/*
 * [The "BSD licence"]
 * Copyright (c) 2010 Ben Gruver (JesusFreke)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.jf.baksmali.Adaptors.Format;

import org.jf.baksmali.Adaptors.MethodDefinition;
import org.jf.baksmali.Adaptors.MethodDefinition.InvalidSwitchPayload;
import org.jf.baksmali.Adaptors.MethodItem;
import org.jf.baksmali.Renderers.LongRenderer;
import org.jf.baksmali.baksmaliOptions;
import org.jf.dexlib2.Opcode;
import org.jf.dexlib2.ReferenceType;
import org.jf.dexlib2.VerificationError;
import org.jf.dexlib2.dexbacked.DexBackedDexFile.InvalidItemIndex;
import org.jf.dexlib2.iface.instruction.*;
import org.jf.dexlib2.iface.instruction.formats.Instruction20bc;
import org.jf.dexlib2.iface.instruction.formats.Instruction31t;
import org.jf.dexlib2.iface.instruction.formats.UnknownInstruction;
import org.jf.dexlib2.iface.reference.Reference;
import org.jf.dexlib2.util.ReferenceUtil;
import org.jf.util.ExceptionWithContext;
import org.jf.util.IndentingWriter;
import org.jf.util.NumberUtils;

import javax.annotation.Nonnull;
import java.io.IOException;
import java.util.Map;

public class InstructionMethodItem<T extends Instruction> extends MethodItem {
    @Nonnull protected final MethodDefinition methodDef;
    @Nonnull protected final T instruction;

    public InstructionMethodItem(@Nonnull MethodDefinition methodDef, int codeAddress, @Nonnull T instruction) {
        super(codeAddress);
        this.methodDef = methodDef;
        this.instruction = instruction;
    }

    public double getSortOrder() {
        //instructions should appear after everything except an "end try" label and .catch directive
        return 100;
    }

    private boolean isAllowedOdex(@Nonnull Opcode opcode) {
        baksmaliOptions options = methodDef.classDef.options;
        if (options.allowOdex) {
            return true;
        }

        if (methodDef.classDef.options.apiLevel >= 14) {
            return false;
        }

        return opcode.isVolatileFieldAccessor() || opcode == Opcode.THROW_VERIFICATION_ERROR;
    }

    @Override
    public boolean writeTo(IndentingWriter writer) throws IOException {
        Opcode opcode = instruction.getOpcode();
        String verificationErrorName = null;
        String referenceString = null;

        boolean commentOutInstruction = false;

        if (instruction instanceof Instruction20bc) {
            int verificationError = ((Instruction20bc)instruction).getVerificationError();
            verificationErrorName = VerificationError.getVerificationErrorName(verificationError);
            if (verificationErrorName == null) {
                writer.write("#was invalid verification error type: ");
                writer.printSignedIntAsDec(verificationError);
                writer.write("\n");
                verificationErrorName = "generic-error";
            }
        }

        if (instruction instanceof ReferenceInstruction) {
            ReferenceInstruction referenceInstruction = (ReferenceInstruction)instruction;
            try {
                Reference reference = referenceInstruction.getReference();

                String classContext = null;
                if (methodDef.classDef.options.useImplicitReferences) {
                    classContext = methodDef.method.getDefiningClass();
                }

                referenceString = ReferenceUtil.getReferenceString(reference, classContext);
                assert referenceString != null;
            } catch (InvalidItemIndex ex) {
                writer.write("#");
                writer.write(ex.getMessage());
                writer.write("\n");
                commentOutInstruction = true;

                referenceString = String.format("%s@%d",
                    ReferenceType.toString(referenceInstruction.getReferenceType()),
                    ex.getInvalidIndex());
            } catch (ReferenceType.InvalidReferenceTypeException ex) {
                writer.write("#invalid reference type: ");
                writer.printSignedIntAsDec(ex.getReferenceType());
                commentOutInstruction = true;

                referenceString = "invalid_reference";
            }
        }

        if (instruction instanceof Instruction31t) {
            boolean validPayload = true;

            switch (instruction.getOpcode()) {
                case PACKED_SWITCH:
                    int baseAddress = methodDef.getPackedSwitchBaseAddress(
                            this.codeAddress + ((Instruction31t)instruction).getCodeOffset());
                    if (baseAddress == -1) {
                        validPayload = false;
                    }
                    break;
                case SPARSE_SWITCH:
                    baseAddress = methodDef.getSparseSwitchBaseAddress(
                            this.codeAddress + ((Instruction31t)instruction).getCodeOffset());
                    if (baseAddress == -1) {
                        validPayload = false;
                    }
                    break;
                case FILL_ARRAY_DATA:
                    try {
                        methodDef.findPayloadOffset(this.codeAddress + ((Instruction31t)instruction).getCodeOffset(),
                                Opcode.ARRAY_PAYLOAD);
                    } catch (InvalidSwitchPayload ex) {
                        validPayload = false;
                    }
                    break;
                default:
                    throw new ExceptionWithContext("Invalid 31t opcode: %s", instruction.getOpcode());
            }

            if (!validPayload) {
                writer.write("#invalid payload reference\n");
                commentOutInstruction = true;
            }
        }

        if (opcode.odexOnly()) {
            if (!isAllowedOdex(opcode)) {
                writer.write("#disallowed odex opcode\n");
                commentOutInstruction = true;
            }
        }

        if (commentOutInstruction) {
            writer.write("#");
        }

        switch (instruction.getOpcode().format) {
            case Format10t:
                writeOpcode(writer);
                writer.write(' ');
                writeTargetLabel(writer);
                break;
            case Format10x:
                if (instruction instanceof UnknownInstruction) {
                    writer.write("#unknown opcode: 0x");
                    writer.printUnsignedLongAsHex(((UnknownInstruction)instruction).getOriginalOpcode());
                    writer.write('\n');
                }
                writeOpcode(writer);
                break;
            case Format11n:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeLiteral(writer);
                break;
            case Format11x:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                break;
            case Format12x:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeSecondRegister(writer);
                break;
            case Format20bc:
                writeOpcode(writer);
                writer.write(' ');
                writer.write(verificationErrorName);
                writer.write(", ");
                writer.write(referenceString);
                break;
            case Format20t:
            case Format30t:
                writeOpcode(writer);
                writer.write(' ');
                writeTargetLabel(writer);
                break;
            case Format21c:
            case Format31c:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writer.write(referenceString);
                break;
            case Format21ih:
            case Format21lh:
            case Format21s:
            case Format31i:
            case Format51l:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeLiteral(writer);
                if (instruction.getOpcode().setsWideRegister()) {
                    writeCommentIfLikelyDouble(writer);
                } else {
                    boolean isResourceId = writeCommentIfResourceId(writer);
                    if (!isResourceId) writeCommentIfLikelyFloat(writer);
                }
                break;
            case Format21t:
            case Format31t:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeTargetLabel(writer);
                break;
            case Format22b:
            case Format22s:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeSecondRegister(writer);
                writer.write(", ");
                writeLiteral(writer);
                break;
            case Format22c:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeSecondRegister(writer);
                writer.write(", ");
                writer.write(referenceString);
                break;
            case Format22cs:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeSecondRegister(writer);
                writer.write(", ");
                writeFieldOffset(writer);
                break;
            case Format22t:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeSecondRegister(writer);
                writer.write(", ");
                writeTargetLabel(writer);
                break;
            case Format22x:
            case Format32x:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeSecondRegister(writer);
                break;
            case Format23x:
                writeOpcode(writer);
                writer.write(' ');
                writeFirstRegister(writer);
                writer.write(", ");
                writeSecondRegister(writer);
                writer.write(", ");
                writeThirdRegister(writer);
                break;
             case Format25x:
                writeOpcode(writer);
                writer.write(' ');
                writeInvoke25xRegisters(writer);  // vC, {vD, ...}
                break;
            case Format35c:
                writeOpcode(writer);
                writer.write(' ');
                writeInvokeRegisters(writer);
                writer.write(", ");
                writer.write(referenceString);
                break;
            case Format35mi:
                writeOpcode(writer);
                writer.write(' ');
                writeInvokeRegisters(writer);
                writer.write(", ");
                writeInlineIndex(writer);
                break;
            case Format35ms:
                writeOpcode(writer);
                writer.write(' ');
                writeInvokeRegisters(writer);
                writer.write(", ");
                writeVtableIndex(writer);
                break;
            case Format3rc:
                writeOpcode(writer);
                writer.write(' ');
                writeInvokeRangeRegisters(writer);
                writer.write(", ");
                writer.write(referenceString);
                break;
            case Format3rmi:
                writeOpcode(writer);
                writer.write(' ');
                writeInvokeRangeRegisters(writer);
                writer.write(", ");
                writeInlineIndex(writer);
                break;
            case Format3rms:
                writeOpcode(writer);
                writer.write(' ');
                writeInvokeRangeRegisters(writer);
                writer.write(", ");
                writeVtableIndex(writer);
                break;
            default:
                assert false;
                return false;
        }

        if (commentOutInstruction) {
            writer.write("\nnop");
        }

        return true;
    }

    protected void writeOpcode(IndentingWriter writer) throws IOException {
        writer.write(instruction.getOpcode().name);
    }

    protected void writeTargetLabel(IndentingWriter writer) throws IOException {
        //this method is overridden by OffsetInstructionMethodItem, and should only be called for the formats that
        //have a target
        throw new RuntimeException();
    }

    protected void writeRegister(IndentingWriter writer, int registerNumber) throws IOException {
        methodDef.registerFormatter.writeTo(writer, registerNumber);
    }

    protected void writeFirstRegister(IndentingWriter writer) throws IOException {
        writeRegister(writer, ((OneRegisterInstruction)instruction).getRegisterA());
    }

    protected void writeSecondRegister(IndentingWriter writer) throws IOException {
        writeRegister(writer, ((TwoRegisterInstruction)instruction).getRegisterB());
    }

    protected void writeThirdRegister(IndentingWriter writer) throws IOException {
        writeRegister(writer, ((ThreeRegisterInstruction) instruction).getRegisterC());
    }

    protected void writeInvokeRegisters(IndentingWriter writer) throws IOException {
        FiveRegisterInstruction instruction = (FiveRegisterInstruction)this.instruction;
        final int regCount = instruction.getRegisterCount();

        writer.write('{');
        switch (regCount) {
            case 1:
                writeRegister(writer, instruction.getRegisterC());
                break;
            case 2:
                writeRegister(writer, instruction.getRegisterC());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterD());
                break;
            case 3:
                writeRegister(writer, instruction.getRegisterC());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterD());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterE());
                break;
            case 4:
                writeRegister(writer, instruction.getRegisterC());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterD());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterE());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterF());
                break;
            case 5:
                writeRegister(writer, instruction.getRegisterC());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterD());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterE());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterF());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterG());
                break;
        }
        writer.write('}');
    }

    protected void writeInvoke25xRegisters(IndentingWriter writer) throws IOException {
        OneFixedFourParameterRegisterInstruction instruction =
                (OneFixedFourParameterRegisterInstruction)this.instruction;
        final int parameterRegCount = instruction.getParameterRegisterCount();

        writeRegister(writer, instruction.getRegisterFixedC());  // fixed register always present

        writer.write(", {");
        switch (parameterRegCount) {
            case 1:
                writeRegister(writer, instruction.getRegisterParameterD());
                break;
            case 2:
                writeRegister(writer, instruction.getRegisterParameterD());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterParameterE());
                break;
            case 3:
                writeRegister(writer, instruction.getRegisterParameterD());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterParameterE());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterParameterF());
                break;
            case 4:
                writeRegister(writer, instruction.getRegisterParameterD());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterParameterE());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterParameterF());
                writer.write(", ");
                writeRegister(writer, instruction.getRegisterParameterG());
                break;
        }
        writer.write('}');
    }

    protected void writeInvokeRangeRegisters(IndentingWriter writer) throws IOException {
        RegisterRangeInstruction instruction = (RegisterRangeInstruction)this.instruction;

        int regCount = instruction.getRegisterCount();
        if (regCount == 0) {
            writer.write("{}");
        } else {
            int startRegister = instruction.getStartRegister();
            methodDef.registerFormatter.writeRegisterRange(writer, startRegister, startRegister+regCount-1);
        }
    }

    protected void writeLiteral(IndentingWriter writer) throws IOException {
        LongRenderer.writeSignedIntOrLongTo(writer, ((WideLiteralInstruction)instruction).getWideLiteral());
    }

    protected void writeCommentIfLikelyFloat(IndentingWriter writer) throws IOException {
        writeCommentIfLikelyFloat(writer, ((NarrowLiteralInstruction)instruction).getNarrowLiteral());
    }

    protected void writeCommentIfLikelyFloat(IndentingWriter writer, int val) throws IOException {
        if (NumberUtils.isLikelyFloat(val)) {
            writer.write("    # ");
            float fval = Float.intBitsToFloat(val);
            if (fval == Float.POSITIVE_INFINITY)
                writer.write("Float.POSITIVE_INFINITY");
            else if (fval == Float.NEGATIVE_INFINITY)
                writer.write("Float.NEGATIVE_INFINITY");
            else if (fval == Float.NaN)
                writer.write("Float.NaN");
            else if (fval == Float.MAX_VALUE)
                writer.write("Float.MAX_VALUE");
            else if (fval == (float)Math.PI)
                writer.write("(float)Math.PI");
            else if (fval == (float)Math.E)
                writer.write("(float)Math.E");
            else {
                writer.write(Float.toString(fval));
                writer.write('f');
            }
        }
    }

    protected void writeCommentIfLikelyDouble(IndentingWriter writer) throws IOException {
        writeCommentIfLikelyDouble(writer, ((WideLiteralInstruction)instruction).getWideLiteral());
    }

    protected void writeCommentIfLikelyDouble(IndentingWriter writer, long val) throws IOException {
        if (NumberUtils.isLikelyDouble(val)) {
            writer.write("    # ");
            double dval = Double.longBitsToDouble(val);
            if (dval == Double.POSITIVE_INFINITY)
                writer.write("Double.POSITIVE_INFINITY");
            else if (dval == Double.NEGATIVE_INFINITY)
                writer.write("Double.NEGATIVE_INFINITY");
            else if (dval == Double.NaN)
                writer.write("Double.NaN");
            else if (dval == Double.MAX_VALUE)
                writer.write("Double.MAX_VALUE");
            else if (dval == Math.PI)
                writer.write("Math.PI");
            else if (dval == Math.E)
                writer.write("Math.E");
            else
                writer.write(Double.toString(dval));
        }
    }

    protected boolean writeCommentIfResourceId(IndentingWriter writer) throws IOException {
        return writeCommentIfResourceId(writer, ((NarrowLiteralInstruction)instruction).getNarrowLiteral());
    }

    protected boolean writeCommentIfResourceId(IndentingWriter writer, int val) throws IOException {
        Map<Integer,String> resourceIds = methodDef.classDef.options.resourceIds;
        String resource = resourceIds.get(Integer.valueOf(val));
        if (resource != null) {
            writer.write("    # ");
            writer.write(resource);
            return true;
        }
        return false;
    }

    protected void writeFieldOffset(IndentingWriter writer) throws IOException {
        writer.write("field@0x");
        writer.printUnsignedLongAsHex(((FieldOffsetInstruction)instruction).getFieldOffset());
    }

    protected void writeInlineIndex(IndentingWriter writer) throws IOException {
        writer.write("inline@");
        writer.printSignedIntAsDec(((InlineIndexInstruction)instruction).getInlineIndex());
    }

    protected void writeVtableIndex(IndentingWriter writer) throws IOException {
        writer.write("vtable@");
        writer.printSignedIntAsDec(((VtableIndexInstruction)instruction).getVtableIndex());
    }
}
