/*
 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
 * 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
 * published by the Free Software Foundation.
 *
 * 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.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.oracle.graal.hotspot.hsail;

import java.lang.reflect.*;
import java.util.*;

import com.oracle.graal.api.code.*;
import com.oracle.graal.api.meta.*;
import com.oracle.graal.api.replacements.*;
import com.oracle.graal.hotspot.replacements.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.spi.*;
import com.oracle.graal.phases.util.*;
import com.oracle.graal.replacements.*;
import com.oracle.graal.replacements.hsail.*;

/**
 * The substitutions and snippets supported by HSAIL.
 */
public class HSAILHotSpotReplacementsImpl extends ReplacementsImpl {

    private final Replacements host;
    private HashSet<ResolvedJavaMethod> ignoredResolvedMethods = new HashSet<>();
    private HashMap<ResolvedJavaMethod, ResolvedJavaMethod> arrayCopyRedirectMethods = new HashMap<>();

    public HSAILHotSpotReplacementsImpl(Providers providers, SnippetReflectionProvider snippetReflection, Assumptions assumptions, TargetDescription target, Replacements host) {
        super(providers, snippetReflection, assumptions, target);
        this.host = host;
    }

    public void addIgnoredResolvedMethod(Class<?> cls, String methName, Class<?>... params) {
        try {
            Method m = cls.getMethod(methName, params);
            ResolvedJavaMethod rjm = providers.getMetaAccess().lookupJavaMethod(m);
            ignoredResolvedMethods.add(rjm);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void completeInitialization() {
        // Register the substitutions for java.lang.Math routines.
        registerSubstitutions(Math.class, HSAILMathSubstitutions.class);

        // Register the ignored substitutions
        addIgnoredResolvedMethod(String.class, "equals", Object.class);

        /*
         * Register the special arraycopy snippet handling This basically ignores the sense of the
         * CallArrayCopy flag and always directs to the snippets from UnsafeArrayCopyNode
         */
        redirectArraycopySnippetMethod(Kind.Byte);
        redirectArraycopySnippetMethod(Kind.Boolean);
        redirectArraycopySnippetMethod(Kind.Char);
        redirectArraycopySnippetMethod(Kind.Short);
        redirectArraycopySnippetMethod(Kind.Int);
        redirectArraycopySnippetMethod(Kind.Long);
        redirectArraycopySnippetMethod(Kind.Float);
        redirectArraycopySnippetMethod(Kind.Double);
        redirectArraycopySnippetMethod(Kind.Object);
    }

    private void redirectArraycopySnippetMethod(Kind kind) {
        ResolvedJavaMethod foreignCallMethod = providers.getMetaAccess().lookupJavaMethod(ArrayCopySnippets.getSnippetForKind(kind, false, true));
        ResolvedJavaMethod nonForeignCallMethod = providers.getMetaAccess().lookupJavaMethod(ArrayCopySnippets.getSnippetForKind(kind, false, false));
        if (!foreignCallMethod.equals(nonForeignCallMethod)) {
            arrayCopyRedirectMethods.put(foreignCallMethod, nonForeignCallMethod);
        }
    }

    @Override
    protected ResolvedJavaMethod registerMethodSubstitution(ClassReplacements cr, Member originalMethod, Method substituteMethod) {
        // TODO: decide if we want to override this in any way
        return super.registerMethodSubstitution(cr, originalMethod, substituteMethod);
    }

    @Override
    public Class<? extends FixedWithNextNode> getMacroSubstitution(ResolvedJavaMethod method) {
        Class<? extends FixedWithNextNode> klass = super.getMacroSubstitution(method);
        if (klass == null) {
            /*
             * Eventually we want to only defer certain macro substitutions to the host, but for now
             * we will do everything.
             */
            return host.getMacroSubstitution(method);
        }
        return klass;
    }

    @Override
    public StructuredGraph getSnippet(ResolvedJavaMethod method, ResolvedJavaMethod recursiveEntry) {
        /*
         * Must work in cooperation with HSAILHotSpotLoweringProvider. Before asking for the host
         * snippet, see if it is one of the arraycopy methods which we want to redirect to the
         * non-foreign-call version, regardless of the sense of CallArrayCopy option
         */
        ResolvedJavaMethod snippetMethod = method;
        ResolvedJavaMethod snippetRecursiveEntry = recursiveEntry;
        ResolvedJavaMethod redirect = arrayCopyRedirectMethods.get(method);
        if (redirect != null) {
            snippetMethod = redirect;
            if (recursiveEntry != null && recursiveEntry.equals(method)) {
                snippetRecursiveEntry = redirect;
            }
        }
        return host.getSnippet(snippetMethod, snippetRecursiveEntry);
    }

    @Override
    public StructuredGraph getMethodSubstitution(ResolvedJavaMethod original) {
        StructuredGraph m = super.getMethodSubstitution(original);
        if (m == null) {
            /*
             * We check for a few special cases we do NOT want to defer here but basically we defer
             * everything else to the host.
             */
            if (ignoredResolvedMethods.contains(original)) {
                return null;
            } else {
                return host.getMethodSubstitution(original);
            }
        }
        return m;
    }
}