package com.xuqm.tenant.controller;

import com.xuqm.tenant.config.PrivateDeploymentProperties;
import com.xuqm.tenant.service.SystemUpdateService;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;

import java.util.List;
import java.util.Map;

import com.xuqm.common.model.ApiResponse;

@RestController
@RequestMapping("/api/system")
public class SystemUpdateController {

    private final PrivateDeploymentProperties deployProps;
    private final SystemUpdateService updateService;

    public SystemUpdateController(PrivateDeploymentProperties deployProps,
                                  SystemUpdateService updateService) {
        this.deployProps = deployProps;
        this.updateService = updateService;
    }

    /** 返回当前正在运行的服务列表。仅 PRIVATE 模式可用。 */
    @GetMapping("/services")
    public ResponseEntity<?> services() {
        if (!deployProps.isPrivate()) {
            return ResponseEntity.status(403).body(Map.of("message", "此接口仅在私有化部署可用"));
        }
        List<String> svcList = updateService.getRunningServices();
        return ResponseEntity.ok(Map.of("data", svcList));
    }

    /** 返回指定服务最近 N 行日志。仅 PRIVATE 模式可用。 */
    @GetMapping(value = "/logs/{service}", produces = MediaType.TEXT_PLAIN_VALUE)
    public ResponseEntity<String> logs(
            @PathVariable String service,
            @RequestParam(defaultValue = "200") int lines) {
        if (!deployProps.isPrivate()) {
            return ResponseEntity.status(403).body("此接口仅在私有化部署可用");
        }
        try {
            return ResponseEntity.ok(updateService.getServiceLogs(service, lines));
        } catch (IllegalArgumentException e) {
            return ResponseEntity.status(400).body(e.getMessage());
        } catch (Exception e) {
            return ResponseEntity.status(500).body(e.getMessage());
        }
    }

    /** 返回当前部署版本号。仅 PRIVATE 模式可用。 */
    @GetMapping("/version")
    public ResponseEntity<?> version() {
        if (!deployProps.isPrivate()) {
            return ResponseEntity.status(403).body(Map.of("message", "此接口仅在私有化部署可用"));
        }
        String currentVersion = updateService.readCurrentVersion();
        return ResponseEntity.ok(Map.of("data", Map.of("currentVersion", currentVersion)));
    }

    /**
     * 检查是否有可用更新。
     * 对比本地版本与 versions.json 中的最新版本，返回各服务的版本差异。
     * 仅 PRIVATE 模式可用。
     */
    @GetMapping("/check-update")
    public ResponseEntity<?> checkUpdate() {
        if (!deployProps.isPrivate()) {
            return ResponseEntity.status(403).body(Map.of("message", "此接口仅在私有化部署可用"));
        }
        return ResponseEntity.ok(updateService.checkForUpdates());
    }

    /**
     * 拉取最新镜像并重建所有容器。耗时较长（需 docker pull）。
     * 仅 PRIVATE 模式可用。
     */
    @PostMapping(value = "/update", produces = MediaType.TEXT_PLAIN_VALUE)
    public ResponseEntity<StreamingResponseBody> update() {
        if (!deployProps.isPrivate()) {
            return ResponseEntity.status(403)
                    .contentType(MediaType.TEXT_PLAIN)
                    .body(out -> out.write("此接口仅在私有化部署可用\n".getBytes()));
        }
        return stream(emit -> updateService.runUpdate(emit));
    }

    /**
     * 选择性更新：只更新指定的服务。
     * 仅 PRIVATE 模式可用。
     */
    @PostMapping(value = "/update-selective", produces = MediaType.TEXT_PLAIN_VALUE)
    public ResponseEntity<StreamingResponseBody> updateSelective(
            @RequestParam(required = false) List<String> services) {
        if (!deployProps.isPrivate()) {
            return ResponseEntity.status(403)
                    .contentType(MediaType.TEXT_PLAIN)
                    .body(out -> out.write("此接口仅在私有化部署可用\n".getBytes()));
        }
        return stream(emit -> updateService.runSelectiveUpdate(emit, services));
    }

    /**
     * 保留数据，重置容器和数据库表结构。
     * 流程：备份核心数据 → 删表 → 重建容器 → 恢复数据 → 执行迁移。
     * 仅 PRIVATE 模式可用。
     */
    @PostMapping(value = "/reset", produces = MediaType.TEXT_PLAIN_VALUE)
    public ResponseEntity<StreamingResponseBody> reset() {
        if (!deployProps.isPrivate()) {
            return ResponseEntity.status(403)
                    .contentType(MediaType.TEXT_PLAIN)
                    .body(out -> out.write("此接口仅在私有化部署可用\n".getBytes()));
        }
        return stream(emit -> updateService.runReset(emit));
    }

    private ResponseEntity<StreamingResponseBody> stream(java.util.function.Consumer<java.util.function.Consumer<String>> action) {
        StreamingResponseBody body = outputStream -> action.accept(line -> {
            try {
                outputStream.write((line + "\n").getBytes());
                outputStream.flush();
            } catch (Exception ignored) {}
        });
        return ResponseEntity.ok()
                .contentType(MediaType.TEXT_PLAIN)
                .header("X-Accel-Buffering", "no")
                .header("Cache-Control", "no-cache, no-store")
                .body(body);
    }
}