import { useState, useEffect } from 'react';
import { useTranslation } from 'react-i18next';
import { useAuth } from '@/lib/auth';
import { api } from '@/lib/api';
import { useToast } from '@/hooks/useToast';
import { Phone, RefreshCw, Plus, X, ArrowLeft, Info } from 'lucide-react';

export default function WhatsAppNumbers() {
    const { t } = useTranslation();
    const { token } = useAuth();
    const toast = useToast();
    const [numbers, setNumbers] = useState<any[]>([]);
    const [loading, setLoading] = useState(true);

    const [showRegister, setShowRegister] = useState(false);
    const [regStep, setRegStep] = useState<1 | 2>(1);
    const [regOrgId, setRegOrgId] = useState('');
    const [regPhoneNumberId, setRegPhoneNumberId] = useState('');
    const [regPin, setRegPin] = useState('');
    const [regCode, setRegCode] = useState('');
    const [regLoading, setRegLoading] = useState(false);
    const [regError, setRegError] = useState('');
    const [orgOptions, setOrgOptions] = useState<{ id: string; name: string }[]>([]);

    async function load() {
        if (!token) return;
        setLoading(true);
        try {
            const data = await api.get('/v1/super-admin/whatsapp/numbers', token);
            setNumbers(data.data ?? []);
        } catch { toast.error(t('super_admin.err_load_numbers')); }
        finally { setLoading(false); }
    }

    useEffect(() => { load(); }, [token]);

    async function loadOrgs() {
        if (!token) return;
        try {
            const data = await api.get('/v1/super-admin/organizations?limit=100', token);
            setOrgOptions(data.data ?? []);
        } catch { /* ignore */ }
    }

    function openModal() {
        setRegStep(1);
        setRegOrgId('');
        setRegPhoneNumberId('');
        setRegPin('');
        setRegCode('');
        setRegError('');
        setRegLoading(false);
        setShowRegister(true);
        loadOrgs();
    }

    function closeModal() {
        setShowRegister(false);
        setRegStep(1);
        setRegOrgId('');
        setRegPhoneNumberId('');
        setRegPin('');
        setRegCode('');
        setRegError('');
        setRegLoading(false);
    }

    async function handleRegister() {
        setRegError('');
        if (!regOrgId) { setRegError(t('super_admin.wa_select_org_error')); return; }
        if (!regPhoneNumberId || !/^\d{12,18}$/.test(regPhoneNumberId)) {
            setRegError(t('super_admin.wa_phone_id_error'));
            return;
        }
        const pin = regPin.trim() === '' ? '000000' : regPin.trim();
        if (!/^\d{6}$/.test(pin)) { setRegError(t('super_admin.wa_pin_error')); return; }
        setRegLoading(true);
        try {
            const res = await api.post('/v1/super-admin/whatsapp/numbers/register', {
                orgId: regOrgId,
                phoneNumberId: regPhoneNumberId,
                pin,
            }, token);
            if (res.ok) {
                setRegStep(2);
            } else {
                setRegError(res.metaResponse?.detail || res.metaResponse?.message || t('super_admin.wa_reg_error'));
            }
        } catch (e: any) {
            setRegError(e?.message || t('super_admin.wa_net_error'));
        } finally {
            setRegLoading(false);
        }
    }

    async function handleVerify() {
        setRegError('');
        if (!regCode || !/^\d{4,8}$/.test(regCode)) {
            setRegError(t('super_admin.wa_otp_error'));
            return;
        }
        setRegLoading(true);
        try {
            const res = await api.post('/v1/super-admin/whatsapp/numbers/verify', {
                orgId: regOrgId,
                phoneNumberId: regPhoneNumberId,
                code: regCode,
            }, token);
            if (res.ok) {
                toast.success(t('super_admin.wa_number_registered'));
                closeModal();
                load();
            } else {
                setRegError(res.metaResponse?.detail || res.metaResponse?.message || t('super_admin.wa_otp_invalid'));
            }
        } catch (e: any) {
            setRegError(e?.message || t('super_admin.wa_net_error'));
        } finally {
            setRegLoading(false);
        }
    }

    const selectedOrg = orgOptions.find(o => o.id === regOrgId);

    return (
        <div className="space-y-4">
            <div className="flex items-center justify-between">
                <div>
                    <h1 className="text-xl font-bold text-white">{t('super_admin.wa_numbers_title')}</h1>
                    <p className="text-sm text-slate-400 mt-0.5">{t('super_admin.wa_numbers_total', { count: numbers.length })}</p>
                </div>
                <div className="flex items-center gap-2">
                    <button onClick={load} className="flex items-center gap-2 px-3 py-2 bg-slate-800 hover:bg-slate-700 text-slate-300 text-sm rounded-lg transition-colors">
                        <RefreshCw className="w-3.5 h-3.5" />
                        {t('super_admin.wa_refresh')}
                    </button>
                    <button onClick={openModal} className="flex items-center gap-2 px-3 py-2 bg-violet-600 hover:bg-violet-500 text-white text-sm rounded-lg transition-colors font-medium">
                        <Plus className="w-4 h-4" />
                        {t('super_admin.wa_register_number')}
                    </button>
                </div>
            </div>

            <div className="bg-slate-900 rounded-xl border border-slate-800 overflow-hidden">
                {loading ? (
                    <div className="p-8 text-center text-slate-500 animate-pulse">{t('super_admin.org_loading')}</div>
                ) : numbers.length === 0 ? (
                    <div className="p-12 flex flex-col items-center gap-3 text-slate-500">
                        <Phone className="w-8 h-8" />
                        <p>{t('super_admin.wa_no_numbers')}</p>
                    </div>
                ) : (
                    <div className="overflow-x-auto">
                        <table className="w-full text-sm">
                            <thead>
                                <tr className="border-b border-slate-800">
                                    <th className="text-left px-4 py-3 text-xs font-medium text-slate-400 uppercase tracking-wider">{t('super_admin.col_number')}</th>
                                    <th className="text-left px-4 py-3 text-xs font-medium text-slate-400 uppercase tracking-wider">{t('super_admin.col_org')}</th>
                                    <th className="text-left px-4 py-3 text-xs font-medium text-slate-400 uppercase tracking-wider">{t('super_admin.col_id')}</th>
                                    <th className="text-left px-4 py-3 text-xs font-medium text-slate-400 uppercase tracking-wider">{t('super_admin.col_added_at')}</th>
                                </tr>
                            </thead>
                            <tbody className="divide-y divide-slate-800">
                                {numbers.map(n => (
                                    <tr key={n.id} className="hover:bg-slate-800/50 transition-colors">
                                        <td className="px-4 py-3 font-medium text-white">{n.displayPhone}</td>
                                        <td className="px-4 py-3 text-slate-300">{n.organization?.name || '—'}</td>
                                        <td className="px-4 py-3 text-xs font-mono text-slate-500">{n.id}</td>
                                        <td className="px-4 py-3 text-xs text-slate-400">{new Date(n.createdAt).toLocaleDateString()}</td>
                                    </tr>
                                ))}
                            </tbody>
                        </table>
                    </div>
                )}
            </div>

            {showRegister && (
                <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 px-4">
                    <div className="bg-slate-900 border border-slate-700 rounded-2xl max-w-md w-full p-6 shadow-2xl">
                        <div className="flex items-start justify-between mb-5">
                            <div>
                                <h2 className="text-base font-semibold text-white">{t('super_admin.wa_register_title')}</h2>
                                <p className="text-xs text-slate-400 mt-0.5">{t('super_admin.wa_step', { step: regStep })}</p>
                            </div>
                            <button onClick={closeModal} className="text-slate-400 hover:text-white transition-colors ml-4 shrink-0">
                                <X className="w-5 h-5" />
                            </button>
                        </div>

                        {regStep === 1 && (
                            <div className="space-y-4">
                                <div>
                                    <label className="block text-xs font-medium text-slate-300 mb-1.5">{t('super_admin.label_org')}</label>
                                    <select
                                        value={regOrgId}
                                        onChange={e => setRegOrgId(e.target.value)}
                                        className="w-full bg-slate-800 border border-slate-700 text-white text-sm rounded-lg px-3 py-2 focus:outline-none focus:ring-2 focus:ring-violet-500 focus:border-transparent"
                                    >
                                        <option value="">{t('super_admin.org_select_placeholder')}</option>
                                        {orgOptions.map(o => (
                                            <option key={o.id} value={o.id}>{o.name}</option>
                                        ))}
                                    </select>
                                </div>

                                <div>
                                    <label className="block text-xs font-medium text-slate-300 mb-1.5">{t('super_admin.label_phone_number_id')}</label>
                                    <input
                                        type="text"
                                        inputMode="numeric"
                                        value={regPhoneNumberId}
                                        onChange={e => setRegPhoneNumberId(e.target.value.replace(/\D/g, ''))}
                                        placeholder="123456789012345"
                                        maxLength={18}
                                        className="w-full bg-slate-800 border border-slate-700 text-white text-sm rounded-lg px-3 py-2 placeholder-slate-500 focus:outline-none focus:ring-2 focus:ring-violet-500 focus:border-transparent font-mono"
                                    />
                                    <p className="text-xs text-slate-500 mt-1">{t('super_admin.phone_id_hint')}</p>
                                </div>

                                <div>
                                    <label className="block text-xs font-medium text-slate-300 mb-1.5">{t('super_admin.label_pin')}</label>
                                    <input
                                        type="password"
                                        inputMode="numeric"
                                        value={regPin}
                                        onChange={e => setRegPin(e.target.value.replace(/\D/g, ''))}
                                        placeholder="000000"
                                        maxLength={6}
                                        className="w-full bg-slate-800 border border-slate-700 text-white text-sm rounded-lg px-3 py-2 placeholder-slate-500 focus:outline-none focus:ring-2 focus:ring-violet-500 focus:border-transparent font-mono tracking-widest"
                                    />
                                    <p className="text-xs text-slate-500 mt-1">{t('super_admin.pin_hint')}</p>
                                </div>

                                {regError && (
                                    <p className="text-xs text-red-400 bg-red-900/20 border border-red-800/40 rounded-lg px-3 py-2">{regError}</p>
                                )}

                                <button
                                    onClick={handleRegister}
                                    disabled={regLoading}
                                    className="w-full mt-1 flex items-center justify-center gap-2 px-4 py-2.5 bg-violet-600 hover:bg-violet-500 disabled:opacity-50 disabled:cursor-not-allowed text-white text-sm font-medium rounded-lg transition-colors"
                                >
                                    {regLoading ? <RefreshCw className="w-4 h-4 animate-spin" /> : null}
                                    {regLoading ? t('super_admin.wa_sending') : t('super_admin.wa_send_otp')}
                                </button>
                            </div>
                        )}

                        {regStep === 2 && (
                            <div className="space-y-4">
                                <div className="bg-slate-800 rounded-lg px-4 py-3 space-y-1">
                                    <p className="text-xs text-slate-400">{t('super_admin.label_org')} : <span className="text-slate-200 font-medium">{selectedOrg?.name || regOrgId}</span></p>
                                    <p className="text-xs text-slate-400">{t('super_admin.label_phone_number_id')} : <span className="text-slate-200 font-mono">{regPhoneNumberId}</span></p>
                                </div>

                                <div className="flex items-start gap-2.5 bg-blue-900/20 border border-blue-800/40 rounded-lg px-3 py-3">
                                    <Info className="w-4 h-4 text-blue-400 shrink-0 mt-0.5" />
                                    <p className="text-xs text-blue-300">{t('super_admin.wa_otp_hint')}</p>
                                </div>

                                <div>
                                    <label className="block text-xs font-medium text-slate-300 mb-1.5">{t('super_admin.label_otp')}</label>
                                    <input
                                        type="text"
                                        inputMode="numeric"
                                        value={regCode}
                                        onChange={e => setRegCode(e.target.value.replace(/\D/g, ''))}
                                        placeholder="123456"
                                        maxLength={8}
                                        className="w-full bg-slate-800 border border-slate-700 text-white text-sm rounded-lg px-3 py-2 placeholder-slate-500 focus:outline-none focus:ring-2 focus:ring-violet-500 focus:border-transparent font-mono tracking-widest text-center text-lg"
                                        autoFocus
                                    />
                                </div>

                                {regError && (
                                    <p className="text-xs text-red-400 bg-red-900/20 border border-red-800/40 rounded-lg px-3 py-2">{regError}</p>
                                )}

                                <div className="flex gap-2 mt-1">
                                    <button
                                        onClick={() => { setRegStep(1); setRegError(''); setRegCode(''); }}
                                        disabled={regLoading}
                                        className="flex items-center gap-1.5 px-4 py-2.5 bg-slate-800 hover:bg-slate-700 disabled:opacity-50 disabled:cursor-not-allowed text-slate-300 text-sm rounded-lg transition-colors"
                                    >
                                        <ArrowLeft className="w-3.5 h-3.5" />
                                        {t('super_admin.wa_back')}
                                    </button>
                                    <button
                                        onClick={handleVerify}
                                        disabled={regLoading}
                                        className="flex-1 flex items-center justify-center gap-2 px-4 py-2.5 bg-violet-600 hover:bg-violet-500 disabled:opacity-50 disabled:cursor-not-allowed text-white text-sm font-medium rounded-lg transition-colors"
                                    >
                                        {regLoading ? <RefreshCw className="w-4 h-4 animate-spin" /> : null}
                                        {regLoading ? t('super_admin.wa_verifying') : t('super_admin.wa_verify')}
                                    </button>
                                </div>
                            </div>
                        )}
                    </div>
                </div>
            )}
        </div>
    );
}