package com.config;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

import java.util.concurrent.Executor;
import java.util.concurrent.ThreadPoolExecutor;
import org.springframework.context.annotation.Primary;
@Configuration
@EnableAsync
public class ThreadPoolConfig {

    @Value("${app.processor.thread-pool.core-pool-size:10}")
    private int corePoolSize;

    @Value("${app.processor.thread-pool.max-pool-size:20}")
    private int maxPoolSize;

    @Value("${app.processor.thread-pool.queue-capacity:2000}")
    private int queueCapacity;

    @Value("${app.processor.thread-pool.keep-alive-seconds:60}")
    private int keepAliveSeconds;

    @Value("${dm.standardized-write.writer-concurrency:2}")
    private int dmWriterConcurrency;

    @Value("${dm.standardized-write.writer-queue-capacity:100}")
    private int dmWriterQueueCapacity;

    @Bean("logNormalProcessorExecutor")
    @Primary
    public Executor logNormalProcessorExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(corePoolSize);
        executor.setMaxPoolSize(maxPoolSize);
        executor.setQueueCapacity(queueCapacity);
        executor.setKeepAliveSeconds(keepAliveSeconds);
        executor.setThreadNamePrefix("log-processor-");

        // 队列耗尽时明确失败并保留 Kafka offset，不能在 listener 线程中无限兜底执行而掩盖过载。
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.AbortPolicy());

        // 等待所有任务结束后再关闭线程池
        executor.setWaitForTasksToCompleteOnShutdown(true);
        executor.setAwaitTerminationSeconds(60);
        executor.initialize();
        return executor;
    }

    /**
     * 达梦批写使用独立的有界线程池，不能复用规则计算线程池。
     *
     * <p>分离后，少量慢 SQL 不会占满所有标准化计算线程；AbortPolicy 会把过载明确返回到
     * Kafka ACK 边界，由消费者保留 offset 形成背压，而不是在内存中无限排队。</p>
     */
    @Bean("dmStandardizedWriterExecutor")
    public Executor dmStandardizedWriterExecutor() {
        int concurrency = Math.max(1, dmWriterConcurrency);
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(concurrency);
        executor.setMaxPoolSize(concurrency);
        executor.setQueueCapacity(Math.max(1, dmWriterQueueCapacity));
        executor.setThreadNamePrefix("dm-batch-writer-");
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.AbortPolicy());
        executor.setWaitForTasksToCompleteOnShutdown(true);
        executor.setAwaitTerminationSeconds(60);
        executor.initialize();
        return executor;
    }
}