package org.kuali.common.util.ssh.model;
   
   import org.kuali.common.util.Assert;
   import org.kuali.common.util.spring.env.EnvUtils;
   import org.kuali.common.util.spring.env.EnvironmentService;
   
   import com.google.common.base.Optional;
   
   public final class GenerateKeyPairContext {
  
  	private final String name;
  	private final Algorithm algorithm;
  	private final int size;
  
  	public static class Builder {
  
  		// Required
  		private final String name;
  
  		// Optional
  		private Algorithm algorithm = Algorithm.RSA;
  		private int size = 2048;
  
  		private Optional<EnvironmentService> env = EnvUtils.ABSENT;
  		private static final String NAME_KEY = "ssh.keyName";
  		private static final String ALGORITHM_KEY = "ssh.algorithm";
  		private static final String SIZE_KEY = "ssh.keySize";
  
  		public Builder(String name) {
  			this(EnvUtils.ABSENT, name);
  		}
  
  		public Builder(EnvironmentService env, String name) {
  			this(Optional.of(env), name);
  		}
  
  		private Builder(Optional<EnvironmentService> env, String name) {
  			this.env = env;
  			if (env.isPresent()) {
  				this.name = env.get().getString(NAME_KEY, name);
  			} else {
  				this.name = name;
  			}
  		}
  
  		public Builder algorithm(Algorithm algorithm) {
  			this.algorithm = algorithm;
  			return this;
  		}
  
  		public Builder size(int size) {
  			this.size = size;
  			return this;
  		}
  
  		private void validate(GenerateKeyPairContext context) {
  			Assert.noBlanks(context.getName());
  			Assert.positive(context.getSize());
  		}
  
  		private void override() {
  			if (env.isPresent()) {
  				algorithm(env.get().getProperty(ALGORITHM_KEY, Algorithm.class, algorithm));
  				size(env.get().getInteger(SIZE_KEY, size));
  			}
  		}
  
  		public GenerateKeyPairContext build() {
  			override();
  			GenerateKeyPairContext context = new GenerateKeyPairContext(this);
  			validate(context);
  			return context;
  		}
  
  	}
  
  	private GenerateKeyPairContext(Builder builder) {
  		this.name = builder.name;
  		this.algorithm = builder.algorithm;
  		this.size = builder.size;
  	}
  
  	public String getName() {
  		return name;
  	}
  
  	public Algorithm getAlgorithm() {
  		return algorithm;
  	}
  
  	public int getSize() {
  		return size;
  	}
  
  }