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;
}

type SmsApiResponse = {
  requestId?: string;
  requestTime?: string;
  statusCode?: string | number;
  statusName?: 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),
  };
}

function smsProvider(): string {
  return process.env.ACS_SMS_PROVIDER ?? env.smsProvider;
}

function smsApiUrl(): string | undefined {
  return process.env.ACS_SMS_API_URL ?? env.smsApiUrl;
}

function smsApiKey(): string | undefined {
  return process.env.ACS_SMS_API_KEY ?? env.smsApiKey;
}

function smsSender(): string | undefined {
  return process.env.ACS_SMS_SENDER ?? env.smsSender;
}

function smsTimeoutMs(): number {
  return Number(process.env.ACS_SMS_TIMEOUT_MS ?? env.smsTimeoutMs);
}

export async function sendSms(message: SmsMessage): Promise<SmsSendResult> {
  const configuredProvider = smsProvider();
  const provider = configuredProvider.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 === 'hanbank' || provider === 'bok') {
    return sendHanbankSms(recipient, message.text);
  }

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

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

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

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

function resolveHanbankSmsUrl(): string {
  const baseUrl = smsApiUrl() ?? 'http://210.104.132.59:8000';
  if (/\/sens\/sms\/?$/i.test(baseUrl)) {
    return baseUrl;
  }
  return `${baseUrl.replace(/\/+$/, '')}/sens/sms`;
}

function isSuccessResponse(response: SmsApiResponse): boolean {
  const statusCode = String(response.statusCode ?? '').trim();
  const statusName = String(response.statusName ?? '').trim().toLowerCase();
  return statusCode === '202' || statusName === 'success';
}

async function sendHanbankSms(recipient: string, text: string): Promise<SmsSendResult> {
  const controller = new AbortController();
  const timeout = setTimeout(() => controller.abort(), smsTimeoutMs());

  try {
    const response = await fetch(resolveHanbankSmsUrl(), {
      method: 'POST',
      headers: {
        accept: 'application/json',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        receive_number: recipient,
        content: text,
        msg_type: 'LMS',
        reserve_time: '',
      }),
      signal: controller.signal,
    });

    const rawBody = await response.text().catch(() => '');
    let body: SmsApiResponse = {};
    if (rawBody) {
      try {
        body = JSON.parse(rawBody) as SmsApiResponse;
      } catch {
        body = {};
      }
    }

    if (!response.ok || (body.statusCode !== undefined && !isSuccessResponse(body))) {
      const detail = rawBody ? `: ${rawBody.slice(0, 300)}` : '';
      throw new Error(`사내 SMS API 발송 실패 HTTP ${response.status}${detail}`);
    }

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