const admin = require("firebase-admin");
const axios = require("axios");
const { User, PushToken, Group } = PG.models;

const fs = require('fs');
const path = require('path');

const serviceAccountFile = fs.readFileSync(path.resolve(__dirname, '../flutter-app-firebase-adminsdk.json'), { encoding: 'utf8' });
const serviceAccount = JSON.parse(serviceAccountFile || "{}");

const firebaseServerKey = process.env.FIREBASE_SERVER_KEY;

admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
  databaseURL: process.env.FIREBASE_DB_URL
  // databaseURL: "https://push-notifications-test-a1443.firebaseio.com"
});

module.exports = {
  async checkToken(token){
    try {
      const result = await axios.get(`https://iid.googleapis.com/iid/info/${token}`, {
        headers:{
          Authorization: `key=${firebaseServerKey}`
        }
      });
      return !result.data.error;
    } catch (e) {
      return false;
    }
  },

  sendToToken(token, { title, body, action, navigate }){
    let skillary_obj = {};
    if(action)
      skillary_obj.skillary_action = action;
    if(navigate)
      skillary_obj.skillary_navigate = navigate;


    return admin.messaging().send({
      notification:{
        title,
        body
      },
      data:{
          click_action: "FLUTTER_NOTIFICATION_CLICK",
          ...skillary_obj
      },
      token
    });
  },

  async sendToUser(email, { title, body, action, navigate }) {
    const user = await User.findOne({
      where: {
        email,
      },
      include:[
        {
          model: PushToken,
          as: 'tokens',
        }
      ]
    });

    if(!user)
      throw new Error("No user found");

    let requests = [];
    // Iterate every token of the user
    user.tokens.map(_=>_.token).forEach( token => {
      // Send notification to token
      requests.push(
        this.sendToToken(token, { title, body, action, navigate})
      );
    });

    return Promise.all(requests);
  },

  async sendToGroup({ id, name }, { title, body }) {
    // send to user where id = id if id && email
    let paramName = id ? "id": name ? "name": null;
    let param = id? id: name? name: null;

    // If neither email or id are setted
    if(!paramName || !param)
      throw new Error("Invalid parameters");

    const group = await Group.findOne({
      where: {
        [paramName]: param
      },
      include: [{
        model: User,
        as: 'users',
        include: [{
          model: PushToken,
          as: 'tokens',
        }]
      }]
    });


    if(!group)
      return null;

    const { users } = group;

    let requests = [];
    //Iterate users
    users.forEach( user => {
      // Iterate tokens
      user.tokens.map(_=>_.token).forEach( token => {
        requests.push(this.sendToToken(token, { title, body }));
      })
    });

    return Promise.all(requests);

  }
};