package ch.epfl.alpano.dem;

import static org.junit.Assert.*;
import static ch.epfl.alpano.Preconditions.checkArgument;
import java.io.File;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.junit.Test;

public class HgtDiscreteElevationModelTest {

    @Test
    public void testHgtDiscreteElevationModel() {
        String[] files = {"N45E006.hgt","N45E007.hgt","N45E008.hgt","N45E009.hgt",
                          "N45E010.hgt","N45E011.hgt","N46E006.hgt","N46E007.hgt",
                          "N46E008.hgt","N46E009.hgt","N46E010.hgt","N46E011.hgt",
                          "N47E006.hgt","N47E007.hgt","N47E008.hgt","N47E009.hgt",
                          "N47E010.hgt","N47E011.hgt","N00E000.hgt","S89W120"};
        File file;
        for(String txt: files){
            file =  new File("HGT"+File.separatorChar+txt);
            if(file.exists())
                new HgtDiscreteElevationModel(file);
        }
        assertTrue(true);
    }
    
    @Test(expected=IllegalArgumentException.class)
    public void testHgtDiscreteElevationModelFails() {
        String[] files = {"N45E180.hgt","N45E007.hgt",};
        File file;
        for(String txt: files){
            file =  new File("HGT"+File.separatorChar+txt);
            new HgtDiscreteElevationModel(file);
        }
    }

    @Test
    public void checkFileNameSuccess() {
        assertTrue(checkFileName("S00E000.hgt")!=null);
        assertTrue(checkFileName("N00E000.hgt")!=null);
        assertTrue(checkFileName("S00W129.hgt")!=null);
        assertTrue(checkFileName("N00W000.hgt")!=null);
        assertTrue(checkFileName("S69E139.hgt")!=null);
        assertTrue(checkFileName("S90W180.hgt")!=null);
        assertTrue(checkFileName("N90E180.hgt")!=null);
        assertTrue(checkFileName("S90W180.hgt")!=null);
    }

    @Test(expected=IllegalArgumentException.class)
    public void checkFileNameFails() {
        checkFileName("E46E006.hgt");
        checkFileName("N4gE006.hgt");
        checkFileName("N46E0g6.hgt");
        checkFileName("N46E006lhgt");
        checkFileName("N46E006.hGT");  
        checkFileName("N4gE006.hgt"); 
        checkFileName("N46E0g6.hgt"); 
        checkFileName("N46E006phgt");
        checkFileName("Q99E006.hGT");  
    }
    
    private static final Matcher checkFileName(String txt){
        final Pattern P = Pattern.compile("([NS])(\\d{2})([EW])(\\d{3})\\.hgt");

        Matcher m = P.matcher(txt);

        checkArgument((txt.length()==11 && m.find()));
        int lat = Integer.parseInt(m.group(2));
        int lon = Integer.parseInt(m.group(4));
        checkArgument(!(lat>90 || lon>180 ));
        return m;
    }
    

}