/*\
title: $:/core/modules/macros/story/story.js
type: application/javascript
module-type: macro

Displays a sequence of tiddlers defined in a JSON structure:

	{
		tiddlers: [
			{title: <string>, template: <string>}
		]	
	}

The storyview is a plugin that extends the story macro to implement different navigation experiences.

\*/
(function(){

/*jslint node: true, browser: true */
/*global $tw: false */
"use strict";

exports.info = {
	name: "story",
	params: {
		story: {byName: "default", type: "tiddler"},
		defaultViewTemplate: {byName: true, type: "tiddler"},
		defaultEditTemplate: {byName: true, type: "tiddler"},
		storyview: {byName: true, type: "text"}
	},
	events: ["tw-navigate","tw-EditTiddler","tw-SaveTiddler"]
};

exports.getStory = function() {
	var storyTiddler = this.wiki.getTiddler(this.params.story),
		story = {tiddlers: []};
	if(storyTiddler && $tw.utils.hop(storyTiddler.fields,"text")) {
		return JSON.parse(storyTiddler.fields.text);
	} else {
		return {
			tiddlers: []
		};
	}
};

exports.handleEvent = function(event) {
	if(this.eventMap[event.type]) {
		this.eventMap[event.type].call(this,event);
	}
};

exports.eventMap = {};

// Navigate to a specified tiddler
exports.eventMap["tw-navigate"] = function(event) {
	var template = this.params.defaultViewTemplate || "$:/templates/ViewTemplate",
		story = this.getStory(),
		navTiddler,t,tiddler;
	// See if the tiddler we want is already there
	for(t=0; t<story.tiddlers.length; t++) {
		if(story.tiddlers[t].title === event.navigateTo) {
			navTiddler = t;
		}
	}
	if(typeof(navTiddler) !== "undefined") {
		// If we found our tiddler, just tell the storyview to navigate to it
		if(this.storyview && this.storyview.navigate) {
			this.storyview.navigate(this.children[0].children[navTiddler],false,event);
		}
	} else {
		// Add the tiddler to the bottom of the story (subsequently there will be a refreshInDom() call which is when we'll actually do the navigation)
		story.tiddlers.unshift({title: event.navigateTo, template: template});
		this.wiki.addTiddler(new $tw.Tiddler(this.wiki.getTiddler(this.params.story),{text: JSON.stringify(story)}));
		// Record the details of the navigation for us to pick up in refreshInDom()
		this.lastNavigationEvent = event;
	}
	event.stopPropagation();
	return false;
};

// Place a tiddler in edit mode
exports.eventMap["tw-EditTiddler"] = function(event) {
	var template, storyTiddler, story, storyRecord, tiddler, t;
	// Put the specified tiddler into edit mode
	template = this.params.defaultEditTemplate || "$:/templates/EditTemplate";
	story = this.getStory();
	for(t=0; t<story.tiddlers.length; t++) {
		storyRecord = story.tiddlers[t];
		if(storyRecord.title === event.tiddlerTitle && storyRecord.template !== template) {
			storyRecord.title = "Draft " + (new Date()) + " of " + event.tiddlerTitle;
			storyRecord.template = template;
			tiddler = this.wiki.getTiddler(event.tiddlerTitle);
			this.wiki.addTiddler(new $tw.Tiddler(
				{
					text: "Type the text for the tiddler '" + event.tiddlerTitle + "'"
				},
				tiddler,
				{
					title: storyRecord.title,
					"draft.title": event.tiddlerTitle,
					"draft.of": event.tiddlerTitle
				}));
		}
	}
	this.wiki.addTiddler(new $tw.Tiddler(this.wiki.getTiddler(this.params.story),{text: JSON.stringify(story)}));
	event.stopPropagation();
	return false;
};

// Take a tiddler out of edit mode, saving the changes
exports.eventMap["tw-SaveTiddler"] = function(event) {
	var template, storyTiddler, story, storyRecord, tiddler, storyTiddlerModified, t;
	template = this.params.defaultEditTemplate || "$:/templates/ViewTemplate";
	story = this.getStory();
	storyTiddlerModified = false;
	for(t=0; t<story.tiddlers.length; t++) {
		storyRecord = story.tiddlers[t];
		if(storyRecord.title === event.tiddlerTitle && storyRecord.template !== template) {
			tiddler = this.wiki.getTiddler(storyRecord.title);
			if(tiddler && $tw.utils.hop(tiddler.fields,"draft.title")) {
				// Save the draft tiddler as the real tiddler
				this.wiki.addTiddler(new $tw.Tiddler(tiddler,{title: tiddler.fields["draft.title"],"draft.title": undefined, "draft.of": undefined}));
				// Remove the draft tiddler
				this.wiki.deleteTiddler(storyRecord.title);
				// Remove the original tiddler if we're renaming it
				if(tiddler.fields["draft.of"] !== tiddler.fields["draft.title"]) {
					this.wiki.deleteTiddler(tiddler.fields["draft.of"]);
				}
				// Make the story record point to the newly saved tiddler
				storyRecord.title = tiddler.fields["draft.title"];
				storyRecord.template = template;
				// Check if we're modifying the story tiddler itself
				if(tiddler.fields["draft.title"] === this.params.story) {
					storyTiddlerModified = true;
				}
			}
		}
	}
	if(!storyTiddlerModified) {
		this.wiki.addTiddler(new $tw.Tiddler(this.wiki.getTiddler(this.params.story),{text: JSON.stringify(story)}));
	}
	event.stopPropagation();
	return false;
};

exports.executeMacro = function() {
	var story = this.getStory(),
		storyNode = $tw.Tree.Element("div",{"class": "tw-story-frame"},[]);
	for(var t=0; t<story.tiddlers.length; t++) {
		var m = $tw.Tree.Macro("tiddler",{
									srcParams: {target: story.tiddlers[t].title,template: story.tiddlers[t].template},
									wiki: this.wiki
								});
		m.execute(this.parents,this.tiddlerTitle);
		storyNode.children.push($tw.Tree.Element("div",{"class": "tw-story-element"},[m]));
	}
	return [storyNode];
};

exports.postRenderInDom = function() {
	// Instantiate the story view
	var StoryView = this.wiki.macros.story.viewers[this.params.storyview];
	if(StoryView) {
		this.storyview = new StoryView(this);
	}
	if(!this.storyview) {
		StoryView = this.wiki.macros.story.viewers.scroller;
		if(StoryView) {
			this.storyview = new StoryView(this);
		}
	}
};

exports.refreshInDom = function(changes) {
	var t;
	/*jslint browser: true */
	if(this.dependencies.hasChanged(changes,this.tiddlerTitle)) {
		// Get the tiddlers we're supposed to be displaying
		var self = this,
			story = this.getStory(),
			template = this.params.template,
			n,domNode,
			findTiddler = function (childIndex,tiddlerTitle,templateTitle) {
				while(childIndex < self.children[0].children.length) {
					var params = self.children[0].children[childIndex].children[0].params;
					if(params.target === tiddlerTitle) {
						if(!templateTitle || params.template === templateTitle) {
							return childIndex;
						}
					}
					childIndex++;
				}
				return null;
			};
		for(t=0; t<story.tiddlers.length; t++) {
			// See if the node we want is already there
			var tiddlerNode = findTiddler(t,story.tiddlers[t].title,story.tiddlers[t].template);
			if(tiddlerNode === null) {
				// If not, render the tiddler
				var m = $tw.Tree.Element("div",{"class": "tw-story-element"},[
							$tw.Tree.Macro("tiddler",{
											srcParams: {target: story.tiddlers[t].title,template: story.tiddlers[t].template},
											wiki: this.wiki
										})
							]);
				m.execute(this.parents,this.tiddlerTitle);
				m.renderInDom(this.children[0].domNode,this.children[0].domNode.childNodes[t]);
				this.children[0].children.splice(t,0,m);
				// Invoke the storyview to animate the navigation
				if(this.storyview && this.storyview.navigate) {
					this.storyview.navigate(this.children[0].children[t],true,this.lastNavigationEvent);
				}
			} else {
				// Delete any nodes preceding the one we want
				if(tiddlerNode > t) {
					// First delete the DOM nodes
					for(n=t; n<tiddlerNode; n++) {
						domNode = this.children[0].children[n].domNode;
						domNode.parentNode.removeChild(domNode);
					}
					// Then delete the actual renderer nodes
					this.children[0].children.splice(t,tiddlerNode-t);
				}
				// Refresh the DOM node we're reusing
				this.children[0].children[t].refreshInDom(changes);
			}
		}
		// Remove any left over nodes
		if(this.children[0].children.length > story.tiddlers.length) {
			for(t=story.tiddlers.length; t<this.children[0].children.length; t++) {
				domNode = this.children[0].children[t].domNode;
				domNode.parentNode.removeChild(domNode);
			}
			this.children[0].children.splice(story.tiddlers.length,this.children[0].children.length-story.tiddlers.length);
		}
	} else {
		// If our dependencies didn't change, just refresh the children
		for(t=0; t<this.children.length; t++) {
			this.children[t].refreshInDom(changes);
		}
	}
	// Clear the details of the last navigation
	this.lastNavigationEvent = undefined;
};

})();