/*
    GriefPrevention Server Plugin for Minecraft
    Copyright (C) 2012 Ryan Hamshire

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package me.ryanhamshire.GriefPrevention;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import java.util.*;

import org.bukkit.*;

//manages data stored in the file system
public class DatabaseDataStore extends DataStore
{
	private Connection databaseConnection = null;
	
	private String databaseUrl;
	private String userName;
	private String password;
	
	DatabaseDataStore(String url, String userName, String password) throws Exception
	{
		this.databaseUrl = url;
		this.userName = userName;
		this.password = password;
		
		this.initialize();
	}
	
	@Override
	void initialize() throws Exception
	{
		try
		{
			//load the java driver for mySQL
			Class.forName("com.mysql.jdbc.Driver");
		}
		catch(Exception e)
		{
			GriefPrevention.AddLogEntry("ERROR: Unable to load Java's mySQL database driver.  Check to make sure you've installed it properly.");
			throw e;
		}
		
		try
		{
			this.refreshDataConnection();
		}
		catch(Exception e2)
		{
			GriefPrevention.AddLogEntry("ERROR: Unable to connect to database.  Check your config file settings.");
			throw e2;
		}
		
		try
		{
			//ensure the data tables exist
			Statement statement = databaseConnection.createStatement();
			
			statement.execute("CREATE TABLE IF NOT EXISTS griefprevention_nextclaimid (nextid INT(15));");
			
			statement.execute("CREATE TABLE IF NOT EXISTS griefprevention_claimdata (id INT(15), owner VARCHAR(50), lessercorner VARCHAR(100), greatercorner VARCHAR(100), builders TEXT, containers TEXT, accessors TEXT, managers TEXT, parentid INT(15));");
			
			statement.execute("CREATE TABLE IF NOT EXISTS griefprevention_playerdata (name VARCHAR(50), lastlogin DATETIME, accruedblocks INT(15), bonusblocks INT(15));");
			
			statement.execute("CREATE TABLE IF NOT EXISTS griefprevention_schemaversion (version INT(15));");
			
			statement.execute("ALTER TABLE griefprevention_claimdata MODIFY builders TEXT;");
			statement.execute("ALTER TABLE griefprevention_claimdata MODIFY containers TEXT;");
			statement.execute("ALTER TABLE griefprevention_claimdata MODIFY accessors TEXT;");
			statement.execute("ALTER TABLE griefprevention_claimdata MODIFY managers TEXT;");
			
			//if the next claim id table is empty, this is a brand new database which will write using the latest schema
			//otherwise, schema version is determined by schemaversion table (or =0 if table is empty, see getSchemaVersion())
			ResultSet results = statement.executeQuery("SELECT * FROM griefprevention_nextclaimid;");
	        if(!results.next())
			{
                this.setSchemaVersion(latestSchemaVersion);
            }
		}
		catch(Exception e3)
		{
			GriefPrevention.AddLogEntry("ERROR: Unable to create the necessary database table.  Details:");
			GriefPrevention.AddLogEntry(e3.getMessage());
			e3.printStackTrace();
			throw e3;
		}
		
		//load group data into memory
		Statement statement = databaseConnection.createStatement();
		ResultSet results = statement.executeQuery("SELECT * FROM griefprevention_playerdata;");
		
		while(results.next())
		{
			String name = results.getString("name");
			
			//ignore non-groups.  all group names start with a dollar sign.
			if(!name.startsWith("$")) continue;
			
			String groupName = name.substring(1);
			if(groupName == null || groupName.isEmpty()) continue;  //defensive coding, avoid unlikely cases
			
			int groupBonusBlocks = results.getInt("bonusblocks");
				
			this.permissionToBonusBlocksMap.put(groupName, groupBonusBlocks);			
		}
		
		//load next claim number into memory
		results = statement.executeQuery("SELECT * FROM griefprevention_nextclaimid;");
		
		//if there's nothing yet, add it
		if(!results.next())
		{
			statement.execute("INSERT INTO griefprevention_nextclaimid VALUES(0);");
			this.nextClaimID = (long)0;
		}

		//otherwise load it
		else
		{
			this.nextClaimID = results.getLong("nextid");
		}
		
		if(this.getSchemaVersion() == 0)
        {
            try
            {
                this.refreshDataConnection();
                
                //pull ALL player data from the database
                statement = this.databaseConnection.createStatement();
                results = statement.executeQuery("SELECT * FROM griefprevention_playerdata;");
            
                //make a list of changes to be made
                HashMap<String, UUID> changes = new HashMap<String, UUID>();
                
                ArrayList<String> namesToConvert = new ArrayList<String>();
                while(results.next())
                {
                    //get the id
                    String playerName = results.getString("name");
                    
                    //add to list of names to convert to UUID
                    namesToConvert.add(playerName);
                }
                
                //resolve and cache as many as possible through various means
                try
                {
                    UUIDFetcher fetcher = new UUIDFetcher(namesToConvert);
                    fetcher.call();
                }
                catch(Exception e)
                {
                    GriefPrevention.AddLogEntry("Failed to resolve a batch of names to UUIDs.  Details:" + e.getMessage());
                    e.printStackTrace();
                }
                
                //reset results cursor
                results.beforeFirst();
                
                //for each result
                while(results.next())
                {
                    //get the id
                    String playerName = results.getString("name");
                    
                    //try to convert player name to UUID
                    try
                    {
                        UUID playerID = UUIDFetcher.getUUIDOf(playerName);
                        
                        //if successful, update the playerdata row by replacing the player's name with the player's UUID
                        if(playerID != null)
                        {
                            changes.put(playerName, playerID);
                        }
                    }
                    //otherwise leave it as-is. no harm done - it won't be requested by name, and this update only happens once.
                    catch(Exception ex){ }
                }
                
                //refresh data connection in case data migration took a long time
                this.refreshDataConnection();
                
                for(String name : changes.keySet())
                {
                    try
                    {
                        statement = this.databaseConnection.createStatement();
                        statement.execute("UPDATE griefprevention_playerdata SET name = '" + changes.get(name).toString() + "' WHERE name = '" + name + "';");
                    }
                    catch(SQLException e)
                    {
                        GriefPrevention.AddLogEntry("Unable to convert player data for " + name + ".  Skipping.");
                        GriefPrevention.AddLogEntry(e.getMessage());
                    }
                }
            }
            catch(SQLException e)
            {
                GriefPrevention.AddLogEntry("Unable to convert player data.  Details:");
                GriefPrevention.AddLogEntry(e.getMessage());
                e.printStackTrace();
            }
        }
		
		//load claims data into memory		
		results = statement.executeQuery("SELECT * FROM griefprevention_claimdata;");
		
		ArrayList<Claim> claimsToRemove = new ArrayList<Claim>();
		ArrayList<Claim> subdivisionsToLoad = new ArrayList<Claim>();
		List<World> validWorlds = Bukkit.getServer().getWorlds();
		
		Long claimID = null;
		while(results.next())
		{
			try
			{
			    //problematic claims will be removed from secondary storage, and never added to in-memory data store
			    boolean removeClaim = false;
			    
			    long parentId = results.getLong("parentid");
				claimID = results.getLong("id");
					
				Location lesserBoundaryCorner = null;
				Location greaterBoundaryCorner = null;
				String lesserCornerString = "(location not available)";
				try
				{
    				lesserCornerString = results.getString("lessercorner");
    				lesserBoundaryCorner = this.locationFromString(lesserCornerString, validWorlds);
    				
    				String greaterCornerString = results.getString("greatercorner");
    				greaterBoundaryCorner = this.locationFromString(greaterCornerString, validWorlds);
				}
				catch(Exception e)
				{
				    if(e.getMessage().contains("World not found"))
				    {
				        GriefPrevention.AddLogEntry("Failed to load a claim (ID:" + claimID.toString() + ") because its world isn't loaded (yet?).  Please delete the claim or contact the GriefPrevention developer with information about which plugin(s) you're using to load or create worlds.  " + lesserCornerString);
				        continue;
				    }
				    else
				    {
				        throw e;
				    }
				}
				
				String ownerName = results.getString("owner");
				UUID ownerID = null;
                if(ownerName.isEmpty() || ownerName.startsWith("--"))
                {
                    ownerID = null;  //administrative land claim or subdivision
                }
                else if(this.getSchemaVersion() < 1)
                {
                    try
                    {
                        ownerID = UUIDFetcher.getUUIDOf(ownerName);
                    }
                    catch(Exception ex)
                    {
                        GriefPrevention.AddLogEntry("This owner name did not convert to a UUID: " + ownerName + ".");
                        GriefPrevention.AddLogEntry("  Converted land claim to administrative @ " + lesserBoundaryCorner.toString());
                    }
                }
                else
                {
                    try
                    {
                        ownerID = UUID.fromString(ownerName);
                    }
                    catch(Exception ex)
                    {
                        GriefPrevention.AddLogEntry("This owner entry is not a UUID: " + ownerName + ".");
                        GriefPrevention.AddLogEntry("  Converted land claim to administrative @ " + lesserBoundaryCorner.toString());
                    }
                }
	
				String buildersString = results.getString("builders");
				List<String> builderNames = Arrays.asList(buildersString.split(";"));
				builderNames = this.convertNameListToUUIDList(builderNames);
				
				String containersString = results.getString("containers");
				List<String> containerNames = Arrays.asList(containersString.split(";"));
				containerNames = this.convertNameListToUUIDList(containerNames);
				
				String accessorsString = results.getString("accessors");
				List<String> accessorNames = Arrays.asList(accessorsString.split(";"));
				accessorNames = this.convertNameListToUUIDList(accessorNames);
				
				String managersString = results.getString("managers");
				List<String> managerNames = Arrays.asList(managersString.split(";"));
				managerNames = this.convertNameListToUUIDList(managerNames);
				
				Claim claim = new Claim(lesserBoundaryCorner, greaterBoundaryCorner, ownerID, builderNames, containerNames, accessorNames, managerNames, claimID);
				
				if(removeClaim)
				{
				    claimsToRemove.add(claim);
				}
				else if(parentId == -1)
				{
				    //top level claim
				    this.addClaim(claim, false);
				}
				else
				{
				    //subdivision
				    subdivisionsToLoad.add(claim);
				}
			}
			catch(SQLException e)
			{
				GriefPrevention.AddLogEntry("Unable to load a claim.  Details: " + e.getMessage() + " ... " + results.toString());
				e.printStackTrace();
			}
		}
		
		//add subdivisions to their parent claims
        for(Claim childClaim : subdivisionsToLoad)
        {
            //find top level claim parent
            Claim topLevelClaim = this.getClaimAt(childClaim.getLesserBoundaryCorner(), true, null);
            
            if(topLevelClaim == null)
            {
                claimsToRemove.add(childClaim);
                GriefPrevention.AddLogEntry("Removing orphaned claim subdivision: " + childClaim.getLesserBoundaryCorner().toString());
                continue;
            }
            
            //add this claim to the list of children of the current top level claim
            childClaim.parent = topLevelClaim;
            topLevelClaim.children.add(childClaim);
            childClaim.inDataStore = true;
        }
		
		for(int i = 0; i < claimsToRemove.size(); i++)
		{
			this.deleteClaimFromSecondaryStorage(claimsToRemove.get(i));
		}
		
		if(this.getSchemaVersion() <= 2)
		{
		    this.refreshDataConnection();
            statement = this.databaseConnection.createStatement();
            statement.execute("DELETE FROM griefprevention_claimdata WHERE id='-1';");
		}
		
		super.initialize();
	}
	
	@Override
	synchronized void writeClaimToStorage(Claim claim)  //see datastore.cs.  this will ALWAYS be a top level claim
	{
		try
		{
			this.refreshDataConnection();
			
			//wipe out any existing data about this claim
			this.deleteClaimFromSecondaryStorage(claim);
			
			//write claim data to the database
			this.writeClaimData(claim);
		}
		catch(SQLException e)
		{
			GriefPrevention.AddLogEntry("Unable to save data for claim at " + this.locationToString(claim.lesserBoundaryCorner) + ".  Details:");
			GriefPrevention.AddLogEntry(e.getMessage());
		}
	}
	
	//actually writes claim data to the database
	synchronized private void writeClaimData(Claim claim) throws SQLException
	{
		String lesserCornerString = this.locationToString(claim.getLesserBoundaryCorner());
		String greaterCornerString = this.locationToString(claim.getGreaterBoundaryCorner());
		String owner = "";
		if(claim.ownerID != null) owner = claim.ownerID.toString();
		
		ArrayList<String> builders = new ArrayList<String>();
		ArrayList<String> containers = new ArrayList<String>();
		ArrayList<String> accessors = new ArrayList<String>();
		ArrayList<String> managers = new ArrayList<String>();
		
		claim.getPermissions(builders, containers, accessors, managers);
		
		String buildersString = "";
		for(int i = 0; i < builders.size(); i++)
		{
			buildersString += builders.get(i) + ";";
		}
		
		String containersString = "";
		for(int i = 0; i < containers.size(); i++)
		{
			containersString += containers.get(i) + ";";
		}
		
		String accessorsString = "";
		for(int i = 0; i < accessors.size(); i++)
		{
			accessorsString += accessors.get(i) + ";";
		}

		String managersString = "";
		for(int i = 0; i < managers.size(); i++)
		{
			managersString += managers.get(i) + ";";
		}
		
		long parentId;
		if(claim.parent == null)
		{
			parentId = -1;
		}
		else
		{
			parentId = claim.parent.id;
		}
		
		try
		{
			this.refreshDataConnection();
			
			Statement statement = databaseConnection.createStatement();
			statement.execute("INSERT INTO griefprevention_claimdata (id, owner, lessercorner, greatercorner, builders, containers, accessors, managers, parentid) VALUES(" +
					claim.id + ", '" +
					owner + "', '" +
					lesserCornerString + "', '" +
					greaterCornerString + "', '" +
					buildersString + "', '" +
					containersString + "', '" +
					accessorsString + "', '" +
					managersString + "', " +
					parentId +		
					");");
		}
		catch(SQLException e)
		{
			GriefPrevention.AddLogEntry("Unable to save data for claim at " + this.locationToString(claim.lesserBoundaryCorner) + ".  Details:");
			GriefPrevention.AddLogEntry(e.getMessage());
		}
	}
	
	//deletes a claim from the database
	@Override
	synchronized void deleteClaimFromSecondaryStorage(Claim claim)
	{
	    try
		{
			this.refreshDataConnection();

						
			Statement statement = this.databaseConnection.createStatement();
			statement.execute("DELETE FROM griefprevention_claimdata WHERE id='" + claim.id + "';");
		}
		catch(SQLException e)
		{
			GriefPrevention.AddLogEntry("Unable to delete data for claim " + claim.id + ".  Details:");
			GriefPrevention.AddLogEntry(e.getMessage());
			e.printStackTrace();
		}
	}
	
	@Override
	synchronized PlayerData getPlayerDataFromStorage(UUID playerID)
	{
		PlayerData playerData = new PlayerData();
		playerData.playerID = playerID;
		
		try
		{
			this.refreshDataConnection();
			
			Statement statement = this.databaseConnection.createStatement();
			ResultSet results = statement.executeQuery("SELECT * FROM griefprevention_playerdata WHERE name='" + playerID.toString() + "';");
		
			//if data for this player exists, use it
			if(results.next())
			{			
				playerData.setLastLogin(results.getTimestamp("lastlogin"));
				playerData.setAccruedClaimBlocks(results.getInt("accruedblocks"));
				playerData.setBonusClaimBlocks(results.getInt("bonusblocks"));				
			}
		}
		catch(SQLException e)
		{
		    StringWriter errors = new StringWriter();
            e.printStackTrace(new PrintWriter(errors));
            GriefPrevention.AddLogEntry(playerID + " " + errors.toString(), CustomLogEntryTypes.Exception);
		}
			
		return playerData;
	}
	
	//saves changes to player data.  MUST be called after you're done making changes, otherwise a reload will lose them
	@Override
	public void overrideSavePlayerData(UUID playerID, PlayerData playerData)
	{
		//never save data for the "administrative" account.  an empty string for player name indicates administrative account
		if(playerID == null) return;
		
		this.savePlayerData(playerID.toString(), playerData);
	}
	
	private void savePlayerData(String playerID, PlayerData playerData)
	{
		try
		{
			this.refreshDataConnection();
			
			SimpleDateFormat sqlFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
			String dateString = sqlFormat.format(playerData.getLastLogin());
			
			Statement statement = databaseConnection.createStatement();
			statement.execute("DELETE FROM griefprevention_playerdata WHERE name='" + playerID.toString() + "';");
			statement = databaseConnection.createStatement();
			statement.execute("INSERT INTO griefprevention_playerdata (name, lastlogin, accruedblocks, bonusblocks) VALUES ('" + playerID.toString() + "', '" + dateString + "', " + playerData.getAccruedClaimBlocks() + ", " + playerData.getBonusClaimBlocks() + ");");
		}
		catch(SQLException e)
		{
		    StringWriter errors = new StringWriter();
		    e.printStackTrace(new PrintWriter(errors));
		    GriefPrevention.AddLogEntry(playerID + " " + errors.toString(), CustomLogEntryTypes.Exception);
		}
	}
	
	@Override
	synchronized void incrementNextClaimID()
	{
		this.setNextClaimID(this.nextClaimID + 1);
	}
	
	//sets the next claim ID.  used by incrementNextClaimID() above, and also while migrating data from a flat file data store
	synchronized void setNextClaimID(long nextID)
	{
		this.nextClaimID = nextID;
		
		try
		{
			this.refreshDataConnection();
			
			Statement statement = databaseConnection.createStatement();
			statement.execute("DELETE FROM griefprevention_nextclaimid;");
			statement.execute("INSERT INTO griefprevention_nextclaimid VALUES (" + nextID + ");");
		}
		catch(SQLException e)
		{
			GriefPrevention.AddLogEntry("Unable to set next claim ID to " + nextID + ".  Details:");
			GriefPrevention.AddLogEntry(e.getMessage());
		}
	}
	
	//updates the database with a group's bonus blocks
	@Override
	synchronized void saveGroupBonusBlocks(String groupName, int currentValue)
	{
		//group bonus blocks are stored in the player data table, with player name = $groupName
	    try
        {
            this.refreshDataConnection();
            
            SimpleDateFormat sqlFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            String dateString = sqlFormat.format(new Date());
            
            Statement statement = databaseConnection.createStatement();
            statement.execute("DELETE FROM griefprevention_playerdata WHERE name='$" + groupName + "';");
            statement = databaseConnection.createStatement();
            statement.execute("INSERT INTO griefprevention_playerdata (name, lastlogin, accruedblocks, bonusblocks) VALUES ('$" + groupName + "', '" + dateString + "', " + "0" + ", " + String.valueOf(currentValue) + ");");
        }
        catch(SQLException e)
        {
            GriefPrevention.AddLogEntry("Unable to save data for group " + groupName + ".  Details:");
            GriefPrevention.AddLogEntry(e.getMessage());
        }
	}
	
	@Override
	synchronized void close()
	{
		if(this.databaseConnection != null)
		{
			try
			{
				if(!this.databaseConnection.isClosed())
				{
					this.databaseConnection.close();
				}
			}
			catch(SQLException e){};
		}
		
		this.databaseConnection = null;
	}
	
	private synchronized void refreshDataConnection() throws SQLException
	{
		if(this.databaseConnection == null || !this.databaseConnection.isValid(3))
		{
			if(this.databaseConnection != null && !this.databaseConnection.isClosed())
	        {
			    this.databaseConnection.close();
	        }
		    
		    //set username/pass properties
			Properties connectionProps = new Properties();
			connectionProps.put("user", this.userName);
			connectionProps.put("password", this.password);
			connectionProps.put("autoReconnect", "true");
			connectionProps.put("maxReconnects", String.valueOf(Integer.MAX_VALUE));
			
			//establish connection
			this.databaseConnection = DriverManager.getConnection(this.databaseUrl, connectionProps); 
		}
	}

    @Override
    protected int getSchemaVersionFromStorage()
    {
        try
        {
            this.refreshDataConnection();
            
            Statement statement = this.databaseConnection.createStatement();
            ResultSet results = statement.executeQuery("SELECT * FROM griefprevention_schemaversion;");
            
            //if there's nothing yet, assume 0 and add it
            if(!results.next())
            {
                this.setSchemaVersion(0);
                return 0;
            }
            
            //otherwise return the value that's in the table
            else
            {
                return results.getInt("version");
            }
            
        }
        catch(SQLException e)
        {
            GriefPrevention.AddLogEntry("Unable to retrieve schema version from database.  Details:");
            GriefPrevention.AddLogEntry(e.getMessage());
            e.printStackTrace();
            return 0;
        }
    }

    @Override
    protected void updateSchemaVersionInStorage(int versionToSet)
    {
        try
        {
            this.refreshDataConnection();
            
            Statement statement = databaseConnection.createStatement();
            statement.execute("DELETE FROM griefprevention_schemaversion;");
            statement.execute("INSERT INTO griefprevention_schemaversion VALUES (" + versionToSet + ");");
        }
        catch(SQLException e)
        {
            GriefPrevention.AddLogEntry("Unable to set next schema version to " + versionToSet + ".  Details:");
            GriefPrevention.AddLogEntry(e.getMessage());
        }
    }
}