/*
    * Copyright (C) 2022 B3Partners B.V.
    *
    * SPDX-License-Identifier: MIT
    */
   package org.tailormap.api.controller;
   
   import jakarta.servlet.http.HttpServletRequest;
   import org.springframework.beans.factory.annotation.Value;
  import org.springframework.http.HttpStatus;
  import org.springframework.http.MediaType;
  import org.springframework.http.ResponseEntity;
  import org.springframework.web.bind.WebDataBinder;
  import org.springframework.web.bind.annotation.ExceptionHandler;
  import org.springframework.web.bind.annotation.InitBinder;
  import org.springframework.web.bind.annotation.ModelAttribute;
  import org.springframework.web.bind.annotation.PathVariable;
  import org.springframework.web.bind.annotation.RequestParam;
  import org.springframework.web.bind.annotation.RestControllerAdvice;
  import org.springframework.web.server.ResponseStatusException;
  import org.tailormap.api.annotation.AppRestController;
  import org.tailormap.api.persistence.Application;
  import org.tailormap.api.persistence.GeoService;
  import org.tailormap.api.persistence.helper.ApplicationHelper;
  import org.tailormap.api.persistence.json.AppTreeLayerNode;
  import org.tailormap.api.persistence.json.GeoServiceLayer;
  import org.tailormap.api.repository.ApplicationRepository;
  import org.tailormap.api.repository.GeoServiceRepository;
  import org.tailormap.api.security.AuthorizationService;
  import org.tailormap.api.viewer.model.ErrorResponse;
  import org.tailormap.api.viewer.model.RedirectResponse;
  import org.tailormap.api.viewer.model.ViewerResponse;
  
  @RestControllerAdvice(annotations = AppRestController.class)
  public class AppRestControllerAdvice {
    private final ApplicationRepository applicationRepository;
    private final GeoServiceRepository geoServiceRepository;
    private final ApplicationHelper applicationHelper;
    private final AuthorizationService authorizationService;
  
    @Value("${tailormap-api.base-path}")
    private String basePath;
  
    public AppRestControllerAdvice(
        ApplicationRepository applicationRepository,
        GeoServiceRepository geoServiceRepository,
        ApplicationHelper applicationHelper,
        AuthorizationService authorizationService) {
      this.applicationRepository = applicationRepository;
      this.geoServiceRepository = geoServiceRepository;
      this.applicationHelper = applicationHelper;
      this.authorizationService = authorizationService;
    }
  
    @InitBinder
    protected void initBinder(WebDataBinder binder) {
      // WARNING! These fields must NOT match properties of ModelAttribute classes, otherwise they
      // will be overwritten (for instance GeoServiceLayer.name might be set to the app name)
      binder.setAllowedFields("viewerName", "appLayerId", "base", "projection");
    }
  
    @ExceptionHandler(ResponseStatusException.class)
    protected ResponseEntity<?> handleResponseStatusException(ResponseStatusException ex) {
      if (HttpStatus.UNAUTHORIZED.equals(ex.getStatusCode())) {
        return ResponseEntity.status(ex.getStatusCode())
            .contentType(MediaType.APPLICATION_JSON)
            .body(new RedirectResponse());
      }
      return ResponseEntity.status(ex.getStatusCode())
          .contentType(MediaType.APPLICATION_JSON)
          .body(new ErrorResponse()
              .message(
                  ex.getReason() != null
                      ? ex.getReason()
                      : ex.getBody().getTitle())
              .code(ex.getStatusCode().value()));
    }
  
    @ModelAttribute
    public ViewerResponse.KindEnum populateViewerKind(HttpServletRequest request) {
      if (request.getServletPath().startsWith(basePath + "/app/")) {
        return ViewerResponse.KindEnum.APP;
      } else if (request.getServletPath().startsWith(basePath + "/service/")) {
        return ViewerResponse.KindEnum.SERVICE;
      } else {
        return null;
      }
    }
  
    @ModelAttribute
    public Application populateApplication(
        @ModelAttribute ViewerResponse.KindEnum viewerKind,
        @PathVariable(required = false) String viewerName,
        @RequestParam(required = false) String base,
        @RequestParam(required = false) String projection) {
      if (viewerKind == null || viewerName == null) {
        // No binding required for ViewerController.defaultApp()
        return null;
      }
 
     Application app;
     if (viewerKind == ViewerResponse.KindEnum.APP) {
       app = applicationRepository.findByName(viewerName);
       if (app == null) {
         throw new ResponseStatusException(HttpStatus.NOT_FOUND);
       }
     } else if (viewerKind == ViewerResponse.KindEnum.SERVICE) {
       GeoService service = geoServiceRepository.findById(viewerName).orElse(null);
 
       if (service == null) {
         throw new ResponseStatusException(HttpStatus.NOT_FOUND);
       }
 
       if (!authorizationService.mayUserRead(service)) {
         throw new ResponseStatusException(HttpStatus.UNAUTHORIZED);
       }
 
       // TODO: skip this check for users with admin role
       if (!service.isPublished()) {
         throw new ResponseStatusException(HttpStatus.NOT_FOUND);
       }
       app = applicationHelper.getServiceApplication(base, projection, service);
     } else {
       throw new ResponseStatusException(HttpStatus.BAD_REQUEST);
     }
 
     if (!this.authorizationService.mayUserRead(app)) {
       throw new ResponseStatusException(HttpStatus.UNAUTHORIZED);
     }
     return app;
   }
 
   @ModelAttribute
   public AppTreeLayerNode populateAppTreeLayerNode(
       @ModelAttribute Application app, @PathVariable(required = false) String appLayerId) {
     if (app == null || appLayerId == null) {
       // No binding
       return null;
     }
 
     final AppTreeLayerNode layerNode = app.getAllAppTreeLayerNode()
         .filter(r -> r.getId().equals(appLayerId))
         .findFirst()
         .orElse(null);
     if (layerNode == null) {
       throw new ResponseStatusException(
           HttpStatus.NOT_FOUND, "Application layer with id " + appLayerId + " not found");
     }
 
     // TODO
     //    if (!this.authorizationService.mayUserRead(applicationLayer, application)) {
     //      throw new ResponseStatusException(HttpStatus.FORBIDDEN, "Access denied");
     //    }
     return layerNode;
   }
 
   @ModelAttribute
   public GeoService populateGeoService(
       @ModelAttribute Application app, @ModelAttribute AppTreeLayerNode appTreeLayerNode) {
     if (appTreeLayerNode == null) {
       // No binding
       return null;
     }
     if (appTreeLayerNode.getServiceId() == null) {
       return null;
     }
     GeoService service =
         geoServiceRepository.findById(appTreeLayerNode.getServiceId()).orElse(null);
     if (service != null && !authorizationService.mayUserRead(service)) {
       throw new ResponseStatusException(HttpStatus.UNAUTHORIZED);
     }
 
     if (service != null && authorizationService.mustDenyAccessForSecuredProxy(app, service)) {
       throw new ResponseStatusException(HttpStatus.FORBIDDEN);
     }
 
     return service;
   }
 
   @ModelAttribute
   public GeoServiceLayer populateGeoServiceLayer(
       @ModelAttribute AppTreeLayerNode appTreeLayerNode, @ModelAttribute GeoService service) {
     if (service == null) {
       // No binding
       return null;
     }
     GeoServiceLayer layer = service.getLayers().stream()
         .filter(l -> appTreeLayerNode.getLayerName().equals(l.getName()))
         .findFirst()
         .orElse(null);
 
     if (layer != null && !authorizationService.mayUserRead(service, layer)) {
       throw new ResponseStatusException(HttpStatus.UNAUTHORIZED);
     }
 
     return layer;
   }
 }