// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
package org.jetbrains.java.decompiler.util;

import org.jetbrains.java.decompiler.code.CodeConstants;
import org.jetbrains.java.decompiler.main.ClassesProcessor;
import org.jetbrains.java.decompiler.main.DecompilerContext;
import org.jetbrains.java.decompiler.main.extern.IFernflowerPreferences;
import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;

import java.util.Arrays;
import java.util.HashSet;

public final class TextUtil {
  private static final HashSet<String> KEYWORDS = new HashSet<>(Arrays.asList(
    "abstract", "default", "if", "private", "this", "boolean", "do", "implements", "protected", "throw", "break", "double", "import",
    "public", "throws", "byte", "else", "instanceof", "return", "transient", "case", "extends", "int", "short", "try", "catch", "final",
    "interface", "static", "void", "char", "finally", "long", "strictfp", "volatile", "class", "float", "native", "super", "while",
    "const", "for", "new", "switch", "continue", "goto", "package", "synchronized", "true", "false", "null", "assert"));

  public static void writeQualifiedSuper(TextBuffer buf, String qualifier) {
    ClassesProcessor.ClassNode classNode = (ClassesProcessor.ClassNode)DecompilerContext.getProperty(DecompilerContext.CURRENT_CLASS_NODE);
    if (!qualifier.equals(classNode.classStruct.qualifiedName)) {
      buf.append(DecompilerContext.getImportCollector().getShortName(ExprProcessor.buildJavaClassName(qualifier))).append('.');
    }
    buf.append("super");
  }

  public static String getIndentString(int length) {
    if (length == 0) return "";
    StringBuilder buf = new StringBuilder();
    String indent = (String)DecompilerContext.getProperty(IFernflowerPreferences.INDENT_STRING);
    append(buf, indent, length);
    return buf.toString();
  }

  public static void append(StringBuilder buf, String string, int times) {
    while (times-- > 0) buf.append(string);
  }

  public static boolean isPrintableUnicode(char c) {
    int t = Character.getType(c);
    return t != Character.UNASSIGNED && t != Character.LINE_SEPARATOR && t != Character.PARAGRAPH_SEPARATOR &&
           t != Character.CONTROL && t != Character.FORMAT && t != Character.PRIVATE_USE && t != Character.SURROGATE;
  }

  public static String charToUnicodeLiteral(int value) {
    String sTemp = Integer.toHexString(value);
    sTemp = ("0000" + sTemp).substring(sTemp.length());
    return "\\u" + sTemp;
  }

  public static boolean isValidIdentifier(String id, int version) {
    return isJavaIdentifier(id) && !isKeyword(id, version);
  }

  private static boolean isJavaIdentifier(String id) {
    if (id.isEmpty() || !Character.isJavaIdentifierStart(id.charAt(0))) {
      return false;
    }

    for (int i = 1; i < id.length(); i++) {
      if (!Character.isJavaIdentifierPart(id.charAt(i))) {
        return false;
      }
    }

    return true;
  }

  private static boolean isKeyword(String id, int version) {
    return KEYWORDS.contains(id) || version >= CodeConstants.BYTECODE_JAVA_5 && "enum".equals(id);
  }

  public static String getInstructionName(int opcode) {
    return opcodeNames[opcode];
  }

  private static final String[] opcodeNames = {
    "nop",
    "aconst_null",
    "iconst_m1",
    "iconst_0",
    "iconst_1",
    "iconst_2",
    "iconst_3",
    "iconst_4",
    "iconst_5",
    "lconst_0",
    "lconst_1",
    "fconst_0",
    "fconst_1",
    "fconst_2",
    "dconst_0",
    "dconst_1",
    "bipush",
    "sipush",
    "ldc",
    "ldc_w",
    "ldc2_w",
    "iload",
    "lload",
    "fload",
    "dload",
    "aload",
    "iload_0",
    "iload_1",
    "iload_2",
    "iload_3",
    "lload_0",
    "lload_1",
    "lload_2",
    "lload_3",
    "fload_0",
    "fload_1",
    "fload_2",
    "fload_3",
    "dload_0",
    "dload_1",
    "dload_2",
    "dload_3",
    "aload_0",
    "aload_1",
    "aload_2",
    "aload_3",
    "iaload",
    "laload",
    "faload",
    "daload",
    "aaload",
    "baload",
    "caload",
    "saload",
    "istore",
    "lstore",
    "fstore",
    "dstore",
    "astore",
    "istore_0",
    "istore_1",
    "istore_2",
    "istore_3",
    "lstore_0",
    "lstore_1",
    "lstore_2",
    "lstore_3",
    "fstore_0",
    "fstore_1",
    "fstore_2",
    "fstore_3",
    "dstore_0",
    "dstore_1",
    "dstore_2",
    "dstore_3",
    "astore_0",
    "astore_1",
    "astore_2",
    "astore_3",
    "iastore",
    "lastore",
    "fastore",
    "dastore",
    "aastore",
    "bastore",
    "castore",
    "sastore",
    "pop",
    "pop2",
    "dup",
    "dup_x1",
    "dup_x2",
    "dup2",
    "dup2_x1",
    "dup2_x2",
    "swap",
    "iadd",
    "ladd",
    "fadd",
    "dadd",
    "isub",
    "lsub",
    "fsub",
    "dsub",
    "imul",
    "lmul",
    "fmul",
    "dmul",
    "idiv",
    "ldiv",
    "fdiv",
    "ddiv",
    "irem",
    "lrem",
    "frem",
    "drem",
    "ineg",
    "lneg",
    "fneg",
    "dneg",
    "ishl",
    "lshl",
    "ishr",
    "lshr",
    "iushr",
    "lushr",
    "iand",
    "land",
    "ior",
    "lor",
    "ixor",
    "lxor",
    "iinc",
    "i2l",
    "i2f",
    "i2d",
    "l2i",
    "l2f",
    "l2d",
    "f2i",
    "f2l",
    "f2d",
    "d2i",
    "d2l",
    "d2f",
    "i2b",
    "i2c",
    "i2s",
    "lcmp",
    "fcmpl",
    "fcmpg",
    "dcmpl",
    "dcmpg",
    "ifeq",
    "ifne",
    "iflt",
    "ifge",
    "ifgt",
    "ifle",
    "if_icmpeq",
    "if_icmpne",
    "if_icmplt",
    "if_icmpge",
    "if_icmpgt",
    "if_icmple",
    "if_acmpeq",
    "if_acmpne",
    "goto",
    "jsr",
    "ret",
    "tableswitch",
    "lookupswitch",
    "ireturn",
    "lreturn",
    "freturn",
    "dreturn",
    "areturn",
    "return",
    "getstatic",
    "putstatic",
    "getfield",
    "putfield",
    "invokevirtual",
    "invokespecial",
    "invokestatic",
    "invokeinterface",
    "invokedynamic",  // since Java 7
    "new",
    "newarray",
    "anewarray",
    "arraylength",
    "athrow",
    "checkcast",
    "instanceof",
    "monitorenter",
    "monitorexit",
    "wide",
    "multianewarray",
    "ifnull",
    "ifnonnull",
    "goto_w",
    "jsr_w"
  };
}