/**

 * Copyright (c) 2010-2011 julewa.com.  

 * All rights reserved. 

 * 

 * @author Huang Benhua

 * @date 2011-8-20

 * 

**/

package com.julewan.mongo.impl;



import java.util.Collections;

import java.util.HashMap;

import java.util.Map;

import java.util.Properties;

import java.util.Set;



import com.julewan.mongo.Mongoes;

import com.julewan.mongo.ql.Statement;

import com.mongodb.DB;

import com.mongodb.DBCollection;

import com.mongodb.Mongo;



public class MongoLoader {

	//这是唯一可用的方法

	public Mongoes getMongoes(String name){

		if(name == null)return null;

		name = name.toLowerCase();

		Mongoes mongoes = mongoesMap.get(name);

		if(mongoes != null)return mongoes;

		return _load_mongoes_(name, null);

	}

	

	//////////////////

	private Mongo mongo = null;

	private Map<String, DB> mongoDBs = Collections.synchronizedMap(new HashMap<String, DB>());

	private Map<String, Mongoes> mongoesMap = Collections.synchronizedMap(new HashMap<String, Mongoes>());

	public MongoLoader(Properties props){

		if(props == null)return;

		try {

			//TODO 先不处理登陆和连接池等问题

			_load_mongo_(props.getProperty("mongo.url", "127.0.0.1"));

			//boolean auth = db.authenticate(myUserName, myPassword);

		} catch (Exception e) {

			e.printStackTrace();

			mongo = null;

		}

		if(mongo == null)return;

		load(props);

	}

	

	public boolean isValid(){

		return mongo != null;

	}

	

	private DB _get_DB_(String name){

		//防止错误

		name = name.replace(".", "").replaceAll("\\s", "");

		DB db = mongoDBs.get(name);

		if(db == null){

			db = mongo.getDB(name);

			mongoDBs.put(name, db);

		}

		return db;

	}

	private Map<String, Map<String, Statement>> global_db_statements 

				= Collections.synchronizedMap(new HashMap<String, Map<String, Statement>>());

	private Map<String, Map<String, Statement>> global_collection_statements 

				= Collections.synchronizedMap(new HashMap<String, Map<String, Statement>>());

	private void load(Properties props){

		//collection statements

		Map<String, Map<String, Statement>> local_statements  = new HashMap<String, Map<String, Statement>>();

		//load all statements

		Set<Object> keys = props.keySet();

		for(Object k:keys){

			String key = k.toString().replaceAll("\\s", "");

			if(!key.startsWith("q."))continue;

			key = key.substring("q.".length());

			int idx = key.indexOf("*.");

			if(idx < 0){

				//

				idx = key.lastIndexOf(".");

				if(idx < 1)continue;

				if(idx == key.indexOf("."))continue;

				//

				_create_statement_(local_statements, key, props.get(k).toString());

			}else{

				key = key.replace("*.", "");

				k = props.get(k);

				if(idx == 0){

					_create_statement_(global_collection_statements, key, k.toString());

				}else{

					_create_statement_(global_db_statements, key, k.toString());

				}

			}

		}

		//create default db collections

		for(String key:local_statements.keySet()){

			_load_mongoes_(key, local_statements.get(key));

		}

	}

	

	private void _create_statement_(Map<String, Map<String, Statement>> map, String key, String ql){

		int idx = key.lastIndexOf(".");

		String k = key.substring(0, idx);

		key = key.substring(idx + 1);

		//

		Map<String, Statement> m = map.get(k);

		if(m == null){

			m = Collections.synchronizedMap(new HashMap<String, Statement>());

			map.put(k, m);

		}

		m.put(key, new Statement(ql));

	}

	

	private void _load_mongo_(String url) throws Exception{

		url = url.replaceAll("\\s", "");

		int idx = url.indexOf(":");

		if(idx < 0){

			mongo = new Mongo(url);

		}else if(idx == 0){

			mongo = new Mongo("127.0.0.1", Integer.parseInt(url.substring(1)));

		}else{

			mongo = new Mongo(url.substring(0, idx), Integer.parseInt(url.substring(idx + 1)));

		}

	}



	private Mongoes _load_mongoes_(String name, Map<String, Statement> mymap){

		int idx = name.indexOf(".");

		if(idx < 1 || name.lastIndexOf(".") != idx){

			System.err.println("INVALID MONGO DB NAME:" + name);

			return null;

		}

		String dbname = name.substring(0, idx);

		String colname = name.substring(idx + 1);

		//

		Map<String, Statement> lmap, statements = new HashMap<String, Statement>();

		lmap = global_collection_statements.get(colname);

		if(lmap != null) statements.putAll(lmap);

		lmap = global_db_statements.get(dbname);

		if(lmap != null) statements.putAll(lmap);

		if(mymap != null) statements.putAll(mymap);

		//

		DB db = _get_DB_(dbname);

		DBCollection col = db.getCollection(colname);

		//

		Mongoes mg = new Mongoes(col, statements);

		//

		mongoesMap.put(name, mg);

		return mg;

	}

}