/*
    * Copyright (C) 2026 B3Partners B.V.
    *
    * SPDX-License-Identifier: MIT
    */
   package org.tailormap.api.controller;
   
   import static org.tailormap.api.persistence.helper.TMFeatureTypeHelper.getConfiguredAttributes;
   
  import io.micrometer.core.annotation.Counted;
  import io.micrometer.core.annotation.Timed;
  import jakarta.validation.Valid;
  import java.io.IOException;
  import java.lang.invoke.MethodHandles;
  import java.net.MalformedURLException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Set;
  import java.util.regex.Pattern;
  import org.apache.commons.lang3.StringUtils;
  import org.geotools.api.data.Query;
  import org.geotools.api.data.SimpleFeatureSource;
  import org.geotools.api.filter.Filter;
  import org.geotools.api.filter.sort.SortOrder;
  import org.geotools.filter.text.cql2.CQLException;
  import org.geotools.filter.text.ecql.ECQL;
  import org.jspecify.annotations.Nullable;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.beans.factory.annotation.Value;
  import org.springframework.core.io.Resource;
  import org.springframework.core.io.UrlResource;
  import org.springframework.http.HttpHeaders;
  import org.springframework.http.HttpStatus;
  import org.springframework.http.MediaType;
  import org.springframework.http.ResponseEntity;
  import org.springframework.transaction.annotation.Transactional;
  import org.springframework.web.bind.annotation.GetMapping;
  import org.springframework.web.bind.annotation.ModelAttribute;
  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.server.ResponseStatusException;
  import org.tailormap.api.annotation.AppRestController;
  import org.tailormap.api.geotools.data.excel.ExcelDataStore;
  import org.tailormap.api.geotools.featuresources.FeatureSourceFactoryHelper;
  import org.tailormap.api.persistence.Application;
  import org.tailormap.api.persistence.GeoService;
  import org.tailormap.api.persistence.TMFeatureType;
  import org.tailormap.api.persistence.json.AppLayerSettings;
  import org.tailormap.api.persistence.json.AppTreeLayerNode;
  import org.tailormap.api.persistence.json.GeoServiceLayer;
  import org.tailormap.api.repository.FeatureSourceRepository;
  import org.tailormap.api.service.CreateLayerExtractService;
  
  @AppRestController
  @RequestMapping(path = "${tailormap-api.base-path}/{viewerKind}/{viewerName}/layer/{appLayerId}/extract")
  public class LayerExtractController {
    private static final Logger logger =
        LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
    private static final Pattern SAFE_DOWNLOAD_ID = Pattern.compile("^[A-Za-z0-9._-]+$");
    private final FeatureSourceRepository featureSourceRepository;
    private final CreateLayerExtractService createLayerExtractService;
    private final FeatureSourceFactoryHelper featureSourceFactoryHelper;
  
    @Value("#{'${tailormap-api.extract.allowed-outputformats}'.split(',')}")
    private List<ExtractOutputFormat> allowedExtractOutputFormats;
  
    public LayerExtractController(
        FeatureSourceRepository featureSourceRepository,
        CreateLayerExtractService createLayerExtractService,
        FeatureSourceFactoryHelper featureSourceFactoryHelper) {
      this.featureSourceRepository = featureSourceRepository;
      this.createLayerExtractService = createLayerExtractService;
      this.featureSourceFactoryHelper = featureSourceFactoryHelper;
    }
  
    /**
     * Download the result of an extract request. The extract generation should be initiated first by a POST to
     * {@code /{viewerKind}/{viewerName}/layer/{appLayerId}/extract/{clientId}}.
     */
    @GetMapping(path = "/download/{downloadId}")
    @Counted(value = "tailormap_api_extract_download", description = "Count of layer extract downloads")
    public ResponseEntity<?> download(
        @ModelAttribute GeoService service,
        @ModelAttribute GeoServiceLayer layer,
        @ModelAttribute Application application,
        @ModelAttribute AppTreeLayerNode appTreeLayerNode,
        @PathVariable String downloadId)
        throws MalformedURLException {
  
      if (downloadId == null || !SAFE_DOWNLOAD_ID.matcher(downloadId).matches()) {
        throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid downloadId");
      }
     Path exportRoot = Path.of(createLayerExtractService.getExportFilesLocation())
         .toAbsolutePath()
         .normalize();
     Path filePath = exportRoot.resolve(downloadId).normalize();
     if (!filePath.startsWith(exportRoot)) {
       throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid downloadId");
     }
 
     Resource resource = new UrlResource(filePath.toUri());
     if (!resource.exists() || !resource.isReadable() || !resource.isFile()) {
       throw new ResponseStatusException(HttpStatus.NOT_FOUND, "Download file not found");
     }
 
     String contentType = MediaType.APPLICATION_OCTET_STREAM_VALUE;
     try {
       String detectedContentType = Files.probeContentType(filePath);
       if (detectedContentType != null) {
         contentType = detectedContentType;
       }
     } catch (IOException e) {
       logger.debug("Could not determine content type for {}", filePath, e);
     }
 
     return ResponseEntity.ok()
         .contentType(MediaType.parseMediaType(contentType))
         .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + filePath.getFileName() + "\"")
         .body(resource);
   }
 
   @GetMapping("/formats")
   public ResponseEntity<?> formats(
       @Valid @ModelAttribute GeoServiceLayer layer,
       @ModelAttribute GeoService service,
       @ModelAttribute Application application,
       @ModelAttribute AppTreeLayerNode appTreeLayerNode) {
     return ResponseEntity.ok(allowedExtractOutputFormats.stream()
         .map(ExtractOutputFormat::getValue)
         .toList());
   }
 
   @Transactional
   @PostMapping("/{clientId}")
   @Timed(value = "tailormap_api_extract", description = "Time taken to process a layer extract request")
   public ResponseEntity<?> extract(
       @Valid @ModelAttribute GeoServiceLayer layer,
       @ModelAttribute GeoService service,
       @ModelAttribute Application application,
       @ModelAttribute AppTreeLayerNode appTreeLayerNode,
       @PathVariable String clientId,
       @RequestParam ExtractOutputFormat outputFormat,
       @RequestParam(required = false) Set<String> attributes,
       @RequestParam(required = false) String filter,
       @RequestParam(required = false) String sortBy,
       @RequestParam(required = false, defaultValue = "asc") String sortOrder) {
 
     try {
       createLayerExtractService.validateClientId(clientId);
     } catch (IllegalArgumentException e) {
       logger.warn("Invalid clientId for extract request: {}", clientId);
       throw new ResponseStatusException(HttpStatus.BAD_REQUEST, e.getMessage());
     }
 
     if (!allowedExtractOutputFormats.contains(outputFormat)) {
       logger.debug("Invalid output format requested: {}", outputFormat);
       throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid output format");
     }
 
     TMFeatureType sourceFT = service.findFeatureTypeForLayer(layer, featureSourceRepository);
     if (sourceFT == null) {
       logger.debug("Layer export requested for layer without feature type");
       throw new ResponseStatusException(HttpStatus.NOT_FOUND);
     }
     if (attributes == null) {
       attributes = new HashSet<>();
     }
 
     AppLayerSettings appLayerSettings = application.getAppLayerSettings(appTreeLayerNode);
     // Get attributes in configured or original order
     Set<String> nonHiddenAttributes =
         getConfiguredAttributes(sourceFT, appLayerSettings).keySet();
 
     if (!attributes.isEmpty()) {
       // Only export non-hidden property names
       if (!nonHiddenAttributes.containsAll(attributes)) {
         throw new ResponseStatusException(
             HttpStatus.BAD_REQUEST,
             "One or more requested attributes are not available on the feature type");
       }
     } else if (!sourceFT.getSettings().getHideAttributes().isEmpty()) {
       // Only specify specific propNames if there are hidden attributes. Having no propNames
       // request parameter to request all propNames is less error-prone than specifying the ones
       // we have saved in the feature type
       attributes = new HashSet<>(nonHiddenAttributes);
     }
 
     // Empty attributes means we won't specify propNames in the GetFeature request. However, if we do select only
     // some property names, we need the geometry attribute which is not in the 'attributes' request param so spatial
     // export formats don't have the geometry missing.
     if (!attributes.isEmpty() && sourceFT.getDefaultGeometryAttribute() != null) {
       attributes.add(sourceFT.getDefaultGeometryAttribute());
     }
 
     // check if filter has valid syntax (it could still be invalid wrt feature type)
     Filter parsedCQL = null;
     try {
       if (!StringUtils.isBlank(filter)) {
         parsedCQL = ECQL.toFilter(filter);
       }
     } catch (CQLException e) {
       throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid filter");
     }
 
     if (ExtractOutputFormat.XLSX.equals(outputFormat)) {
       validateExcelLimits(sourceFT, attributes, parsedCQL);
     }
 
     SortOrder sortingOrder = SortOrder.ASCENDING;
     if (null != sortOrder && (sortOrder.equalsIgnoreCase("desc") || sortOrder.equalsIgnoreCase("asc"))) {
       sortingOrder = SortOrder.valueOf(sortOrder.toUpperCase(Locale.ROOT));
     }
 
     final String outputFileName =
         this.createLayerExtractService.createExtractFilename(clientId, sourceFT, outputFormat);
     this.createLayerExtractService.emitProgress(clientId, outputFileName, 0, false, "Extract task received");
 
     //noinspection JvmTaintAnalysis Not a Path Traversal Sink because the clientId is validated
     this.createLayerExtractService.createLayerExtract(
         clientId, sourceFT, attributes, parsedCQL, sortBy, sortingOrder, outputFormat, outputFileName);
 
     //noinspection JvmTaintAnalysis Not an XSS sink because the response is a json message
     return ResponseEntity.accepted()
         .body(Map.of("message", "Extract request accepted", "downloadId", outputFileName));
   }
 
   /**
    * Check that neither the number of columns nor the number of rows requested for the extract exceed the limits of
    * Excel format. This is required to block extract requests that would fail later on in the ExcelFeatureWriter when
    * the limits are exceeded. NOTE: cell size limits are handled in the ExcelFeatureWriter.
    *
    * @param featureType requested FT
    * @param attributes requested attributes
    * @param filter requested filter
    */
   private void validateExcelLimits(TMFeatureType featureType, Set<String> attributes, @Nullable Filter filter) {
     if (attributes.size() > ExcelDataStore.getMaxColumns()) {
       throw new ResponseStatusException(
           HttpStatus.BAD_REQUEST,
           "Excel format does not support more than " + ExcelDataStore.getMaxColumns() + " columns");
     }
     SimpleFeatureSource inputFeatureSource = null;
     try {
       // count all the features; this is expensive but required to block extract when the Excel limits for
       // row/columns are exceeded
       inputFeatureSource = featureSourceFactoryHelper.openGeoToolsFeatureSource(featureType);
       Query q = new Query(inputFeatureSource.getName().toString());
       if (!attributes.isEmpty()) {
         q.setPropertyNames(attributes.toArray(new String[0]));
       }
 
       if (filter != null) {
         q.setFilter(filter);
       }
       final int featCount = inputFeatureSource.getCount(q);
       if (featCount >= ExcelDataStore.getMaxRows()) {
         throw new ResponseStatusException(
             HttpStatus.BAD_REQUEST,
             "Excel format does not support more than " + ExcelDataStore.getMaxRows() + " rows");
       }
     } catch (IOException e) {
       throw new ResponseStatusException(
           HttpStatus.INTERNAL_SERVER_ERROR,
           "Failed to count all features for Excel extract: " + e.getMessage());
     } catch (IllegalArgumentException e) {
       throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid filter");
     } finally {
       if (inputFeatureSource != null) {
         inputFeatureSource.getDataStore().dispose();
       }
     }
   }
 
   public enum ExtractOutputFormat {
     GEOPACKAGE("geopackage", ".gpkg"),
     CSV("csv", ".csv"),
     GEOJSON("geojson", ".geojson"),
     XLSX("xlsx", ".xlsx"),
     SHAPE("shape", ".zip");
 
     private final String value;
     private final String extension;
 
     ExtractOutputFormat(String value, String extension) {
       this.value = value;
       this.extension = extension;
     }
 
     public static ExtractOutputFormat fromValue(String value) {
       for (ExtractOutputFormat format : ExtractOutputFormat.values()) {
         if (format.value.equalsIgnoreCase(value)) {
           return format;
         }
       }
       throw new IllegalArgumentException("Invalid output format: " + value);
     }
 
     public String getValue() {
       return this.value;
     }
 
     public String getExtension() {
       return this.extension;
     }
 
     @Override
     public String toString() {
       return String.valueOf(this.value);
     }
   }
 }