(function(back) {
  function writeSettings(key, value) {
    var s = require('Storage').readJSON(FILE, true) || {};
    s[key] = value;
    require('Storage').writeJSON(FILE, s);
    readSettings();
  }
  
  function readSettings(){
    settings = Object.assign(
      require('Storage').readJSON("bthrm.default.json", true) || {},
      require('Storage').readJSON(FILE, true) || {}
    );
  }
  
  var FILE="bthrm.json";
  var settings;
  readSettings();

  function buildMainMenu(){
    var mainmenu = {
      '': { 'title': 'Bluetooth HRM' },
      '< Back': back,
      'Mode': {
        value: 0 | settings.mode,
        min: 0,
        max: 3,
        format: v => ["Off", "Default", "Both", "Custom"][v],
        onchange: v => {
          settings.mode = v;
          switch (v){
            case 0:
              writeSettings("enabled",false);
              break;
            case 1:
              writeSettings("enabled",true);
              writeSettings("replace",true);
              writeSettings("debuglog",false);
              writeSettings("startWithHrm",true);
              writeSettings("allowFallback",true);
              writeSettings("fallbackTimeout",10);
              break;
            case 2:
              writeSettings("enabled",true);
              writeSettings("replace",false);
              writeSettings("debuglog",false);
              writeSettings("startWithHrm",false);
              writeSettings("allowFallback",false);
              break;
            case 3:
              writeSettings("enabled",true);
              writeSettings("replace",settings.custom_replace);
              writeSettings("debuglog",settings.custom_debuglog);
              writeSettings("startWithHrm",settings.custom_startWithHrm);
              writeSettings("allowFallback",settings.custom_allowFallback);
              writeSettings("fallbackTimeout",settings.custom_fallbackTimeout);
              break;
          }
          writeSettings("mode",v);
        }
      }
    };

    if (settings.btname){
      var name = "Clear " + settings.btname;
      mainmenu[name] = function() {
      E.showPrompt("Clear current device name?").then((r)=>{
          if (r) {
            writeSettings("btname",undefined);
          }
          E.showMenu(buildMainMenu());
        });
      };
    }

    mainmenu["BLE Scan"] = ()=> createMenuFromScan();
    mainmenu["Custom Mode"] = function() { E.showMenu(submenu_custom); };
    mainmenu.Debug = function() { E.showMenu(submenu_debug); };
    return mainmenu;
  }
  

  
  var submenu_debug = {
    '' : { title: "Debug"},
    '< Back': function() { E.showMenu(buildMainMenu()); },
    'Alert on disconnect': {
      value: !!settings.warnDisconnect,
      format: v => settings.warnDisconnect ? "On" : "Off",
      onchange: v => {
        writeSettings("warnDisconnect",v);
      }
    },
    'Debug log': {
      value: !!settings.debuglog,
      format: v => settings.debuglog ? "On" : "Off",
      onchange: v => {
        writeSettings("debuglog",v);
      }
    },
    'Grace periods': function() { E.showMenu(submenu_grace); }
  };

  function createMenuFromScan(){
    E.showMenu();
    E.showMessage("Scanning");

    var submenu_scan = {
      '' : { title: "Scan"},
      '< Back': function() { E.showMenu(buildMainMenu()); }
    };
    var packets=10;
    var scanStart=Date.now();
    NRF.setScan(function(d) {
      packets--;
      if (packets<=0 || Date.now() - scanStart > 5000){
        NRF.setScan();
        E.showMenu(submenu_scan);
      } else if (d.name){
        print("Found device", d);
        submenu_scan[d.name] = function(){
          E.showPrompt("Set "+d.name+"?").then((r)=>{
          if (r) {
            writeSettings("btname",d.name);
          }
          E.showMenu(buildMainMenu());
        });
        };
      }
    }, { filters: [{services: [ "180d" ]}]});
  }
  

  
  var submenu_custom = {
    '' : { title: "Custom mode"},
    '< Back': function() { E.showMenu(buildMainMenu()); },
    'Replace HRM': {
      value: !!settings.custom_replace,
      format: v => settings.custom_replace ? "On" : "Off",
      onchange: v => {
        writeSettings("custom_replace",v);
      }
    },
    'Start w. HRM': {
      value: !!settings.custom_startWithHrm,
      format: v => settings.custom_startWithHrm ? "On" : "Off",
      onchange: v => {
        writeSettings("custom_startWithHrm",v);
      }
    },
    'HRM Fallback': {
      value: !!settings.custom_allowFallback,
      format: v => settings.custom_allowFallback ? "On" : "Off",
      onchange: v => {
        writeSettings("custom_allowFallback",v);
      }
    },
    'Fallback Timeout': {
      value: settings.custom_fallbackTimeout,
      min: 5,
      max: 60,
      step: 5,
      format: v=>v+"s",
      onchange: v => {
        writeSettings("custom_fallbackTimout",v*1000);
      }
    },
  };
  
  var submenu_grace = {
    '' : { title: "Grace periods"},
    '< Back': function() { E.showMenu(submenu_debug); },
    'Request': {
      value: settings.gracePeriodRequest,
      min: 0,
      max: 3000,
      step: 100,
      format: v=>v+"ms",
      onchange: v => {
        writeSettings("gracePeriodRequest",v);
      }
    },
    'Connect': {
      value: settings.gracePeriodConnect,
      min: 0,
      max: 3000,
      step: 100,
      format: v=>v+"ms",
      onchange: v => {
        writeSettings("gracePeriodConnect",v);
      }
    },
    'Notification': {
      value: settings.gracePeriodNotification,
      min: 0,
      max: 3000,
      step: 100,
      format: v=>v+"ms",
      onchange: v => {
        writeSettings("gracePeriodNotification",v);
      }
    },
    'Service': {
      value: settings.gracePeriodService,
      min: 0,
      max: 3000,
      step: 100,
      format: v=>v+"ms",
      onchange: v => {
        writeSettings("gracePeriodService",v);
      }
    }
  };
  
  var submenu = {
    '' : { title: "Grace periods"},
    '< Back': function() { E.showMenu(buildMainMenu()); },
    'Request': {
      value: settings.gracePeriodRequest,
      min: 0,
      max: 3000,
      step: 100,
      format: v=>v+"ms",
      onchange: v => {
        writeSettings("gracePeriodRequest",v);
      }
    },
    'Connect': {
      value: settings.gracePeriodConnect,
      min: 0,
      max: 3000,
      step: 100,
      format: v=>v+"ms",
      onchange: v => {
        writeSettings("gracePeriodConnect",v);
      }
    },
    'Notification': {
      value: settings.gracePeriodNotification,
      min: 0,
      max: 3000,
      step: 100,
      format: v=>v+"ms",
      onchange: v => {
        writeSettings("gracePeriodNotification",v);
      }
    },
    'Service': {
      value: settings.gracePeriodService,
      min: 0,
      max: 3000,
      step: 100,
      format: v=>v+"ms",
      onchange: v => {
        writeSettings("gracePeriodService",v);
      }
    }
  };
  
  E.showMenu(buildMainMenu());
})