package ru.kirillius.XCP.Logging;

import ru.kirillius.XCP.Commons.Context;
import ru.kirillius.java.utils.events.EventHandler;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogRecord;

public class LogHandlerImpl extends Handler {
    private final EventHandler<LogMessage> eventHandler;


    public LogHandlerImpl(LoggingSystem loggingSystem, Context context) {
        eventHandler = loggingSystem.getEventHandler();

        this.context = context;
    }

    private final Context context;

    private final static SimpleDateFormat dateFormat = new SimpleDateFormat("dd.MM.yyyy HH:mm:ss", Locale.US);

    private String format(LogRecord logRecord) {
        var date = new Date(logRecord.getMillis());
        var builder = new StringBuilder();
        builder.append("[");
        builder.append(dateFormat.format(date));
        builder.append("][");
        builder.append(convertLevel(logRecord.getLevel()));
        builder.append("] ");
        builder.append(logRecord.getMessage().trim());
        var thrown = logRecord.getThrown();
        if (thrown != null) {
            builder.append("\n\tThrown ").append(thrown.getClass().getSimpleName()).append(": ").append(thrown.getMessage());
            if (context.isDebuggingEnabled()) {
                builder.append("\nStack trace:\n");

                try (var writer = new StringWriter()) {
                    try (var printWriter = new PrintWriter(writer)) {
                        thrown.printStackTrace(printWriter);
                        builder.append(writer);
                    }
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            } else {
                var cause = thrown.getCause();
                while (cause != null) {
                    builder.append("\n\t\tCaused by ").append(cause.getClass().getSimpleName()).append(": ").append(cause.getMessage());
                    cause = cause.getCause();
                }
                builder.append("\n\t(Stack trace is hidden due to --debug flag)");
            }
        }
        return builder.toString();
    }

    @Override
    public synchronized void publish(LogRecord logRecord) {
        //TODO сделать асинхронным чтобы не лочить треды
        print(logRecord);
        var message = LogMessage.builder().message(logRecord.getMessage()).level(convertLevel(logRecord.getLevel())).date(logRecord.getInstant()).build();
        try {
            eventHandler.invoke(message);
        } catch (Exception e) {
            print(new LogRecord(Level.SEVERE, "Unhandled error in logger event listener: " + e.getClass().getSimpleName() + ": " + e.getMessage()));
        }
    }

    private void print(LogRecord logRecord) {
        System.out.println(format(logRecord));
    }

    public LogLevel convertLevel(Level level) {
        if (level == Level.SEVERE) {
            return LogLevel.ERROR;
        }
        if (level == Level.WARNING) {
            return LogLevel.WARNING;
        }
        return LogLevel.INFO;
    }

    @Override
    public void flush() {

    }

    @Override
    public void close() throws SecurityException {

    }
}