/*\
title: js/WikiStore.js

\*/
(function(){

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

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

/* Creates a new WikiStore object

Available options are:
	shadowStore: An existing WikiStore to use for shadow tiddler storage. Pass null to prevent a default shadow store from being created
*/
var WikiStore = function WikiStore(options) {
	options = options || {};
	this.tiddlers = {};
	this.parsers = {};
	this.macros = {};
	this.tiddlerSerializers = {};
	this.tiddlerDeserializers = {};
	this.sandbox = options.sandbox;
	this.shadows = options.shadowStore !== undefined ? options.shadowStore : new WikiStore({
		shadowStore: null
	});
};

WikiStore.prototype.registerParser = function(type,parser) {
	this.parsers[type] = parser;
};

WikiStore.prototype.registerTiddlerSerializer = function(extension,mimeType,serializer) {
	this.tiddlerSerializers[extension] = serializer;
	this.tiddlerSerializers[mimeType] = serializer;
};

WikiStore.prototype.registerTiddlerDeserializer = function(extension,mimeType,deserializer) {
	this.tiddlerDeserializers[extension] = deserializer;
	this.tiddlerDeserializers[mimeType] = deserializer;	
};

WikiStore.prototype.getTiddler = function(title) {
	var t = this.tiddlers[title];
	if(t instanceof Tiddler) {
		return t;
	} else if(this.shadows) {
		return this.shadows.getTiddler(title);
	} else {
		return null;
	}
};

WikiStore.prototype.getTiddlerText = function(title) {
	var t = this.getTiddler(title);
	return t instanceof Tiddler ? t.fields.text : null;
};

WikiStore.prototype.deleteTiddler = function(title) {
	delete this.tiddlers[title];
};

WikiStore.prototype.tiddlerExists = function(title) {
	var exists = this.tiddlers[title] instanceof Tiddler;
	if(exists) {
		return true;
	} else if (this.shadows) {
		return this.shadows.tiddlerExists(title);
	}
	return ;
};

WikiStore.prototype.addTiddler = function(tiddler) {
	this.tiddlers[tiddler.fields.title] = tiddler;
};

WikiStore.prototype.forEachTiddler = function(/* [sortField,[excludeTag,]]callback */) {
	var a = 0,
		sortField = arguments.length > 1 ? arguments[a++] : null,
		excludeTag = arguments.length > 2 ? arguments[a++] : null,
		callback = arguments[a++],
		t,
		tiddlers = [],
		tiddler;
	if(sortField) {
		for(t in this.tiddlers) {
			tiddlers.push(this.tiddlers[t]); 
		}
		tiddlers.sort(function (a,b) {
			var aa = a.fields[sortField] || 0,
				bb = b.fields[sortField] || 0;
			if(aa < bb) {
				return -1;
			} else {
				if(aa > bb) {
					return 1;
				} else {
					return 0;
				}
			}
		});
		for(t=0; t<tiddlers.length; t++) {
			if(!tiddlers[t].hasTag(excludeTag)) {
				callback.call(this,tiddlers[t].fields.title,tiddlers[t]);
			}
		}
	} else {
		for(t in this.tiddlers) {
			tiddler = this.tiddlers[t];
			if(tiddler instanceof Tiddler && !tiddler.hasTag(excludeTag))
				callback.call(this,t,tiddler);
		}
	}
};

WikiStore.prototype.getTitles = function(sortField,excludeTag) {
	sortField = sortField || "title";
	var tiddlers = [];
	this.forEachTiddler(sortField,excludeTag,function(title,tiddler) {
		tiddlers.push(title);
	});
	return tiddlers;
};

WikiStore.prototype.getMissingTitles = function() {
	return [];
};

WikiStore.prototype.getOrphanTitles = function() {
	return [];
};

WikiStore.prototype.getShadowTitles = function() {
	return this.shadows ? this.shadows.getTitles() : [];
};

WikiStore.prototype.serializeTiddler = function(type,tiddler) {
	var serializer = this.tiddlerSerializers[type];
	if(serializer) {
		return serializer(tiddler);
	} else {
		return null;
	}
};

WikiStore.prototype.deserializeTiddlers = function(type,text,srcFields) {
	var fields = {},
		deserializer = this.tiddlerDeserializers[type],
		t;
	if(srcFields) {
		for(t in srcFields) {
			fields[t] = srcFields[t];		
		}
	}
	if(deserializer) {
		return deserializer(text,fields);
	} else {
		// Return a raw tiddler for unknown types
		fields.text = text;
		return [fields];
	}
};

WikiStore.prototype.classesForLink = function(target) {
	var className = "",
		externalRegExp = /(?:file|http|https|mailto|ftp|irc|news|data):[^\s'"]+(?:\/|\b)/i;
	if (this.tiddlerExists(target)) {
		className = "linkInternalResolves";
	} else if(externalRegExp.test(target)) {
		className = "linkExternal";
	} else {
		className = "linkInternalMissing";
	}
	return className !== "" ? " class=\"" + className + "\"" : "";
};

WikiStore.prototype.parseText = function(type,text) {
	var parser = this.parsers[type];
	if(!parser) {
		parser = this.parsers["text/x-tiddlywiki"];
	}
	if(parser) {
		return parser.parse(text);
	} else {
		return null;
	}
};

WikiStore.prototype.parseTiddler = function(title) {
	var tiddler = this.getTiddler(title);
	if(tiddler) {
		// Check the cache
		if(!tiddler.parseTree) {
			tiddler.parseTree = this.parseText(tiddler.fields.type,tiddler.fields.text);
		}
		return tiddler.parseTree;
	} else {
		return null;
	}
};

/*
Compiles a block of text of a specified type into a JavaScript function that renders the text in a particular MIME type
*/
WikiStore.prototype.compileText = function(type,text,targetType) {
	/*jslint evil: true */
	var tree = this.parseText(type,text);
	return eval(tree.compile(targetType));
};

/*
Compiles a JavaScript function that renders a tiddler in a particular MIME type
*/
WikiStore.prototype.compileTiddler = function(title,type) {
	/*jslint evil: true */
	var tiddler = this.getTiddler(title);
	if(tiddler) {
		if(!tiddler.renderers[type]) {
			var tree = this.parseTiddler(title);
			tiddler.renderers[type] = eval(tree.compile(type));
		}
		return tiddler.renderers[type];
	} else {
		return null;	
	}
};

/*
Render a block of text of a specified type into a particular MIME type
*/
WikiStore.prototype.renderText = function(type,text,targetType,asTitle) {
	var tiddler = this.getTiddler(asTitle),
		fn = this.compileText(type,text,targetType);
	return fn(tiddler,this,utils);
};

/*
Render a tiddler to a particular MIME type. Optionally render it with a different tiddler
as the context. This option is used to render a tiddler through a template eg
store.renderTiddler("text/html",templateTitle,tiddlerTitle)
*/
WikiStore.prototype.renderTiddler = function(type,title,asTitle) {
	var tiddler = this.getTiddler(title),
		fn = this.compileTiddler(title,type);
	if(tiddler) {
		if(asTitle) {
			var asTiddler = this.getTiddler(asTitle);
			return fn(asTiddler,this,utils);
		} else {
			if(!tiddler.renditions[type]) {
				tiddler.renditions[type] = fn(tiddler,this,utils);
			}
			return tiddler.renditions[type];
		}
	}
	return null;
};

WikiStore.prototype.installMacro = function(macro) {
	this.macros[macro.name] = macro;
};

exports.WikiStore = WikiStore;

})();