package com.xuqm.tenant.service;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.function.Consumer;

@Service
public class SystemUpdateService {

    private static final Logger log = LoggerFactory.getLogger(SystemUpdateService.class);

    private static final List<String> OTHER_SERVICES = List.of(
            "file-service", "tenant-web", "im-service", "push-service", "update-service", "license-service"
    );

    @Value("${PRIVATE_DEPLOY_ROOT:/opt/xuqm-private}")
    private String deployRoot;

    public void runUpdate(Consumer<String> emit) {
        String composeFile = deployRoot + "/docker-compose.yml";

        emit.accept(">>> 拉取最新镜像...");
        for (String svc : OTHER_SERVICES) {
            if (isRunning(svc)) {
                emit.accept("  pulling " + svc + " ...");
                exec(emit, "docker-compose", "-f", composeFile, "-p", "xuqm", "pull", "--quiet", svc);
            }
        }
        emit.accept("  pulling tenant-service ...");
        exec(emit, "docker-compose", "-f", composeFile, "-p", "xuqm", "pull", "--quiet", "tenant-service");
        emit.accept(">>> 镜像拉取完成");

        emit.accept(">>> 重启各服务...");
        for (String svc : OTHER_SERVICES) {
            if (isRunning(svc)) {
                emit.accept("  restarting " + svc + " ...");
                exec(emit, "docker-compose", "-f", composeFile, "-p", "xuqm",
                        "up", "-d", "--no-deps", "--force-recreate", svc);
                emit.accept("  " + svc + " ✓");
            }
        }

        emit.accept(">>> 即将重启 tenant-service，连接将短暂中断...");
        emit.accept("RESTART_SELF");

        // 延迟 3 秒后重启自身，确保 SSE 事件已发送到客户端
        CompletableFuture.runAsync(() -> {
            try {
                Thread.sleep(3000);
                exec(msg -> log.info("[self-restart] {}", msg),
                        "docker-compose", "-f", composeFile, "-p", "xuqm",
                        "up", "-d", "--no-deps", "--force-recreate", "tenant-service");
            } catch (Exception e) {
                log.error("self-restart failed", e);
            }
        });
    }

    private boolean isRunning(String service) {
        String containerName = "xuqm-" + service;
        try {
            Process p = new ProcessBuilder("docker", "inspect", "--type=container", containerName)
                    .redirectErrorStream(true)
                    .start();
            p.getInputStream().transferTo(java.io.OutputStream.nullOutputStream());
            return p.waitFor() == 0;
        } catch (Exception e) {
            return false;
        }
    }

    private void exec(Consumer<String> emit, String... cmd) {
        try {
            Process p = new ProcessBuilder(cmd)
                    .redirectErrorStream(true)
                    .start();
            try (BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()))) {
                String line;
                while ((line = reader.readLine()) != null) {
                    if (!line.isBlank()) emit.accept("    " + line);
                }
            }
            int code = p.waitFor();
            if (code != 0) emit.accept("    [warn] exit code " + code);
        } catch (Exception e) {
            emit.accept("    [error] " + e.getMessage());
            log.error("exec failed: {}", String.join(" ", cmd), e);
        }
    }
}