package dev.dinauer.inspect.log;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import dev.dinauer.utils.ClientProvider;
import io.fabric8.kubernetes.client.dsl.LogWatch;
import jakarta.enterprise.context.ApplicationScoped;
import jakarta.inject.Inject;
import jakarta.websocket.OnClose;
import jakarta.websocket.OnOpen;
import jakarta.websocket.Session;
import jakarta.websocket.server.PathParam;
import jakarta.websocket.server.ServerEndpoint;
import org.eclipse.microprofile.context.ManagedExecutor;
import org.jboss.logging.Logger;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.*;
import java.util.concurrent.Future;

@ServerEndpoint("/logs/{namespace}/{name}")
@ApplicationScoped
public class LogWebsocket
{
    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper().registerModule(new JavaTimeModule()).disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    private final Map<Session, LogWatch> sessions = new HashMap<>();

    @Inject
    Logger LOG;

    @Inject
    ClientProvider clientProvider;

    @Inject
    ManagedExecutor executor;

    @OnOpen
    public void onOpen(Session session, @PathParam("namespace") String namespace, @PathParam("name") String name)
    {
        executor.submit(() -> {
            List<String> existingLogs = Arrays.stream(clientProvider.getClient().pods().inNamespace(namespace).withName(name).usingTimestamps().tailingLines(200).getLog().split("\n")).toList();
            send(session, toLog(existingLogs));

            LogWatch watch = clientProvider.getClient().pods().inNamespace(namespace).withName(name).usingTimestamps().tailingLines(0).watchLog();
            sessions.put(session, watch);

            try(BufferedReader reader = new BufferedReader(new InputStreamReader(watch.getOutput())))
            {
                String line;
                while ((line = reader.readLine()) != null && !Thread.currentThread().isInterrupted())
                {
                    send(session, toLog(List.of(line)));
                }
                LOG.info("Ended");
            }
            catch (Exception e)
            {
                LOG.errorf("Error reading output of log watch: %s", e.getMessage());
            }
        });
    }

    @OnClose
    public void onClose(Session session) throws IOException
    {
        LogWatch watch = sessions.remove(session);
        if (watch != null)
        {
            watch.close();
        }
        session.close();
    }

    private void send(Session session, List<KubernetesLog> logs)
    {
        try
        {
            session.getAsyncRemote().sendText(OBJECT_MAPPER.writeValueAsString(logs));
        }
        catch (Exception e)
        {
            LOG.errorf("Error sending logs to frontend via websocket: %s", e.getMessage());
        }
    }

    private List<KubernetesLog> toLog(List<String> logs)
    {
        List<KubernetesLog> result = new ArrayList<>();
        for (String log : logs)
        {
            int indexFirstSpace = log.indexOf(" ");
            if (indexFirstSpace != -1)
            {
                String timestampRaw = log.substring(0, indexFirstSpace);
                String message = log.substring(indexFirstSpace).trim();
                try
                {
                    result.add(new KubernetesLog(LocalDateTime.parse(timestampRaw, DateTimeFormatter.ISO_DATE_TIME), message));
                }
                catch (Exception e)
                {
                    LOG.errorf("Error parsing log: %s", e.getMessage());
                }
            }
        }
        return result;
    }
}