/**
 * ChannelReact (JavaScript / Node.js Engine)
 * Automated WhatsApp Channel Reaction Sender
 * 
 * Features:
 *  - Session Handshake & Token Acquisition
 *  - Automatic retry with exponential backoff
 *  - Multi-reaction batch sender
 */

const BASE_URL = "https://satriareact.satriadeveloperz.workers.dev";
const BROWSER_USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36";

const EMOJI_REGEX = /[\u{1F300}-\u{1FAFF}\u{2600}-\u{27BF}\u{FE0F}]/u;

export function isEmoji(str) {
  const val = String(str || "").trim();
  if (!val) return false;
  return val.length <= 8 && EMOJI_REGEX.test(val);
}

export class ChannelReactClient {
  constructor(options = {}) {
    this.baseUrl = options.baseUrl || BASE_URL;
    this.userAgent = options.userAgent || BROWSER_USER_AGENT;
    this.cookies = "";
  }

  getHeaders() {
    const headers = {
      "User-Agent": this.userAgent,
      "Content-Type": "application/json",
      "Origin": this.baseUrl,
      "Referer": `${this.baseUrl}/`,
      "Accept": "application/json, text/plain, */*",
    };
    if (this.cookies) {
      headers["Cookie"] = this.cookies;
    }
    return headers;
  }

  async handshake(maxRetries = 5) {
    let lastError = null;

    for (let attempt = 1; attempt <= maxRetries; attempt++) {
      if (attempt > 1) {
        await new Promise((res) => setTimeout(res, 2000 * attempt));
      }

      try {
        const response = await fetch(`${this.baseUrl}/api/handshake`, {
          method: "POST",
          headers: this.getHeaders(),
          body: JSON.stringify({}),
        });

        // Store session cookies if returned
        const setCookie = response.headers.get("set-cookie");
        if (setCookie) {
          this.cookies = setCookie.split(";")[0];
        }

        const data = await response.json();
        if (response.ok && data?.success && data?.token) {
          return {
            token: data.token,
            clientId: data.clientId,
            username: data.step1?.username || data.username,
            expiresInMs: data.expiresInMs || 60000,
          };
        }
        lastError = `HTTP ${response.status}: ${JSON.stringify(data)}`;
      } catch (err) {
        lastError = err.message;
      }
    }

    throw new Error(`Handshake failed after ${maxRetries} attempts (${lastError})`);
  }

  async react(url, reactions = ["👍"], token = null, maxRetries = 3) {
    let currentToken = token;
    if (!currentToken) {
      const hs = await this.handshake();
      currentToken = hs.token;
    }

    const reactionList = Array.isArray(reactions) ? reactions : [reactions];

    for (let attempt = 1; attempt <= maxRetries; attempt++) {
      try {
        const response = await fetch(`${this.baseUrl}/api/react`, {
          method: "POST",
          headers: this.getHeaders(),
          body: JSON.stringify({
            url,
            reactions: reactionList,
            token: currentToken,
          }),
        });

        const data = await response.json();
        if (response.ok && data?.success) {
          return {
            success: true,
            count: data.count || reactionList.length,
            message: data.message || "Terkirim",
            task: data.task?.status || "pending",
            vip: data.vip?.packageName || "VIP API",
          };
        }

        // Token expired or handshake invalid -> re-handshake and retry
        if ((response.status === 401 || response.status === 403 || response.status === 502) && attempt < maxRetries) {
          await new Promise((res) => setTimeout(res, 2000 * attempt));
          const newHs = await this.handshake();
          currentToken = newHs.token;
          continue;
        }

        throw new Error(`Reaction request failed (HTTP ${response.status}): ${JSON.stringify(data)}`);
      } catch (err) {
        if (attempt >= maxRetries) throw err;
        await new Promise((res) => setTimeout(res, 1500 * attempt));
      }
    }

    throw new Error(`Failed to send reactions after ${maxRetries} attempts`);
  }
}

export default ChannelReactClient;