/*
 * Copyright (c) 2016, Natacha Porté
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

var cfg_endpoint = null;
var cfg_data_field = null;
var cfg_bundle_max = 1;
var cfg_bundle_separator = "\r\n";

var to_send = [];
var senders = [new XMLHttpRequest(), new XMLHttpRequest()];
var i_sender = 1;
var bundle_size = 0;

function sendPayload(payload) {
   var data = new FormData();
   data.append(cfg_data_field, payload);
   i_sender = 1 - i_sender;
   senders[i_sender].open("POST", cfg_endpoint, true);
   senders[i_sender].send(data);
}

function sendHead() {
   if (to_send.length < 1) return;
   bundle_size = 0;
   var payload = [];
   while (bundle_size < cfg_bundle_max && bundle_size < to_send.length) {
      payload.push(to_send[bundle_size].split(";")[1]);
      bundle_size += 1;
   }
   sendPayload(payload.join(cfg_bundle_separator));
}

function enqueue(key, line) {
   to_send.push(key + ";" + line);
   localStorage.setItem("toSend", to_send.join("|"));
   localStorage.setItem("lastSent", key);
   if (to_send.length === 1) {
      Pebble.sendAppMessage({ "uploadStart": parseInt(key, 10) });
      sendHead();
   }
}

function uploadDone() {
   if (bundle_size > 1) {
      to_send.splice(0, bundle_size - 1);
   }
   var sent_key = to_send.shift().split(";")[0];
   localStorage.setItem("toSend", to_send.join("|"));
   Pebble.sendAppMessage({ "uploadDone": parseInt(sent_key, 10) });
   sendHead();
}

function uploadError() { console.log(this.statusText); }

senders[0].addEventListener("load", uploadDone);
senders[0].addEventListener("error", uploadError);
senders[1].addEventListener("load", uploadDone);
senders[1].addEventListener("error", uploadError);

Pebble.addEventListener("ready", function() {
   console.log("Health Export PebbleKit JS ready!");

   var str_to_send = localStorage.getItem("toSend");
   to_send = str_to_send ? str_to_send.split("|") : [];

   cfg_endpoint = localStorage.getItem("cfgEndpoint");
   cfg_data_field = localStorage.getItem("cfgDataField");
   cfg_bundle_max = parseInt(localStorage.getItem("cfgBundleMax") || "1", 10);
   cfg_bundle_separator = localStorage.getItem("cfgBundleSeparator");

   if (!(cfg_bundle_max >= 1)) cfg_bundle_max = 1;

   var msg = {};

   if (cfg_endpoint && cfg_data_field) {
      msg.lastSent = parseInt(localStorage.getItem("lastSent") || "0", 10);
   } else {
      msg.modalMessage = "Not configured";
   }

   if (to_send.length >= 1) {
      msg.uploadStart = parseInt(to_send[0].split(";")[0]);
   }

   Pebble.sendAppMessage(msg);

   if (to_send.length >= 1) {
      sendHead();
   }
});

Pebble.addEventListener("appmessage", function(e) {
   if (e.payload.dataKey && e.payload.dataLine) {
      enqueue(e.payload.dataKey, e.payload.dataLine);
   }
});

Pebble.addEventListener("showConfiguration", function() {
   var settings = "?v=1.0";

   if (cfg_endpoint) {
      settings += "&url=" + encodeURIComponent(cfg_endpoint);
   }
   if (cfg_data_field) {
      settings += "&data_field=" + encodeURIComponent(cfg_data_field);
   }
   if (cfg_bundle_max) {
      settings += "&bundle_max=" + encodeURIComponent(cfg_bundle_max);
   }
   if (cfg_bundle_separator) {
      settings += "&bundle_sep=" + encodeURIComponent(cfg_bundle_separator);
   }

   Pebble.openURL("https://cdn.rawgit.com/faelys/pebble-health-export/v1.0/config.html" + settings);
});

Pebble.addEventListener("webviewclosed", function(e) {
   var configData = JSON.parse(decodeURIComponent(e.response));
   var wasConfigured = (cfg_endpoint && cfg_data_field);

   if (configData.url) {
      cfg_endpoint = configData.url;
      localStorage.setItem("cfgEndpoint", cfg_endpoint);
   }

   if (configData.dataField) {
      cfg_data_field = configData.dataField;
      localStorage.setItem("cfgDataField", cfg_data_field);
   }

   if (configData.bundleMax) {
      cfg_bundle_max = parseInt(configData.bundleMax, 10);
      if (!(cfg_bundle_max >= 1)) cfg_bundle_max = 1;
      localStorage.setItem("cfgBundleMax", cfg_bundle_max);
   }

   if (configData.bundleSeparator) {
      cfg_bundle_separator = decodeURIComponent(configData.bundleSeparator);
      localStorage.setItem("cfgBundleSeparator", cfg_bundle_separator);
   }

   if (configData.resend) {
      senders[0].abort();
      senders[1].abort();
      localStorage.setItem("toSend", "");
      localStorage.setItem("lastSent", "0");
      to_send = [];
      wasConfigured = false;
   }

   if (!wasConfigured && cfg_endpoint && cfg_data_field) {
      Pebble.sendAppMessage({ "lastSent": 0 });
   }
});