package it.tdlight.tdnative;

import it.tdlight.jni.TdApi;
import java.util.function.Consumer;

/**
 * Class used for managing internal TDLib logging. Use TdApi.*Log* methods instead.
 */
public class NativeLog {

	private static final Consumer<String> defaultFatalErrorCallbackPtr = System.err::println;
	private static Consumer<String> fatalErrorCallback = defaultFatalErrorCallbackPtr;

	/**
	 * Sets file path for writing TDLib internal log. By default TDLib writes logs to the System.err. Use this method to
	 * write the log to a file instead.
	 *
	 * @param filePath Path to a file for writing TDLib internal log. Use an empty path to switch back to logging to the
	 *                 System.err.
	 * @return whether opening the log file succeeded.
	 * @deprecated As of TDLib 1.4.0 in favor of {@link TdApi.SetLogStream}, to be removed in the future.
	 */
	@Deprecated
	public static native boolean setFilePath(String filePath);

	/**
	 * Changes the maximum size of TDLib log file.
	 *
	 * @param maxFileSize The maximum size of the file to where the internal TDLib log is written before the file will be
	 *                    auto-rotated. Must be positive. Defaults to 10 MB.
	 * @deprecated As of TDLib 1.4.0 in favor of {@link TdApi.SetLogStream}, to be removed in the future.
	 */
	@Deprecated
	public static native void setMaxFileSize(long maxFileSize);

	/**
	 * Changes TDLib log verbosity.
	 *
	 * @param verbosityLevel New value of log verbosity level. Must be non-negative. Value 0 corresponds to fatal errors,
	 *                       value 1 corresponds to java.util.logging.Level.SEVERE, value 2 corresponds to
	 *                       java.util.logging.Level.WARNING, value 3 corresponds to java.util.logging.Level.INFO, value 4
	 *                       corresponds to java.util.logging.Level.FINE, value 5 corresponds to
	 *                       java.util.logging.Level.FINER, value greater than 5 can be used to enable even more logging.
	 *                       Default value of the log verbosity level is 5.
	 * @deprecated As of TDLib 1.4.0 in favor of {@link TdApi.SetLogVerbosityLevel}, to be removed in the future.
	 */
	@Deprecated
	public static native void setVerbosityLevel(int verbosityLevel);

	/**
	 * This function is called from the JNI when a fatal error happens to provide a better error message. The function
	 * does not return.
	 *
	 * @param errorMessage Error message.
	 */
	private static synchronized void onFatalError(String errorMessage) {
		new Thread(() -> NativeLog.fatalErrorCallback.accept(errorMessage)).start();
	}

	/**
	 * Sets the callback that will be called when a fatal error happens. None of the TDLib methods can be called from the
	 * callback. The TDLib will crash as soon as callback returns. By default the callback set to print in stderr.
	 *
	 * @param fatalErrorCallback Callback that will be called when a fatal error happens. Pass null to restore default
	 *                           callback.
	 */
	public static synchronized void setFatalErrorCallback(Consumer<String> fatalErrorCallback) {
		if (fatalErrorCallback == null) {
			NativeLog.fatalErrorCallback = defaultFatalErrorCallbackPtr;
		} else {
			NativeLog.fatalErrorCallback = fatalErrorCallback;
		}
	}
}