package xiaozhi.modules.parent.mqtt;

import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;

import org.apache.commons.lang3.StringUtils;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import org.springframework.stereotype.Component;

import com.fasterxml.jackson.databind.ObjectMapper;

import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import xiaozhi.common.exception.RenException;
import xiaozhi.modules.sys.service.SysParamsService;

@Slf4j
@Component
@RequiredArgsConstructor
public class ParentMqttPublisher {
    private static final int PAYLOAD_SOFT_MAX = 7800;

    private final SysParamsService sysParamsService;
    private final ObjectMapper objectMapper;

    public void publishCtl(String macAddress, String action, Object payload) {
        String host = StringUtils.trimToEmpty(sysParamsService.getValue("server.parent_mqtt_host", true));
        String portText = StringUtils.trimToEmpty(sysParamsService.getValue("server.parent_mqtt_port", true));
        String username = StringUtils.trimToEmpty(sysParamsService.getValue("server.parent_mqtt_username", true));
        String password = StringUtils.trimToEmpty(sysParamsService.getValue("server.parent_mqtt_password", true));
        if (StringUtils.isBlank(host) || "null".equalsIgnoreCase(host)) {
            throw new RenException("未配置 server.parent_mqtt_host，无法下发到设备");
        }
        int port = 2100;
        try {
            if (StringUtils.isNotBlank(portText) && !"null".equalsIgnoreCase(portText)) {
                port = Integer.parseInt(portText);
            }
        } catch (NumberFormatException ex) {
            throw new RenException("server.parent_mqtt_port 无效");
        }

        String mac = normalizeMac(macAddress);
        String topic = "snlp/v1/" + mac + "/cmd/ctl";
        Map<String, Object> header = new LinkedHashMap<>();
        header.put("version", "1.0");
        header.put("device_id", mac);
        header.put("req_id", UUID.randomUUID().toString());
        header.put("timestamp", System.currentTimeMillis() / 1000L);
        header.put("ttl", 60);

        Map<String, Object> body = new LinkedHashMap<>();
        body.put("header", header);
        body.put("action", action);
        body.put("payload", payload == null ? Map.of() : payload);

        String json;
        try {
            json = objectMapper.writeValueAsString(body);
        } catch (Exception ex) {
            throw new RenException("家长任务 JSON 序列化失败");
        }
        if (json.length() > PAYLOAD_SOFT_MAX) {
            throw new RenException("下发内容超过设备 MQTT 8KB 上限，请减少计划条数（不要下发展开后的课文清单）");
        }

        String broker = "tcp://" + host + ":" + port;
        String clientId = "parent-api-" + UUID.randomUUID();
        try (MqttClient client = new MqttClient(broker, clientId, new MemoryPersistence())) {
            MqttConnectOptions options = new MqttConnectOptions();
            options.setAutomaticReconnect(false);
            options.setCleanSession(true);
            options.setConnectionTimeout(8);
            if (StringUtils.isNotBlank(username) && !"null".equalsIgnoreCase(username)) {
                options.setUserName(username);
            }
            if (StringUtils.isNotBlank(password) && !"null".equalsIgnoreCase(password)) {
                options.setPassword(password.toCharArray());
            }
            client.connect(options);
            MqttMessage message = new MqttMessage(json.getBytes(java.nio.charset.StandardCharsets.UTF_8));
            message.setQos(0);
            message.setRetained(false);
            client.publish(topic, message);
            client.disconnect();
            log.info("parent mqtt {} -> {} bytes={}", action, topic, json.length());
        } catch (MqttException ex) {
            log.error("parent mqtt publish failed: {}", ex.getMessage());
            throw new RenException("下发设备失败: " + ex.getMessage());
        }
    }

    public void publishLessonManifest(String macAddress, String courseId, String baseUrl, List<String> files) {
        if (files == null || files.isEmpty()) {
            return;
        }
        String course = StringUtils.defaultIfBlank(courseId, "lesson-sync").trim();
        if (!course.matches("[A-Za-z0-9_-]{1,31}")) {
            course = "lesson-sync";
        }
        String base = StringUtils.trimToEmpty(baseUrl).replaceAll("/+$", "");
        if (StringUtils.isBlank(base) || "null".equalsIgnoreCase(base) || base.contains("你")) {
            throw new RenException("未配置课文音频下载地址 server.lesson_audio_public_url");
        }
        Map<String, Object> payload = new LinkedHashMap<>();
        payload.put("course_id", course);
        payload.put("base_url", base);
        payload.put("files", files);
        publishCtl(macAddress, "UPDATE_MANIFEST", payload);
    }

    public static String normalizeMac(String macAddress) {
        return StringUtils.trimToEmpty(macAddress).toLowerCase().replace('-', ':');
    }
}