package com.xuqm.bugcollect.service;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.xuqm.bugcollect.dto.WebhookRequest;
import com.xuqm.bugcollect.dto.WebhookResponse;
import com.xuqm.bugcollect.entity.LogIssueEntity;
import com.xuqm.bugcollect.entity.LogWebhookEntity;
import com.xuqm.bugcollect.repository.LogWebhookRepository;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CompletableFuture;

@Service
public class WebhookService {

    private static final Logger log = LoggerFactory.getLogger(WebhookService.class);
    private static final String COOLDOWN_KEY_PREFIX = "log:webhook:cooldown:";

    private final LogWebhookRepository webhookRepository;
    private final StringRedisTemplate redisTemplate;
    private final ObjectMapper objectMapper;
    private final HttpClient httpClient;

    public WebhookService(LogWebhookRepository webhookRepository,
                          StringRedisTemplate redisTemplate,
                          ObjectMapper objectMapper) {
        this.webhookRepository = webhookRepository;
        this.redisTemplate = redisTemplate;
        this.objectMapper = objectMapper;
        this.httpClient = HttpClient.newBuilder()
                .connectTimeout(Duration.ofMillis(3000))
                .build();
    }

    public void checkAndNotify(LogIssueEntity issue) {
        List<LogWebhookEntity> webhooks = webhookRepository.findByAppKeyAndEnabledTrue(issue.getAppKey());

        for (LogWebhookEntity webhook : webhooks) {
            if (!matchesEventType(webhook.getEvents(), issue.getType())) {
                continue;
            }

            String cooldownKey = COOLDOWN_KEY_PREFIX + webhook.getId() + ":" + issue.getFingerprint();
            Boolean acquired = redisTemplate.opsForValue()
                    .setIfAbsent(cooldownKey, "1", Duration.ofSeconds(webhook.getCooldownSec()));

            if (Boolean.TRUE.equals(acquired)) {
                sendWebhook(webhook, issue);
            } else {
                log.debug("Webhook cooldown active: webhookId={}, fingerprint={}", webhook.getId(), issue.getFingerprint());
            }
        }
    }

    private void sendWebhook(LogWebhookEntity webhook, LogIssueEntity issue) {
        try {
            Map<String, Object> body = Map.of(
                    "event", "issue.new",
                    "appKey", issue.getAppKey(),
                    "issue", Map.of(
                            "fingerprint", issue.getFingerprint(),
                            "type", issue.getType(),
                            "title", issue.getTitle(),
                            "count", issue.getCount(),
                            "lastSeenAt", issue.getLastSeenAt().toString(),
                            "platform", issue.getPlatform() != null ? issue.getPlatform() : "",
                            "appVersion", issue.getAppVersion() != null ? issue.getAppVersion() : ""
                    )
            );

            String jsonBody = objectMapper.writeValueAsString(body);

            HttpRequest request = HttpRequest.newBuilder()
                    .uri(URI.create(webhook.getUrl()))
                    .header("Content-Type", "application/json")
                    .POST(HttpRequest.BodyPublishers.ofString(jsonBody))
                    .timeout(Duration.ofMillis(5000))
                    .build();

            httpClient.sendAsync(request, HttpResponse.BodyHandlers.ofString())
                    .thenAccept(response -> {
                        if (response.statusCode() >= 200 && response.statusCode() < 300) {
                            log.info("Webhook sent successfully: webhookId={}, status={}", webhook.getId(), response.statusCode());
                        } else {
                            log.warn("Webhook returned non-2xx: webhookId={}, status={}", webhook.getId(), response.statusCode());
                        }
                    })
                    .exceptionally(ex -> {
                        log.error("Webhook send failed: webhookId={}, url={}", webhook.getId(), webhook.getUrl(), ex);
                        return null;
                    });
        } catch (Exception e) {
            log.error("Failed to serialize webhook body: webhookId={}", webhook.getId(), e);
        }
    }

    private boolean matchesEventType(String eventsJson, String eventType) {
        try {
            @SuppressWarnings("unchecked")
            List<String> events = objectMapper.readValue(eventsJson, List.class);
            return events.contains(eventType);
        } catch (Exception e) {
            return false;
        }
    }

    @Transactional(readOnly = true)
    public List<WebhookResponse> listWebhooks(String appKey) {
        return webhookRepository.findByAppKey(appKey).stream()
                .map(this::toResponse)
                .toList();
    }

    @Transactional
    public WebhookResponse createWebhook(WebhookRequest request) {
        LogWebhookEntity entity = new LogWebhookEntity();
        entity.setAppKey(request.appKey());
        entity.setUrl(request.url());
        entity.setCooldownSec(request.cooldownSec() > 0 ? request.cooldownSec() : 3600);
        entity.setEnabled(true);
        entity.setCreatedAt(LocalDateTime.now());
        try {
            entity.setEvents(objectMapper.writeValueAsString(request.events()));
        } catch (Exception e) {
            entity.setEvents("[]");
        }
        entity = webhookRepository.save(entity);
        return toResponse(entity);
    }

    @Transactional
    public WebhookResponse updateWebhook(Long id, WebhookRequest request) {
        LogWebhookEntity entity = webhookRepository.findById(id)
                .orElseThrow(() -> new IllegalArgumentException("Webhook not found: " + id));
        entity.setAppKey(request.appKey());
        entity.setUrl(request.url());
        entity.setCooldownSec(request.cooldownSec() > 0 ? request.cooldownSec() : 3600);
        try {
            entity.setEvents(objectMapper.writeValueAsString(request.events()));
        } catch (Exception e) {
            // keep existing
        }
        entity = webhookRepository.save(entity);
        return toResponse(entity);
    }

    @Transactional
    public void deleteWebhook(Long id) {
        webhookRepository.deleteById(id);
    }

    private WebhookResponse toResponse(LogWebhookEntity entity) {
        List<String> events;
        try {
            events = objectMapper.readValue(entity.getEvents(), List.class);
        } catch (Exception e) {
            events = List.of();
        }
        return new WebhookResponse(
                entity.getId(), entity.getAppKey(), entity.getUrl(),
                events, entity.getCooldownSec(), entity.isEnabled(),
                entity.getCreatedAt()
        );
    }
}