var _ = require('underscore'),
	fs = require('fs'),
	jade = require('../node_modules/keystone/node_modules/jade'),
	cloudinary = require('cloudinary'),
	moment = require('moment'),
	numeral = require('../node_modules/keystone/node_modules/numeral'),
	utils = require('../node_modules/keystone/node_modules/keystone-utils'),
	dir = require('node-dir');

/**
 * Renders a Keystone View
 *
 * @api private
 */

var templateCache = {};

function render(req, res, view, ext) {
	var keystone = this;

	var templatePath = 'node_modules/keystone/templates/views/' + view + '.jade';

	var jadeOptions = {
		filename: templatePath,
		pretty: keystone.get('env') !== 'production'
	};

	// TODO: Allow custom basePath for extensions... like this or similar
	// if (keystone.get('extensions')) {
	// 	jadeOptions.basedir = keystone.getPath('extensions') + '/templates';
	// }

	var compileTemplate = function() {
		return jade.compile(fs.readFileSync(templatePath, 'utf8'), jadeOptions);
	};

	var template = keystone.get('viewCache')
		? templateCache[view] || (templateCache[view] = compileTemplate())
		: compileTemplate();

	var flashMessages = {
		info: res.req.flash('info'),
		success: res.req.flash('success'),
		warning: res.req.flash('warning'),
		error: res.req.flash('error'),
		hilight: res.req.flash('hilight')
	};

	var locals = {
		_: _,
		moment: moment,
		numeral: numeral,
		env: keystone.get('env'),
		brand: keystone.get('brand'),
		appversion : keystone.get('appversion'),
		nav: keystone.nav,
		messages: _.any(flashMessages, function(msgs) { return msgs.length; }) ? flashMessages : false,
		lists: keystone.lists,
		js: 'javascript:;',
		utils: utils,
		User: keystone.lists[keystone.get('user model')],
		user: req.user,
		title: 'Keystone',
		signout: keystone.get('signout url'),
		backUrl: keystone.get('back url') || '/',
		section: {},
		version: keystone.version,
		csrf_token_key: keystone.security.csrf.TOKEN_KEY,
		csrf_token_value: keystone.security.csrf.getToken(req, res),
		csrf_query: '&' + keystone.security.csrf.TOKEN_KEY + '=' + keystone.security.csrf.getToken(req, res),
		ga: {
			property: keystone.get('ga property'),
			domain: keystone.get('ga domain')
		},
		wysiwygOptions: {
			enableImages: keystone.get('wysiwyg images') ? true : false,
			enableCloudinaryUploads: keystone.get('wysiwyg cloudinary images') ? true : false,
			additionalButtons: keystone.get('wysiwyg additional buttons') || '',
			additionalPlugins: keystone.get('wysiwyg additional plugins') || '',
			additionalOptions: keystone.get('wysiwyg additional options') || {},
			overrideToolbar: keystone.get('wysiwyg override toolbar'),
			skin: keystone.get('wysiwyg skin') || 'keystone',
			menubar: keystone.get('wysiwyg menubar')
		}
	};

	// optional extensions to the local scope
	_.extend(locals, ext);

	// add cloudinary locals if configured
	if (keystone.get('cloudinary config')) {
		try {
			var cloudinaryUpload = cloudinary.uploader.direct_upload();
			locals.cloudinary = {
				cloud_name: keystone.get('cloudinary config').cloud_name,
				api_key: keystone.get('cloudinary config').api_key,
				timestamp: cloudinaryUpload.hidden_fields.timestamp,
				signature: cloudinaryUpload.hidden_fields.signature,
				prefix: keystone.get('cloudinary prefix') || '',
				folders: keystone.get('cloudinary folders'),
				uploader: cloudinary.uploader
			};
			locals.cloudinary_js_config = cloudinary.cloudinary_js_config();
		} catch(e) {
			if (e === 'Must supply api_key') {
				throw new Error('Invalid Cloudinary Config Provided\n\n' +
					'See http://keystonejs.com/docs/configuration/#services-cloudinary for more information.');
			} else {
				throw e;
			}
		}
	}

	// fieldLocals defines locals that are provided to each field's `render` method
	locals.fieldLocals = _.pick(locals, '_', 'moment', 'numeral', 'env', 'js', 'utils', 'user', 'cloudinary');

	//build template
	var html = template(_.extend(locals, ext));

	//Add custom admin tweaks
	if(keystone.get('backend static mount') && keystone.get('backend static path')){
		//Env variables
		var static_mount = keystone.get('backend static mount'),
			static_path = keystone.get('backend static path');

		//Inject Admin Custom CSS
		var head = html.split('</head>')[0],
			body = html.split('</head>')[1].split('</body>');

		return dir.files(static_path, function(err, files) {
		    if (err) throw err;

			files.forEach(function(file, i){
				var filename = file.split(static_path)[1],
					isCSS = filename.match(/.css$/);

				if(isCSS) {
					head +='<link rel="stylesheet" href="'+static_mount+filename+'">';
				} else {
					body +='<script src="'+static_mount+filename+'"></script>';
				}

				if(i == files.length - 1){
					head += '</head>';
					body += '</body></html>';
					res.send(head+body);					
				}
			})
		})
	} else {
		res.send(html);
	}
}

module.exports = render;