import { useState, useEffect, useCallback } from "react";
import { useTranslation } from "react-i18next";
import { openUrl } from "@tauri-apps/plugin-opener";
import { KeyRound, CheckCircle, AlertCircle, Loader2, ExternalLink, Monitor, ChevronDown, ChevronUp } from "lucide-react";
import { useLicense } from "../../hooks/useLicense";
import {
  MachineInfo,
  ActivationStatus,
  activateMachine,
  deactivateMachine,
  listActivatedMachines,
  getActivationStatus,
} from "../../services/licenseService";

const PURCHASE_URL = "https://lacompagniemaximus.com/simpl-resultat";

export default function LicenseCard() {
  const { t } = useTranslation();
  const { state, submitKey } = useLicense();
  const [keyInput, setKeyInput] = useState("");
  const [showInput, setShowInput] = useState(false);
  const [showMachines, setShowMachines] = useState(false);
  const [machines, setMachines] = useState<MachineInfo[]>([]);
  const [activation, setActivation] = useState<ActivationStatus | null>(null);
  const [machineLoading, setMachineLoading] = useState(false);
  const [deactivatingId, setDeactivatingId] = useState<string | null>(null);
  const [machineError, setMachineError] = useState<string | null>(null);

  const hasLicense = state.edition !== "free";

  const loadActivation = useCallback(async () => {
    if (!hasLicense) return;
    try {
      const status = await getActivationStatus();
      setActivation(status);
    } catch {
      // Ignore — activation status is best-effort
    }
  }, [hasLicense]);

  const loadMachines = useCallback(async () => {
    setMachineLoading(true);
    setMachineError(null);
    try {
      const list = await listActivatedMachines();
      setMachines(list);
    } catch (e) {
      setMachineError(e instanceof Error ? e.message : String(e));
    } finally {
      setMachineLoading(false);
    }
  }, []);

  useEffect(() => {
    void loadActivation();
  }, [loadActivation]);

  const handleActivate = async () => {
    setMachineLoading(true);
    setMachineError(null);
    try {
      await activateMachine();
      await loadActivation();
    } catch (e) {
      setMachineError(e instanceof Error ? e.message : String(e));
    } finally {
      setMachineLoading(false);
    }
  };

  const handleDeactivate = async (machineId: string) => {
    setDeactivatingId(machineId);
    try {
      await deactivateMachine(machineId);
      await loadActivation();
      await loadMachines();
    } catch (e) {
      setMachineError(e instanceof Error ? e.message : String(e));
    } finally {
      setDeactivatingId(null);
    }
  };

  const toggleMachines = async () => {
    const next = !showMachines;
    setShowMachines(next);
    if (next && machines.length === 0) {
      await loadMachines();
    }
  };

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    const trimmed = keyInput.trim();
    if (!trimmed) return;
    const result = await submitKey(trimmed);
    if (result.ok) {
      setKeyInput("");
      setShowInput(false);
    }
  };

  const handlePurchase = () => {
    void openUrl(PURCHASE_URL);
  };

  const formatExpiry = (timestamp: number) => {
    return new Date(timestamp * 1000).toLocaleDateString();
  };

  const editionLabel = t(`license.editions.${state.edition}`);

  return (
    <div className="bg-[var(--card)] border border-[var(--border)] rounded-xl p-6 space-y-4">
      <h2 className="text-lg font-semibold flex items-center gap-2">
        <KeyRound size={18} />
        {t("license.title")}
      </h2>

      <div className="flex items-center justify-between">
        <div>
          <p className="text-sm text-[var(--muted-foreground)]">
            {t("license.currentEdition")}
          </p>
          <p className="text-base font-medium">
            {editionLabel}
            {state.edition !== "free" && (
              <CheckCircle size={16} className="inline ml-2 text-[var(--positive)]" />
            )}
          </p>
        </div>
        {state.info && state.info.expires_at > 0 && (
          <div className="text-right">
            <p className="text-xs text-[var(--muted-foreground)]">
              {t("license.expiresAt")}
            </p>
            <p className="text-sm">{formatExpiry(state.info.expires_at)}</p>
          </div>
        )}
      </div>

      {state.status === "error" && state.error && (
        <div className="flex items-start gap-2 text-sm text-[var(--negative)]">
          <AlertCircle size={16} className="mt-0.5 shrink-0" />
          <p>{state.error}</p>
        </div>
      )}

      {!showInput && (
        <div className="flex flex-wrap gap-3">
          <button
            type="button"
            onClick={() => setShowInput(true)}
            className="px-4 py-2 border border-[var(--border)] rounded-lg hover:bg-[var(--border)] transition-colors text-sm"
          >
            {t("license.enterKey")}
          </button>
          {state.edition === "free" && (
            <button
              type="button"
              onClick={handlePurchase}
              className="flex items-center gap-2 px-4 py-2 bg-[var(--primary)] text-white rounded-lg hover:opacity-90 transition-opacity text-sm"
            >
              <ExternalLink size={14} />
              {t("license.purchase")}
            </button>
          )}
        </div>
      )}

      {showInput && (
        <form onSubmit={handleSubmit} className="space-y-3">
          <input
            type="text"
            value={keyInput}
            onChange={(e) => setKeyInput(e.target.value)}
            placeholder={t("license.keyPlaceholder")}
            className="w-full px-3 py-2 bg-[var(--background)] border border-[var(--border)] rounded-lg text-sm font-mono focus:outline-none focus:border-[var(--primary)]"
            autoFocus
          />
          <div className="flex gap-2">
            <button
              type="submit"
              disabled={state.status === "validating" || !keyInput.trim()}
              className="flex items-center gap-2 px-4 py-2 bg-[var(--primary)] text-white rounded-lg hover:opacity-90 transition-opacity text-sm disabled:opacity-50"
            >
              {state.status === "validating" && <Loader2 size={14} className="animate-spin" />}
              {t("license.activate")}
            </button>
            <button
              type="button"
              onClick={() => {
                setShowInput(false);
                setKeyInput("");
              }}
              className="px-4 py-2 border border-[var(--border)] rounded-lg hover:bg-[var(--border)] transition-colors text-sm"
            >
              {t("common.cancel")}
            </button>
          </div>
        </form>
      )}

      {hasLicense && (
        <div className="border-t border-[var(--border)] pt-4 space-y-3">
          <div className="flex items-center justify-between">
            <h3 className="text-sm font-medium flex items-center gap-2">
              <Monitor size={16} />
              {t("license.machines.title")}
            </h3>
            <div className="flex items-center gap-2">
              {activation && !activation.is_activated && (
                <button
                  type="button"
                  onClick={handleActivate}
                  disabled={machineLoading}
                  className="flex items-center gap-1 px-3 py-1 bg-[var(--primary)] text-white rounded-lg hover:opacity-90 transition-opacity text-xs disabled:opacity-50"
                >
                  {machineLoading && <Loader2 size={12} className="animate-spin" />}
                  {t("license.activate")}
                </button>
              )}
              {activation?.is_activated && (
                <span className="flex items-center gap-1 text-xs text-[var(--positive)]">
                  <CheckCircle size={12} />
                  {t("license.machines.activated")}
                </span>
              )}
              <button
                type="button"
                onClick={toggleMachines}
                className="p-1 hover:bg-[var(--border)] rounded transition-colors"
              >
                {showMachines ? <ChevronUp size={16} /> : <ChevronDown size={16} />}
              </button>
            </div>
          </div>

          {machineError && (
            <div className="flex items-start gap-2 text-xs text-[var(--negative)]">
              <AlertCircle size={14} className="mt-0.5 shrink-0" />
              <p>{machineError}</p>
            </div>
          )}

          {showMachines && (
            <div className="space-y-2">
              {machineLoading && machines.length === 0 && (
                <div className="flex items-center gap-2 text-xs text-[var(--muted-foreground)]">
                  <Loader2 size={12} className="animate-spin" />
                  {t("common.loading")}
                </div>
              )}
              {!machineLoading && machines.length === 0 && (
                <p className="text-xs text-[var(--muted-foreground)]">
                  {t("license.machines.noMachines")}
                </p>
              )}
              {machines.map((m) => {
                const isThis = activation?.machine_id === m.machine_id;
                return (
                  <div
                    key={m.machine_id}
                    className="flex items-center justify-between px-3 py-2 bg-[var(--background)] border border-[var(--border)] rounded-lg text-sm"
                  >
                    <div>
                      <span className="font-medium">
                        {m.machine_name || m.machine_id.slice(0, 12)}
                      </span>
                      {isThis && (
                        <span className="ml-2 text-xs text-[var(--positive)]">
                          ({t("license.machines.thisMachine")})
                        </span>
                      )}
                      <p className="text-xs text-[var(--muted-foreground)]">
                        {new Date(m.activated_at).toLocaleDateString()}
                      </p>
                    </div>
                    <button
                      type="button"
                      onClick={() => handleDeactivate(m.machine_id)}
                      disabled={deactivatingId === m.machine_id}
                      className="flex items-center gap-1 px-2 py-1 text-xs border border-[var(--border)] rounded hover:bg-[var(--border)] transition-colors disabled:opacity-50"
                    >
                      {deactivatingId === m.machine_id && (
                        <Loader2 size={10} className="animate-spin" />
                      )}
                      {t("license.machines.deactivate")}
                    </button>
                  </div>
                );
              })}
            </div>
          )}
        </div>
      )}
    </div>
  );
}