// This is the utils plugin
// It provides function wrapping method
// and some events for the rest plugins

// Disable CSS loading for this plugin
Plugins.utils.no_css = true;

// Utils plugin version
Plugins.utils._version = 0.1;

/**
 * Wrap an existing function with before and after callbacks.
 * @param {string} name The name of function to wrap with before and after callbacks.
 * @param {function(orig, thisArg, args):boolean} before_cb Callback before original. Return true to call the original.
 * @param {function(result, orig, thisArg, args):void} after_cb Callback after original, will receive the result of original
 * @param {object} obj [optional] Object to look for function into. Default is 'window'
 * @description
 *   - Before Callback:
 *     - Params:
 *       - orig: Original function (in case you want to call it, you have to return false to prevent second calling)
 *       - thisArg: local 'this' for the original function
 *       - args: arguments passed to the original function
 *     - Returns: Boolean. Return false to prevent execution of original function and the after callback.
 *   - After Callback:
 *     - Params:
 *       - res: Result of the original function
 *       - thisArg: local 'this' for the original function
 *       - args: arguments passed to the original function
 *
 * @example
 * // Using before and after callbacks.
 * Plugins.utils.wrap_func('sdr_profile_changed',
 *   function (orig, thisArg, args) { // before callback
 *     console.log(orig.name);
 *     if (something_bad)
 *       console.log('This profile is disabled by proxy function');
 *       return false; // return false to prevent the calling of the original function and the after_cb()
 *     }
 *     return true; // always return true, to call the original function
 *   },
 *   function (res, thisArg, args) { // after callback
 *     console.log(res);
 *   }
 * );
 *
 * @example
 * // Using only before callback and handle original.
 * Plugins.utils.wrap_func('sdr_profile_changed',
 *   function (orig, thisArg, args) { // before callback
 *     // if we need to call the original in the middle of our work
 *     do_something_before_original();
 *     var res = orig.apply(thisArg, args);
 *     do_something_after_original(res);
 *     return false; // to prevent calling the original and after_cb
 *   },
 *   function (res, thisArg, args) { // after callback
 *     // ignored
 *   }
 * );
 *
 */
Plugins.utils.wrap_func = function (name, before_cb, after_cb, obj = window) {
    if (typeof(obj[name]) !== "function") {
        console.error("Cannot wrap non existing function: '" + obj + '.' + name + "'");
        return false;
    }

    var fn_original = obj[name];
    var proxy = new Proxy(obj[name], {
        apply: function (target, thisArg, args) {
            if (before_cb(target, thisArg, args)) {
                after_cb(fn_original.apply(thisArg, args), thisArg, args);
            }
        }
    });

    obj[name] = proxy;
}

// Init utils plugin
Plugins.utils.init = function () {
    var send_events_for = {};

    // function name to proxy.
    send_events_for['sdr_profile_changed'] = {
        // [optional] event name (prepended with 'event:'). Default is function name.
        name: 'profile_changed',
        // [optional] data to send with the event (should be function).
        data: function () {
            return $('#openwebrx-sdr-profiles-listbox').find(':selected').text()
        }
    };

    send_events_for['on_ws_recv'] = {
        // if handler exist, it will replace the before_cb
        handler: function (orig, thisArg, args) {
            if (typeof(args[0].data) === 'string' && args[0].data.substr(0, 16) !== "CLIENT DE SERVER") {
                try {
                    var json = JSON.parse(args[0].data);
                    $(document).trigger('server:' + json.type + ":before", [json['value']]);
                } catch (e) {}
            }

            // we handle original function here
            orig.apply(thisArg, args);

            if (typeof(json) === 'object') {
                  $(document).trigger('server:' + json.type + ":after", [json['value']]);
            }

            // do not call the after_cb
            return false;
        }
    };

    $.each(send_events_for, function (key, obj) {
        Plugins.utils.wrap_func(
            key,
            typeof(obj.handler)==='function'? obj.handler : function () { return true; },
            function (res) {
                var ev_data;
                var ev_name = key;
                if (typeof(obj.name) === 'string') ev_name = obj.name;
                if (typeof(obj.data) === 'function') ev_data = obj.data(res);
                $(document).trigger('event:' + ev_name, [ev_data]);
            }
        );
    });

    var interval = setInterval(function () {
        if (typeof(clock) === 'undefined') return;
        clearInterval(interval);
        $(document).trigger('event:owrx_initialized');
    }, 10);

    return true;
}