/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * particular file as subject to the "Classpath" exception as provided

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

package sun.dyn;

import sun.dyn.util.BytecodeDescriptor;

import java.dyn.*;

import java.lang.reflect.Constructor;

import java.lang.reflect.Field;

import java.lang.reflect.Method;

import java.lang.reflect.Member;

import java.lang.reflect.Modifier;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.Iterator;

import java.util.List;

import static sun.dyn.MethodHandleNatives.Constants.*;

/**

 * Compact information which fully characterizes a method or field reference.

 * When resolved, it includes a direct pointer to JVM metadata.

 * This representation is stateless and only decriptive.

 * It provides no private information and no capability to use the member.

 * <p>

 * By contrast, a java.lang.reflect.Method contains fuller information

 * about the internals of a method (except its bytecodes) and also

 * allows invocation.  A MemberName is much lighter than a reflect.Method,

 * since it contains about 7 fields to Method's 16 (plus its sub-arrays),

 * and those seven fields omit much of the information in Method.

 * @author jrose

 */

public final class MemberName implements Member, Cloneable {

    private Class<?>   clazz;       // class in which the method is defined

    private String     name;        // may be null if not yet materialized

    private Object     type;        // may be null if not yet materialized

    private int        flags;       // modifier bits; see reflect.Modifier

    private Object     vmtarget;    // VM-specific target value

    private int        vmindex;     // method index within class or interface

    { vmindex = VM_INDEX_UNINITIALIZED; }

    public Class<?> getDeclaringClass() {

        if (clazz == null && isResolved()) {

            expandFromVM();

        }

        return clazz;

    }

    public ClassLoader getClassLoader() {

        return clazz.getClassLoader();

    }

    public String getName() {

        if (name == null) {

            expandFromVM();

            if (name == null)  return null;

        }

        return name;

    }

    public MethodType getMethodType() {

        if (type == null) {

            expandFromVM();

            if (type == null)  return null;

        }

        if (!isInvocable())

            throw newIllegalArgumentException("not invocable, no method type");

        if (type instanceof MethodType) {

            return (MethodType) type;

        }

        if (type instanceof String) {

            String sig = (String) type;

            MethodType res = MethodType.fromMethodDescriptorString(sig, getClassLoader());

            this.type = res;

            return res;

        }

        if (type instanceof Object[]) {

            Object[] typeInfo = (Object[]) type;

            Class<?>[] ptypes = (Class<?>[]) typeInfo[1];

            Class<?> rtype = (Class<?>) typeInfo[0];

            MethodType res = MethodType.methodType(rtype, ptypes);

            this.type = res;

            return res;

        }

        throw new InternalError("bad method type "+type);

    }

    public MethodType getInvocationType() {

        MethodType itype = getMethodType();

        if (!isStatic())

            itype = itype.insertParameterTypes(0, clazz);

        return itype;

    }

    public Class<?>[] getParameterTypes() {

        return getMethodType().parameterArray();

    }

    public Class<?> getReturnType() {

        return getMethodType().returnType();

    }

    public Class<?> getFieldType() {

        if (type == null) {

            expandFromVM();

            if (type == null)  return null;

        }

        if (isInvocable())

            throw newIllegalArgumentException("not a field or nested class, no simple type");

        if (type instanceof Class<?>) {

            return (Class<?>) type;

        }

        if (type instanceof String) {

            String sig = (String) type;

            MethodType mtype = MethodType.fromMethodDescriptorString("()"+sig, getClassLoader());

            Class<?> res = mtype.returnType();

            this.type = res;

            return res;

        }

        throw new InternalError("bad field type "+type);

    }

    public Object getType() {

        return (isInvocable() ? getMethodType() : getFieldType());

    }

    public String getSignature() {

        if (type == null) {

            expandFromVM();

            if (type == null)  return null;

        }

        if (type instanceof String)

            return (String) type;

        if (isInvocable())

            return BytecodeDescriptor.unparse(getMethodType());

        else

            return BytecodeDescriptor.unparse(getFieldType());

    }

    public int getModifiers() {

        return (flags & RECOGNIZED_MODIFIERS);

    }

    private void setFlags(int flags) {

        this.flags = flags;

        assert(testAnyFlags(ALL_KINDS));

    }

    private boolean testFlags(int mask, int value) {

        return (flags & mask) == value;

    }

    private boolean testAllFlags(int mask) {

        return testFlags(mask, mask);

    }

    private boolean testAnyFlags(int mask) {

        return !testFlags(mask, 0);

    }

    public boolean isStatic() {

        return Modifier.isStatic(flags);

    }

    public boolean isPublic() {

        return Modifier.isPublic(flags);

    }

    public boolean isPrivate() {

        return Modifier.isPrivate(flags);

    }

    public boolean isProtected() {

        return Modifier.isProtected(flags);

    }

    public boolean isFinal() {

        return Modifier.isFinal(flags);

    }

    public boolean isAbstract() {

        return Modifier.isAbstract(flags);

    }

    // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo

    // unofficial modifier flags, used by HotSpot:

    static final int BRIDGE    = 0x00000040;

    static final int VARARGS   = 0x00000080;

    static final int SYNTHETIC = 0x00001000;

    static final int ANNOTATION= 0x00002000;

    static final int ENUM      = 0x00004000;

    public boolean isBridge() {

        return testAllFlags(IS_METHOD | BRIDGE);

    }

    public boolean isVarargs() {

        return testAllFlags(VARARGS) && isInvocable();

    }

    public boolean isSynthetic() {

        return testAllFlags(SYNTHETIC);

    }

    static final String CONSTRUCTOR_NAME = "<init>";  // the ever-popular

    // modifiers exported by the JVM:

    static final int RECOGNIZED_MODIFIERS = 0xFFFF;

    // private flags, not part of RECOGNIZED_MODIFIERS:

    static final int

            IS_METHOD      = MN_IS_METHOD,      // method (not constructor)

            IS_CONSTRUCTOR = MN_IS_CONSTRUCTOR, // constructor

            IS_FIELD       = MN_IS_FIELD,       // field

            IS_TYPE        = MN_IS_TYPE;        // nested type

    static final int  // for MethodHandleNatives.getMembers

            SEARCH_SUPERCLASSES = MN_SEARCH_SUPERCLASSES,

            SEARCH_INTERFACES   = MN_SEARCH_INTERFACES;

    static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;

    static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE;

    static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR;

    static final int IS_FIELD_OR_METHOD = IS_METHOD | IS_FIELD;

    static final int SEARCH_ALL_SUPERS = SEARCH_SUPERCLASSES | SEARCH_INTERFACES;

    public boolean isInvocable() {

        return testAnyFlags(IS_INVOCABLE);

    }

    public boolean isFieldOrMethod() {

        return testAnyFlags(IS_FIELD_OR_METHOD);

    }

    public boolean isMethod() {

        return testAllFlags(IS_METHOD);

    }

    public boolean isConstructor() {

        return testAllFlags(IS_CONSTRUCTOR);

    }

    public boolean isField() {

        return testAllFlags(IS_FIELD);

    }

    public boolean isType() {

        return testAllFlags(IS_TYPE);

    }

    public boolean isPackage() {

        return !testAnyFlags(ALL_ACCESS);

    }

    /** Initialize a query.   It is not resolved. */

    private void init(Class<?> defClass, String name, Object type, int flags) {

        // defining class is allowed to be null (for a naked name/type pair)

        name.toString();  // null check

        type.equals(type);  // null check

        // fill in fields:

        this.clazz = defClass;

        this.name = name;

        this.type = type;

        setFlags(flags);

        assert(!isResolved());

    }

    private void expandFromVM() {

        if (!isResolved())  return;

        if (type instanceof Object[])

            type = null;  // don't saddle JVM w/ typeInfo

        MethodHandleNatives.expand(this);

    }

    // Capturing information from the Core Reflection API:

    private static int flagsMods(int flags, int mods) {

        assert((flags & RECOGNIZED_MODIFIERS) == 0);

        assert((mods & ~RECOGNIZED_MODIFIERS) == 0);

        return flags | mods;

    }

    public MemberName(Method m) {

        Object[] typeInfo = { m.getReturnType(), m.getParameterTypes() };

        init(m.getDeclaringClass(), m.getName(), typeInfo, flagsMods(IS_METHOD, m.getModifiers()));

        // fill in vmtarget, vmindex while we have m in hand:

        MethodHandleNatives.init(this, m);

        assert(isResolved());

    }

    public MemberName(Constructor ctor) {

        Object[] typeInfo = { void.class, ctor.getParameterTypes() };

        init(ctor.getDeclaringClass(), CONSTRUCTOR_NAME, typeInfo, flagsMods(IS_CONSTRUCTOR, ctor.getModifiers()));

        // fill in vmtarget, vmindex while we have ctor in hand:

        MethodHandleNatives.init(this, ctor);

        assert(isResolved());

    }

    public MemberName(Field fld) {

        init(fld.getDeclaringClass(), fld.getName(), fld.getType(), flagsMods(IS_FIELD, fld.getModifiers()));

        // fill in vmtarget, vmindex while we have fld in hand:

        MethodHandleNatives.init(this, fld);

        assert(isResolved());

    }

    public MemberName(Class<?> type) {

        init(type.getDeclaringClass(), type.getSimpleName(), type, flagsMods(IS_TYPE, type.getModifiers()));

        vmindex = 0;  // isResolved

        assert(isResolved());

    }

    // bare-bones constructor; the JVM will fill it in

    MemberName() { }

    // locally useful cloner

    @Override protected MemberName clone() {

        try {

            return (MemberName) super.clone();

        } catch (CloneNotSupportedException ex) {

            throw new InternalError();

        }

     }

    // %%% define equals/hashcode?

    // Construction from symbolic parts, for queries:

    public MemberName(Class<?> defClass, String name, Class<?> type, int modifiers) {

        init(defClass, name, type, IS_FIELD | (modifiers & RECOGNIZED_MODIFIERS));

    }

    public MemberName(Class<?> defClass, String name, Class<?> type) {

        this(defClass, name, type, 0);

    }

    public MemberName(Class<?> defClass, String name, MethodType type, int modifiers) {

        int flagBit = (name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);

        init(defClass, name, type, flagBit | (modifiers & RECOGNIZED_MODIFIERS));

    }

    public MemberName(Class<?> defClass, String name, MethodType type) {

        this(defClass, name, type, 0);

    }

    boolean isResolved() {

        return (vmindex != VM_INDEX_UNINITIALIZED);

    }

    public boolean hasReceiverTypeDispatch() {

        return (isMethod() && getVMIndex(Access.TOKEN) >= 0);

    }

    @Override

    public String toString() {

        if (isType())

            return type.toString();  // class java.lang.String

        // else it is a field, method, or constructor

        StringBuilder buf = new StringBuilder();

        if (!isResolved())

            buf.append("*.");

        if (getDeclaringClass() != null) {

            buf.append(getName(clazz));

            buf.append('.');

        }

        buf.append(getName());

        if (!isInvocable())  buf.append('/');

        buf.append(getName(getType()));

        /*

        buf.append('/');

        // key: Public, private, pRotected, sTatic, Final, sYnchronized,

        // transient/Varargs, native, (interface), abstract, sTrict, sYnthetic,

        // (annotation), Enum, (unused)

        final String FIELD_MOD_CHARS  = "PprTF?vt????Y?E?";

        final String METHOD_MOD_CHARS = "PprTFybVn?atY???";

        String modChars = (isInvocable() ? METHOD_MOD_CHARS : FIELD_MOD_CHARS);

        for (int i = 0; i < modChars.length(); i++) {

            if ((flags & (1 << i)) != 0) {

                char mc = modChars.charAt(i);

                if (mc != '.')

                    buf.append(mc);

            }

        }

         */

        return buf.toString();

    }

    private static String getName(Object obj) {

        if (obj instanceof Class<?>)

            return ((Class<?>)obj).getName();

        return String.valueOf(obj);

    }

    // Queries to the JVM:

    public int getVMIndex(Access token) {

        Access.check(token);

        if (!isResolved())

            throw newIllegalStateException("not resolved");

        return vmindex;

    }

//    public Object getVMTarget(Access token) {

//        Access.check(token);

//        if (!isResolved())

//            throw newIllegalStateException("not resolved");

//        return vmtarget;

//    }

    private RuntimeException newIllegalStateException(String message) {

        return new IllegalStateException(message+": "+this);

    }

    // handy shared exception makers (they simplify the common case code)

    public static RuntimeException newIllegalArgumentException(String message) {

        return new IllegalArgumentException(message);

    }

    public static NoAccessException newNoAccessException(MemberName name, Class<?> lookupClass) {

        return newNoAccessException("cannot access", name, lookupClass);

    }

    public static NoAccessException newNoAccessException(MemberName name, MethodHandles.Lookup lookup) {

        return newNoAccessException(name, lookup.lookupClass());

    }

    public static NoAccessException newNoAccessException(String message,

            MemberName name, Class<?> lookupClass) {

        message += ": " + name;

        if (lookupClass != null)  message += ", from " + lookupClass.getName();

        return new NoAccessException(message);

    }

    /** Actually making a query requires an access check. */

    public static Factory getFactory(Access token) {

        Access.check(token);

        return Factory.INSTANCE;

    }

    public static Factory getFactory() {

        return getFactory(Access.getToken());

    }

    public static class Factory {

        private Factory() { } // singleton pattern

        static Factory INSTANCE = new Factory();

        private static int ALLOWED_FLAGS = SEARCH_ALL_SUPERS | ALL_KINDS;

        /// Queries

        List<MemberName> getMembers(Class<?> defc,

                String matchName, Object matchType,

                int matchFlags, Class<?> lookupClass) {

            matchFlags &= ALLOWED_FLAGS;

            String matchSig = null;

            if (matchType != null) {

                matchSig = BytecodeDescriptor.unparse(matchType);

                if (matchSig.startsWith("("))

                    matchFlags &= ~(ALL_KINDS & ~IS_INVOCABLE);

                else

                    matchFlags &= ~(ALL_KINDS & ~IS_FIELD);

            }

            final int BUF_MAX = 0x2000;

            int len1 = matchName == null ? 10 : matchType == null ? 4 : 1;

            MemberName[] buf = newMemberBuffer(len1);

            int totalCount = 0;

            ArrayList<MemberName[]> bufs = null;

            int bufCount = 0;

            for (;;) {

                bufCount = MethodHandleNatives.getMembers(defc,

                        matchName, matchSig, matchFlags,

                        lookupClass,

                        totalCount, buf);

                if (bufCount <= buf.length) {

                    if (bufCount < 0)  bufCount = 0;

                    totalCount += bufCount;

                    break;

                }

                // JVM returned to us with an intentional overflow!

                totalCount += buf.length;

                int excess = bufCount - buf.length;

                if (bufs == null)  bufs = new ArrayList<MemberName[]>(1);

                bufs.add(buf);

                int len2 = buf.length;

                len2 = Math.max(len2, excess);

                len2 = Math.max(len2, totalCount / 4);

                buf = newMemberBuffer(Math.min(BUF_MAX, len2));

            }

            ArrayList<MemberName> result = new ArrayList<MemberName>(totalCount);

            if (bufs != null) {

                for (MemberName[] buf0 : bufs) {

                    Collections.addAll(result, buf0);

                }

            }

            result.addAll(Arrays.asList(buf).subList(0, bufCount));

            // Signature matching is not the same as type matching, since

            // one signature might correspond to several types.

            // So if matchType is a Class or MethodType, refilter the results.

            if (matchType != null && matchType != matchSig) {

                for (Iterator<MemberName> it = result.iterator(); it.hasNext();) {

                    MemberName m = it.next();

                    if (!matchType.equals(m.getType()))

                        it.remove();

                }

            }

            return result;

        }

        boolean resolveInPlace(MemberName m, boolean searchSupers, Class<?> lookupClass) {

            MethodHandleNatives.resolve(m, lookupClass);

            if (m.isResolved())  return true;

            int matchFlags = m.flags | (searchSupers ? SEARCH_ALL_SUPERS : 0);

            String matchSig = m.getSignature();

            MemberName[] buf = { m };

            int n = MethodHandleNatives.getMembers(m.getDeclaringClass(),

                    m.getName(), matchSig, matchFlags, lookupClass, 0, buf);

            if (n != 1)  return false;

            return m.isResolved();

        }

        public MemberName resolveOrNull(MemberName m, boolean searchSupers, Class<?> lookupClass) {

            MemberName result = m.clone();

            if (resolveInPlace(result, searchSupers, lookupClass))

                return result;

            return null;

        }

        public MemberName resolveOrFail(MemberName m, boolean searchSupers, Class<?> lookupClass) {

            MemberName result = resolveOrNull(m, searchSupers, lookupClass);

            if (result != null)

                return result;

            throw newNoAccessException(m, lookupClass);

        }

        public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,

                Class<?> lookupClass) {

            return getMethods(defc, searchSupers, null, null, lookupClass);

        }

        public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,