import 'dart:async';
import 'dart:convert';

import 'package:angular2/core.dart';
import 'package:http/browser_client.dart';

import 'product.dart';

@Injectable()
class ProductService {
	final BrowserClient _http;

	static const _server='http://10.8.0.1:5984';
	static const _db='tavern';
	static const _byname='_design/products/_view/byname';
	static const _bycategory='_design/products/_view/bycategory';

	ProductService(this._http);

	Future<List<Product>> getAll() async {
		try {
			var url=_server+'/'+_db+'/'+_byname;
			List<Product> prods=[];
			final response = await _http.get(url);
			for(var item in JSON.decode(response.body)['rows']) {
				prods.add(new Product(item['id'],
				                      item['value']['name'],
				                      item['value']['price'],
				                      item['value']['type'],
				                      item['value']['category']
				));
			}
			return prods;
		}
		catch(e) {
			throw _handleError(e);
		}
	}

	Future<List<Product>> getByCategory(String id) async {
		try {
			var url=_server+'/'+_db+'/'+_bycategory+'?key="'+id+'"';
			List<Product> prods=[];
			final response = await _http.get(url);
			for(var item in JSON.decode(response.body)['rows']) {
				prods.add(new Product(item['id'],
				                      item['value']['name'],
				                      item['value']['price'],
				                      item['value']['type'],
				                      item['value']['category']
				));
			}
			return prods;
		}
		catch(e) {
			throw _handleError(e);
		}
	}

	Future<String> createProduct(String name,double pri,String cat) async {
		try {
			var url=_server+'/'+_db;
			var response = await _http.post(
				url,
				headers: {'Content-Type': 'application/json'},
				body: JSON.encode({
					'name': name,
					'price': pri,
					'type': 'product',
					'category': cat
				})
			);
			return(JSON.decode(response.body)['id']);
		}
		catch(e) {
			throw _handleError(e);
		}
	}

	Future<Null> deleteProduct(String id) async {
		try {
			var url=_server+'/'+_db+'/'+id;
			var resp = await _http.get(url);
			var reso=JSON.decode(resp.body);
			url=_server+'/'+_db+'/_purge/';
			await _http.post(
				url,
				headers: {'Content-Type': 'application/json'},
				body: JSON.encode({
					reso['_id']: [reso['_rev']]
				})
			);
		}
		catch(e) {
			throw _handleError(e);
		}
	}

	Future<Product> getById(String id) async {
		try {
			var url=_server+'/'+_db+'/'+id;
			Product prod;
			final response = await _http.get(url);
			var item=JSON.decode(response.body);
			prod=(new Product(item['_id'],item['name'],
			                  item['price'],item['type'],
			                  item['category']));
			return prod;
		}
		catch(e) {
			throw _handleError(e);
		}
	}

	Future<Null> updateProd(String id,String name,double price,
	                        String category) async {
		try {
			var url=_server+'/'+_db+'/'+id;
			var resp = await _http.get(url);
			var reso=JSON.decode(resp.body);
			reso['name']=name;
			reso['price']=price;
			reso['category']=category;
			await _http.put(
				url,
				headers: {'Content-Type': 'application/json'},
				body: JSON.encode(reso)
			);
		}
		catch(e) {
			throw _handleError(e);
		}
	}

	Exception _handleError(dynamic e) {
		print(e);
		return new Exception('Server error; cause: $e');
	}

}