import { useState, useEffect, useCallback } from "react";
import { Link } from "react-router-dom";
import { motion } from "framer-motion";
import { useAuth } from "../context/AuthContext";
import { useAlert } from "../context/AlertContext";
import useModalLock from "../hooks/useModalLock";
import apiFetch from "../utils/api";
import { getCzechDate } from "../utils/dashboardHelpers";
import DashKpiCards from "../components/dashboard/DashKpiCards";
import DashQuickActions from "../components/dashboard/DashQuickActions";
import DashActivityFeed from "../components/dashboard/DashActivityFeed";
import DashAttendanceToday from "../components/dashboard/DashAttendanceToday";
import DashProfile from "../components/dashboard/DashProfile";
import DashSessions from "../components/dashboard/DashSessions";

const API_BASE = "/api/admin";

interface DashData {
  my_shift?: { has_ongoing: boolean };
  attendance?: {
    present_today: number;
    total_active: number;
    on_leave: number;
    users: Array<{
      user_id: number | string;
      name: string;
      initials?: string;
      status: string;
      leave_type?: string;
      arrived_at?: string;
    }>;
  };
  offers?: {
    open_count: number;
    converted_count: number;
    expired_count: number;
    created_this_month: number;
  };
  projects?: {
    active_projects: Array<{
      id: number;
      name: string;
      customer_name: string | null;
    }>;
  };
  invoices?: {
    revenue_this_month: Array<{ amount: number; currency: string }>;
    unpaid_count: number;
    revenue_czk: number | null;
  };
  leave_pending?: { count: number };
  recent_activity?: Array<{
    id: number | string;
    action: string;
    entity_type: string;
    description: string;
    username?: string;
    created_at: string;
  }>;
  users_count?: number;
  active_projects?: number;
  pending_orders?: number;
  unpaid_invoices?: number;
  pending_leave_requests?: number;
  [key: string]: unknown;
}

export default function Dashboard() {
  const { user, updateUser, hasPermission } = useAuth();
  const alert = useAlert();

  const [dashData, setDashData] = useState<DashData | null>(null);
  const [dashLoading, setDashLoading] = useState(true);
  const [punching, setPunching] = useState(false);

  // 2FA state - sdileny mezi profilem a bannerem
  const [totpEnabled, setTotpEnabled] = useState(false);
  const [totpLoading, setTotpLoading] = useState(true);
  const [show2FASetup, setShow2FASetup] = useState(false);
  const [show2FADisable, setShow2FADisable] = useState(false);
  const [totpSecret, setTotpSecret] = useState<string | null>(null);
  const [totpQrUri, setTotpQrUri] = useState<string | null>(null);
  const [totpCode, setTotpCode] = useState("");
  const [totpSubmitting, setTotpSubmitting] = useState(false);
  const [backupCodes, setBackupCodes] = useState<string[] | null>(null);
  const [disableCode, setDisableCode] = useState("");

  useModalLock(show2FASetup);
  useModalLock(show2FADisable);

  const fetchDashboard = useCallback(async () => {
    try {
      const response = await apiFetch(`${API_BASE}/dashboard`);
      const data = await response.json();
      if (data.success !== false) {
        setDashData(data.data || data);
      }
    } catch (err) {
      if (import.meta.env.DEV) {
        console.error("Dashboard fetch error:", err);
      }
    } finally {
      setDashLoading(false);
    }
  }, []);

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

  // 2FA status fetch
  const fetch2FAStatus = useCallback(async () => {
    try {
      const response = await apiFetch(`${API_BASE}/totp/setup`);
      const data = await response.json();
      if (data.success) {
        setTotpEnabled(!!user?.totpEnabled);
      }
    } catch {
      // 2FA status fetch failed silently
      setTotpEnabled(!!user?.totpEnabled);
    } finally {
      setTotpLoading(false);
    }
  }, [user?.totpEnabled]);

  useEffect(() => {
    fetch2FAStatus();
  }, [fetch2FAStatus]);

  // Punch (prichod/odchod) primo z dashboardu
  const handleQuickPunch = () => {
    const action = dashData?.my_shift?.has_ongoing ? "departure" : "arrival";
    setPunching(true);

    const submitPunch = async (gpsData: Record<string, unknown> = {}) => {
      try {
        const response = await apiFetch(`${API_BASE}/attendance`, {
          method: "POST",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify({ punch_action: action, ...gpsData }),
        });
        const result = await response.json();
        if (result.success) {
          alert.success(result.data?.message || "Docházka zaznamenána");
          fetchDashboard();
        } else {
          alert.error(result.error || "Chyba při záznamu docházky");
        }
      } catch {
        alert.error("Chyba pripojeni");
      } finally {
        setPunching(false);
      }
    };

    if (!navigator.geolocation) {
      submitPunch({});
      return;
    }

    navigator.geolocation.getCurrentPosition(
      (pos) => {
        const { latitude, longitude, accuracy } = pos.coords;
        submitPunch({ latitude, longitude, accuracy, address: "" });
      },
      () => submitPunch({}),
      { enableHighAccuracy: true, timeout: 10000, maximumAge: 60000 },
    );
  };

  // 2FA handlery
  const handleStart2FASetup = async () => {
    setTotpSubmitting(true);
    try {
      const response = await apiFetch(`${API_BASE}/totp/setup`);
      const data = await response.json();
      if (data.success) {
        setTotpSecret(data.data.secret);
        setTotpQrUri(data.data.uri || data.data.qr_uri);
        setTotpCode("");
        setBackupCodes(null);
        setShow2FASetup(true);
      } else {
        alert.error(data.error || "Nepodařilo se vygenerovat 2FA klíč");
      }
    } catch {
      alert.error("Chyba připojení");
    } finally {
      setTotpSubmitting(false);
    }
  };

  const handleConfirm2FA = async () => {
    if (!totpCode.trim()) return;
    setTotpSubmitting(true);
    try {
      const response = await apiFetch(`${API_BASE}/totp/enable`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ secret: totpSecret, code: totpCode.trim() }),
      });
      const data = await response.json();
      if (data.success) {
        setTotpEnabled(true);
        setBackupCodes(data.data?.backup_codes || null);
        setTotpSecret(null);
        setTotpQrUri(null);
        updateUser({ totpEnabled: true });
        alert.success("2FA bylo aktivováno");
      } else {
        alert.error(data.error || "Neplatný kód");
        setTotpCode("");
      }
    } catch {
      alert.error("Chyba připojení");
    } finally {
      setTotpSubmitting(false);
    }
  };

  const handleDisable2FA = async () => {
    if (!disableCode.trim()) return;
    setTotpSubmitting(true);
    try {
      const response = await apiFetch(`${API_BASE}/totp/disable`, {
        method: "PUT",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ code: disableCode.trim() }),
      });
      const data = await response.json();
      if (data.success) {
        setTotpEnabled(false);
        setShow2FADisable(false);
        setDisableCode("");
        updateUser({ totpEnabled: false });
        alert.success("2FA bylo deaktivováno");
      } else {
        alert.error(data.error || "Neplatný kód");
        setDisableCode("");
      }
    } catch {
      alert.error("Chyba připojení");
    } finally {
      setTotpSubmitting(false);
    }
  };

  return (
    <div className="dash">
      {/* Header */}
      <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">
            Vítejte zpět, {user?.fullName || user?.username}
          </h1>
          <p className="admin-page-subtitle">{getCzechDate()}</p>
        </div>
      </motion.div>

      {/* 2FA Required Banner */}
      {user?.require2FA && !user?.totpEnabled && (
        <motion.div
          className="admin-card"
          initial={{ opacity: 0, y: 12 }}
          animate={{ opacity: 1, y: 0 }}
          transition={{ duration: 0.25, delay: 0.06 }}
          style={{
            border: "2px solid var(--danger)",
            background: "var(--danger-light)",
          }}
        >
          <div
            className="admin-card-body"
            style={{
              display: "flex",
              alignItems: "center",
              justifyContent: "space-between",
              gap: "1rem",
              flexWrap: "wrap",
            }}
          >
            <div className="flex-row-gap">
              <div
                style={{
                  width: 40,
                  height: 40,
                  borderRadius: "50%",
                  display: "flex",
                  alignItems: "center",
                  justifyContent: "center",
                  background: "var(--danger-light)",
                  color: "var(--danger)",
                  flexShrink: 0,
                }}
              >
                <svg
                  width="20"
                  height="20"
                  viewBox="0 0 24 24"
                  fill="none"
                  stroke="currentColor"
                  strokeWidth="2"
                >
                  <path d="M10.29 3.86L1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z" />
                  <line x1="12" y1="9" x2="12" y2="13" />
                  <line x1="12" y1="17" x2="12.01" y2="17" />
                </svg>
              </div>
              <div>
                <div className="fw-600">Dvoufaktorové ověření je povinné</div>
                <div
                  className="text-secondary"
                  style={{ fontSize: "0.875rem" }}
                >
                  Administrátor vyžaduje aktivaci 2FA. Dokud ji neaktivujete,
                  nemáte přístup k ostatním sekcím systému.
                </div>
              </div>
            </div>
            <button
              onClick={handleStart2FASetup}
              disabled={totpSubmitting}
              className="admin-btn admin-btn-primary"
              style={{ flexShrink: 0 }}
            >
              {totpSubmitting ? "Generuji..." : "Aktivovat 2FA nyní"}
            </button>
          </div>
        </motion.div>
      )}

      {/* Skeleton loading */}
      {dashLoading && (
        <div className="admin-skeleton" style={{ padding: 0, gap: "1.25rem" }}>
          <div className="admin-kpi-grid admin-kpi-4">
            {[0, 1, 2, 3].map((i) => (
              <div
                key={i}
                className="admin-skeleton-line h-24"
                style={{ borderRadius: "10px" }}
              />
            ))}
          </div>
          <div className="dash-quick-actions">
            {[0, 1, 2, 3].map((i) => (
              <div
                key={i}
                className="admin-skeleton-line"
                style={{ height: "52px", borderRadius: "10px" }}
              />
            ))}
          </div>
          <div className="dash-main-grid">
            <div
              className="admin-skeleton-line"
              style={{ height: "320px", borderRadius: "10px" }}
            />
            <div
              className="admin-skeleton-line"
              style={{ height: "320px", borderRadius: "10px" }}
            />
            <div
              style={{
                display: "flex",
                flexDirection: "column",
                gap: "1.25rem",
              }}
            >
              <div
                className="admin-skeleton-line"
                style={{ height: "150px", borderRadius: "10px" }}
              />
              <div
                className="admin-skeleton-line"
                style={{ height: "150px", borderRadius: "10px" }}
              />
            </div>
          </div>
          <div className="dash-bottom">
            <div
              className="admin-skeleton-line"
              style={{ height: "200px", borderRadius: "10px" }}
            />
            <div
              className="admin-skeleton-line"
              style={{ height: "200px", borderRadius: "10px" }}
            />
          </div>
        </div>
      )}

      {/* KPI cards — only show if user has any admin-level permissions */}
      {!dashLoading &&
        (hasPermission("offers.view") ||
          hasPermission("invoices.view") ||
          hasPermission("projects.view") ||
          hasPermission("orders.view")) && <DashKpiCards dashData={dashData} />}

      {/* Quick actions */}
      {!dashLoading && (
        <DashQuickActions
          dashData={dashData}
          punching={punching}
          onPunch={handleQuickPunch}
        />
      )}

      {/* Main content grid */}
      {!dashLoading && (
        <motion.div
          className="dash-main-grid"
          initial={{ opacity: 0, y: 12 }}
          animate={{ opacity: 1, y: 0 }}
          transition={{ duration: 0.25, delay: 0.12 }}
        >
          {hasPermission("settings.audit") && (
            <DashActivityFeed activities={dashData?.recent_activity ?? null} />
          )}

          {hasPermission("attendance.admin") && (
            <DashAttendanceToday attendance={dashData?.attendance ?? null} />
          )}

          {/* Pravy sloupec: projekty + nabidky */}
          <div className="dash-right-col">
            {dashData?.projects && (
              <div className="admin-card">
                <div className="admin-card-header flex-between">
                  <h2 className="admin-card-title">Aktivní projekty</h2>
                  <Link
                    to="/projects"
                    className="admin-btn admin-btn-primary admin-btn-sm"
                  >
                    Vše &rarr;
                  </Link>
                </div>
                <div className="admin-card-body" style={{ padding: 0 }}>
                  {dashData.projects.active_projects.length === 0 && (
                    <div className="dash-empty-row">Žádné aktivní projekty</div>
                  )}
                  {dashData.projects.active_projects.map(
                    (p: {
                      id: number;
                      name: string;
                      customer_name: string | null;
                    }) => (
                      <Link
                        key={p.id}
                        to={`/projects/${p.id}`}
                        className="dash-project-row"
                      >
                        <div className="dash-project-name">{p.name}</div>
                        {p.customer_name && (
                          <div className="dash-project-customer">
                            {p.customer_name}
                          </div>
                        )}
                      </Link>
                    ),
                  )}
                </div>
              </div>
            )}

            {dashData?.offers && (
              <div className="admin-card">
                <div className="admin-card-header flex-between">
                  <h2 className="admin-card-title">Nabídky</h2>
                  <Link
                    to="/offers"
                    className="admin-btn admin-btn-primary admin-btn-sm"
                  >
                    Zobrazit &rarr;
                  </Link>
                </div>
                <div className="admin-card-body" style={{ padding: 0 }}>
                  <div className="dash-stat-row">
                    <span>Otevřené</span>
                    <span className="admin-badge admin-badge-info">
                      {dashData.offers.open_count}
                    </span>
                  </div>
                  <div className="dash-stat-row">
                    <span>Převedené na objednávku</span>
                    <span className="admin-badge admin-badge-success">
                      {dashData.offers.converted_count}
                    </span>
                  </div>
                  <div className="dash-stat-row">
                    <span>Zneplatněné</span>
                    <span className="admin-badge admin-badge-warning">
                      {dashData.offers.expired_count}
                    </span>
                  </div>
                </div>
              </div>
            )}
          </div>
        </motion.div>
      )}

      {/* Profile + Sessions */}
      {!dashLoading && (
        <div className="dash-bottom">
          <DashProfile
            totpEnabled={totpEnabled}
            totpLoading={totpLoading}
            totpSubmitting={totpSubmitting}
            onStart2FASetup={handleStart2FASetup}
            onConfirm2FA={handleConfirm2FA}
            onDisable2FA={handleDisable2FA}
            totpSecret={totpSecret}
            totpQrUri={totpQrUri}
            totpCode={totpCode}
            setTotpCode={setTotpCode}
            backupCodes={backupCodes}
            setBackupCodes={setBackupCodes}
            show2FASetup={show2FASetup}
            setShow2FASetup={setShow2FASetup}
            show2FADisable={show2FADisable}
            setShow2FADisable={setShow2FADisable}
            disableCode={disableCode}
            setDisableCode={setDisableCode}
          />
          <DashSessions />
        </div>
      )}
    </div>
  );
}