package pt.utl.ist.codeGenerator.database;

import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.List;

public class UpgradesFinder 
{
	public List<File> listUpgradeDirs(File baseDir,Date lastVersionDate)
	{
		//Get all the upgrades directories inside the first level
		ArrayList<File> upgradesDirectories=new ArrayList<File>();
		UpgradeDirFilter upgradeDirFilter=new UpgradeDirFilter(lastVersionDate);
		upgradesDirectories.addAll(Arrays.asList(baseDir.listFiles(upgradeDirFilter)));
		//Now find all the subdir with possible upgrades (R2005,R2006,...)
		List<File> upgradeSubDirs=listSubDirsWithPossibleUpgrades(baseDir, lastVersionDate);
		for(File upgradeSubDir:upgradeSubDirs)
		{//for each subdir with upgrades, add the upgrades directories inside it
			upgradesDirectories.addAll(Arrays.asList(upgradeSubDir.listFiles(upgradeDirFilter)));
		}
		
		return upgradesDirectories;
	}
	
	public List<File> listSubDirsWithPossibleUpgrades(File baseDir,Date lastVersionDate)
	{
		return Arrays.asList(baseDir.listFiles(new UpgradeSubDirFilter(lastVersionDate)));
	}
	
	public class UpgradeSubDirFilter implements java.io.FileFilter
	{
		private long millisLastVersion = Long.MAX_VALUE;
		
		public UpgradeSubDirFilter(Date lastVersionDate) {
			this.millisLastVersion = lastVersionDate.getTime();
		}

		public boolean accept(File f) {
			if (f.isDirectory() && f.canRead()) {
				String dirName = f.getName();
				// name should be in format R2006 - Ryyyy
				if (dirName.startsWith("R") && dirName.length() >= "Ryyyy".length()) {
					String yearStr = dirName.substring(1, 5);
					try {
						int year = Integer.parseInt(yearStr);
						Calendar c = new GregorianCalendar(year, 12, 31);
						if (millisLastVersion <= c.getTimeInMillis()) return true;
					}
					catch (Exception e) {

					}

				}
			}

			return false;
		}

		
	}
	
	
	public class UpgradeDirFilter implements java.io.FileFilter {
		private long millisLastVersion = Long.MAX_VALUE;
		
		public UpgradeDirFilter(Date lastVersionDate) {
			this.millisLastVersion = lastVersionDate.getTime();
		}

		public boolean accept(File f) {
			if (f.isDirectory() && f.canRead()) {
				// check if it has a "run" file inside
				File[] runFiles = f.listFiles(runFileFilter);
				if (runFiles == null || runFiles.length == 0) return false;

				String dirName = f.getName();
				// name should be in format R2006-06-12 - Ryyyy-mm-dd
				if (dirName.startsWith("R") && dirName.contains("-") && dirName.length() >= "Ryyyy-mm-dd".length()) {
					String yearStr = dirName.substring(1, 5);
					String monthStr = dirName.substring(6, 8);
					String dayStr = dirName.substring(9, 11);
					try {
						int day = Integer.parseInt(dayStr);
						int month = Integer.parseInt(monthStr);
						int year = Integer.parseInt(yearStr);
						Calendar c = new GregorianCalendar(year, month, day);
						if (millisLastVersion <= c.getTimeInMillis()) return true;
					}
					catch (Exception e) {

					}

				}
			}

			return false;
		}


	}
	private RunFileFilter runFileFilter=new RunFileFilter();
	private class RunFileFilter implements java.io.FileFilter {
		public boolean accept(File file) {
			return file.isFile() && file.canRead() && file.getName().equals("run");
		}
	}

	public List<File> listUpgradeFiles(File upgradeDir)
	{
		return Arrays.asList(upgradeDir.listFiles(runFileFilter));
	}
	
}