Base.mjs

import {buffer, debounce, intercept, throttle} from '../util/Function.mjs';
import IdGenerator                             from './IdGenerator.mjs'

const configSymbol       = Symbol.for('configSymbol'),
      forceAssignConfigs = Symbol('forceAssignConfigs'),
      isInstance         = Symbol('isInstance');

/**
 * The base class for (almost) all classes inside the Neo namespace
 * Exceptions are e.g. core.IdGenerator, vdom.VNode
 * @class Neo.core.Base
 */
class Base {
    /**
     * You can define methods which should get delayed.
     * Types are buffer, debounce & throttle.
     * @example
     *  delayable: {
     *      fireChangeEvent: {
     *          type : 'debounce',
     *          timer: 300
     *      }
     *  }
     * @member {Object} delayable={}
     * @protected
     * @static
     */
    static delayable = {}
    /**
     * Flag which will get set to true once manager.Instance got created
     * @member {Boolean} instanceManagerAvailable=false
     * @static
     */
    static instanceManagerAvailable = false
    /**
     * Regex to grab the MethodName from an error
     * which is a second generation function
     * @member {RegExp} methodNameRegex
     * @static
     */
    static methodNameRegex = /\n.*\n\s+at\s+.*\.(\w+)\s+.*/
    /**
     * True automatically applies the core.Observable mixin
     * @member {Boolean} observable=false
     * @static
     */
    static observable = false
    /**
     * Keep the overwritten methods
     * @member {Object} overwrittenMethods={}
     * @protected
     * @static
     */
    static overwrittenMethods = {}
    /**
     * Configs will get merged throughout the class hierarchy
     * @returns {Object} config
     */
    static config = {
        /**
         * The class name which will get mapped into the Neo or app namespace
         * @member {String} className='Neo.core.Base'
         * @protected
         */
        className: 'Neo.core.Base',
        /**
         * The class shortcut-name to use for e.g. creating child components inside a JSON-format
         * @member {String} ntype='base'
         * @protected
         */
        ntype: 'base',
        /**
         * While it is recommended to change the static delayable configs on class level,
         * you can change it on instance level too. If not null, we will do a deep merge.
         * @member {Object} delayable=null
         */
        delayable: null,
        /**
         * The unique component id
         * @member {String|null} id_=null
         */
        id_: null,
        /**
         * Neo.create() will change this flag to true after the onConstructed() chain is done.
         * @member {Boolean} isConstructed=false
         * @protected
         */
        isConstructed: false,
        /**
         * Add mixins as an array of classNames, imported modules or a mixed version
         * @member {String[]|Neo.core.Base[]|null} mixins=null
         */
        mixins: null,
        /**
         * You can create a new instance by passing an imported class (JS module default export)
         * @member {Class} module=null
         * @protected
         */
        module: null
    }

    /**
     * Internal cache for all timeout ids when using this.timeout()
     * @member {Number[]} timeoutIds=[]
     * @private
     */
    #timeoutIds = []

    /**
     * Applies the observable mixin if needed, grants remote access if needed.
     * @param {Object} config={}
     */
    construct(config={}) {
        let me = this;

        Object.defineProperties(me, {
            [configSymbol]: {
                configurable: true,
                enumerable  : false,
                value       : {},
                writable    : true
            },
            [isInstance]: {
                enumerable: false,
                value     : true
            }
        });

        me.createId(config.id || me.id);
        delete config.id;

        if (me.constructor.config) {
            delete me.constructor.config.id
        }

        me.getStaticConfig('observable') && me.initObservable(config);

        // assign class field values prior to configs
        config = me.setFields(config);

        me.initConfig(config);

        Object.defineProperty(me, 'configsApplied', {
            enumerable: false,
            value     : true
        });

        me.applyDelayable();

        /*
         * We do not want to force devs to check for the `isDestroyed` flag in every possible class extension.
         * So, we are intercepting the top-most `destroy()` call to check for the flag there.
         * Rationale: `destroy()` must only get called once.
         */
        intercept(me, 'destroy', me.isDestroyedCheck, me);

        me.remote && setTimeout(me.initRemote.bind(me), 1)
    }

    /**
     * Triggered after the id config got changed.
     * You can dynamically change instance ids if needed. They need to stay unique at any given point.
     * Use case: e.g. component based lists, where you want to re-use item instances.
     * @param {String|null} value
     * @param {String|null} oldValue
     * @protected
     */
    afterSetId(value, oldValue) {
        let me         = this,
            hasManager = Base.instanceManagerAvailable === true;

        if (oldValue) {
            if (hasManager) {
                Neo.manager.Instance.unregister(oldValue)
            } else {
                delete Neo.idMap[oldValue]
            }
        }

        if (value) {
            if (hasManager) {
                Neo.manager.Instance.register(me);
            } else {
                Neo.idMap = Neo.idMap || {};
                Neo.idMap[me.id] = me
            }
        }
    }

    /**
     * Adjusts all methods inside static delayable
     */
    applyDelayable() {
        let me            = this,
            ctorDelayable = me.constructor.delayable,
            delayable     = me.delayable ? Neo.merge({}, me.delayable, ctorDelayable) : ctorDelayable;

        Object.entries(delayable).forEach(([key, value]) => {
            if (value) {
                let map = {
                    buffer()   {me[key] = new buffer(me[key],   me, value.timer)},
                    debounce() {me[key] = new debounce(me[key], me, value.timer)},
                    throttle() {me[key] = new throttle(me[key], me, value.timer)}
                };

                map[value.type]?.()
            }
        })
    }

    /**
     * Applying overwrites and adding overwrittenMethods to the class constructors
     * @param {Object} cfg
     * @protected
     */
    static applyOverwrites(cfg) {
        let overwrites = Neo.ns(cfg.className, false, Neo.overwrites),
            cls, item;

        if (overwrites) {
            // Apply all methods
            for (item in overwrites) {
                if (Neo.isFunction(overwrites[item])) {
                    // Already existing ones
                    cls = this.prototype;

                    if (cls[item]) {
                        // add to overwrittenMethods
                        cls.constructor.overwrittenMethods[item] = cls[item]
                    }
                }
            }

            // Apply configs to prototype
            Object.assign(cfg, overwrites)
        }
    }

    /**
     * Convenience method for beforeSet functions which test if a given value is inside a static array
     * @param {String|Number} value
     * @param {String|Number} oldValue
     * @param {String} name config name
     * @param {Array|String} [staticName=name + 's'] name of the static config array
     * @returns {String|Number} value or oldValue
     */
    beforeSetEnumValue(value, oldValue, name, staticName = name + 's') {
        let values = Array.isArray(staticName) ? staticName : this.getStaticConfig(staticName);

        if (!values.includes(value)) {
            console.error(`Supported values for ${name} are:`, ...values, this);
            return oldValue
        }

        return value
    }

    /**
     * From within an overwrite, a method can call a parent method, by using callOverwritten.
     *
     * @example
     *    afterSetHeight(value, oldValue) {
     *        // do the standard
     *        this.callOverwritten(...arguments);
     *        // do you own stuff
     *    }
     *
     * We create an error to get the caller.name and then run that method on the constructor.
     * This is based on the following error structure, e.g. afterSetHeight.
     *
     *     Error
     *         at Base.callOverwritten (Base.mjs:176:21)
     *         at Base.afterSetHeight (Overrides.mjs:19:26)
     *
     * @param args
     */
    callOverwritten(...args) {
        let stack      = new Error().stack,
            methodName = stack.match(Base.methodNameRegex)[1];

        this.__proto__.constructor.overwrittenMethods[methodName].call(this, ...args)
    }

    /**
     * Uses the IdGenerator to create an id if a static one is not explicitly set.
     * Registers the instance to manager.Instance if this one is already created,
     * otherwise stores it inside a tmp map.
     * @param {String} id
     */
    createId(id) {
        this.id = id || IdGenerator.getId(this.getIdKey())
    }

    /**
     * Unregisters this instance from Neo.manager.Instance
     * and removes all object entries from this instance
     */
    destroy() {
        let me = this;

        me.#timeoutIds.forEach(id => {
            clearTimeout(id)
        });

        if (Base.instanceManagerAvailable === true) {
            Neo.manager.Instance.unregister(me)
        } else if (Neo.idMap) {
            delete Neo.idMap[me.id]
        }

        Object.keys(me).forEach(key => {
            if (Object.getOwnPropertyDescriptor(me, key).writable) {
                // We must not delete the custom destroy() interceptor
                if (key !== 'destroy' && key !== '_id') {
                    delete me[key]
                }
            }
        });

        // We do want to prevent delayed event calls after an observable instance got destroyed.
        if (Neo.isFunction(me.fire)) {
            me.fire = Neo.emptyFn
        }

        me.isDestroyed = true
    }

    /**
     * Used inside createId() as the default value passed to the IdGenerator.
     * Override this method as needed.
     * @returns {String}
     */
    getIdKey() {
        return this.ntype
    }

    /**
     * Returns the value of a static config key or the staticConfig object itself in case no value is set
     * @param {String} key The key of a staticConfig defined inside static getStaticConfig
     * @returns {*}
     */
    getStaticConfig(key) {
        return this.constructor[key]
    }

    /**
     * Check if a given ntype exists inside the proto chain, including the top level class
     * @param {String} ntype
     * @returns {Boolean}
     */
    hasNtype(ntype) {
        return this.constructor.ntypeChain.includes(ntype)
    }

    /**
     * Gets triggered after onConstructed() is done
     * @see {@link Neo.core.Base#onConstructed onConstructed}
     * @tutorial 02_ClassSystem
     */
    init() {}

    /**
     * Applies all class configs to this instance
     * @param {Object} config
     * @param {Boolean} [preventOriginalConfig] True prevents the instance from getting an originalConfig property
     * @protected
     */
    initConfig(config, preventOriginalConfig) {
        let me = this;

        me.isConfiguring = true;
        Object.assign(me[configSymbol], me.mergeConfig(config, preventOriginalConfig));
        me.processConfigs();
        me.isConfiguring = false;
    }

    /**
     * Does get triggered with a delay to ensure that Neo.workerId & Neo.worker.Manager are defined
     * Remote method access via promises
     * @protected
     */
    initRemote() {
        let me                  = this,
            {className, remote} = me,
            {currentWorker}     = Neo;

        if (!me.singleton && !me.isMainThreadAddon) {
            throw new Error('Remote method access is only functional for Singleton classes ' + className)
        }

        if (!Neo.config.unitTestMode && Neo.isObject(remote)) {
            if (Neo.workerId !== 'main' && currentWorker.isSharedWorker && !currentWorker.isConnected) {
                currentWorker.on('connected', () => {
                    Base.sendRemotes(className, remote)
                }, me, {once: true})
            } else {
                Base.sendRemotes(className, remote)
            }
        }
    }

    /**
     * Intercepts destroy() calls to ensure they will only get called once
     * @returns {Boolean}
     */
    isDestroyedCheck() {
        return !this.isDestroyed
    }

    /**
     * Override this method to change the order configs are applied to this instance.
     * @param {Object} config
     * @param {Boolean} [preventOriginalConfig] True prevents the instance from getting an originalConfig property
     * @returns {Object} config
     * @protected
     */
    mergeConfig(config, preventOriginalConfig) {
        let me   = this,
            ctor = me.constructor;

        if (!ctor.config) {
            throw new Error('Neo.applyClassConfig has not been run on ' + me.className)
        }

        if (!preventOriginalConfig) {
            me.originalConfig = Neo.clone(config, true, true)
        }

        return {...ctor.config, ...config}
    }

    /**
     *
     */
    onAfterConstructed() {
        let me = this;

        me.isConstructed = true;

        // We can only fire the event in case the Observable mixin is included.
        me.getStaticConfig('observable') && me.fire('constructed', me)
    }

    /**
     * Gets triggered after all constructors are done
     * @tutorial 02_ClassSystem
     */
    onConstructed() {}

    /**
     * Helper method to replace string based values containing "@config:" with the matching config value
     * of this instance.
     * @param {Object|Object[]} items
     */
    parseItemConfigs(items) {
        let me = this,
            ns, nsArray, nsKey, symbolNs;

        if (items) {
            if (!Array.isArray(items)) {
                items = [items]
            }

            items.forEach(item => {
                item && Object.entries(item).forEach(([key, value]) => {
                    if (Array.isArray(value)) {
                        me.parseItemConfigs(value);
                    } else if (typeof value === 'string' && value.startsWith('@config:')) {
                        nsArray = value.substring(8).trim().split('.');
                        nsKey   = nsArray.pop();
                        ns      = Neo.ns(nsArray, false, me);

                        if (ns[nsKey] === undefined) {
                            console.error('The used @config does not exist:', nsKey, nsArray.join('.'))
                        } else {
                            symbolNs = Neo.ns(nsArray, false, me[configSymbol]);

                            // The config might not be processed yet, especially for configs
                            // not ending with an underscore, so we need to check the configSymbol first.
                            if (symbolNs && Object.hasOwn(symbolNs, nsKey)) {
                                item[key] = symbolNs[nsKey]
                            } else {
                                item[key] = ns[nsKey]
                            }
                        }
                    }
                })
            })
        }
    }

    /**
     * When using set(), configs without a trailing underscore can already be assigned,
     * so the hasOwnProperty() check will return true
     * @param {Boolean} [forceAssign=false]
     * @protected
     */
    processConfigs(forceAssign=false) {
        let me   = this,
            keys = Object.keys(me[configSymbol]);

        me[forceAssignConfigs] = forceAssign;

        // We do not want to iterate over the keys, since 1 config can remove more than 1 key (beforeSetX, afterSetX)
        if (keys.length > 0) {
            // The hasOwnProperty check is intended for configs without a trailing underscore
            // => they could already have been assigned inside an afterSet-method
            if (forceAssign || !me.hasOwnProperty(keys[0])) {
                me[keys[0]] = me[configSymbol][keys[0]]
            }

            // there is a delete-call inside the config getter as well (Neo.mjs => autoGenerateGetSet())
            // we need to keep this one for configs, which do not use getters (no trailing underscore)
            delete me[configSymbol][keys[0]];

            me.processConfigs(forceAssign)
        }
    }

    /**
     * @param {String} className
     * @param {Object} remote
     * @protected
     */
    static sendRemotes(className, remote) {
        let origin;

        Object.entries(remote).forEach(([worker, methods]) => {
            if (Neo.workerId !== worker) {
                origin = Neo.workerId === 'main' ? Neo.worker.Manager : Neo.currentWorker;

                origin.sendMessage(worker, {
                    action: 'registerRemote',
                    className,
                    methods
                })
            }
        })
    }

    /**
     * Change multiple configs at once, ensuring that all afterSet methods get all new assigned values
     * @param {Object} values={}
     */
    set(values={}) {
        let me = this;

        values = me.setFields(values);

        // If the initial config processing is still running,
        // finish this one first before dropping new values into the configSymbol.
        // see: https://github.com/neomjs/neo/issues/2201
        if (me[forceAssignConfigs] !== true && Object.keys(me[configSymbol]).length > 0) {
            me.processConfigs()
        }

        Object.assign(me[configSymbol], values);

        me.processConfigs(true)
    }

    /**
     * We want to assign class fields first and remove them from the config object,
     * so that afterSet(), beforeGet() and beforeSet() methods can get the new values right away
     * @param {Object} config
     * @returns {Object}
     * @protected
     */
    setFields(config) {
        let me          = this,
            configNames = me.constructor.config;

        Object.entries(config).forEach(([key, value]) => {
            if (!configNames.hasOwnProperty(key) && !Neo.hasPropertySetter(me, key)) {
                me[key] = value;
                delete config[key]
            }
        })

        return config
    }

    /**
     * Sets the value of a static config by a given key
     * @param {String} key The key of a staticConfig defined inside static getStaticConfig
     * @param {*} value
     * @returns {Boolean} true in case the config exists and got changed
     */
    setStaticConfig(key, value) {
        let staticConfig = this.constructor.staticConfig;

        if (staticConfig.hasOwnProperty(key)) {
            staticConfig[key] = value;
            return true
        }

        return false
    }

    /**
     * Stores timeoutIds internally, so that destroy() can clear them if needed
     * @param {Number} time in milliseconds
     * @returns {Promise<any>}
     */
    timeout(time) {
        return new Promise(resolve => {
            let timeoutIds = this.#timeoutIds,
                timeoutId  = setTimeout(() => {timeoutIds.splice(timeoutIds.indexOf(timeoutId), 1); resolve()}, time);

            timeoutIds.push(timeoutId)
        })
    }

    /**
     * <p>Enhancing the toString() method, e.g.</p>
     * `Neo.create('Neo.button.Base').toString() => "[object Neo.button.Base (neo-button-1)]"`
     * @returns {String}
     */
    get [Symbol.toStringTag]() {
        return `${this.className} (id: ${this.id})`
    }

    /**
     * <p>Enhancing the instanceof method. Without this change:</p>
     * `Neo.collection.Base.prototype instanceof Neo.core.Base => true`
     * <p>With this change:</p>
     * `Neo.collection.Base.prototype instanceof Neo.core.Base => false`<br>
     * `Neo.create(Neo.collection.Base) instanceof Neo.core.Base => true`
     * @returns {Boolean}
     */
    static [Symbol.hasInstance](instance) {
        if (!instance) {
            return false
        }

        return instance[isInstance] === true ? super[Symbol.hasInstance](instance) : false
    }
}

export default Neo.setupClass(Base);