package com.atlassian.dbexporter;
   
   import java.util.Locale;
   
   /**
    * A class that gives easy access to some database information
    *
    * @author Samuel Le Berrigaud
    */
  public final class DatabaseInformations {
      private DatabaseInformations() {
      }
  
      public static Database database(DatabaseInformation info) {
          return new DatabaseImpl(info.get("database.name", new DatabaseTypeConverter()));
      }
  
      public static interface Database {
          Type getType();
  
          static enum Type {
              H2,
              HSQL,
              MYSQL,
              POSTGRES,
              ORACLE,
              MSSQL,
              UNKNOWN
          }
      }
  
      private static class DatabaseTypeConverter extends DatabaseInformation.AbstractStringConverter<Database.Type> {
          @Override
          public Database.Type convert(String dbName) {
              if (isEmpty(dbName)) {
                  return Database.Type.UNKNOWN;
              }
  
              if (isH2(dbName)) {
                  return Database.Type.H2;
              }
  
              if (isHsql(dbName)) {
                  return Database.Type.HSQL;
              }
  
              if (isMySql(dbName)) {
                  return Database.Type.MYSQL;
              }
  
              if (isPostgres(dbName)) {
                  return Database.Type.POSTGRES;
              }
  
              if (isOracle(dbName)) {
                  return Database.Type.ORACLE;
              }
  
              if (isMsSql(dbName)) {
                  return Database.Type.MSSQL;
              }
  
              return Database.Type.UNKNOWN;
          }
  
          private boolean isEmpty(String dbName) {
              return dbName == null || dbName.trim().length() == 0;
          }
  
          private boolean isH2(String dbName) {
              return startsWithIgnoreCase(dbName, "H2");
          }
  
          private boolean isHsql(String dbName) {
              return startsWithIgnoreCase(dbName, "HSQL");
          }
  
          private boolean isMySql(String dbName) {
              return startsWithIgnoreCase(dbName, "MySQL");
          }
  
          private boolean isPostgres(String dbName) {
              return startsWithIgnoreCase(dbName, "PostgreSQL");
          }
  
          private boolean isOracle(String dbName) {
              return startsWithIgnoreCase(dbName, "Oracle");
          }
  
          private boolean isMsSql(String dbName) {
              return startsWithIgnoreCase(dbName, "Microsoft");
          }
  
          private boolean startsWithIgnoreCase(String s, String start) {
              return toLowerCase(s).startsWith(toLowerCase(start));
          }
  
          private String toLowerCase(String s) {
              return s == null ? s : s.toLowerCase(Locale.ENGLISH);
         }
     }
 
     private static class DatabaseImpl implements Database {
         private final Type type;
 
         public DatabaseImpl(Type type) {
             this.type = type;
         }
 
         @Override
         public Type getType() {
             return type;
         }
 
         @Override
         public String toString() {
             return new StringBuilder().append(getType()).toString();
         }
     }
 }