// comp-data.ts - definition and methods of the Data component

import { sendMsg } from './common'

// Data component

export function Data(name, action, domain: string): object {
	domain = domain || this.conf.domain
	const comp = {
		id: this.conf.itemid,
		name: name, // also used as class of incoming/outgoing message
		action: action, // (default) action of outgoing message
		domain: domain, // domain of incoming/outgoing message
		data: {}, 	// model (2-way data store)
		data_bak: {}, // backup copy when leaving view or edit mode
		meta: {},	// metadata (params) for each data field
		mode: 'view',
		handle,		// handle incoming messages
		exec,		// default function to execute upon button click
		initField,	// initialize field (= @mounted)
		chmode,
		copynew
	}
	this.components[name] = comp
	if (comp.id) {
		sendMsg(this.conf, [domain, 'query', name, comp.id], {})
	}
	return comp
}

// Data methods

function handle(domain, action, class_, item, payload: string) {
	if (action == 'data') {
		const data = JSON.parse(payload)
		Object.assign(this.data, data)
	}
}

function exec(action: string) {
	action = action || this.action
	const data = this.data
	const conf = this.conf
	let value = ''
	for (const k of Object.keys(data)) {
		value += `${k}: ${data[k]}, `
	}
	this.output += '\n' + value
	console.log('exec:', value)
	sendMsg(conf, [this.domain, action, this.name, data.id], data)
}

function initField(name: string, meta: any) {
	if (meta.defexpr) {
		meta.default = eval(meta.defexpr)
	}
	this.data[name] = meta.default || ""
	this.meta[name] = meta
}

function chmode(action: string) {
	if (this.mode == action) {
		return
	}
	if (this.mode == 'view') {
		Object.assign(this.data_bak, this.data)
	}
	switch(action) {
		case 'query':
			setQuery(this)
			break
		case 'new':
			setNew(this)
			break
		default:
			Object.assign(this.data, this.data_bak)
	}
	this.mode = action
}

function copynew(action: string) {
	Object.assign(this.data, this.data_bak)
	this.data.id = ''
	this.mode = 'new'
}

// helper functions for data manipulation (used by Data component)

function setQuery(obj) {
	for (const key in obj.data) {
		obj.data[key] = ''
	}
}

function setNew(obj) {
	for (const key in obj.data) {
		obj.data[key] = ''
		const meta = obj.meta[key]
		if (meta) {
			obj.data[key] = meta.default || ''
		}
	}
	obj.data.id = ''
}