// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.
package com.cloud.uuididentity.dao;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import javax.ejb.Local;

import org.apache.log4j.Logger;
import org.springframework.stereotype.Component;

import com.cloud.exception.InvalidParameterValueException;
import com.cloud.server.ResourceTag.TaggedResourceType;
import com.cloud.utils.Pair;
import com.cloud.utils.db.DB;
import com.cloud.utils.db.GenericDaoBase;
import com.cloud.utils.db.Transaction;

@Component
@Local(value={IdentityDao.class})
public class IdentityDaoImpl extends GenericDaoBase<IdentityVO, Long> implements IdentityDao {
    private static final Logger s_logger = Logger.getLogger(IdentityDaoImpl.class);
    
    public IdentityDaoImpl() {
    }
    
    @DB
    public Long getIdentityId(String tableName, String identityString) {
		assert(tableName != null);
		assert(identityString != null);

        PreparedStatement pstmt = null;
		Transaction txn = Transaction.open(Transaction.CLOUD_DB);
		try {
	        try {
	            try {
	                pstmt = txn.prepareAutoCloseStatement(String.format("SELECT uuid FROM `%s`", tableName));
	                pstmt.executeQuery();
	            } catch (SQLException e) {
	                throw new InvalidParameterValueException("uuid field doesn't exist in table " + tableName);
	            }
	            
	            pstmt = txn.prepareAutoCloseStatement(
	        		String.format("SELECT id FROM `%s` WHERE id=? OR uuid=?", tableName)
	        		
	        		// TODO : after graceful period, use following line turn on more secure check
	        		// String.format("SELECT id FROM %s WHERE (id=? AND uuid IS NULL) OR uuid=?", mapper.entityTableName())
	            );
	            
	            long id = 0;
	            try {
	            	// TODO : use regular expression to determine
	            	id = Long.parseLong(identityString);
	            } catch(NumberFormatException e) {
	            	// this could happen when it is a uuid string, so catch and ignore it
	            }
	            
	            pstmt.setLong(1, id);
	            pstmt.setString(2, identityString);
	            
	            ResultSet rs = pstmt.executeQuery();
	            if(rs.next()) {
	            	return rs.getLong(1);
	            } else {
	            	if(id == -1L)
	            		return id;
	            	
	        		throw new InvalidParameterValueException("Object " + tableName + "(uuid: " + identityString + ") does not exist.");
	            }
	        } catch (SQLException e) {
	        	s_logger.error("Unexpected exception ", e);
	        }
		} finally {
			txn.close();
		}
		return null;
    }
    
    @DB
    @Override
    public Pair<Long, Long> getAccountDomainInfo(String tableName, Long identityId, TaggedResourceType resourceType) {
        assert(tableName != null);
        
        PreparedStatement pstmt = null;
        Transaction txn = Transaction.open(Transaction.CLOUD_DB);
        try {
            Long domainId = null;
            Long accountId = null;
            //get domainId
            try {
                pstmt = txn.prepareAutoCloseStatement(String.format("SELECT domain_id FROM `%s` WHERE id=?", tableName));
                pstmt.setLong(1, identityId);
                ResultSet rs = pstmt.executeQuery();
                if (rs.next()) {
                    domainId = rs.getLong(1);
                }
            } catch (SQLException e) {
            }
            
            //get accountId
            try {
                String account = "account_id";
                if (resourceType == TaggedResourceType.Project) {
                    account = "project_account_id";
                }
                pstmt = txn.prepareAutoCloseStatement(String.format("SELECT " + account + " FROM `%s` WHERE id=?", tableName));
                pstmt.setLong(1, identityId);
                ResultSet rs = pstmt.executeQuery();
                if (rs.next()) {
                    accountId = rs.getLong(1);
                }
            } catch (SQLException e) {
            }
            return new Pair<Long, Long>(accountId, domainId);  
        } finally {
            txn.close();
        }
    }
	
    @DB
    @Override
	public String getIdentityUuid(String tableName, String identityString) {
		assert(tableName != null);
		assert(identityString != null);
		
        PreparedStatement pstmt = null;
		Transaction txn = Transaction.open(Transaction.CLOUD_DB);
		try {
	        try {
	            pstmt = txn.prepareAutoCloseStatement(
	            	String.format("SELECT uuid FROM `%s` WHERE id=? OR uuid=?", tableName)
	        		// String.format("SELECT uuid FROM %s WHERE (id=? AND uuid IS NULL) OR uuid=?", tableName)
	        	);
	            
	            long id = 0;
	            try {
	            	// TODO : use regular expression to determine
	            	id = Long.parseLong(identityString);
	            } catch(NumberFormatException e) {
	            	// this could happen when it is a uuid string, so catch and ignore it
	            }
	            
	            pstmt.setLong(1, id);
	            pstmt.setString(2, identityString);
	            
	            ResultSet rs = pstmt.executeQuery();
	            if(rs.next()) {
	            	String uuid = rs.getString(1);
	            	if(uuid != null && !uuid.isEmpty())
	            		return uuid;
	            	return identityString;
	            }
	        } catch (SQLException e) {
	        	s_logger.error("Unexpected exception ", e);
	        }
		} finally {
			txn.close();
		}
		
		return identityString;
	}
    
    @DB
    public void initializeDefaultUuid(String tableName) {
        assert(tableName != null);
        List<Long> l = getNullUuidRecords(tableName);
        
        Transaction txn = Transaction.open(Transaction.CLOUD_DB);
        try {
            try {
                txn.start();
                for(Long id : l) {
                    setInitialUuid(tableName, id);
                }
                txn.commit();
            } catch (SQLException e) {
                txn.rollback();
                s_logger.error("Unexpected exception ", e);
            }
        } finally {
            txn.close();
        }
    }
    
    @DB
    List<Long> getNullUuidRecords(String tableName) {
        List<Long> l = new ArrayList<Long>();
        
        PreparedStatement pstmt = null;
        Transaction txn = Transaction.open(Transaction.CLOUD_DB);
        try {
            try {
                pstmt = txn.prepareAutoCloseStatement(
                    String.format("SELECT id FROM `%s` WHERE uuid IS NULL", tableName)
                );
                
                ResultSet rs = pstmt.executeQuery();
                while(rs.next()) {
                    l.add(rs.getLong(1));
                }
            } catch (SQLException e) {
                s_logger.error("Unexpected exception ", e);
            }
        } finally {
            txn.close();
        }
        return l;
    }
    
    @DB
    void setInitialUuid(String tableName, long id) throws SQLException {
        Transaction txn = Transaction.currentTxn();
        
        PreparedStatement pstmtUpdate = null;
        pstmtUpdate = txn.prepareAutoCloseStatement(
            String.format("UPDATE `%s` SET uuid=? WHERE id=?", tableName)
        );
        
        pstmtUpdate.setString(1, String.valueOf(id));
        pstmtUpdate.setLong(2, id);
        pstmtUpdate.executeUpdate();
    }
}

