const fetch = require("node-fetch");

class BankBot {
  static TAG = "BankBot";

  constructor() {
    this.stateMap = new Map();
  }

  async process(message, metalog) {
    console.log(`[${BankBot.TAG}] ${metalog} process:`, message);
    try {
      const { success, data } = await this.flow(message, metalog);
        return { success, data };
    } catch (e) {
      console.error(`[${BankBot.TAG}] Error:`, e);
    }
    return { success: false, data: null };
  }

  async flow(message, metalog) {
    let text = message.body.trim();
    if (!text.includes("@bsb")) return false;
    text = text.replace("@bsb", "").trim();

    let url = "https://nexilis.io/ibotbank_wsgi/predict";
    let reqJsonObject = { prompt: text };

    const session = this.stateMap.get(message.to);

    if (session) {
      console.log(`[${BankBot.TAG}] ${metalog} session:`, session);
      if (session.state === "PREDICT") {
        const parameters = session.data.parameters || {};
        if (parameters.confirmation === "1") {
          url = url.replace("predict", "auth");
          session.state = "AUTH";
        }
      } else if (session.state === "AUTH") {
        url = url.replace("predict", "execute");
        const { data } = session;
        delete data.content;
        delete data.explanation;
        delete data.confidence;
        delete data.role;
        data.message = session.prompt;
        reqJsonObject = data;
        session.state = "EXECUTE";
      }
    }

    console.log(`[${BankBot.TAG}] ${metalog} POST [${url}] ->`, reqJsonObject);

    let body;
    try {
      const res = await fetch(url, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(reqJsonObject)
      });
      body = await res.text();
    } catch (err) {
      console.error("HTTP Error:", err);
      body = JSON.stringify({
        role: "assistant",
        content: "Server Busy.. please try again later."
      });
    }

    console.log(`[${BankBot.TAG}] ${metalog} response body:`, body);

    let resJson;
    try {
      resJson = JSON.parse(body);
    } catch (e) {
      resJson = {
        role: "assistant",
        content: "Invalid JSON from server."
      };
    }

    if (resJson.parameters) {
      this.stateMap.set(
        message.to,
        new Session(text, "PREDICT", resJson)
      );
    }

    return { success: true, data: resJson };
  }
}

class Session {
  constructor(prompt, state, data) {
    this.prompt = prompt;
    this.state = state;
    this.data = data;
  }

  toString() {
    return `Session{prompt='${this.prompt}', state=${this.state}, data=${JSON.stringify(this.data)}}`;
  }
}

const State = {
  PREDICT: "PREDICT",
  AUTH: "AUTH",
  EXECUTE: "EXECUTE"
};


module.exports.BankBot =  BankBot;