/*\
title: js/macros/slider.js

!Introduction
The slider macro is used to selectively reveal a chunk of text. By default, it renders as a button that may be clicked or touched to reveal the enclosed text.

The enclosed text can be a string of WikiText or be taken from a target tiddler.

The current state of the slider can be stored as the string "open" or "closed" in a specified tiddler. If the value of that tiddler changes then the slider is automatically updated.
!!Parameters
|`state` //(defaults to 1st parameter)// |The title of the tiddler to contain the current state of the slider |
|`default` |The initial state of the slider, either `open` or `closed` |
|`content` |The WikiText to be enclosed in the slider. Overrides the `target` parameter, if present |
|`target` //(defaults to 2nd parameter)// |The title of the tiddler that contains the enclosed text. Ignored if the `content` parameter is specified |
|`label` //(defaults to 3rd parameter)// |The plain text to be displayed as the label for the slider button |
|`tooltip` //(defaults to 4th parameter)// |The plain text tooltip to be displayed when the mouse hovers over the slider button |
!!Examples
A minimal slider:
{{{
<<slider target:MyTiddler>>
}}}
!!Notes
The slider is a good study example of a simple interactive macro.
\*/
(function(){

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

var Renderer = require("../Renderer.js").Renderer,
    Dependencies = require("../Dependencies.js").Dependencies,
	Tiddler = require("../Tiddler.js").Tiddler,
	utils = require("../Utils.js");


function getOpenState() {
	if(this.params.hasOwnProperty("state")) {
		var stateTiddler = this.store.getTiddler(this.params.state);
		if(stateTiddler) {
			return stateTiddler.text.trim() === "open";
		}
	}
	if(this.params.hasOwnProperty("default")) {
		return this.params["default"] === "open";
	}
	return false;
};

function saveOpenState() {
	if(this.params.hasOwnProperty("state")) {
		var stateTiddler = this.store.getTiddler(this.params.state) ||
							new Tiddler({title: this.params.state, text: ""});
		this.store.addTiddler(new Tiddler(stateTiddler,{text: this.isOpen ? "open" : "closed"}));
		return true;
	}
	return false;
}

function getSliderContent() {
	if(this.params.hasOwnProperty("content")) {
		return this.store.parseText("text/x-tiddlywiki",this.params.content).nodes;
	} else if(this.params.hasOwnProperty("target")) {
		return [Renderer.MacroNode(
								"tiddler",
								{target: this.params.target},
								null,
								this.store)];
	} else {
		return [Renderer.ErrorNode("No content specified for slider")];
	}
};

exports.macro = {
	name: "slider",
	types: ["text/html","text/plain"],
	params: {
		state: {byPos: 0, type: "tiddler"},
		"default": {byName: true, type: "text"},
		target: {byPos: 1, type: "tiddler"},
		label: {byPos: 2, type: "text"},
		tooltip: {byPos: 3, type: "text"},
		content: {byName: true, type: "text"}
	},
	events: {
		click: function(event) {
			if(event.target === this.domNode.firstChild.firstChild) {
				this.isOpen = !this.isOpen;
				if(!saveOpenState.call(this)) {
					exports.macro.refreshInDom.call(this,{});
				}
				event.preventDefault();
				return false;
			} else {
				return true;	
			}
		}
	},
	execute: function() {
			this.isOpen = getOpenState.call(this);
			var sliderContent = [];
			if(this.isOpen) {
				sliderContent = getSliderContent.call(this);
			}
			var content = Renderer.SliderNode(this.params.state,
										this.params.label ? this.params.label : this.params.target,
										this.params.tooltip,
										this.isOpen,
										sliderContent);
			content.execute(this.parents,this.store.getTiddler(this.tiddlerTitle));
			return [content];
	},
	refreshInDom: function(changes) {
		var needContentRefresh = true; // Avoid refreshing the content nodes if we don't need to
		// If the state tiddler has changed then reset the open state
		if(this.params.hasOwnProperty("state") && changes.hasOwnProperty(this.params.state)) {
			this.isOpen = getOpenState.call(this);
		}
		// Render the content if the slider is open and we don't have any content yet
		if(this.isOpen && this.content[0].children[1].children.length === 0) {
			// Get the slider content and execute it
			this.content[0].children[1].children = getSliderContent.call(this);
			this.content[0].children[1].execute(this.parents,this.store.getTiddler(this.tiddlerTitle));
			// Replace the existing slider body DOM node
			this.domNode.firstChild.removeChild(this.domNode.firstChild.firstChild.nextSibling);
			this.content[0].children[1].renderInDom(this.domNode.firstChild,this.domNode.firstChild.firstChild.nextSibling);
			needContentRefresh = false; // Don't refresh the children if we've just created them
		}
		// Set the visibility of the slider content
		var el = this.domNode.firstChild.firstChild.nextSibling;
		el.style.display = this.isOpen ? "block" : "none";
		// Refresh any children
		if(needContentRefresh) {
			for(var t=0; t<this.content.length; t++) {
				this.content[t].refreshInDom(changes);
			}
		}
	}
};

})();