/* jslint node: true */
'use strict';

const FileEntry     = require('./file_entry');
const UserProps     = require('./user_property');
const Events        = require('./events');

//  deps
const _ = require('lodash');

module.exports = class DownloadQueue {
    constructor(client) {
        this.client = client;

        if(!Array.isArray(this.client.user.downloadQueue)) {
            if(this.client.user.properties[UserProps.DownloadQueue]) {
                this.loadFromProperty(this.client.user.properties[UserProps.DownloadQueue]);
            } else {
                this.client.user.downloadQueue = [];
            }
        }
    }

    static get(client) {
        return new DownloadQueue(client);
    }

    get items() {
        return this.client.user.downloadQueue;
    }

    clear() {
        this.client.user.downloadQueue = [];
    }

    toggle(fileEntry, systemFile=false) {
        if(this.isQueued(fileEntry)) {
            this.client.user.downloadQueue = this.client.user.downloadQueue.filter(e => fileEntry.fileId !== e.fileId);
        } else {
            this.add(fileEntry, systemFile);
        }
    }

    add(fileEntry, systemFile=false) {
        this.client.user.downloadQueue.push({
            fileId      : fileEntry.fileId,
            areaTag     : fileEntry.areaTag,
            fileName    : fileEntry.fileName,
            path        : fileEntry.filePath,
            byteSize    : fileEntry.meta.byte_size || 0,
            systemFile  : systemFile,
        });
    }

    removeItems(fileIds) {
        if(!Array.isArray(fileIds)) {
            fileIds = [ fileIds ];
        }

        const [ remain, removed ] = _.partition(this.client.user.downloadQueue, e => ( -1 === fileIds.indexOf(e.fileId) ));
        this.client.user.downloadQueue = remain;
        return removed;
    }

    isQueued(entryOrId) {
        if(entryOrId instanceof FileEntry) {
            entryOrId = entryOrId.fileId;
        }

        return this.client.user.downloadQueue.find(e => entryOrId === e.fileId) ? true : false;
    }

    toProperty() { return JSON.stringify(this.client.user.downloadQueue); }

    loadFromProperty(prop) {
        try {
            this.client.user.downloadQueue = JSON.parse(prop);
        } catch(e) {
            this.client.user.downloadQueue = [];

            this.client.log.error( { error : e.message, property : prop }, 'Failed parsing download queue property');
        }
    }

    addTemporaryDownload(entry) {
        this.add(entry, true);    //  true=systemFile

        //  clean up after ourselves when the session ends
        const thisUniqueId = this.client.session.uniqueId;
        Events.once(Events.getSystemEvents().ClientDisconnected, evt => {
            if(thisUniqueId === _.get(evt, 'client.session.uniqueId')) {
                FileEntry.removeEntry(entry, { removePhysFile : true }, err => {
                    const Log = require('./logger').log;
                    if(err) {
                        Log.warn( { fileId : entry.fileId, path : entry.filePath }, 'Failed removing temporary session download' );
                    } else {
                        Log.debug( { fileId : entry.fileId, path : entry.filePath }, 'Removed temporary session download item' );
                    }
                });
            }
        });
    }
};