/*jslint vars: true, unparam: true, white: true */
/*global jQuery, tiddlyspy, Showdown */

tiddlyspy.ui = (function($, ts, Showdown) {

"use strict";

ts.renderers = {
	"text/x-markdown": (new Showdown.converter()).makeHtml
};

var ui = {};
var onEntityClick, onLinkClick;

ui.loadPage = function(page) {
	if(page.tiddler) {
		ui.displayTiddler(page.tiddler);
	} else if(page.list) {
		ui.listTiddlers(ts.store.tiddlers); // TODO: simply restore (unhide) existing elements
	}
};

ui.listTiddlers = function(tiddlers) {
	// sort (case-insensitive) -- XXX: inefficient!?
	var ordered = $.map(tiddlers, function(tid, id) {
		return [[id, tid]]; // nested array prevents flattening
	}).sort(function(a, b) {
		var x = a[1].title.toLowerCase();
		var y = b[1].title.toLowerCase();
		return ((x < y) ? -1 : ((x > y) ? 1 : 0));
	});
	// generate list
	var els = $.map(ordered, function(arr, i) {
		var id = arr[0];
		var tid = arr[1];
		var link = $("<a />").attr("href", tid.uri).text(tid.title)
			.data("id", id).click(onEntityClick); // TODO: s/click/live/ for efficiency
		return $("<li />").append(link)[0];
	});
	// render
	$("#tiddler_view").hide(); // XXX: hardcoded selector -- XXX: breaks encapsulation
	$("#tiddler_index").empty().append(els).show(); // XXX: hardcoded selector
	ts.history.push({ list: "all" });
};

ui.displayTiddler = function(id) {
	var tid = ts.store.get(id);

	$("#tiddler_index").hide(); // XXX: hardcoded selector -- XXX: breaks encapsulation
	var el = $("#tiddler_view"); // XXX: hardcoded selector
	var renderer = ts.renderers[tid.type];
	if(renderer) {
		el.html(renderer(tid.text)).show();
		$("a", el).data("srcBag", tid.bag.name).live("click", onLinkClick);
	} else {
		el.text(tid.text).show();
	}

	$("<a />").attr("href", tid.uri).text("link").prependTo(el);

	ts.history.push({ tiddler: id });
};

onEntityClick = function(ev) { // TODO: rename
	var id = $(this).data("id");
	ui.displayTiddler(id);
	ev.preventDefault();
	return false;
};

onLinkClick = function(ev) { // TODO: rename
	var el = $(this),
		target = el.attr("href"),
		bag = el.data("srcBag"), // XXX: this gets lost when repeatedly following internal links
		candidates = ts.store.titles[target], // XXX: should use accessor?
		tid, i;
	// select matching tiddler from the same bag if available, using last
	// candidate as fallback -- XXX: overly simplistic?
	for(i = 0; i < candidates.length; i++) {
		tid = candidates[i];
		if(tid.bag === bag) {
			break;
		}
	}
	if(tid) { // XXX: what if tiddler only exists remotely?
		ui.displayTiddler(tid.bag.name + "/" + tid.title); // XXX: might be more efficient to pass `tid` directly
		ev.preventDefault();
	}
};

return ui;

}(jQuery, tiddlyspy, Showdown));