"use strict"

var Vnode = require("../render/vnode")

module.exports = function(redrawService) {
	function throttle(callback) {
		//60fps translates to 16.6ms, round it down since setTimeout requires int
		var time = 16
		var last = 0, pending = null
		var timeout = typeof requestAnimationFrame === "function" ? requestAnimationFrame : setTimeout
		return function() {
			var now = Date.now()
			if (last === 0 || now - last >= time) {
				last = now
				callback()
			}
			else if (pending === null) {
				pending = timeout(function() {
					pending = null
					callback()
					last = Date.now()
				}, time - (now - last))
			}
		}
	}
	
	return function(root, component) {
		if (component === null) {
			redrawService.render(root, [])
			redrawService.unsubscribe(root)
			return
		}
		
		if (component.view == null) throw new Error("m.mount(element, component) expects a component, not a vnode")
		
		var run = throttle(function() {
			redrawService.render(root, Vnode(component))
		})
		redrawService.subscribe(root, run)
		run()
	}
}