import { env } from '../config/env.js';

export interface SmsSendResult {
  channel: string;
  recipient: string;
  status: 'SENT' | 'FAILED';
  lastError: string | null;
}

export interface SmsMessage {
  to: string;
  text: string;
}

function normalizePhone(value: string | null | undefined): string {
  return String(value ?? '').replace(/[^\d+]/g, '');
}

function fail(channel: string, recipient: string, error: unknown): SmsSendResult {
  const message = error instanceof Error ? error.message : String(error);
  return {
    channel,
    recipient,
    status: 'FAILED',
    lastError: message.slice(0, 500),
  };
}

export async function sendSms(message: SmsMessage): Promise<SmsSendResult> {
  const provider = env.smsProvider.toLowerCase();
  const recipient = normalizePhone(message.to);

  if (!recipient) {
    return fail(provider.toUpperCase(), recipient, '수신자 휴대폰 번호가 없습니다.');
  }

  if (provider === 'dev') {
    console.log('[sms:dev]', { to: recipient, text: message.text });
    return { channel: 'DEV', recipient, status: 'SENT', lastError: null };
  }

  if (provider !== 'http') {
    return fail(provider.toUpperCase(), recipient, `지원하지 않는 SMS provider입니다: ${env.smsProvider}`);
  }

  if (!env.smsApiUrl) {
    return fail('SMS', recipient, 'ACS_SMS_API_URL이 설정되지 않았습니다.');
  }

  const controller = new AbortController();
  const timeout = setTimeout(() => controller.abort(), env.smsTimeoutMs);

  try {
    const response = await fetch(env.smsApiUrl, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        ...(env.smsApiKey ? { Authorization: `Bearer ${env.smsApiKey}` } : {}),
      },
      body: JSON.stringify({
        to: recipient,
        from: env.smsSender,
        message: message.text,
      }),
      signal: controller.signal,
    });

    if (!response.ok) {
      const text = await response.text().catch(() => '');
      throw new Error(`SMS API HTTP ${response.status}${text ? `: ${text.slice(0, 300)}` : ''}`);
    }

    return { channel: 'SMS', recipient, status: 'SENT', lastError: null };
  } catch (error) {
    return fail('SMS', recipient, error);
  } finally {
    clearTimeout(timeout);
  }
}