package de.aikiit.bilanzanalyser.upload;
   
   import de.aikiit.bilanzanalyser.reader.BilanzRowParserResult;
   import de.aikiit.bilanzanalyser.reader.BilanzRowParserStatistic;
   import lombok.extern.log4j.Log4j2;
   import org.springframework.beans.factory.annotation.Value;
   import org.springframework.web.bind.annotation.GetMapping;
   import org.springframework.web.bind.annotation.PostMapping;
   import org.springframework.web.bind.annotation.RequestParam;
  import org.springframework.web.bind.annotation.RestController;
  import org.springframework.web.multipart.MultipartFile;
  import org.springframework.web.servlet.ModelAndView;
  import org.springframework.web.util.HtmlUtils;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  
  @Log4j2
  @RestController
  public final class UploadController {
      private static final String UPLOAD_DIR = "uploads-bilanz-analyser";
  
      private final UploadAnalysisService uploadAnalysisService;
      private final SourceService sourceService;
  
      @Value("${java.io.tmpdir}")
      private String tempDir;
  
      public UploadController(UploadAnalysisService uploadAnalysisService, SourceService sourceService) {
          this.uploadAnalysisService = uploadAnalysisService;
          this.sourceService = sourceService;
      }
  
      @GetMapping("/upload")
      public ModelAndView upload() {
          ModelAndView mav = new ModelAndView("upload");
          mav.addObject("worksheets", sourceService.getSources());
          mav.addObject("selectedWorksheet", "Ausgaben");
          return mav;
      }
  
      @PostMapping("/upload")
      public ModelAndView handleFileUpload(@RequestParam("file") MultipartFile file, @RequestParam("selectedWorksheet") String selectedWorksheet) {
  
          // Create ModelAndView for the "upload" view
          ModelAndView mav = new ModelAndView("upload");
          mav.addObject("worksheets", sourceService.getSources());
  
          // prevent mingling with selected worksheet and properly escape user-provided value
          if (!sourceService.getSources().contains(selectedWorksheet)) {
              mav.addObject("message", "Invalid worksheet selected");
              return mav;
          }
          String escapedSelectedWorksheet = HtmlUtils.htmlEscape(selectedWorksheet);
          mav.addObject("selectedWorksheet", escapedSelectedWorksheet);
  
          if (file.isEmpty()) {
              mav.addObject("message", "Please select a file to upload");
              return mav;
          }
  
          if (!"application/vnd.oasis.opendocument.spreadsheet".equals(file.getContentType())) {
              mav.addObject("message", "Only ODS spreadsheet files allowed");
              return mav;
          }
  
          try {
              // Create directory if not exists under current temp base dir
              Path uploadDir = Paths.get(tempDir + File.separatorChar + UPLOAD_DIR);
              Files.createDirectories(uploadDir);
  
              // Save file
              Path destination = Paths.get(uploadDir.toString(), System.currentTimeMillis() + ".ods");
              file.transferTo(destination);
  
              // Process rows and cleanup afterwards
              BilanzRowParserResult result = uploadAnalysisService.processFile(selectedWorksheet, destination);
              Files.delete(destination);
              // flush to DB asynchronously
              uploadAnalysisService.flushDataIntoDatabase(result);
  
              mav.addObject("sucmessage", "File uploaded successfully. Processed " + result.rowCount() + " rows in table " + escapedSelectedWorksheet);
              mav.addObject("statistic", BilanzRowParserStatistic.from(result));
          } catch (IOException e) {
              log.error(e.getMessage());
              mav.addObject("message", "Upload failed: " + e.getMessage());
          }
          return mav;
      }
  
  }