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/*
 * Jython Database Specification API 2.0
 *
 *
 * Copyright (c) 2001 brian zimmer 
 *
 */
package com.ziclix.python.sql.connect;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.SQLException;

import javax.sql.ConnectionPoolDataSource;
import javax.sql.DataSource;

import org.python.core.Py;
import org.python.core.PyObject;
import org.python.core.PyString;
import org.python.core.Untraversable;

import com.ziclix.python.sql.PyConnection;
import com.ziclix.python.sql.zxJDBC;
import com.ziclix.python.sql.util.PyArgParser;

/**
 * Connect using through a javax.sql.DataSource or javax.sql.ConnectionPooledDataSource.
 *
 * @author brian zimmer
 */
@Untraversable
public class Connectx extends PyObject {

    private static final String SET = "set";
    private static final PyString _doc =
            new PyString("establish a connection through a javax.sql.DataSource or "
                         + "javax.sql.ConnectionPooledDataSource");

    @Override
    public PyObject __findattr_ex__(String name) {
        if ("__doc__".equals(name)) {
            return _doc;
        }
        return super.__findattr_ex__(name);
    }

    /**
     * Construct a javax.sql.DataSource or javax.sql.ConnectionPooledDataSource
     */
    @Override
    public PyObject __call__(PyObject[] args, String[] keywords) {
        Connection c = null;
        PyConnection pc = null;
        Object datasource = null;
        PyArgParser parser = new PyArgParser(args, keywords);

        try {
            String klass = (String) parser.arg(0).__tojava__(String.class);
            datasource = Class.forName(klass).newInstance();
        } catch (Exception e) {
            throw zxJDBC.makeException(zxJDBC.DatabaseError, "unable to instantiate datasource");
        }

        String[] kws = parser.kws();
        for (int i = 0; i < kws.length; i++) {
            String methodName = kws[i];

            if (methodName == null) {
                continue;
            }

            Object value = parser.kw(kws[i]).__tojava__(Object.class);
            if (methodName.length() > SET.length()) {
                if (!SET.equals(methodName.substring(0, SET.length()))) {
                    // prepend "set"
                    invoke(datasource, SET + methodName.substring(0, 1).toUpperCase()
                           + methodName.substring(1), value);
                } else {
                    // starts with "set" so just pass it on
                    invoke(datasource, methodName, value);
                }
            } else {

                // shorter than "set" so it can't be a full method name
                invoke(datasource,
                       SET + methodName.substring(0, 1).toUpperCase() + methodName.substring(1),
                       value);
            }
        }

        try {
            if (datasource instanceof ConnectionPoolDataSource) {
                c = ((ConnectionPoolDataSource) datasource).getPooledConnection().getConnection();
            } else if (datasource instanceof DataSource) {
                c = ((DataSource) datasource).getConnection();
            }
        } catch (SQLException e) {
            throw zxJDBC.makeException(zxJDBC.DatabaseError, e);
        }

        try {
            if (c == null || c.isClosed()) {
                throw zxJDBC.makeException(zxJDBC.DatabaseError, "unable to establish connection");
            }

            pc = new PyConnection(c);
        } catch (SQLException e) {
            throw zxJDBC.makeException(zxJDBC.DatabaseError, e);
        }

        return pc;
    }

    /**
     * Method toString
     *
     * @return String
     */
    @Override
    public String toString() {
        return String.format("", Py.id(this));
    }

    /**
     * Method invoke
     *
     * @param Object src
     * @param String methodName
     * @param Object value
     */
    protected void invoke(Object src, String methodName, Object value) {
        Method method = null;
        StringBuffer exceptionMsg = new StringBuffer("method [");
        exceptionMsg.append(methodName).append("] using arg type [");
        exceptionMsg.append(value.getClass()).append("], value [");
        exceptionMsg.append(value.toString()).append("]");

        try {
            method = getMethod(src.getClass(), methodName, value.getClass());
            if (method == null) {
                throw zxJDBC.makeException("no such " + exceptionMsg);
            }
            method.invoke(src, new Object[]{value});
        } catch (IllegalAccessException e) {
            throw zxJDBC.makeException("illegal access for " + exceptionMsg);
        } catch (InvocationTargetException e) {
            throw zxJDBC.makeException("invocation target exception for " + exceptionMsg);
        }

        return;
    }

    /**
     * Try to find the method by the given name.  If failing that, see if the valueClass
     * is perhaps a primitive and attempt to recurse using the primitive type.  Failing
     * that return null.
     */
    protected Method getMethod(Class srcClass, String methodName, Class valueClass) {
        Method method = null;

        try {
            method = srcClass.getMethod(methodName, new Class[]{valueClass});
        } catch (NoSuchMethodException e) {
            Class primitive = null;

            try {
                Field f = valueClass.getField("TYPE");
                primitive = (Class) f.get(valueClass);
            } catch (NoSuchFieldException ex) {
            } catch (IllegalAccessException ex) {
            } catch (ClassCastException ex) {
            }

            if (primitive != null && primitive.isPrimitive()) {
                return getMethod(srcClass, methodName, primitive);
            }
        }

        return method;
    }
}