/*
 * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
 *
 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
 * derivative works of, display, perform, and distribute the Software and make,
 * use, sell, offer for sale, import, export, have made, and have sold the
 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
 *
 * This license is subject to the following condition:
 *
 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must be included in all copies or substantial
 * portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package com.oracle.graal.python.lib;

import static com.oracle.graal.python.builtins.PythonBuiltinClassType.TypeError;
import static com.oracle.graal.python.nodes.SpecialMethodNames.__STR__;

import com.oracle.graal.python.builtins.PythonBuiltinClassType;
import com.oracle.graal.python.builtins.objects.PNone;
import com.oracle.graal.python.builtins.objects.str.PString;
import com.oracle.graal.python.builtins.objects.type.SpecialMethodSlot;
import com.oracle.graal.python.nodes.ErrorMessages;
import com.oracle.graal.python.nodes.PNodeWithContext;
import com.oracle.graal.python.nodes.PRaiseNode;
import com.oracle.graal.python.nodes.call.special.CallUnaryMethodNode;
import com.oracle.graal.python.nodes.call.special.LookupSpecialMethodSlotNode;
import com.oracle.graal.python.nodes.classes.IsSubtypeNode;
import com.oracle.graal.python.nodes.object.GetClassNode;
import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.GenerateUncached;
import com.oracle.truffle.api.dsl.ImportStatic;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.frame.Frame;
import com.oracle.truffle.api.frame.VirtualFrame;

/**
 * Equivalent of CPython's {@code PyObject_Str}. Converts object to a string using its
 * {@code __str__} special method.
 * <p>
 * The output can be either a {@link String} or a {@link PString}.
 *
 * @see PyObjectStrAsJavaStringNode
 */
@GenerateUncached
@ImportStatic(SpecialMethodSlot.class)
public abstract class PyObjectStrAsObjectNode extends PNodeWithContext {
    public abstract Object execute(Frame frame, Object object);

    @Specialization
    static Object str(String obj) {
        return obj;
    }

    @Specialization
    static String str(boolean object) {
        return object ? "True" : "False";
    }

    @Specialization
    @TruffleBoundary
    static String str(int object) {
        return Integer.toString(object);
    }

    @Specialization
    @TruffleBoundary
    static String str(long object) {
        return Long.toString(object);
    }

    @Specialization(guards = "!isJavaString(obj)")
    static Object str(VirtualFrame frame, Object obj,
                    @Cached GetClassNode getClassNode,
                    @Cached(parameters = "Str") LookupSpecialMethodSlotNode lookupStr,
                    @Cached CallUnaryMethodNode callStr,
                    @Cached GetClassNode getResultClassNode,
                    @Cached IsSubtypeNode isSubtypeNode,
                    @Cached PRaiseNode raiseNode) {
        Object type = getClassNode.execute(obj);
        Object strDescr = lookupStr.execute(frame, type, obj);
        // All our objects should have __str__
        assert strDescr != PNone.NO_VALUE;
        Object result = callStr.executeObject(frame, strDescr, obj);
        if (result instanceof String || isSubtypeNode.execute(getResultClassNode.execute(result), PythonBuiltinClassType.PString)) {
            return result;
        } else {
            throw raiseNode.raise(TypeError, ErrorMessages.RETURNED_NON_STRING, __STR__, result);
        }
    }

    public static PyObjectStrAsObjectNode create() {
        return PyObjectStrAsObjectNodeGen.create();
    }

    public static PyObjectStrAsObjectNode getUncached() {
        return PyObjectStrAsObjectNodeGen.getUncached();
    }
}
