Application: gvSIG desktop » gvSIG scripting

package org.python.jsr223;

import java.lang.reflect.Method;

import org.python.core.*;

import java.io.Reader;

import java.lang.reflect.InvocationHandler;

import java.lang.reflect.Proxy;

import java.util.List;

import javax.script.AbstractScriptEngine;

import javax.script.Bindings;

import javax.script.Compilable;

import javax.script.CompiledScript;

import javax.script.Invocable;

import javax.script.ScriptContext;

import javax.script.ScriptEngine;

import javax.script.ScriptEngineFactory;

import javax.script.ScriptException;

import javax.script.SimpleBindings;

import org.python.util.PythonInterpreter;

public class MyPyScriptEngine extends AbstractScriptEngine implements Compilable, Invocable, AutoCloseable {

    //http://stackoverflow.com/questions/29543532/how-to-call-a-function-inside-a-python-script-and-pass-parameters-while-using-sc

    private final PythonInterpreter interp;

    private final ScriptEngineFactory factory;

    public MyPyScriptEngine(ScriptEngineFactory factory) {

        this.factory = factory;

        interp = PythonInterpreter.threadLocalStateInterpreter(new PyScriptEngineScope(this, context));

    }

    public PythonInterpreter getPythonInterpreter() {

        return this.interp;

    }

    @Override

    public Object eval(String script, ScriptContext context) throws ScriptException {

        return eval(compileScript(script, context), context);

    }

    private Object eval(PyCode code, ScriptContext context) throws ScriptException {

        try {

            interp.setIn(context.getReader());

            interp.setOut(context.getWriter());

            interp.setErr(context.getErrorWriter());

            interp.setLocals(new PyScriptEngineScope(this, context));

            return interp.eval(code).__tojava__(Object.class);

        } catch (PyException pye) {

            throw scriptException(pye);

        }

    }

    @Override

    public Object eval(Reader reader, ScriptContext context) throws ScriptException {

        return eval(compileScript(reader, context), context);

    }

    @Override

    public Bindings createBindings() {

        return new SimpleBindings();

    }

    @Override

    public ScriptEngineFactory getFactory() {

        return factory;

    }

    @Override

    public CompiledScript compile(String script) throws ScriptException {

        return new PyCompiledScript(compileScript(script, context));

    }

    @Override

    public CompiledScript compile(Reader reader) throws ScriptException {

        return new PyCompiledScript(compileScript(reader, context));

    }

    private PyCode compileScript(String script, ScriptContext context) throws ScriptException {

        try {

            String filename = (String) context.getAttribute(ScriptEngine.FILENAME);

            if (filename == null) {

                return interp.compile(script);

            } else {

                return interp.compile(script, filename);

            }

        } catch (PyException pye) {

            throw scriptException(pye);

        }

    }

    private PyCode compileScript(Reader reader, ScriptContext context) throws ScriptException {

        try {

            String filename = (String) context.getAttribute(ScriptEngine.FILENAME);

            if (filename == null) {

                return interp.compile(reader);

            } else {

                return interp.compile(reader, filename);

            }

        } catch (PyException pye) {

            throw scriptException(pye);

        }

    }

    @Override

    public Object invokeMethod(Object thiz, String name, Object... args) throws ScriptException,

            NoSuchMethodException {

        try {

            interp.setLocals(new PyScriptEngineScope(this, context));

            if (!(thiz instanceof PyObject)) {

                thiz = Py.java2py(thiz);

            }

            PyObject method = ((PyObject) thiz).__findattr__(name);

            if (method == null) {

                throw new NoSuchMethodException(name);

            }

            //return method.__call__(Py.javas2pys(args)).__tojava__(Object.class);

            PyObject result;

            if(args != null) {

               result = method.__call__(Py.javas2pys(args));

            } else {

               result = method.__call__();

            }

            return result.__tojava__(Object.class);

        } catch (PyException pye) {

            throw scriptException(pye);

        }

    }

    @Override

    public Object invokeFunction(String name, Object... args) throws ScriptException,

            NoSuchMethodException {

        try {

            interp.setIn(context.getReader());

            interp.setOut(context.getWriter());

            interp.setErr(context.getErrorWriter());

            interp.setLocals(new PyScriptEngineScope(this, context));

            PyObject function = interp.get(name);

            if (function == null) {

                throw new NoSuchMethodException(name);

            }

            PyObject result;

            ThreadState state = new ThreadState(this.interp.getSystemState());

            if(args != null) {

                result = function.__call__(state,Py.javas2pys(args));

            } else {

                result = function.__call__(state);

            }

            return result.__tojava__(Object.class);

        } catch (PyException pye) {

            throw scriptException(pye);

        }

    }

    @Override

    public <T> T getInterface(Class<T> clazz) {

        return getInterface(new PyModule("__jsr223__", interp.getLocals()), clazz);

    }

    @Override

    public <T> T getInterface(Object obj, Class<T> clazz) {

        if (obj == null) {

            throw new IllegalArgumentException("object expected");

        }

        if (clazz == null || !clazz.isInterface()) {

            throw new IllegalArgumentException("interface expected");

        }

        interp.setLocals(new PyScriptEngineScope(this, context));

        final PyObject thiz = Py.java2py(obj);

        @SuppressWarnings("unchecked")

        T proxy = (T) Proxy.newProxyInstance(

            clazz.getClassLoader(),

            new Class[] { clazz },

            new InvocationHandler() {

                @Override

                public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

                    try {

                        interp.setLocals(new PyScriptEngineScope(MyPyScriptEngine.this, context));

                        PyObject pyMethod = thiz.__findattr__(method.getName());

                        if (pyMethod == null)

                            throw new NoSuchMethodException(method.getName());

                        PyObject result;

                        if(args != null) {

                            result = pyMethod.__call__(Py.javas2pys(args));

                        } else {

                            result = pyMethod.__call__();

                        }

                        return result.__tojava__(Object.class);

                    } catch (PyException pye) {

                        throw scriptException(pye);

                    }

                }

            });

        return proxy;

    }

    private static ScriptException scriptException(PyException pye) {

        ScriptException se;

        try {

            pye.normalize();

            PyObject type = pye.type;

            PyObject value = pye.value;

            PyTraceback tb = pye.traceback;

            if (__builtin__.isinstance(value, Py.SyntaxError)) {

                PyObject filename = value.__findattr__("filename");

                PyObject lineno = value.__findattr__("lineno");

                PyObject offset = value.__findattr__("offset");

                value = value.__findattr__("msg");

                se = new ScriptException(

                        Py.formatException(type, value),

                        filename == null ? "<script>" : filename.toString(),

                        lineno == null ? 0 : lineno.asInt(),

                        offset == null ? 0 : offset.asInt());

            } else if (tb != null) {

                String filename;

                if (tb.tb_frame == null || tb.tb_frame.f_code == null) {

                    filename = null;

                } else {

                    filename = tb.tb_frame.f_code.co_filename;

                }

                se = new ScriptException(

                        Py.formatException(type, value),

                        filename,

                        tb.tb_lineno);

            } else {

                se = new ScriptException(Py.formatException(type, value));

            }

            se.initCause(pye);

            return se;

        } catch (Exception ee) {

            se = new ScriptException(pye);

        }

        return se;

    }

    private class PyCompiledScript extends CompiledScript {

        private final PyCode code;

        PyCompiledScript(PyCode code) {

            this.code = code;

        }

        @Override

        public ScriptEngine getEngine() {

            return MyPyScriptEngine.this;

        }

        @Override

        public Object eval(ScriptContext ctx) throws ScriptException {

            return MyPyScriptEngine.this.eval(code, ctx);

        }

    }

    @Override

    public void close() {

        interp.close();

    }

    public List<String> getLocalNames() {

        PyScriptEngineScope locals = (PyScriptEngineScope) interp.getLocals();

        PyList names = (PyList) locals.scope_keys();

        return names;

    }

}