'use client';

import { Loader2, Mail, MessageSquare, Save, Send } from 'lucide-react';
import { useMemo, useState } from 'react';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { PhoneInput, phoneCountries } from '@/components/ui/phone-input';
import { apiFetch, SystemSetting } from '@/lib/api';
import {
  EMAIL_SETTING_KEYS,
  isSettingVisible,
  SMS_SETTING_KEYS
} from '@/lib/system-settings-catalog';
import { SettingsFieldRow } from '@/components/id/settings-field-row';

function parseBoolean(value: string) {
  return ['true', '1', 'yes'].includes(value.trim().toLowerCase());
}

interface MessagingSettingsSectionProps {
  settings: SystemSetting[];
  token: string | null;
  savingGroup: string | null;
  onUpdateValue: (key: string, value: string) => void;
  onSaveGroup: (groupKey: string, groupSettings: SystemSetting[]) => Promise<void>;
  showToast: (message: string) => void;
}

function getSettingValue(settings: SystemSetting[], key: string) {
  return settings.find((item) => item.key === key)?.value ?? '';
}

function shouldShowMessagingField(setting: SystemSetting, settings: SystemSetting[]) {
  if (!isSettingVisible(setting, settings)) return false;

  const provider = getSettingValue(settings, 'SMS_PROVIDER');
  if (setting.key === 'SMS_API_KEY') return provider === 'smsru';
  if (setting.key === 'SMS_LOGIN' || setting.key === 'SMS_PASSWORD') return provider === 'smsc';
  if (
    setting.key === 'SMS_GATEWAY_URL' ||
    setting.key === 'SMS_GATEWAY_USERNAME' ||
    setting.key === 'SMS_GATEWAY_PASSWORD' ||
    setting.key === 'SMS_GATEWAY_MESSAGE_TEMPLATE'
  ) {
    return provider === 'huawei_modem';
  }

  const emailProvider = getSettingValue(settings, 'EMAIL_PROVIDER');
  if (setting.key.startsWith('EMAIL_SMTP_') || setting.key.startsWith('EMAIL_FROM_')) {
    return parseBoolean(getSettingValue(settings, 'EMAIL_ENABLED')) && emailProvider === 'smtp';
  }
  if (setting.key === 'EMAIL_PROVIDER') {
    return parseBoolean(getSettingValue(settings, 'EMAIL_ENABLED'));
  }
  if (setting.key === 'SMS_PROVIDER') {
    return parseBoolean(getSettingValue(settings, 'SMS_ENABLED'));
  }

  return true;
}

function MessagingBlock({
  title,
  description,
  groupKey,
  blockSettings,
  allSettings,
  savingGroup,
  onUpdateValue,
  onSaveGroup
}: {
  title: string;
  description: string;
  groupKey: string;
  blockSettings: SystemSetting[];
  allSettings: SystemSetting[];
  savingGroup: string | null;
  onUpdateValue: (key: string, value: string) => void;
  onSaveGroup: (groupKey: string, groupSettings: SystemSetting[]) => Promise<void>;
}) {
  const visibleSettings = blockSettings.filter((setting) => shouldShowMessagingField(setting, allSettings));
  const saving = savingGroup === groupKey;

  return (
    <div className="rounded-[24px] bg-[#f4f5f8] p-5">
      <div className="mb-4 flex flex-col gap-3 border-b border-[#e0e3ea] pb-4 md:flex-row md:items-start md:justify-between">
        <div>
          <h4 className="text-lg font-medium">{title}</h4>
          <p className="mt-1 text-sm text-[#667085]">{description}</p>
        </div>
        <Button disabled={saving || visibleSettings.length === 0} onClick={() => void onSaveGroup(groupKey, blockSettings)}>
          {saving ? <Loader2 className="h-4 w-4 animate-spin" /> : <Save className="h-4 w-4" />}
          Сохранить блок
        </Button>
      </div>

      <div>
        {visibleSettings.map((setting) => (
          <SettingsFieldRow
            key={setting.key}
            setting={setting}
            onChange={(value) => onUpdateValue(setting.key, value)}
          />
        ))}
      </div>
    </div>
  );
}

export function MessagingSettingsSection({
  settings,
  token,
  savingGroup,
  onUpdateValue,
  onSaveGroup,
  showToast
}: MessagingSettingsSectionProps) {
  const [testEmail, setTestEmail] = useState('');
  const [testPhone, setTestPhone] = useState('');
  const [testPhoneCountry, setTestPhoneCountry] = useState(phoneCountries[0]);
  const [testingChannel, setTestingChannel] = useState<'email' | 'sms' | null>(null);

  const emailSettings = useMemo(
    () => settings.filter((item) => EMAIL_SETTING_KEYS.includes(item.key)),
    [settings]
  );
  const smsSettings = useMemo(
    () => settings.filter((item) => SMS_SETTING_KEYS.includes(item.key)),
    [settings]
  );

  async function sendTest(channel: 'email' | 'sms') {
    if (!token) return;
    const target = channel === 'email' ? testEmail.trim() : `${testPhoneCountry.code}${testPhone}`;
    if (!target) {
      showToast(channel === 'email' ? 'Укажите email для теста' : 'Укажите номер телефона для теста');
      return;
    }

    setTestingChannel(channel);
    try {
      const response = await apiFetch<{ message?: string }>(
        '/admin/settings/messaging/test',
        {
          method: 'POST',
          body: JSON.stringify({ channel, target })
        },
        token
      );
      showToast(response.message ?? 'Тестовое сообщение отправлено');
    } catch (error) {
      showToast(error instanceof Error ? error.message : 'Не удалось отправить тестовое сообщение');
    } finally {
      setTestingChannel(null);
    }
  }

  const emailEnabled = parseBoolean(getSettingValue(emailSettings, 'EMAIL_ENABLED'));
  const smsEnabled = parseBoolean(getSettingValue(smsSettings, 'SMS_ENABLED'));
  const emailReady =
    emailEnabled ||
    (Boolean(getSettingValue(emailSettings, 'EMAIL_SMTP_HOST')) &&
      Boolean(getSettingValue(emailSettings, 'EMAIL_FROM_ADDRESS')));

  return (
    <section className="mb-10">
      <div className="mb-4 flex items-center gap-3">
        <MessageSquare className="h-6 w-6" />
        <div>
          <h3 className="text-xl font-medium">Email и SMS провайдеры</h3>
          <p className="mt-1 text-sm text-[#667085]">
            Измените параметры блока и нажмите «Сохранить блок» — все поля блока сохранятся одним действием.
          </p>
        </div>
      </div>

      <div className="space-y-4">
        <MessagingBlock
          title="Email (SMTP)"
          description="Отправка OTP-кодов на почту через SMTP-провайдера."
          groupKey="messaging-email"
          blockSettings={emailSettings}
          allSettings={settings}
          savingGroup={savingGroup}
          onUpdateValue={onUpdateValue}
          onSaveGroup={onSaveGroup}
        />

        <MessagingBlock
          title="SMS"
          description="Отправка OTP-кодов по SMS через sms.ru, smsc.ru или локальный модем Huawei."
          groupKey="messaging-sms"
          blockSettings={smsSettings}
          allSettings={settings}
          savingGroup={savingGroup}
          onUpdateValue={onUpdateValue}
          onSaveGroup={onSaveGroup}
        />
      </div>

      <div className="mt-6 grid gap-4 md:grid-cols-2">
        <div className="rounded-[24px] border border-[#e4e7ec] bg-white p-5">
          <div className="flex items-center gap-2 font-semibold">
            <Mail className="h-5 w-5" />
            Тест email
          </div>
          <p className="mt-2 text-sm text-[#667085]">
            {emailReady ? 'Отправит тестовый OTP-код через SMTP.' : 'Сначала сохраните блок Email (SMTP).'}
          </p>
          <Input
            className="mt-4 bg-[#f9fafb]"
            type="email"
            placeholder="admin@example.com"
            value={testEmail}
            onChange={(event) => setTestEmail(event.target.value)}
          />
          <Button className="mt-3" disabled={!emailReady || testingChannel === 'email'} onClick={() => void sendTest('email')}>
            {testingChannel === 'email' ? <Loader2 className="h-4 w-4 animate-spin" /> : <Send className="h-4 w-4" />}
            Отправить тест
          </Button>
        </div>

        <div className="rounded-[24px] border border-[#e4e7ec] bg-white p-5">
          <div className="flex items-center gap-2 font-semibold">
            <MessageSquare className="h-5 w-5" />
            Тест SMS
          </div>
          <p className="mt-2 text-sm text-[#667085]">
            {smsEnabled ? 'Отправит тестовый OTP-код через SMS-провайдера.' : 'Сначала сохраните блок SMS.'}
          </p>
          <div className="mt-4">
            <PhoneInput
              variant="light"
              country={testPhoneCountry}
              value={testPhone}
              onCountryChange={setTestPhoneCountry}
              onValueChange={setTestPhone}
            />
          </div>
          <Button className="mt-3" disabled={!smsEnabled || testingChannel === 'sms'} onClick={() => void sendTest('sms')}>
            {testingChannel === 'sms' ? <Loader2 className="h-4 w-4 animate-spin" /> : <Send className="h-4 w-4" />}
            Отправить тест
          </Button>
        </div>
      </div>
    </section>
  );
}