package org.litesoft.language.model;

import org.litesoft.commonfoundation.annotations.*;
import org.litesoft.commonfoundation.base.*;
import org.litesoft.commonfoundation.issues.*;
import org.litesoft.commonfoundation.typeutils.*;

/**
 * A Language Key is a series of constrained 7bit Ascii Java Identifier (Alpha followed by zero or more by AlphaNumerics or underscores) separated by single
 * dots ('.').
 */
public class Key {
    public Key( @SignificantText String pKey ) {
        Problem zProblem = validate( key = pKey );
        if ( zProblem != null ) {
            throw new IllegalArgumentException( zProblem.toString() );
        }
    }

    public final @SignificantText String getKey() {
        return key;
    }

    public static @Nullable Problem validate( String pKey ) {
        if ( Currently.isNullOrEmpty( pKey ) ) {
            return new Problem( "Empty" );
        }
        String[] zParts = Strings.parseChar( pKey, '.' );
        for ( int i = 0; i < zParts.length; i++ ) {
            String zPart = zParts[i];
            if ( !Strings.isConstrainedAsciiIdentifier( zPart ) ) {
                return new Problem.Builder( "Invalid" )
                        .add( "Part", i )
                        .add( "At", pKey.indexOf( zPart ) )
                        .build();
            }
        }
        return null;
    }

    private /* final */ String key;

    @Deprecated /** for Serialization */
    protected Key() {
    }
}