package com.github.davidmoten.rx.jdbc;
   
   import java.lang.reflect.Method;
   import java.util.HashMap;
   import java.util.Map;
   
   import com.github.davidmoten.rx.jdbc.Util.Col;
   import com.github.davidmoten.rx.jdbc.Util.IndexedCol;
   import com.github.davidmoten.rx.jdbc.Util.NamedCol;
  import com.github.davidmoten.rx.jdbc.annotations.Column;
  import com.github.davidmoten.rx.jdbc.annotations.Index;
  
  class AutoMapCache {
      final Map<String, Col> methodCols;
      public Class<?> cls;
  
      AutoMapCache(Class<?> cls) {
          this.cls = cls;
          this.methodCols = getMethodCols(cls);
      }
  
      private static Map<String, Col> getMethodCols(Class<?> cls) {
          Map<String, Col> methodCols = new HashMap<String, Col>();
          for (Method method : cls.getMethods()) {
              String name = method.getName();
              Column column = method.getAnnotation(Column.class);
              if (column != null) {
                  checkHasNoParameters(method);
                  // TODO check method has a mappable return type
                  String col = column.value();
                  if (col.equals(Column.NOT_SPECIFIED))
                      col = Util.camelCaseToUnderscore(name);
                  methodCols.put(name, new NamedCol(col, method.getReturnType()));
              } else {
                  Index index = method.getAnnotation(Index.class);
                  if (index != null) {
                      // TODO check method has a mappable return type
                      checkHasNoParameters(method);
                      methodCols.put(name, new IndexedCol(index.value(), method.getReturnType()));
                  }
              }
          }
          return methodCols;
      }
  
      private static void checkHasNoParameters(Method method) {
          if (method.getParameterTypes().length > 0) {
              throw new RuntimeException("mapped interface method cannot have parameters");
          }
      }
  
  }