/**
 * OpenWebRx+ Plugin loader
 *
 * You should load your plugins in "plugins/{type}/init.js",
 * where {type} is 'receiver' or 'map'.
 * See the init.js.sample.
 * And check the "plugins/{type}/example" folder for example plugin.
 */

// Wait for the page to load, then load the plugins.
$(document).ready(function () {
    // detect which plugins to load
    Plugins._type = (typeof mapManager !== 'undefined') ? 'map' : 'receiver';
    Plugins.init();
});

// Initialize the Plugins class and some defaults
function Plugins () {}
Plugins._initialized = false;
Plugins._version = 0.1; // version of the plugin sub-system (keep it float)
Plugins._enable_debug = false; // print debug to the console


// Load plugin
Plugins.load = async function (name) {
    var path = 'static/plugins/' + Plugins._type + "/" + name + "/";
    var remote = false;

    // check if we are loading an url
    if (name.toLowerCase().startsWith('https://') || name.toLowerCase().startsWith('http://')) {
        path = name;
        name = path.split('/').pop().split('.').slice(0, -1);
        path = path.split('/').slice(0, -1).join('/') + '/';
        remote = true;
    }

    if (name in Plugins) {
        console.warn(Plugins._banner(name) + 'is already loaded' + (Plugins[name]._script_loaded ? ' from ' + Plugins[name]._script_loaded : ''));
        return;
    }

    Plugins._debug(Plugins._banner(name) + 'loading.');

    var script_src = path + name + ".js";
    var style_src = path + name + '.css';

    // init plugin object with defaults
    Plugins[name] = {
        _version       : 0,
        _script_loaded : false,
        _style_loaded  : false,
        _remote        : remote
    };


    // try to load the plugin
    await Plugins._load_script(script_src).then(function () {
        // plugin script loaded successfully
        Plugins[name]._script_loaded = script_src;

        // check if the plugin has init() method and execute it
        if (typeof Plugins[name].init === 'function') {
            if (!Plugins[name].init()) {
                console.error(Plugins._banner(name) + 'cannot initialize.');
                return;
            }
        }

        // check if plugin has set the 'no_css', otherwise, load the plugin css style
        if (!('no_css' in Plugins[name])) {
            Plugins._load_style(style_src).then(function () {
                Plugins[name]._style_loaded = style_src;
                Plugins._debug(Plugins._banner(name) + 'loaded.');
            }).catch(function () {
                console.warn(Plugins._banner(name) + 'script loaded, but css not found.');
            });
        } else {
            // plugin has no_css
            Plugins._debug(Plugins._banner(name) + 'loaded.');
        }

    }).catch(function () {
        // plugin cannot be loaded
        Plugins._debug(Plugins._banner(name) + 'cannot be loaded (does not exist or has errors).');
    });
}

// Check if plugin is loaded
Plugins.isLoaded = function (name, version = 0) {
    if (typeof(Plugins[name]) === 'object') {
        return (Plugins[name]._script_loaded && Plugins[name]._version >= version);
    }

    return false;
}

// Initialize plugin loading. We should load the init.js for the {type}. This init() is called onDomReady.
Plugins.init = function () {
    Plugins._debug("Loading " + Plugins._type + " plugins.");

    // load the init.js for the {type}... user should load their plugins there.
    Plugins._load_script('static/plugins/' + Plugins._type + "/init.js").then(function () {
        Plugins._initialized = true;
    }).catch(function () {
        Plugins._debug('no plugins to load.');
    })
}

// ---------------------------------------------------------------------------

// internal utility methods
Plugins._load_script = function (src) {
    return new Promise(function (resolve, reject) {
        var script = document.createElement('script');
        script.onload = resolve;
        script.onerror = reject;
        script.src = src;
        document.head.appendChild(script);
    });
}

Plugins._load_style = function (src) {
    return new Promise(function (resolve, reject) {
        var style = document.createElement('link');
        style.onload = resolve;
        style.onerror = reject;
        style.href = src;
        style.type = 'text/css';
        style.rel = 'stylesheet';
        document.head.appendChild(style);
    });
}

Plugins._debug = function (msg) {
    if (Plugins._enable_debug) console.debug(msg);
}

Plugins._banner = function (name) {
    return 'PLUGINS: ' + (Plugins[name] && Plugins[name]._remote ? '[remote]' : '[local]') + ' "' + name + '" ';
}