/*\
title: $:/core/modules/savers/put.js
type: application/javascript
module-type: saver

Saves wiki by performing a PUT request to the server

Works with any server which accepts a PUT request
to the current URL, such as a WebDAV server.

\*/
(function(){

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

/*
Select the appropriate saver module and set it up
*/
var PutSaver = function(wiki) {
	this.wiki = wiki;
	var self = this;
	// Async server probe. Until probe finishes, save will fail fast
	// See also https://github.com/Jermolene/TiddlyWiki5/issues/2276
	var req = new XMLHttpRequest();
	req.open("OPTIONS", encodeURI(window.location.href));
	req.onload = function() {
		// Check DAV header http://www.webdav.org/specs/rfc2518.html#rfc.section.9.1
		self.serverAcceptsPuts = (this.status === 200 && !!this.getResponseHeader('dav'));
	};
	req.send();
};

PutSaver.prototype.save = function(text,method,callback) {
	if (!this.serverAcceptsPuts) {
		return false;
	}
	var req = new XMLHttpRequest();
	// TODO: store/check ETags if supported by server, to protect against overwrites
	// Prompt: Do you want to save over this? Y/N
	// Merging would be ideal, and may be possible using future generic merge flow
	req.onload = function() {
		if (this.status === 200 || this.status === 201) {
			callback(null); // success
		}
		else {
			callback(this.responseText); // fail
		}
	};
	req.open("PUT", encodeURI(window.location.href));
	req.setRequestHeader("Content-Type", "text/html;charset=UTF-8");
	req.send(text);
	return true;
};

/*
Information about this saver
*/
PutSaver.prototype.info = {
	name: "put",
	priority: 2000,
	capabilities: ["save", "autosave"]
};

/*
Static method that returns true if this saver is capable of working
*/
exports.canSave = function(wiki) {
	return /^https?:/.test(location.protocol);
};

/*
Create an instance of this saver
*/
exports.create = function(wiki) {
	return new PutSaver(wiki);
};

})();