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

//	ENiGMA½
const MenuModule					= require('../core/menu_module.js').MenuModule;
const ViewController				= require('../core/view_controller.js').ViewController;
const messageArea					= require('../core/message_area.js');
const stringFormat					= require('../core/string_format.js');
const MessageAreaConfTempSwitcher	= require('../core/mod_mixins.js').MessageAreaConfTempSwitcher;

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

/*
	Available listFormat/focusListFormat members (VM1):

	msgNum			: Message number
	to				: To username/handle
	from			: From username/handle
	subj			: Subject
	ts				: Message mod timestamp (format with config.dateTimeFormat)
	newIndicator	: New mark/indicator (config.newIndicator)

	MCI codes:

	VM1			: Message list
	TL2			: Message info 1: { msgNumSelected, msgNumTotal }	
*/

exports.moduleInfo = {
	name	: 'Message List',
	desc	: 'Module for listing/browsing available messages',
	author	: 'NuSkooler',
};

const MCICodesIDs = {
	MsgList			: 1,	//	VM1
	MsgInfo1		: 2,	//	TL2
};

exports.getModule = class MessageListModule extends MessageAreaConfTempSwitcher(MenuModule) {
	constructor(options) {
		super(options);

		const self		= this;
		const config	= this.menuConfig.config;

		this.messageAreaTag = config.messageAreaTag;

		if(options.extraArgs) {
			//
			//	|extraArgs| can override |messageAreaTag| provided by config
			//	as well as supply a pre-defined message list
			//
			if(options.extraArgs.messageAreaTag) {
				this.messageAreaTag = options.extraArgs.messageAreaTag;
			}

			if(options.extraArgs.messageList) {
				this.messageList = options.extraArgs.messageList;
			}
		}

		this.menuMethods = {
			selectMessage : function(formData, extraArgs, cb) {
				if(1 === formData.submitId) {
					self.initialFocusIndex = formData.value.message;

					const modOpts = {
						extraArgs 	: {
							messageAreaTag		: self.messageAreaTag,
							messageList			: self.messageList,
							messageIndex		: formData.value.message,
						}
					};

					//
					//	Provide a serializer so we don't dump *huge* bits of information to the log
					//	due to the size of |messageList|. See https://github.com/trentm/node-bunyan/issues/189
					//
					modOpts.extraArgs.toJSON = function() {
						const logMsgList = (this.messageList.length <= 4) ? 
							this.messageList : 
							this.messageList.slice(0, 2).concat(this.messageList.slice(-2)); 

						return {
							messageAreaTag		: this.messageAreaTag,
							apprevMessageList	: logMsgList,
							messageCount		: this.messageList.length,
							messageIndex		: formData.value.message,
						};
					};

					return self.gotoMenu(config.menuViewPost || 'messageAreaViewPost', modOpts, cb);
				} else {
					return cb(null);
				}
			},

			fullExit : function(formData, extraArgs, cb) {
				self.menuResult = { fullExit : true };
				return self.prevMenu(cb);
			}
		};
	}

	enter() {
		super.enter();

		//
		//	Config can specify |messageAreaTag| else it comes from
		//	the user's current area
		//
		if(this.messageAreaTag) {
			this.tempMessageConfAndAreaSwitch(this.messageAreaTag);
		} else {
			this.messageAreaTag = this.client.user.properties.message_area_tag;
		}
	}

	leave() {
		this.tempMessageConfAndAreaRestore();
		super.leave();
	}

	mciReady(mciData, cb) {
		super.mciReady(mciData, err => {
			if(err) {
				return cb(err);
			}

			const self	= this;
			const vc	= self.viewControllers.allViews = new ViewController( { client : self.client } );

			async.series(
				[
					function loadFromConfig(callback) {
						const loadOpts = {
							callingMenu		: self,
							mciMap			: mciData.menu
						};

						return vc.loadFromMenuConfig(loadOpts, callback);
					},
					function fetchMessagesInArea(callback) {
						//
						//	Config can supply messages else we'll need to populate the list now
						//
						if(_.isArray(self.messageList)) {
							return callback(0 === self.messageList.length ? new Error('No messages in area') : null);
						}
						
						messageArea.getMessageListForArea( { client : self.client }, self.messageAreaTag, function msgs(err, msgList) {
							if(!msgList || 0 === msgList.length) {
								return callback(new Error('No messages in area'));
							}
							
							self.messageList = msgList;
							return callback(err);						
						});
					},
					function getLastReadMesageId(callback) {
						messageArea.getMessageAreaLastReadId(self.client.user.userId, self.messageAreaTag, function lastRead(err, lastReadId) {
							self.lastReadId = lastReadId || 0;
							return callback(null);	//	ignore any errors, e.g. missing value
						});
					},
					function updateMessageListObjects(callback) {
						const dateTimeFormat	= self.menuConfig.config.dateTimeFormat || 'ddd MMM Do';
						const newIndicator		= self.menuConfig.config.newIndicator || '*';
						const regIndicator		= new Array(newIndicator.length + 1).join(' ');	//	fill with space to avoid draw issues

						let msgNum = 1;
						self.messageList.forEach( (listItem, index) => {
							listItem.msgNum			= msgNum++;
							listItem.ts				= moment(listItem.modTimestamp).format(dateTimeFormat);
							listItem.newIndicator	= listItem.messageId > self.lastReadId ? newIndicator : regIndicator;

							if(_.isUndefined(self.initialFocusIndex) && listItem.messageId > self.lastReadId) {
								self.initialFocusIndex = index;
							}					
						});
						return callback(null);
					},
					function populateList(callback) {
						const msgListView			= vc.getView(MCICodesIDs.MsgList);	
						const listFormat			= self.menuConfig.config.listFormat || '{msgNum} - {subject} - {toUserName}';				
						const focusListFormat		= self.menuConfig.config.focusListFormat || listFormat;	//	:TODO: default change color here
						const messageInfo1Format	= self.menuConfig.config.messageInfo1Format || '{msgNumSelected} / {msgNumTotal}'; 

						//	:TODO: This can take a very long time to load large lists. What we need is to implement the "owner draw" concept in
						//	which items are requested (e.g. their format at least) *as-needed* vs trying to get the format for all of them at once

						msgListView.setItems(_.map(self.messageList, listEntry => {
							return stringFormat(listFormat, listEntry);
						}));

						msgListView.setFocusItems(_.map(self.messageList, listEntry => {
							return stringFormat(focusListFormat, listEntry);
						}));

						msgListView.on('index update', idx => {
							self.setViewText(
								'allViews',
								MCICodesIDs.MsgInfo1, 
								stringFormat(messageInfo1Format, { msgNumSelected : (idx + 1), msgNumTotal : self.messageList.length } ));
						});
						
						if(self.initialFocusIndex > 0) {
							//	note: causes redraw()
							msgListView.setFocusItemIndex(self.initialFocusIndex);
						} else {
							msgListView.redraw();
						}

						return callback(null);
					},
					function drawOtherViews(callback) {
						const messageInfo1Format = self.menuConfig.config.messageInfo1Format || '{msgNumSelected} / {msgNumTotal}';
						self.setViewText(
							'allViews',
							MCICodesIDs.MsgInfo1, 
							stringFormat(messageInfo1Format, { msgNumSelected : self.initialFocusIndex + 1, msgNumTotal : self.messageList.length } ));
						return callback(null);
					},
				],		
				err => {
					if(err) {
						self.client.log.error( { error : err.message }, 'Error loading message list');				
					}
					return cb(err);
				}
			);
		});			
	}

	getSaveState() {
		return { initialFocusIndex : this.initialFocusIndex };	
	}

	restoreSavedState(savedState) {
		if(savedState) {
			this.initialFocusIndex = savedState.initialFocusIndex;
		}	
	}

	getMenuResult() {
		return this.menuResult;
	}
};