// svghmi.js

function dispatch_value(index, value) {

console.log("dispatch_value("+index+value+")");

};

// Open WebSocket to relative "/ws" address

var ws = new WebSocket(window.location.href.replace(/^http(s?:\/\/[^\/]*)\/.*$/, 'ws$1/ws'));

ws.binaryType = 'arraybuffer';

const dvgetters = {

INT: [DataView.prototype.getInt16, 2],

BOOL: [DataView.prototype.getInt8, 1]

/* TODO */

};

// Register message reception handler

ws.onmessage = function (evt) {

let data = evt.data;

let dv = new DataView(data);

let i = 0;

for(let hash_int of hmi_hash) {

if(hash_int != dv.getUint8(i)){

console.log("Recv non maching hash. Reload.");

// 1003 is for "Unsupported Data"

ws.close(1003,"Hash doesn't match");

// TODO : remove debug alert ?

alert("HMI will be reloaded.");

// force reload ignoring cache

location.reload(true);

};

i++;

};

while(i < data.length){

let index = dv.getUint32(i);

i += 4;

let iectype = hmitree_types[index];

let [dvgetter, bytesize] = dvgetters[iectypes];

value = dvgetter.call(dv,i);

dispatch_value(index, value);

i += bytesize;

};

};

function send_blob(data) {

if(data.length > 0) {

ws.send(new Blob([

new Uint8Array(hmi_hash),

data]));

};

};

const typedarray_types = {

INT: Int16Array,

BOOL: Uint8Array

/* TODO */

};

function send_reset() {

send_blob(new Uint8Array([1])); /* reset = 1 */

};

// subscription state, as it should be in hmi server

// hmitree indexed array of integers

var subscriptions = hmitree_types.map(_ignored => 0);

// subscription state as needed by widget now

// hmitree indexed array of Sets of widgets objects

var subscribers = hmitree_types.map(_ignored => new Set());

function update_subscriptions() {

let delta = [];

for(let index = 0; index < subscribers.length; index++){

let widgets = subscribers[index];

// periods are in ms

let previous_period = subscriptions[index];

let new_period;

if(widgets.size > 0) {

let maxfreq = 0;

for(let widget of widgets)

if(maxfreq < widgets.frequency)

maxfreq = widgets.frequency;

new_period = 1000/maxfreq;

} else {

new_period = 0;

}

if(previous_period != new_period) {

subscriptions[index] = new_period;

delta.push([

new Uint8Array([2]), /* subscribe = 2 */

new Uint32Array([index]),

new Uint16Array([new_period])]);

}

}

send_blob(delta);

};

function update_value(index, value) {

iectype = hmitree_types[index];

jstype = typedarray_types[iectypes];

send_blob([

new Uint8Array([0]), /* setval = 0 */

new jstype([value])

]);

};

var current_page;

function switch_page(page_name) {

let old_desc = page_desc[current_page];

let new_desc = page_desc[page_name];

/* TODO hide / show widgets */

/* TODO move viewport */

/* remove subsribers of previous page if any */

if(old_desc) for(let widget of old_desc.widgets){

for(let index of widget.indexes){

subscribers[index].delete(widget);

}

}

/* add new subsribers if any */

if(new_desc) for(let widget of new_desc.widgets){

for(let index of widget.indexes){

subscribers[index].add(widget);

}

}

current_page = page_name;

update_subscriptions();

};

// Once connection established

ws.onopen = function (evt) {

send_reset();

// show main page

switch_page(default_page);

};