/*
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.diffs.builds; import gplx.*; import gplx.dbs.*; import gplx.dbs.diffs.*;
import gplx.dbs.metas.*; import gplx.dbs.diffs.itms.*;
public class Gfdb_diff_wkr__db implements Gfdb_diff_wkr {
	private Dbmeta_fld_itm[] val_flds; private int val_flds_len;
	private Gfdb_diff_tbl tbl; private Db_rdr old_rdr, new_rdr;
	private Gdif_bldr_ctx ctx;
	private Db_conn dif_conn; private Db_stmt stmt;
	private int uid, prog_interval, prog_count;
	private boolean cmd_create;
	public void Init_conn(Gdif_db dif_db, int prog_interval) {this.dif_conn = dif_db.Conn(); this.prog_interval = prog_interval;}
	public void Init_rdrs(Gdif_bldr_ctx ctx, Gfdb_diff_tbl tbl, Db_rdr old_rdr, Db_rdr new_rdr) {
		this.ctx = ctx; this.tbl = tbl; this.old_rdr = old_rdr; this.new_rdr = new_rdr;
		this.val_flds = tbl.Vals; val_flds_len = val_flds.length;
		this.uid = 0; this.prog_count = 0;

		String dif_tbl = tbl.Name; Dbmeta_fld_itm[] dif_flds = Gfdb_diff_wkr__db_.New_dif_flds(tbl.Flds);
		if (!dif_conn.Meta_tbl_exists(dif_tbl)) dif_conn.Meta_tbl_create(Dbmeta_tbl_itm.New(dif_tbl, dif_flds));
		this.stmt = dif_conn.Stmt_insert(dif_tbl, Gfdb_diff_wkr__db_.To_str_ary(dif_flds));
		dif_conn.Txn_bgn("dif_db_tbl_" + dif_tbl);
		cmd_create = true;
	}
	public void Term_tbls() {
		dif_conn.Txn_end();
	}
	public void Handle_old_missing() {Insert(Gdif_db_.Tid__insert, ++uid, new_rdr, tbl.Flds);}
	public void Handle_new_missing() {Insert(Gdif_db_.Tid__delete, ++uid, old_rdr, tbl.Flds);}
	public void Handle_same() {
		if (Gfdb_rdr_utl_.Compare(val_flds, val_flds_len, old_rdr, new_rdr) != CompareAble_.Same)
			Insert(Gdif_db_.Tid__update, ++uid, new_rdr, tbl.Flds);
	}
	private void Insert(byte dif_type, int uid, Db_rdr rdr, Dbmeta_fld_itm[] flds) {
		if (cmd_create) {
			cmd_create = false;
			ctx.Cur_cmd = ctx.Core.New_cmd(ctx, Gdif_cmd_itm.Tid__data);
			ctx.Cur_txn = ctx.Core.New_txn(ctx, ctx.Cur_cmd.Cmd_id, Gdif_txn_itm.Owner_txn__null);
		}
		stmt.Clear();
		stmt.Val_int	(Gdif_db_.Fld__dif_txn		, ctx.Cur_txn.Txn_id)
			.Val_int	(Gdif_db_.Fld__dif_uid		, uid)
			.Val_int	(Gdif_db_.Fld__dif_type		, dif_type)
			.Val_int	(Gdif_db_.Fld__dif_db_src	, -1)
			.Val_int	(Gdif_db_.Fld__dif_db_trg	, -1);
		Gfdb_rdr_utl_.Stmt_args(stmt, flds, flds.length, rdr);
		stmt.Exec_insert();
		if ((++prog_count % prog_interval) == 0) dif_conn.Txn_sav();
	}
}
class Gfdb_diff_wkr__db_ {
	public static Dbmeta_fld_itm[] New_dif_flds(Dbmeta_fld_itm[] cur_flds) {
		int len = cur_flds.length;
		int sys_flds = 5;
		Dbmeta_fld_itm[] rv = new Dbmeta_fld_itm[len + sys_flds];
		rv[0] = Dbmeta_fld_itm.new_int	(Gdif_db_.Fld__dif_txn);
		rv[1] = Dbmeta_fld_itm.new_int	(Gdif_db_.Fld__dif_uid);
		rv[2] = Dbmeta_fld_itm.new_byte	(Gdif_db_.Fld__dif_type);
		rv[3] = Dbmeta_fld_itm.new_int	(Gdif_db_.Fld__dif_db_trg);
		rv[4] = Dbmeta_fld_itm.new_int	(Gdif_db_.Fld__dif_db_src);
		for (int i = 0; i < len; ++i) {
			Dbmeta_fld_itm cur_fld = cur_flds[i];
			Dbmeta_fld_itm dif_fld = new Dbmeta_fld_itm(cur_fld.Name(), cur_fld.Type());
			rv[i + sys_flds] = dif_fld;
		}
		return rv;
	}
	public static String[] To_str_ary(Dbmeta_fld_itm[] ary) {
		int len = ary.length;
		String[] rv = new String[len];
		for (int i = 0; i < len; ++i)
			rv[i] = ary[i].Name();
		return rv;
	}
}