package com.wok.supportbot.controller;

import com.wok.supportbot.service.LogViewerService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.web.bind.annotation.*;

import java.io.File;
import java.util.List;
import java.util.Map;

/**
 * 系统日志查看接口
 * <p>
 * 提供日志文件列表、尾部内容查看、关键词搜索及文件下载功能。
 * 仅 admin 角色可访问，所有文件操作限制在日志目录内，防止路径遍历攻击。
 */
@Slf4j
@RestController
@RequestMapping("/log")
@PreAuthorize("hasRole('admin')")
public class LogController {

    @Autowired
    private LogViewerService logViewerService;

    /**
     * 列出所有日志文件（名称、大小、修改时间等）
     */
    @GetMapping("/files")
    public ResponseEntity<Map<String, Object>> listFiles() {
        try {
            List<Map<String, Object>> files = logViewerService.listFiles();
            return ResponseEntity.ok(Map.of(
                    "success", true,
                    "data", files
            ));
        } catch (Exception e) {
            log.error("获取日志文件列表失败", e);
            return ResponseEntity.status(500).body(Map.of(
                    "success", false,
                    "message", "获取日志文件列表失败：" + e.getMessage()
            ));
        }
    }

    /**
     * 查看日志文件尾部内容
     *
     * @param fileName 日志文件名
     * @param lines    读取最后 N 行（默认 200，上限 5000）
     * @param keyword  可选搜索关键词
     */
    @GetMapping("/view/{fileName}")
    public ResponseEntity<Map<String, Object>> viewLog(
            @PathVariable String fileName,
            @RequestParam(defaultValue = "200") int lines,
            @RequestParam(required = false) String keyword) {
        try {
            Map<String, Object> result = logViewerService.readLogTail(fileName, lines, keyword);
            return ResponseEntity.ok(Map.of(
                    "success", true,
                    "data", result
            ));
        } catch (IllegalArgumentException e) {
            return ResponseEntity.badRequest().body(Map.of(
                    "success", false,
                    "message", e.getMessage()
            ));
        } catch (Exception e) {
            log.error("查看日志失败: {}", fileName, e);
            return ResponseEntity.status(500).body(Map.of(
                    "success", false,
                    "message", "查看日志失败：" + e.getMessage()
            ));
        }
    }

    /**
     * 下载日志文件（原始文件流）
     *
     * @param fileName 日志文件名
     */
    @GetMapping("/download/{fileName}")
    public ResponseEntity<Resource> downloadLog(@PathVariable String fileName) {
        try {
            java.nio.file.Path filePath = logViewerService.resolveSafe(fileName);
            File file = filePath.toFile();
            FileSystemResource resource = new FileSystemResource(file);

            return ResponseEntity.ok()
                    .header(HttpHeaders.CONTENT_DISPOSITION,
                            "attachment; filename=\"" + file.getName() + "\"")
                    .contentType(MediaType.TEXT_PLAIN)
                    .contentLength(file.length())
                    .body(resource);
        } catch (IllegalArgumentException e) {
            return ResponseEntity.badRequest().build();
        } catch (Exception e) {
            log.error("下载日志失败: {}", fileName, e);
            return ResponseEntity.status(500).build();
        }
    }
}