package dev.dinauer.inspect.log;

import java.io.IOException;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.*;

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.jboss.logging.Logger;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;

import io.fabric8.kubernetes.api.model.Pod;
import io.fabric8.kubernetes.client.dsl.LogWatch;
import io.fabric8.kubernetes.client.dsl.PodResource;
import io.smallrye.mutiny.Uni;
import io.smallrye.mutiny.infrastructure.Infrastructure;

import dev.dinauer.inspect.log.model.KubernetesLog;
import dev.dinauer.service.PodService;
import dev.dinauer.utils.ClientProvider;

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

    @Inject
    Logger LOG;

    @Inject
    ClientProvider clientProvider;

    @Inject
    PodService podService;

    @OnOpen
    public void onOpen(Session session, @PathParam("namespace") String namespace, @PathParam("name") String name)
    {
        Uni.createFrom().voidItem().invoke(() -> {
            List<Pod> pods = podService.findByDeployment(namespace, name);
            List<KubernetesLog> existingLogs = new ArrayList<>();
            for (Pod pod : pods)
            {
                PodResource resource = clientProvider.getClient().pods().inNamespace(pod.getMetadata().getNamespace()).withName(pod.getMetadata().getName());
                existingLogs.addAll(podService.getLogs(resource));
            }
            send(session, existingLogs.stream().sorted(KubernetesLog::orderByTimestamp).toList());

            sessions.put(session, new LinkedList<>());
            for (Pod pod : pods)
            {
                PodResource resource = clientProvider.getClient().pods().inNamespace(pod.getMetadata().getNamespace()).withName(pod.getMetadata().getName());
                sessions.get(session).add(podService.watchLogs(resource, (log) -> {
                    send(session, log);
                }));
            }
        }).runSubscriptionOn(Infrastructure.getDefaultWorkerPool()).subscribe().with(result -> {}, error -> {});
    }

    @OnClose
    public void onClose(Session session) throws IOException
    {
        List<LogWatch> watches = sessions.remove(session);
        if (watches != null)
        {
            for (LogWatch watch : watches)
            {
                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, String podName)
    {
        List<KubernetesLog> result = new ArrayList<>();
        for (String log : logs)
        {
            int indexFirstSpace = log.indexOf(" ");
            if (indexFirstSpace != -1)
            {
                String timestampRaw = log.substring(0, indexFirstSpace);
                try
                {
                    String message = log.substring(indexFirstSpace + 1);
                    result.add(new KubernetesLog(LocalDateTime.parse(timestampRaw, DateTimeFormatter.ISO_DATE_TIME), message, podName));
                }
                catch (Exception e)
                {
                    LOG.errorf("Error parsing log: %s", e.getMessage());
                }
            }
        }
        return result;
    }
}