import {Config} from "data";
import ContentManager from "./contentmanager";
import Utilities from "./utilities";
import {Toasts, Modals} from "ui";
import ContentError from "../structs/contenterror";
import Settings from "./settingsmanager";
import {SettingsPanel as SettingsRenderer} from "ui";

const path = require("path");
const electronRemote = require("electron").remote;

export default new class PluginManager extends ContentManager {
    get name() {return "PluginManager";}
    get moduleExtension() {return ".js";}
    get extension() {return ".plugin.js";}
    get contentFolder() {return path.resolve(Config.dataPath, "plugins");}
    get prefix() {return "plugin";}

    constructor() {
        super();
        this.onSwitch = this.onSwitch.bind(this);
        this.observer = new MutationObserver((mutations) => {
            for (let i = 0, mlen = mutations.length; i < mlen; i++) {
                this.onMutation(mutations[i]);
            }
        });
    }

    /* Aliases */
    updatePluginList() {return this.updateList();}

    enablePlugin(idOrContent) {return this.enableContent(idOrContent);}
    disablePlugin(idOrContent) {return this.disableContent(idOrContent);}
    togglePlugin(id) {return this.toggleContent(id);}

    unloadPlugin(idOrFileOrContent) {return this.unloadContent(idOrFileOrContent);}

    loadPlugin(filename) {
        const error = this.loadContent(filename);
        if (error) Modals.showContentErrors({themes: [error]});
    }

    reloadPlugin(idOrFileOrContent) {
        const error = this.reloadContent(idOrFileOrContent);
        if (error) Modals.showContentErrors({plugins: [error]});
        return typeof(idOrFileOrContent) == "string" ? this.contentList.find(c => c.id == idOrFileOrContent || c.filename == idOrFileOrContent) : idOrFileOrContent;
    }

    loadAllPlugins() {
        const errors = this.loadAllContent();
        this.setupFunctions();
        Settings.registerPanel("Plugins", {element: () => SettingsRenderer.getContentPanel("Plugins", this.contentList, this.state, {
            folder: this.contentFolder,
            onChange: this.togglePlugin.bind(this),
            reload: this.reloadPlugin.bind(this),
            refreshList: this.updatePluginList.bind(this)
        })});
        return errors;
    }

    /* Overrides */
    initializeContent(content) {
        if (!content.type) return new ContentError(content.name, content.filename, "Plugin had no exports", {message: "Plugin had no exports or no name property.", stack: ""});
        try {
            const thePlugin = new content.type();
            content.plugin = thePlugin;
            content.name = thePlugin.getName() || content.name;
            content.author = thePlugin.getAuthor() || content.author || "No author";
            content.description = thePlugin.getDescription() || content.description || "No description";
            content.version = thePlugin.getVersion() || content.version || "No version";
            try {
                if (typeof(content.plugin.load) == "function") content.plugin.load();
            }
            catch (error) {
                this.state[content.id] = false;
                return new ContentError(content.name, content.filename, "load() could not be fired.", {message: error.message, stack: error.stack});
            }
        }
        catch (error) {return new ContentError(content.name, content.filename, "Could not be constructed.", {message: error.message, stack: error.stack});}
    }

    getContentModification(module, content, meta) {
        module._compile(content, module.filename);
        const didExport = !Utilities.isEmpty(module.exports);
        if (didExport) {
            meta.type = module.exports;
            module.exports = meta;
            return "";
        }
        content += `\nmodule.exports = ${JSON.stringify(meta)};\nmodule.exports.type = ${meta.exports || meta.name};`;
        return content;
    }

    startContent(id) {return this.startPlugin(id);}
    stopContent(id) {return this.stopPlugin(id);}

    startPlugin(idOrContent) {
        const content = typeof(idOrContent) == "string" ? this.contentList.find(p => p.id == idOrContent) : idOrContent;
        if (!content) return;
        const plugin = content.plugin;
        try {
            plugin.start();
            this.emit("started", content.id);
            Toasts.show(`${content.name} v${content.version} has started.`);
        }
        catch (err) {
            this.state[content.id] = false;
            Toasts.error(`${content.name} v${content.version} could not be started.`);
            Utilities.err("Plugins", content.name + " could not be started.", err);
            return new ContentError(content.name, content.filename, "start() could not be fired.", {message: err.message, stack: err.stack});
        }
    }

    stopPlugin(idOrContent) {
        const content = typeof(idOrContent) == "string" ? this.contentList.find(p => p.id == idOrContent) : idOrContent;
        if (!content) return;
        const plugin = content.plugin;
        try {
            plugin.stop();
            this.emit("stopped", content.id);
            Toasts.show(`${content.name} v${content.version} has stopped.`);
        }
        catch (err) {
            this.state[content.id] = false;
            Toasts.error(`${content.name} v${content.version} could not be stopped.`);
            Utilities.err("Plugins", content.name + " could not be stopped.", err);
            return new ContentError(content.name, content.filename, "stop() could not be fired.", {message: err.message, stack: err.stack});
        }
    }

    setupFunctions() {
        electronRemote.getCurrentWebContents().on("did-navigate-in-page", this.onSwitch.bind(this));
        this.observer.observe(document, {
            childList: true,
            subtree: true
        });
    }

    onSwitch() {
        this.emit("page-switch");
        for (let i = 0; i < this.contentList.length; i++) {
            const plugin = this.contentList[i].plugin;
            if (!this.state[this.contentList[i].id]) continue;
            if (typeof(plugin.onSwitch) === "function") {
                try { plugin.onSwitch(); }
                catch (err) { Utilities.err("Plugins", "Unable to fire onSwitch for " + this.contentList[i].name + ".", err); }
            }
        }
    }

    onMutation(mutation) {
        for (let i = 0; i < this.contentList.length; i++) {
            const plugin = this.contentList[i].plugin;
            if (!this.state[this.contentList[i].id]) continue;
            if (typeof plugin.observer === "function") {
                try { plugin.observer(mutation); }
                catch (err) { Utilities.err("Plugins", "Unable to fire observer for " + this.contentList[i].name + ".", err); }
            }
        }
    }
};