const config = require('./config');

const REQUEST_TIMEOUT_MS = 120000;
const REQUEST_TIMEOUT_IMG_MS = 180000;

module.exports.REQUEST_TIMEOUT_MS = REQUEST_TIMEOUT_MS;
module.exports.REQUEST_TIMEOUT_IMG_MS = REQUEST_TIMEOUT_IMG_MS;

/**
 * run(action, ...args, options?)
 * options: { model?: string, timeoutMs?: number } 可选；未传 model 时各 request 使用 config 默认。
 * 例：run('text2text', '你好', { model: 'gpt-4o-mini' })
 *     run('img2text', prompt, imageUrl, { model: 'gpt-4o', timeoutMs: 60000 })
 *     run('img2text', prompt, [urlScreen, urlTpl], { model: 'gpt-5.4' })  // 多图，如 img-center ROI
 */

function request(path, body, timeoutMs) {
  const baseUrl = (config.BASE_URL || '').replace(/\/$/, '');
  const url = path.startsWith('http') ? path : `${baseUrl}/${path.replace(/^\//, '')}`;
  const controller = new AbortController();
  const timeoutId = setTimeout(() => controller.abort(), timeoutMs);
  return fetch(url, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': `Bearer ${config.API_KEY || ''}`
    },
    body: JSON.stringify(body),
    signal: controller.signal
  })
    .then((res) => {
      clearTimeout(timeoutId);
      return res.json().catch(() => ({})).then((data) => {
        if (!res.ok) throw new Error(data.error?.message || data.error || `HTTP ${res.status}`);
        return data;
      });
    })
    .catch((e) => {
      clearTimeout(timeoutId);
      if (e.name === 'AbortError') throw new Error(`请求超时 (${timeoutMs / 1000} 秒)`);
      throw e;
    });
}

/** images/edits 等：multipart，勿设 Content-Type（由 fetch 带 boundary） */
function requestMultipart (subPath, formData, timeoutMs) {
  const baseUrl = (config.BASE_URL || '').replace(/\/$/, '');
  const url = subPath.startsWith('http') ? subPath : `${baseUrl}/${String(subPath).replace(/^\//, '')}`;
  const controller = new AbortController();
  const timeoutId = setTimeout(() => controller.abort(), timeoutMs);
  return fetch(url, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${config.API_KEY || ''}`,
    },
    body: formData,
    signal: controller.signal,
  })
    .then((res) => {
      clearTimeout(timeoutId);
      return res.json().catch(() => ({})).then((data) => {
        if (!res.ok) throw new Error(data.error?.message || data.error || `HTTP ${res.status}`);
        return data;
      });
    })
    .catch((e) => {
      clearTimeout(timeoutId);
      if (e.name === 'AbortError') throw new Error(`请求超时 (${timeoutMs / 1000} 秒)`);
      throw e;
    });
}

function doubaoRequest(path, body, timeoutMs) {
  const baseUrl = (config.DOUBAO_BASE_URL || '').replace(/\/$/, '');
  const url = path.startsWith('http') ? path : `${baseUrl}/${path.replace(/^\//, '')}`;
  const controller = new AbortController();
  const timeoutId = setTimeout(() => controller.abort(), timeoutMs);
  return fetch(url, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': `Bearer ${config.DOUBAO_API_KEY || ''}`
    },
    body: JSON.stringify(body),
    signal: controller.signal
  })
    .then((res) => {
      clearTimeout(timeoutId);
      return res.json().catch(() => ({})).then((data) => {
        if (!res.ok) throw new Error(data.error?.message || data.error || `HTTP ${res.status}`);
        return data;
      });
    })
    .catch((e) => {
      clearTimeout(timeoutId);
      if (e.name === 'AbortError') throw new Error(`请求超时 (${timeoutMs / 1000} 秒)`);
      throw e;
    });
}

const text2text = require('./request/text2text');
const img2text = require('./request/img2text');
const text2img = require('./request/text2img');
const img2img = require('./request/img2img');

const REQ = { text2text, img2text, text2img, img2img };

/** 最后一个参数可为 { model?: string, timeoutMs?: number }，未传 model 则用各 request 内默认 */
function popRunOptions (args) {
  const last = args[args.length - 1];
  if (
    last != null &&
    typeof last === 'object' &&
    !Array.isArray(last) &&
    (Object.prototype.hasOwnProperty.call(last, 'model') ||
      Object.prototype.hasOwnProperty.call(last, 'timeoutMs'))
  ) {
    return { options: args.pop(), rest: args };
  }
  return { options: {}, rest: args };
}

async function run (action, ...args) {
  const { options, rest } = popRunOptions(args);
  const callArgs = rest;
  if (action.startsWith('doubao_')) {
    return await doRequest(action.substring(7), true, callArgs, options);
  }
  return await doRequest(action, false, callArgs, options);
}

/** 从 request 模块取参数，在 ai.js 内发请求 */
async function doRequest (action, isDoubao, args, options = {}) {
  const req = REQ[action];
  if (!req) return { success: false, error: 'Unknown action: ' + action };
  if (isDoubao && (!config.DOUBAO_MODEL || !config.DOUBAO_MODEL.trim())) {
    return { success: false, error: '豆包未配置：请在 nodejs/ai/config.js 中设置 DOUBAO_MODEL 为你在火山引擎控制台创建的模型接入点 ID（endpoint ID），或设置环境变量 DOUBAO_MODEL' };
  }

  const path = req.path;
  const modelOverride =
    options.model != null && String(options.model).trim() !== ''
      ? String(options.model).trim()
      : undefined;
  const timeoutMs =
    options.timeoutMs != null && Number.isFinite(Number(options.timeoutMs))
      ? Number(options.timeoutMs)
      : req.timeoutMs;

  try {
    if (action === 'img2img' && !isDoubao && typeof req.buildFormData === 'function') {
      const form = req.buildFormData(args[0], args[1], modelOverride);
      const data = await requestMultipart(path, form, timeoutMs);
      return { success: true, data };
    }

    let body;
    if (action === 'text2text') {
      body = isDoubao
        ? req.getDoubaoBody(args[0], modelOverride)
        : req.getBody(args[0], modelOverride);
    } else if (action === 'text2img') {
      body = isDoubao
        ? req.getDoubaoBody(args[0], args[1], modelOverride)
        : req.getBody(args[0], args[1], modelOverride);
    } else {
      body = isDoubao
        ? req.getDoubaoBody(args[0], args[1], modelOverride)
        : req.getBody(args[0], args[1], modelOverride);
    }

    const data = isDoubao
      ? await doubaoRequest(path, body, timeoutMs)
      : await request(path, body, timeoutMs);
    return { success: true, data };
  } catch (e) {
    const msg = e && (e.message || String(e));
    const cause = e && e.cause && (e.cause.message || String(e.cause));
    const err = cause ? `${msg} (${cause})` : msg;
    return { success: false, error: err || '网络请求失败' };
  }
}

module.exports.run = run;
module.exports.request = request;
module.exports.REQUEST_TIMEOUT_MS = REQUEST_TIMEOUT_MS;
module.exports.REQUEST_TIMEOUT_IMG_MS = REQUEST_TIMEOUT_IMG_MS;