import isObject from "lodash-es/isObject";
import log from "@converse/headless/log.js";
import { _converse, api, converse } from "@converse/headless/core.js";
import { getOpenPromise } from '@converse/openpromise';

const { Strophe, $iq } = converse.env;


export default {
    /**
     * The XEP-0030 service discovery API
     *
     * This API lets you discover information about entities on the
     * XMPP network.
     *
     * @namespace api.disco
     * @memberOf api
     */
    disco: {
        /**
         * @namespace api.disco.stream
         * @memberOf api.disco
         */
        stream: {
            /**
             * @method api.disco.stream.getFeature
             * @param {String} name The feature name
             * @param {String} xmlns The XML namespace
             * @example _converse.api.disco.stream.getFeature('ver', 'urn:xmpp:features:rosterver')
             */
            async getFeature (name, xmlns) {
                await api.waitUntil('streamFeaturesAdded');
                if (!name || !xmlns) {
                    throw new Error("name and xmlns need to be provided when calling disco.stream.getFeature");
                }
                if (_converse.stream_features === undefined && !api.connection.connected()) {
                    // Happens during tests when disco lookups happen asynchronously after teardown.
                    const msg = `Tried to get feature ${name} ${xmlns} but _converse.stream_features has been torn down`;
                    log.warn(msg);
                    return;
                }
                return _converse.stream_features.findWhere({'name': name, 'xmlns': xmlns});
            }
        },

        /**
         * @namespace api.disco.own
         * @memberOf api.disco
         */
        own: {
            /**
             * @namespace api.disco.own.identities
             * @memberOf api.disco.own
             */
            identities: {
                /**
                 * Lets you add new identities for this client (i.e. instance of Converse)
                 * @method api.disco.own.identities.add
                 *
                 * @param {String} category - server, client, gateway, directory, etc.
                 * @param {String} type - phone, pc, web, etc.
                 * @param {String} name - "Converse"
                 * @param {String} lang - en, el, de, etc.
                 *
                 * @example _converse.api.disco.own.identities.clear();
                 */
                add (category, type, name, lang) {
                    for (var i=0; i<_converse.disco._identities.length; i++) {
                        if (_converse.disco._identities[i].category == category &&
                            _converse.disco._identities[i].type == type &&
                            _converse.disco._identities[i].name == name &&
                            _converse.disco._identities[i].lang == lang) {
                            return false;
                        }
                    }
                    _converse.disco._identities.push({category: category, type: type, name: name, lang: lang});
                },
                /**
                 * Clears all previously registered identities.
                 * @method api.disco.own.identities.clear
                 * @example _converse.api.disco.own.identities.clear();
                 */
                clear () {
                    _converse.disco._identities = []
                },
                /**
                 * Returns all of the identities registered for this client
                 * (i.e. instance of Converse).
                 * @method api.disco.identities.get
                 * @example const identities = api.disco.own.identities.get();
                 */
                get () {
                    return _converse.disco._identities;
                }
            },

            /**
             * @namespace api.disco.own.features
             * @memberOf api.disco.own
             */
            features: {
                /**
                 * Lets you register new disco features for this client (i.e. instance of Converse)
                 * @method api.disco.own.features.add
                 * @param {String} name - e.g. http://jabber.org/protocol/caps
                 * @example _converse.api.disco.own.features.add("http://jabber.org/protocol/caps");
                 */
                add (name) {
                    for (var i=0; i<_converse.disco._features.length; i++) {
                        if (_converse.disco._features[i] == name) { return false; }
                    }
                    _converse.disco._features.push(name);
                },
                /**
                 * Clears all previously registered features.
                 * @method api.disco.own.features.clear
                 * @example _converse.api.disco.own.features.clear();
                 */
                clear () {
                    _converse.disco._features = []
                },
                /**
                 * Returns all of the features registered for this client (i.e. instance of Converse).
                 * @method api.disco.own.features.get
                 * @example const features = api.disco.own.features.get();
                 */
                get () {
                    return _converse.disco._features;
                }
            }
        },

        /**
         * Query for information about an XMPP entity
         *
         * @method api.disco.info
         * @param {string} jid The Jabber ID of the entity to query
         * @param {string} [node] A specific node identifier associated with the JID
         * @returns {promise} Promise which resolves once we have a result from the server.
         */
        info (jid, node) {
            const attrs = {xmlns: Strophe.NS.DISCO_INFO};
            if (node) {
                attrs.node = node;
            }
            const info = $iq({
                'from': _converse.connection.jid,
                'to':jid,
                'type':'get'
            }).c('query', attrs);
            return api.sendIQ(info);
        },

        /**
         * Query for items associated with an XMPP entity
         *
         * @method api.disco.items
         * @param {string} jid The Jabber ID of the entity to query for items
         * @param {string} [node] A specific node identifier associated with the JID
         * @returns {promise} Promise which resolves once we have a result from the server.
         */
        items (jid, node) {
            const attrs = {'xmlns': Strophe.NS.DISCO_ITEMS};
            if (node) {
                attrs.node = node;
            }
            return api.sendIQ(
                $iq({
                    'from': _converse.connection.jid,
                    'to':jid,
                    'type':'get'
                }).c('query', attrs)
            );
        },

        /**
         * Namespace for methods associated with disco entities
         *
         * @namespace api.disco.entities
         * @memberOf api.disco
         */
        entities: {
            /**
             * Get the corresponding `DiscoEntity` instance.
             *
             * @method api.disco.entities.get
             * @param {string} jid The Jabber ID of the entity
             * @param {boolean} [create] Whether the entity should be created if it doesn't exist.
             * @example _converse.api.disco.entities.get(jid);
             */
            async get (jid, create=false) {
                await api.waitUntil('discoInitialized');
                if (!jid) {
                    return _converse.disco_entities;
                }
                if (_converse.disco_entities === undefined && !api.connection.connected()) {
                    // Happens during tests when disco lookups happen asynchronously after teardown.
                    const msg = `Tried to look up entity ${jid} but _converse.disco_entities has been torn down`;
                    log.warn(msg);
                    return;
                }
                const entity = _converse.disco_entities.get(jid);
                if (entity || !create) {
                    return entity;
                }
                return api.disco.entities.create(jid);
            },

            /**
             * Create a new disco entity. It's identity and features
             * will automatically be fetched from cache or from the
             * XMPP server.
             *
             * Fetching from cache can be disabled by passing in
             * `ignore_cache: true` in the options parameter.
             *
             * @method api.disco.entities.create
             * @param {string} jid The Jabber ID of the entity
             * @param {object} [options] Additional options
             * @param {boolean} [options.ignore_cache]
             *     If true, fetch all features from the XMPP server instead of restoring them from cache
             * @example _converse.api.disco.entities.create(jid, {'ignore_cache': true});
             */
            create (jid, options) {
                return _converse.disco_entities.create({'jid': jid}, options);
            }
        },

        /**
         * @namespace api.disco.features
         * @memberOf api.disco
         */
        features: {
            /**
             * Return a given feature of a disco entity
             *
             * @method api.disco.features.get
             * @param {string} feature The feature that might be
             *     supported. In the XML stanza, this is the `var`
             *     attribute of the `<feature>` element. For
             *     example: `http://jabber.org/protocol/muc`
             * @param {string} jid The JID of the entity
             *     (and its associated items) which should be queried
             * @returns {promise} A promise which resolves with a list containing
             *     _converse.Entity instances representing the entity
             *     itself or those items associated with the entity if
             *     they support the given feature.
             * @example
             * api.disco.features.get(Strophe.NS.MAM, _converse.bare_jid);
             */
            async get (feature, jid) {
                if (!jid) {
                    throw new TypeError('You need to provide an entity JID');
                }
                await api.waitUntil('discoInitialized');
                let entity = await api.disco.entities.get(jid, true);

                if (_converse.disco_entities === undefined && !api.connection.connected()) {
                    // Happens during tests when disco lookups happen asynchronously after teardown.
                    const msg = `Tried to get feature ${feature} for ${jid} but _converse.disco_entities has been torn down`;
                    log.warn(msg);
                    return;
                }
                entity = await entity.waitUntilFeaturesDiscovered;
                const promises = [...entity.items.map(i => i.hasFeature(feature)), entity.hasFeature(feature)];
                const result = await Promise.all(promises);
                return result.filter(isObject);
            }
        },

        /**
         * Used to determine whether an entity supports a given feature.
         *
         * @method api.disco.supports
         * @param {string} feature The feature that might be
         *     supported. In the XML stanza, this is the `var`
         *     attribute of the `<feature>` element. For
         *     example: `http://jabber.org/protocol/muc`
         * @param {string} jid The JID of the entity
         *     (and its associated items) which should be queried
         * @returns {promise} A promise which resolves with `true` or `false`.
         * @example
         * if (await api.disco.supports(Strophe.NS.MAM, _converse.bare_jid)) {
         *     // The feature is supported
         * } else {
         *     // The feature is not supported
         * }
         */
        async supports (feature, jid) {
            const features = await api.disco.features.get(feature, jid) || [];
            return features.length > 0;
        },

        /**
         * Refresh the features, fields and identities associated with a
         * disco entity by refetching them from the server
         * @method api.disco.refresh
         * @param {string} jid The JID of the entity whose features are refreshed.
         * @returns {promise} A promise which resolves once the features have been refreshed
         * @example
         * await api.disco.refresh('room@conference.example.org');
         */
        async refresh (jid) {
            if (!jid) {
                throw new TypeError('api.disco.refresh: You need to provide an entity JID');
            }
            await api.waitUntil('discoInitialized');
            let entity = await api.disco.entities.get(jid);
            if (entity) {
                entity.features.reset();
                entity.fields.reset();
                entity.identities.reset();
                if (!entity.waitUntilFeaturesDiscovered.isPending) {
                    entity.waitUntilFeaturesDiscovered = getOpenPromise()
                }
                entity.queryInfo();
            } else {
                // Create it if it doesn't exist
                entity = await api.disco.entities.create(jid, {'ignore_cache': true});
            }
            return entity.waitUntilFeaturesDiscovered;
        },

        /**
         * @deprecated Use {@link api.disco.refresh} instead.
         * @method api.disco.refreshFeatures
         */
        refreshFeatures (jid) {
            return api.refresh(jid);
        },

        /**
         * Return all the features associated with a disco entity
         *
         * @method api.disco.getFeatures
         * @param {string} jid The JID of the entity whose features are returned.
         * @returns {promise} A promise which resolves with the returned features
         * @example
         * const features = await api.disco.getFeatures('room@conference.example.org');
         */
        async getFeatures (jid) {
            if (!jid) {
                throw new TypeError('api.disco.getFeatures: You need to provide an entity JID');
            }
            await api.waitUntil('discoInitialized');
            let entity = await api.disco.entities.get(jid, true);
            entity = await entity.waitUntilFeaturesDiscovered;
            return entity.features;
        },

        /**
         * Return all the service discovery extensions fields
         * associated with an entity.
         *
         * See [XEP-0129: Service Discovery Extensions](https://xmpp.org/extensions/xep-0128.html)
         *
         * @method api.disco.getFields
         * @param {string} jid The JID of the entity whose fields are returned.
         * @example
         * const fields = await api.disco.getFields('room@conference.example.org');
         */
        async getFields (jid) {
            if (!jid) {
                throw new TypeError('api.disco.getFields: You need to provide an entity JID');
            }
            await api.waitUntil('discoInitialized');
            let entity = await api.disco.entities.get(jid, true);
            entity = await entity.waitUntilFeaturesDiscovered;
            return entity.fields;
        },

        /**
         * Get the identity (with the given category and type) for a given disco entity.
         *
         * For example, when determining support for PEP (personal eventing protocol), you
         * want to know whether the user's own JID has an identity with
         * `category='pubsub'` and `type='pep'` as explained in this section of
         * XEP-0163: https://xmpp.org/extensions/xep-0163.html#support
         *
         * @method api.disco.getIdentity
         * @param {string} The identity category.
         *     In the XML stanza, this is the `category`
         *     attribute of the `<identity>` element.
         *     For example: 'pubsub'
         * @param {string} type The identity type.
         *     In the XML stanza, this is the `type`
         *     attribute of the `<identity>` element.
         *     For example: 'pep'
         * @param {string} jid The JID of the entity which might have the identity
         * @returns {promise} A promise which resolves with a map indicating
         *     whether an identity with a given type is provided by the entity.
         * @example
         * api.disco.getIdentity('pubsub', 'pep', _converse.bare_jid).then(
         *     function (identity) {
         *         if (identity) {
         *             // The entity DOES have this identity
         *         } else {
         *             // The entity DOES NOT have this identity
         *         }
         *     }
         * ).catch(e => log.error(e));
         */
        async getIdentity (category, type, jid) {
            const e = await api.disco.entities.get(jid, true);
            if (e === undefined && !api.connection.connected()) {
                // Happens during tests when disco lookups happen asynchronously after teardown.
                const msg = `Tried to look up category ${category} for ${jid} but _converse.disco_entities has been torn down`;
                log.warn(msg);
                return;
            }
            return e.getIdentity(category, type);
        }
    }
}