: result.pagination?.total_pages ?? 1,
        },
      };
    },
  });

  const logs: AuditLogEntry[] = logsData?.data ?? [];
  const pagination = logsData?.pagination ?? null;

  if (!hasPermission("settings.audit")) {
    return <Forbidden />;
  }

  const cleanupMutation = useApiMutation<
    { days: number; confirm?: string },
    { message?: string; error?: string }
  >({
    url: () => `${API_BASE}/audit-log/cleanup`,
    method: () => "POST",
    invalidate: ["audit-log"],
    onSuccess: (data) => {
      alert.success(data?.message || "Hotovo");
      setShowCleanup(false);
    },
  });

  const handleFilterChange = (key: keyof Filters, value: string) => {
    setFilters((prev) => ({ ...prev, [key]: value }));
    setPage(1);
  };

  const handlePageChange = (newPage: number) => {
    setPage(newPage);
  };

  const handlePerPageChange = (newPerPage: number) => {
    setPage(1);
    setPerPage(newPerPage);
  };

  const handleCleanup = async () => {
    try {
      // Backend requires this literal confirmation token when wiping everything.
      await cleanupMutation.mutateAsync({
        days: cleanupDays,
        ...(cleanupDays === 0 ? { confirm: "DELETE_ALL_AUDIT" } : {}),
      });
    } catch (e) {
      alert.error(e instanceof Error ? e.message : "Chyba připojení");
    }
  };

  const formatDatetime = (dateString: string | null): string => {
    if (!dateString) return "-";
    return new Date(dateString).toLocaleString("cs-CZ");
  };

  if (isPending && logs.length === 0) {
    return (
      <div className="admin-loading">
        <div className="admin-spinner" />
      </div>
    );
  }

  return (
    <div>
      <motion.div
        className="admin-page-header"
        initial={{ opacity: 0, y: 12 }}
        animate={{ opacity: 1, y: 0 }}
        transition={{ duration: 0.25 }}
      >
        <div>
          <h1 className="admin-page-title">Audit log</h1>
          {pagination && (
            <p className="admin-page-subtitle">
              {pagination.total}{" "}
              {czechPlural(pagination.total, "záznam", "záznamy", "záznamů")}
            </p>
          )}
        </div>
        <button
          className="admin-btn admin-btn-secondary admin-btn-sm"
          onClick={() => setShowCleanup(true)}
        >
          <svg
            width="14"
            height="14"
            viewBox="0 0 24 24"
            fill="none"
            stroke="currentColor"
            strokeWidth="2"
          >
            <polyline points="3 6 5 6 21 6" />
            <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2" />
          </svg>
          Vyčistit
        </button>
      </motion.div>

      <FormModal
        isOpen={showCleanup}
        onClose={() => !cleanupMutation.isPending && setShowCleanup(false)}
        onSubmit={handleCleanup}
        title="Vyčistit audit log"
        submitLabel="Smazat"
        loading={cleanupMutation.isPending}
      >
        <p className="admin-confirm-message">Smazat záznamy starší než:</p>
        <div style={{ margin: "0.75rem 0", maxWidth: "200px" }}>
          <select
            className="admin-form-select"
            value={cleanupDays}
            onChange={(e) => setCleanupDays(parseInt(e.target.value))}
          >
            <option value={30}>30 dní</option>
            <option value={60}>60 dní</option>
            <option value={90}>90 dní</option>
            <option value={180}>180 dní</option>
            <option value={365}>1 rok</option>
            <option value={0}>Vše</option>
          </select>
        </div>
        <p
          className="admin-confirm-message"
          style={{ fontSize: "12px", opacity: 0.6 }}
        >
          Tato akce je nevratná.
        </p>
      </FormModal>

      <motion.div
        className="admin-card mb-4"
        initial={{ opacity: 0, y: 12 }}
        animate={{ opacity: 1, y: 0 }}
        transition={{ duration: 0.25, delay: 0.06 }}
      >
        <div className="admin-card-body">
          <div className="admin-form-row admin-form-row-5">
            <FormField label="Hledat">
              <input
                type="text"
                className="admin-form-input"
                placeholder="Popis, uživatel..."
                value={filters.search}
                onChange={(e) => handleFilterChange("search", e.target.value)}
              />
            </FormField>
            <FormField label="Akce">
              <select
                className="admin-form-select"
                value={filters.action}
                onChange={(e) => handleFilterChange("action", e.target.value)}
              >
                <option value="">Všechny</option>
                {ACTION_OPTIONS.map((opt) => (
                  <option key={opt.value} value={opt.value}>
                    {opt.label}
                  </option>
                ))}
              </select>
            </FormField>
            <FormField label="Typ entity">
              <select
                className="admin-form-select"
                value={filters.entity_type}
                onChange={(e) =>
                  handleFilterChange("entity_type", e.target.value)
                }
              >
                <option value="">Všechny</option>
                {ENTITY_OPTIONS.map((opt) => (
                  <option key={opt.value} value={opt.value}>
                    {opt.label}
                  </option>
                ))}
              </select>
            </FormField>
            <FormField label="Od">
              <AdminDatePicker
                mode="date"
                value={filters.date_from}
                onChange={(val: string) => handleFilterChange("date_from", val)}
              />
            </FormField>
            <FormField label="Do">
              <AdminDatePicker
                mode="date"
                value={filters.date_to}
                onChange={(val: string) => handleFilterChange("date_to", val)}
              />
            </FormField>
          </div>
        </div>
      </motion.div>

      <motion.div
        className="admin-card"
        initial={{ opacity: 0, y: 12 }}
        animate={{ opacity: 1, y: 0 }}
        transition={{ duration: 0.25, delay: 0.08 }}
      >
        <div className="admin-card-body">
          <div className="admin-table-responsive">
            {isPending ? (
              <div className="admin-loading">
                <div className="admin-spinner" />
              </div>
            ) : (
              <table className="admin-table">
                <thead>
                  <tr>
                    <th>Čas</th>
                    <th>Uživatel</th>
                    <th>Akce</th>
                    <th>Typ entity</th>
                    <th>Popis</th>
                    <th>IP</th>
                  </tr>
                </thead>
                <tbody>
                  {logs.length === 0 && (
                    <tr>
                      <td colSpan={6}>
                        <div className="admin-empty-state">
                          <div className="admin-empty-icon">
                            <svg
                              width="28"
                              height="28"
                              viewBox="0 0 24 24"
                              fill="none"
                              stroke="currentColor"
                              strokeWidth="1.5"
                            >
                              <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" />
                              <polyline points="14 2 14 8 20 8" />
                              <line x1="16" y1="13" x2="8" y2="13" />
                              <line x1="16" y1="17" x2="8" y2="17" />
                            </svg>
                          </div>
                          <p>Žádné záznamy k zobrazení</p>
                        </div>
                      </td>
                    </tr>
                  )}
                  {logs.length > 0 &&
                    logs.map((log) => (
                      <tr key={log.id}>
                        <td className="admin-mono">
                          {formatDatetime(log.created_at)}
                        </td>
                        <td className="fw-500">{log.username || "-"}</td>
                        <td>
                          <span
                            className={`admin-badge ${ACTION_BADGE_CLASS[log.action] || "admin-badge-secondary"}`}
                          >
                            {ACTION_LABELS[log.action] || log.action}
                          </span>
                        </td>
                        <td>
                          {ENTITY_TYPE_LABELS[log.entity_type || ""] ||
                            log.entity_type ||
                            "-"}
                        </td>
                        <td>{log.description || "-"}</td>
                        <td className="admin-mono">{log.user_ip || "-"}</td>
                      </tr>
                    ))}
                </tbody>
              </table>
            )}
          </div>

          <Pagination
            pagination={pagination}
            onPageChange={handlePageChange}
            onPerPageChange={handlePerPageChange}
          />
        </div>
      </motion.div>
    </div>
  );
}