/*
 * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
 * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
 */

package org.jetbrains.kotlin.config;

import org.jetbrains.annotations.Nullable;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class KotlinCompilerVersion {
  public static final String VERSION_FILE_PATH = "/META-INF/ksp.compiler.version";
  public static final String VERSION;

  // True if the latest stable language version supported by this compiler has not yet been released.
  // Binaries produced by this compiler with that language version (or any future language version) are going to be marked
  // as "pre-release" and will not be loaded by release versions of the compiler.
  // Change this value before and after every major release
  private static final boolean IS_PRE_RELEASE = true;

  public static final String TEST_IS_PRE_RELEASE_SYSTEM_PROPERTY = "kotlin.test.is.pre.release";

  public static boolean isPreRelease() {
    String overridden = System.getProperty(TEST_IS_PRE_RELEASE_SYSTEM_PROPERTY);
    if (overridden != null) {
      return Boolean.parseBoolean(overridden);
    }

    return IS_PRE_RELEASE;
  }

  /**
   * @return version of this compiler, or `null` if it isn't known (if VERSION is "@snapshot@")
   */
  @Nullable
  public static String getVersion() {
    return VERSION.equals("@snapshot@") ? null : VERSION;
  }

  @SuppressWarnings("ConstantConditions")
  private static String loadKotlinCompilerVersion() throws IOException {
    try (BufferedReader versionReader = new BufferedReader(new InputStreamReader(KotlinCompilerVersion.class.getResourceAsStream(VERSION_FILE_PATH)))) {
      return versionReader.readLine();
    }
  }

  static {
    try {
      VERSION = loadKotlinCompilerVersion();
    }
    catch (IOException e) {
      throw new IllegalStateException("Failed to read compiler version from " + VERSION_FILE_PATH);
    }
  }
}