/*
XOWA: the XOWA Offline Wiki Application
Copyright (C) 2012 gnosygnu@gmail.com

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
package gplx.dbs; import gplx.*;
import gplx.dbs.sqls.*;
class TdbEngine implements Db_engine {
	public String Tid() {return Db_url__tdb.Tid_const;}
	public Db_url Url() {return url;} private Db_url url;
	public TdbDatabase Db() {return db;} TdbDatabase db;
	public void Conn_open() {
		Db_url__tdb tdb_url = (Db_url__tdb)url;
		String url_str = tdb_url.Server();
		db = loadMgr.LoadTbls(Io_url_.new_any_(url_str));
	}
	public void Conn_term() {}
	public void Txn_bgn() {}
	public void Txn_end() {}
	public Db_engine New_clone(Db_url url) {
		TdbEngine rv = new TdbEngine();
		rv.CtorTdbEngine(url);
		return rv;
	}
	public Object Exec_as_obj(Db_qry qry) {
		Db_qryWkr wkr = (Db_qryWkr)wkrs.FetchOrFail(qry.Tid());
		return wkr.Exec(this, qry);
	}
	public Db_stmt	New_stmt_prep(Db_qry qry) {return new Db_stmt_sql().Parse(qry, Sql_qry_wtr_.I.Xto_str(qry, true));}
	public Object	New_stmt_prep_as_obj(String sql) {throw Err_.not_implemented_();}
	public Db_rdr	New_rdr_by_obj(Object o, String sql) {return Db_rdr_.Null;}
	public DataRdr	New_rdr(java.sql.ResultSet rdr, String sql) {return DataRdr_.Null;} 
	public TdbTable FetchTbl(String name) {
		TdbTable tbl = db.Tables().FetchOrFail(name);
		if (!tbl.IsLoaded()) loadMgr.LoadTbl(db, tbl);
		return tbl;
	}
	public void FlushAll() {
		saveMgr.SaveDb(db);
	}
	public void FlushTbl(TdbTable tbl) {
		saveMgr.SaveFile(db, tbl.File());
	}

	HashAdp wkrs = HashAdp_.new_(); TdbDbLoadMgr loadMgr = TdbDbLoadMgr.new_(); TdbDbSaveMgr saveMgr = TdbDbSaveMgr.new_();
	@gplx.Internal protected static final TdbEngine _ = new TdbEngine(); 
	void CtorTdbEngine(Db_url url) {
		this.url = url;
		wkrs.Add(Db_qry_.Tid_select, TdbSelectWkr._);
		wkrs.Add(Db_qry_.Tid_insert, TdbInsertWkr.new_());
		wkrs.Add(Db_qry_.Tid_update, TdbUpdateWkr.new_());
		wkrs.Add(Db_qry_.Tid_delete, TdbDeleteWkr.new_());
		wkrs.Add(Db_qry_.Tid_flush, TdbFlushWkr.new_());
	}
	public static TdbEngine as_(Object obj) {return obj instanceof TdbEngine ? (TdbEngine)obj : null;}
	public static TdbEngine cast_(Object obj) {try {return (TdbEngine)obj;} catch(Exception exc) {throw Err_.type_mismatch_exc_(exc, TdbEngine.class, obj);}}
}
interface Db_qryWkr {
	Object Exec(Db_engine engine, Db_qry cmd);
}
class Db_qryWkr_ {
	public static final Db_qryWkr Null = new Db_qryWrk_null();
}
class Db_qryWrk_null implements Db_qryWkr {
	public Object Exec(Db_engine engine, Db_qry cmd) {return null;}
}