/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.apache.tomcat.util;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Hashtable;

import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.res.StringManager;
import org.apache.tomcat.util.security.PermissionCheck;

Utils for introspection and reflection
/**
 * Utils for introspection and reflection
 */
public final class IntrospectionUtils {

    private static final Log log = LogFactory.getLog(IntrospectionUtils.class);
    private static final StringManager sm = StringManager.getManager(IntrospectionUtils.class);

    
Find a method with the right name If found, call the method ( if param is
int or boolean we'll convert value to the right type before) - that means
you can have setDebug(1).
Params:
o – The object to set a property on
name – The property name
value – The property value
Returns:
true if operation was successful/**
     * Find a method with the right name If found, call the method ( if param is
     * int or boolean we'll convert value to the right type before) - that means
     * you can have setDebug(1).
     * @param o The object to set a property on
     * @param name The property name
     * @param value The property value
     * @return <code>true</code> if operation was successful
     */
    public static boolean setProperty(Object o, String name, String value) {
        return setProperty(o, name, value, true, null);
    }

    public static boolean setProperty(Object o, String name, String value,
            boolean invokeSetProperty) {
        return setProperty(o, name, value, invokeSetProperty, null);
    }

    @SuppressWarnings("null") // setPropertyMethodVoid is not null when used
    public static boolean setProperty(Object o, String name, String value,
            boolean invokeSetProperty, StringBuilder actualMethod) {
        if (log.isDebugEnabled())
            log.debug("IntrospectionUtils: setProperty(" +
                    o.getClass() + " " + name + "=" + value + ")");

        if (actualMethod == null && XReflectionIntrospectionUtils.isEnabled()) {
            return XReflectionIntrospectionUtils.setPropertyInternal(o, name, value, invokeSetProperty);
        }

        String setter = "set" + capitalize(name);

        try {
            Method methods[] = findMethods(o.getClass());
            Method setPropertyMethodVoid = null;
            Method setPropertyMethodBool = null;

            // First, the ideal case - a setFoo( String ) method
            for (Method item : methods) {
                Class<?> paramT[] = item.getParameterTypes();
                if (setter.equals(item.getName()) && paramT.length == 1
                        && "java.lang.String".equals(paramT[0].getName())) {
                    item.invoke(o, new Object[]{value});
                    if (actualMethod != null) {
                        actualMethod.append(item.getName()).append("(\"").append(escape(value)).append("\")");
                    }
                    return true;
                }
            }

            // Try a setFoo ( int ) or ( boolean )
            for (Method method : methods) {
                boolean ok = true;
                if (setter.equals(method.getName())
                        && method.getParameterTypes().length == 1) {

                    // match - find the type and invoke it
                    Class<?> paramType = method.getParameterTypes()[0];
                    Object params[] = new Object[1];

                    // Try a setFoo ( int )
                    if ("java.lang.Integer".equals(paramType.getName())
                            || "int".equals(paramType.getName())) {
                        try {
                            params[0] = Integer.valueOf(value);
                        } catch (NumberFormatException ex) {
                            ok = false;
                        }
                        if (actualMethod != null) {
                            actualMethod.append(method.getName()).append("(Integer.valueOf(\"").append(value).append("\"))");
                        }
                        // Try a setFoo ( long )
                    } else if ("java.lang.Long".equals(paramType.getName())
                            || "long".equals(paramType.getName())) {
                        try {
                            params[0] = Long.valueOf(value);
                        } catch (NumberFormatException ex) {
                            ok = false;
                        }
                        if (actualMethod != null) {
                            actualMethod.append(method.getName()).append("(Long.valueOf(\"").append(value).append("\"))");
                        }
                        // Try a setFoo ( boolean )
                    } else if ("java.lang.Boolean".equals(paramType.getName())
                            || "boolean".equals(paramType.getName())) {
                        params[0] = Boolean.valueOf(value);
                        if (actualMethod != null) {
                            actualMethod.append(method.getName()).append("(Boolean.valueOf(\"").append(value).append("\"))");
                        }
                        // Try a setFoo ( InetAddress )
                    } else if ("java.net.InetAddress".equals(paramType
                            .getName())) {
                        try {
                            params[0] = InetAddress.getByName(value);
                        } catch (UnknownHostException exc) {
                            if (log.isDebugEnabled())
                                log.debug("IntrospectionUtils: Unable to resolve host name:" + value);
                            ok = false;
                        }
                        if (actualMethod != null) {
                            actualMethod.append(method.getName()).append("(InetAddress.getByName(\"").append(value).append("\"))");
                        }
                        // Unknown type
                    } else {
                        if (log.isDebugEnabled())
                            log.debug("IntrospectionUtils: Unknown type " +
                                    paramType.getName());
                    }

                    if (ok) {
                        method.invoke(o, params);
                        return true;
                    }
                }

                // save "setProperty" for later
                if ("setProperty".equals(method.getName())) {
                    if (method.getReturnType() == Boolean.TYPE) {
                        setPropertyMethodBool = method;
                    } else {
                        setPropertyMethodVoid = method;
                    }

                }
            }

            // Ok, no setXXX found, try a setProperty("name", "value")
            if (invokeSetProperty && (setPropertyMethodBool != null ||
                    setPropertyMethodVoid != null)) {
                if (actualMethod != null) {
                    actualMethod.append("setProperty(\"").append(name).append("\", \"").append(escape(value)).append("\")");
                }
                Object params[] = new Object[2];
                params[0] = name;
                params[1] = value;
                if (setPropertyMethodBool != null) {
                    try {
                        return ((Boolean) setPropertyMethodBool.invoke(o,
                                params)).booleanValue();
                    }catch (IllegalArgumentException biae) {
                        //the boolean method had the wrong
                        //parameter types. lets try the other
                        if (setPropertyMethodVoid!=null) {
                            setPropertyMethodVoid.invoke(o, params);
                            return true;
                        }else {
                            throw biae;
                        }
                    }
                } else {
                    setPropertyMethodVoid.invoke(o, params);
                    return true;
                }
            }

        } catch (IllegalArgumentException | SecurityException | IllegalAccessException e) {
            log.warn(sm.getString("introspectionUtils.setPropertyError", name, value, o.getClass()), e);
        } catch (InvocationTargetException e) {
            ExceptionUtils.handleThrowable(e.getCause());
            log.warn(sm.getString("introspectionUtils.setPropertyError", name, value, o.getClass()), e);
        }
        return false;
    }

    
Params:
s – 
           the input string
Returns:
escaped string, per Java rule/**
     * @param s
     *            the input string
     * @return escaped string, per Java rule
     */
    public static String escape(String s) {

        if (s == null)
            return "";

        StringBuilder b = new StringBuilder();
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == '"')
                b.append('\\').append('"');
            else if (c == '\\')
                b.append('\\').append('\\');
            else if (c == '\n')
                b.append('\\').append('n');
            else if (c == '\r')
                b.append('\\').append('r');
            else
                b.append(c);
        }
        return b.toString();
    }

    public static Object getProperty(Object o, String name) {
        if (XReflectionIntrospectionUtils.isEnabled()) {
            return XReflectionIntrospectionUtils.getPropertyInternal(o, name);
        }
        String getter = "get" + capitalize(name);
        String isGetter = "is" + capitalize(name);

        try {
            Method methods[] = findMethods(o.getClass());
            Method getPropertyMethod = null;

            // First, the ideal case - a getFoo() method
            for (Method method : methods) {
                Class<?> paramT[] = method.getParameterTypes();
                if (getter.equals(method.getName()) && paramT.length == 0) {
                    return method.invoke(o, (Object[]) null);
                }
                if (isGetter.equals(method.getName()) && paramT.length == 0) {
                    return method.invoke(o, (Object[]) null);
                }

                if ("getProperty".equals(method.getName())) {
                    getPropertyMethod = method;
                }
            }

            // Ok, no setXXX found, try a getProperty("name")
            if (getPropertyMethod != null) {
                Object params[] = new Object[1];
                params[0] = name;
                return getPropertyMethod.invoke(o, params);
            }

        } catch (IllegalArgumentException | SecurityException | IllegalAccessException e) {
            log.warn(sm.getString("introspectionUtils.getPropertyError", name, o.getClass()), e);
        } catch (InvocationTargetException e) {
            if (e.getCause() instanceof NullPointerException) {
                // Assume the underlying object uses a storage to represent an unset property
                return null;
            }
            ExceptionUtils.handleThrowable(e.getCause());
            log.warn(sm.getString("introspectionUtils.getPropertyError", name, o.getClass()), e);
        }
        return null;
    }

    
Replaces ${NAME} in the value with the value of the property 'NAME'.
Replaces ${NAME:DEFAULT} with the value of the property 'NAME:DEFAULT',
if the property 'NAME:DEFAULT' is not set,
the expression is replaced with the value of the property 'NAME',
if the property 'NAME' is not set,
the expression is replaced with 'DEFAULT'.
If the property is not set and there is no default the value will be
returned unmodified.
Params:
value – The value
staticProp – Replacement properties
dynamicProp – Replacement properties
classLoader – Class loader associated with the code requesting the
                   property
Returns:
the replacement value/**
     * Replaces ${NAME} in the value with the value of the property 'NAME'.
     * Replaces ${NAME:DEFAULT} with the value of the property 'NAME:DEFAULT',
     * if the property 'NAME:DEFAULT' is not set,
     * the expression is replaced with the value of the property 'NAME',
     * if the property 'NAME' is not set,
     * the expression is replaced with 'DEFAULT'.
     * If the property is not set and there is no default the value will be
     * returned unmodified.
     *
     * @param value The value
     * @param staticProp Replacement properties
     * @param dynamicProp Replacement properties
     * @param classLoader Class loader associated with the code requesting the
     *                    property
     *
     * @return the replacement value
     */
    public static String replaceProperties(String value,
            Hashtable<Object,Object> staticProp, PropertySource dynamicProp[],
            ClassLoader classLoader) {
            return replaceProperties(value, staticProp, dynamicProp, classLoader, 0);
    }

    private static String replaceProperties(String value,
            Hashtable<Object,Object> staticProp, PropertySource dynamicProp[],
            ClassLoader classLoader, int iterationCount) {
        if (value.indexOf("${") < 0) {
            return value;
        }
        if (iterationCount >=20) {
            log.warn("System property failed to update and remains [" + value + "]");
            return value;
        }
        StringBuilder sb = new StringBuilder();
        int prev = 0;
        // assert value!=nil
        int pos;
        while ((pos = value.indexOf('$', prev)) >= 0) {
            if (pos > 0) {
                sb.append(value.substring(prev, pos));
            }
            if (pos == (value.length() - 1)) {
                sb.append('$');
                prev = pos + 1;
            } else if (value.charAt(pos + 1) != '{') {
                sb.append('$');
                prev = pos + 1; // XXX
            } else {
                int endName = value.indexOf('}', pos);
                if (endName < 0) {
                    sb.append(value.substring(pos));
                    prev = value.length();
                    continue;
                }
                String n = value.substring(pos + 2, endName);
                String v = getProperty(n, staticProp, dynamicProp, classLoader);
                if (v == null) {
                    // {name:default}
                    int col = n.indexOf(":-");
                    if (col != -1) {
                        String dV = n.substring(col + 2);
                        n = n.substring(0, col);
                        v = getProperty(n, staticProp, dynamicProp, classLoader);
                        if (v == null) {
                            v = dV;
                        }
                    } else {
                        v = "${" + n + "}";
                    }
                }
                sb.append(v);
                prev = endName + 1;
            }
        }
        if (prev < value.length())
            sb.append(value.substring(prev));
        String newval = sb.toString();
        if (newval.indexOf("${") < 0) {
            return newval;
        }
        if (newval.equals(value))
            return value;
        if (log.isDebugEnabled())
            log.debug("IntrospectionUtils.replaceProperties iter on: " + newval);
        return replaceProperties(newval, staticProp, dynamicProp, classLoader, iterationCount+1);
    }

    private static String getProperty(String name, Hashtable<Object, Object> staticProp,
            PropertySource[] dynamicProp, ClassLoader classLoader) {
        String v = null;
        if (staticProp != null) {
            v = (String) staticProp.get(name);
        }
        if (v == null && dynamicProp != null) {
            for (PropertySource propertySource : dynamicProp) {
                if (propertySource instanceof SecurePropertySource) {
                    v = ((SecurePropertySource) propertySource).getProperty(name, classLoader);
                } else {
                    v = propertySource.getProperty(name);
                }
                if (v != null) {
                    break;
                }
            }
        }
        return v;
    }

    
Reverse of Introspector.decapitalize.
Params:
name – The name
Returns:
the capitalized string/**
     * Reverse of Introspector.decapitalize.
     * @param name The name
     * @return the capitalized string
     */
    public static String capitalize(String name) {
        if (name == null || name.length() == 0) {
            return name;
        }
        char chars[] = name.toCharArray();
        chars[0] = Character.toUpperCase(chars[0]);
        return new String(chars);
    }

    // -------------------- other utils --------------------
    public static void clear() {
        objectMethods.clear();
    }

    private static final Hashtable<Class<?>,Method[]> objectMethods = new Hashtable<>();

    public static Method[] findMethods(Class<?> c) {
        Method methods[] = objectMethods.get(c);
        if (methods != null)
            return methods;

        methods = c.getMethods();
        objectMethods.put(c, methods);
        return methods;
    }

    @SuppressWarnings("null") // params cannot be null when comparing lengths
    public static Method findMethod(Class<?> c, String name,
            Class<?> params[]) {
        Method methods[] = findMethods(c);
        for (Method method : methods) {
            if (method.getName().equals(name)) {
                Class<?> methodParams[] = method.getParameterTypes();
                if (params == null && methodParams.length == 0) {
                    return method;
                }
                if (params.length != methodParams.length) {
                    continue;
                }
                boolean found = true;
                for (int j = 0; j < params.length; j++) {
                    if (params[j] != methodParams[j]) {
                        found = false;
                        break;
                    }
                }
                if (found) {
                    return method;
                }
            }
        }
        return null;
    }

    public static Object callMethod1(Object target, String methodN,
            Object param1, String typeParam1, ClassLoader cl) throws Exception {
        if (target == null || methodN == null || param1 == null) {
            throw new IllegalArgumentException(sm.getString("introspectionUtils.nullParameter"));
        }
        if (log.isDebugEnabled())
            log.debug("IntrospectionUtils: callMethod1 " +
                    target.getClass().getName() + " " +
                    param1.getClass().getName() + " " + typeParam1);

        Class<?> params[] = new Class[1];
        if (typeParam1 == null)
            params[0] = param1.getClass();
        else
            params[0] = cl.loadClass(typeParam1);
        Method m = findMethod(target.getClass(), methodN, params);
        if (m == null)
            throw new NoSuchMethodException(target.getClass().getName() + " "
                    + methodN);
        try {
            return m.invoke(target, new Object[] { param1 });
        } catch (InvocationTargetException ie) {
            ExceptionUtils.handleThrowable(ie.getCause());
            throw ie;
        }
    }

    public static Object callMethodN(Object target, String methodN,
            Object params[], Class<?> typeParams[]) throws Exception {
        Method m = null;
        m = findMethod(target.getClass(), methodN, typeParams);
        if (m == null) {
            if (log.isDebugEnabled())
                log.debug("IntrospectionUtils: Can't find method " + methodN +
                        " in " + target + " CLASS " + target.getClass());
            return null;
        }
        try {
            Object o = m.invoke(target, params);

            if (log.isDebugEnabled()) {
                // debug
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName()).append('.')
                        .append(methodN).append("( ");
                for (int i = 0; i < params.length; i++) {
                    if (i > 0)
                        sb.append(", ");
                    sb.append(params[i]);
                }
                sb.append(")");
                log.debug("IntrospectionUtils:" + sb.toString());
            }
            return o;
        } catch (InvocationTargetException ie) {
            ExceptionUtils.handleThrowable(ie.getCause());
            throw ie;
        }
    }

    public static Object convert(String object, Class<?> paramType) {
        Object result = null;
        if ("java.lang.String".equals(paramType.getName())) {
            result = object;
        } else if ("java.lang.Integer".equals(paramType.getName())
                || "int".equals(paramType.getName())) {
            try {
                result = Integer.valueOf(object);
            } catch (NumberFormatException ex) {
            }
            // Try a setFoo ( boolean )
        } else if ("java.lang.Boolean".equals(paramType.getName())
                || "boolean".equals(paramType.getName())) {
            result = Boolean.valueOf(object);

            // Try a setFoo ( InetAddress )
        } else if ("java.net.InetAddress".equals(paramType
                .getName())) {
            try {
                result = InetAddress.getByName(object);
            } catch (UnknownHostException exc) {
                if (log.isDebugEnabled())
                    log.debug("IntrospectionUtils: Unable to resolve host name:" +
                            object);
            }

            // Unknown type
        } else {
            if (log.isDebugEnabled())
                log.debug("IntrospectionUtils: Unknown type " +
                        paramType.getName());
        }
        if (result == null) {
            throw new IllegalArgumentException(sm.getString("introspectionUtils.conversionError", object, paramType.getName()));
        }
        return result;
    }


    
Checks to see if the specified class is an instance of or assignable from
the specified type. The class clazz, all its superclasses,
interfaces and those superinterfaces are tested for a match against
the type name type.
This is similar to instanceof or Class.isAssignableFrom except that the target type will not be resolved into a Class object, which provides some security and memory benefits. 
Params:
clazz – The class to test for a match.
type – The name of the type that clazz must be.
Returns:
true if the clazz tested is an
        instance of the specified type,
        false otherwise./**
     * Checks to see if the specified class is an instance of or assignable from
     * the specified type. The class <code>clazz</code>, all its superclasses,
     * interfaces and those superinterfaces are tested for a match against
     * the type name <code>type</code>.
     *
     * This is similar to <code>instanceof</code> or {@link Class#isAssignableFrom}
     * except that the target type will not be resolved into a Class
     * object, which provides some security and memory benefits.
     *
     * @param clazz The class to test for a match.
     * @param type The name of the type that <code>clazz</code> must be.
     *
     * @return <code>true</code> if the <code>clazz</code> tested is an
     *         instance of the specified <code>type</code>,
     *         <code>false</code> otherwise.
     */
    public static boolean isInstance(Class<?> clazz, String type) {
        if (type.equals(clazz.getName())) {
            return true;
        }

        Class<?>[] ifaces = clazz.getInterfaces();
        for (Class<?> iface : ifaces) {
            if (isInstance(iface, type)) {
                return true;
            }
        }

        Class<?> superClazz = clazz.getSuperclass();
        if (superClazz == null) {
            return false;
        } else {
            return isInstance(superClazz, type);
        }
    }


    // -------------------- Get property --------------------
    // This provides a layer of abstraction

    public static interface PropertySource {
        public String getProperty(String key);
    }


    public static interface SecurePropertySource extends PropertySource {

        
Obtain a property value, checking that code associated with the provided class loader has permission to access the property. If the classLoader is null or if classLoader does not implement PermissionCheck then the property value will be looked up without a call to PermissionCheck.check(Permission) 
Params:
key –           The key of the requested property
classLoader –   The class loader associated with the code that
                     trigger the property lookup
Returns:
The property value or null if it could not be found or if PermissionCheck.check(Permission) fails/**
         * Obtain a property value, checking that code associated with the
         * provided class loader has permission to access the property. If the
         * {@code classLoader} is {@code null} or if {@code classLoader} does
         * not implement {@link PermissionCheck} then the property value will be
         * looked up <b>without</b> a call to
         * {@link PermissionCheck#check(java.security.Permission)}
         *
         * @param key           The key of the requested property
         * @param classLoader   The class loader associated with the code that
         *                      trigger the property lookup
         * @return The property value or {@code null} if it could not be found
         *         or if {@link PermissionCheck#check(java.security.Permission)}
         *         fails
         */
        public String getProperty(String key, ClassLoader classLoader);
    }
}