package eu.dnetlib.uoamonitorservice.controllers;

import eu.dnetlib.uoaadmintoolslibrary.handlers.ForbiddenException;
import eu.dnetlib.uoaadmintoolslibrary.handlers.utils.RolesUtils;
import eu.dnetlib.uoamonitorservice.dao.CategoryDAO;
import eu.dnetlib.uoamonitorservice.dao.StakeholderDAO;
import eu.dnetlib.uoamonitorservice.dao.SubCategoryDAO;
import eu.dnetlib.uoamonitorservice.dao.TopicDAO;
import eu.dnetlib.uoamonitorservice.entities.*;
import eu.dnetlib.uoamonitorservice.handlers.EntityNotFoundException;
import eu.dnetlib.uoamonitorservice.handlers.PathNotValidException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.web.bind.annotation.*;

import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;

@RestController
@CrossOrigin(origins = "*")
public class CategoryController {
    private final Logger log = LogManager.getLogger(this.getClass());

    @Autowired
    private RolesUtils rolesUtils;

    @Autowired
    private StakeholderDAO stakeholderDAO;

    @Autowired
    private TopicDAO topicDAO;

    @Autowired
    private CategoryDAO categoryDAO;

    @Autowired
    private SubCategoryDAO subCategoryDAO;

    @Autowired
    private SubCategoryController subCategoryController;

    public Category<SubCategory> buildCategory(Category<SubCategory> categoryFull) {
        Category<String> category = new Category<>(categoryFull);

        List<String> subCategories = new ArrayList<>();
        List<SubCategory> subCategoriesFull = new ArrayList<>();
        for (SubCategory<Section<Indicator>> subCategory : categoryFull.getSubCategories()) {
            SubCategory<Section<Indicator>> subcategoryFull = subCategoryController.buildSubCategory(subCategory);
            subCategoriesFull.add(subcategoryFull);
            subCategories.add(subcategoryFull.getId());
        }
        categoryFull.setSubCategories(subCategoriesFull);
        category.setSubCategories(subCategories);

        Date date = new Date();
        category.setCreationDate(date);
        category.setUpdateDate(date);

        categoryFull.setCreationDate(date);
        categoryFull.setUpdateDate(date);

        categoryDAO.save(category);

        categoryFull.setId(category.getId());
        return categoryFull;
    }

    @PreAuthorize("isAuthenticated()")
    @RequestMapping(value = "/{stakeholderId}/{topicId}/save", method = RequestMethod.POST)
    public Category<SubCategory> saveCategory(@PathVariable("stakeholderId") String stakeholderId,
                                              @PathVariable("topicId") String topicId,
                                              @RequestBody Category<SubCategory> categoryFull) {
        log.debug("save category");
        log.debug("Alias: " + categoryFull.getAlias() + " - Id: " + categoryFull.getId() + " - Stakeholder: " + stakeholderId + " - Topic: " + topicId);

        Stakeholder<String> stakeholder = stakeholderDAO.findById(stakeholderId);

        if (stakeholder != null) {
            if (!rolesUtils.hasUpdateAuthority(stakeholder.getType(), stakeholder.getAlias())) {
                // EXCEPTION - Access denied
                throw new ForbiddenException("Save Category: You are not authorized to update stakeholder with id: " + stakeholderId);
            }

            Category<String> oldCategory = null;
            if (categoryFull.getId() != null) {
                oldCategory = categoryDAO.findById(categoryFull.getId());
                if (oldCategory == null) {
                    // EXCEPTION - Category not found
                    throw new EntityNotFoundException("save category: Category with id: " + categoryFull.getId() + " not found");
                }
            }

            Topic<String> topic = topicDAO.findById(topicId);
            if (topic != null) {
                if (stakeholder.getTopics().contains(topicId)) {
                    Category<String> category = new Category<>(categoryFull);

                    Date date = new Date();
                    category.setUpdateDate(date);
                    categoryFull.setUpdateDate(date);

                    List<String> subCategories = new ArrayList<>();

                    // if category not exists (no id), create a new default subcategory, identical to category
                    if (categoryFull.getId() == null) {
                        category.setCreationDate(date);
                        categoryFull.setCreationDate(date);

                        SubCategory<String> subCategory = new SubCategory<>();
                        subCategory.createOverviewSubCategory(categoryFull);

                        subCategoryDAO.save(subCategory);

                        List<SubCategory> subCategoriesFull = categoryFull.getSubCategories();
                        subCategoriesFull.add(subCategory);

                        for (SubCategory oldSubCategory : subCategoriesFull) {
                            subCategories.add(oldSubCategory.getId());
                        }
                    } else {
                        for (String subCategoryId : oldCategory.getSubCategories()) {
                            SubCategory subCategory = subCategoryDAO.findById(subCategoryId);
                            if (subCategory == null) {
                                // EXCEPTION - SubCategory not found
                                throw new EntityNotFoundException("Save category: SubCategory with id: " + subCategoryId + " not found (subcategory exists in category: " + category.getId() + ")");
                            }
                            subCategories.add(subCategory.getId());
                        }
                    }

                    category.setSubCategories(subCategories);

                    if (stakeholder.getDefaultId() == null) {
                        if (categoryFull.getId() == null) {
                            categoryDAO.save(category);
                            onSaveDefaultCategory(category, topicId);
                        } else {
                            onUpdateDefaultCategory(category, oldCategory);
                            categoryDAO.save(category);
                        }
                    } else {
                        categoryDAO.save(category);
                    }

                    List<String> categories = topic.getCategories();
                    int index = categories.indexOf(category.getId());
                    if (index == -1) {
                        categories.add(category.getId());
                        topicDAO.save(topic);
                        log.debug("Category saved!");

                        categoryFull.setId(category.getId());
                    }
                } else {
                    // EXCEPTION - Topic not found in Stakeholder: stakeholder.getAlias();
                    throw new PathNotValidException("Save category: Topic with id: " + topicId + " not found in Stakeholder: " + stakeholderId);
                }
            } else {
                // EXCEPTION - Topic not found
                throw new EntityNotFoundException("Save category: Topic with id: " + topicId + " not found");
            }
        } else {
            // EXCEPTION - Stakeholder not found
            throw new EntityNotFoundException("Save category: Stakeholder with id: " + stakeholderId + " not found");
        }
        return categoryFull;
    }

    public void onSaveDefaultCategory(Category<String> category, String topicId) {
        log.debug("On save default category");

        List<Topic> topics = topicDAO.findByDefaultId(topicId);
        for (Topic topic : topics) {
            Category categoryNew = new Category();
            categoryNew.copyFromDefault(category);

            categoryDAO.save(categoryNew);

            List<String> categories = topic.getCategories();
            categories.add(categoryNew.getId());

            topicDAO.save(topic);
        }
        String subCategoryOverviewId = category.getSubCategories().get(0);
        SubCategory subCategoryOverview = subCategoryDAO.findById(subCategoryOverviewId);
        subCategoryController.onSaveDefaultSubCategory(subCategoryOverview, category.getId());
    }

    public void onUpdateDefaultCategory(Category category, Category oldCategory) {
        log.debug("On update default category");

        List<Category> categories = categoryDAO.findByDefaultId(category.getId());
        boolean changed = false;
        for (Category categoryBasedOnDefault : categories) {
            if (category.getName() != null && !category.getName().equals(categoryBasedOnDefault.getName())
                    && (oldCategory.getName() == null || oldCategory.getName().equals(categoryBasedOnDefault.getName()))) {

                categoryBasedOnDefault.setName(category.getName());
                categoryBasedOnDefault.setAlias(category.getAlias());
                changed = true;
            }
            if (category.getDescription() != null && !category.getDescription().equals(categoryBasedOnDefault.getDescription())
                    && (oldCategory.getDescription() == null || oldCategory.getDescription().equals(categoryBasedOnDefault.getDescription()))) {

                categoryBasedOnDefault.setDescription(category.getDescription());
                changed = true;
            }

            if (!changed) {
                continue;
            }
            categoryBasedOnDefault.setUpdateDate(category.getUpdateDate());
            categoryDAO.save(categoryBasedOnDefault);
        }
    }

    @PreAuthorize("isAuthenticated()")
    @RequestMapping(value = "/{stakeholderId}/{topicId}/{categoryId}/delete", method = RequestMethod.DELETE)
    public boolean deleteCategory(@PathVariable("stakeholderId") String stakeholderId,
                                  @PathVariable("topicId") String topicId,
                                  @PathVariable("categoryId") String categoryId,
                                  @RequestParam(required = false) String children) {
        log.debug("delete category");
        log.debug("Id: " + categoryId + " - Stakeholder: " + stakeholderId + " - Topic: " + topicId);

        Stakeholder<String> stakeholder = stakeholderDAO.findById(stakeholderId);

        if (stakeholder != null) {
            if (!rolesUtils.hasUpdateAuthority(stakeholder.getType(), stakeholder.getAlias())) {
                // EXCEPTION - Access denied
                throw new ForbiddenException("Delete category: You are not authorized to update stakeholder with id: " + stakeholderId);
            }

            Topic<String> topic = topicDAO.findById(topicId);
            if (topic != null) {
                if (stakeholder.getTopics().contains(topicId)) {

                    Category<String> category = categoryDAO.findById(categoryId);
                    if (category != null) {

                        if (category.getDefaultId() != null && !rolesUtils.hasCreateAndDeleteAuthority(stakeholder.getType())) {
                            // EXCEPTION - Access denied
                            throw new ForbiddenException("Delete category: You are not authorized to delete a default Category in stakeholder with id: " + stakeholderId);
                        }


                        List<String> categories = topic.getCategories();
                        int index = categories.indexOf(categoryId);
                        if (index != -1) {
                            // this category belongs in default profile
                            if (topic.getDefaultId() == null && children != null) {
                                onDeleteDefaultCategory(categoryId, topicId, children);
                            }
                            subCategoryController.deleteTree(category);
                            category.setSubCategories(null);
                            categories.remove(index);
                            topicDAO.save(topic);
                            categoryDAO.delete(categoryId);
                            log.debug("Category deleted!");
                        } else {
                            // EXCEPTION - Category not found in Stakeholder: stakeholder.getAlias(); -> Topic: topic.getAlias();
                            throw new PathNotValidException("Delete category: Category with id: " + categoryId + " not found in Topic: " + topicId);
                        }

                    } else {
                        // EXCEPTION - Category not found
                        throw new EntityNotFoundException("Delete category: Category with id: " + categoryId + " not found");
                    }
                } else {
                    // EXCEPTION - Topic not found in Stakeholder: stakeholder.getAlias();
                    throw new PathNotValidException("Delete category: Topic with id: " + topicId + " not found in Stakeholder: " + stakeholderId);
                }
            } else {
                // EXCEPTION - Topic not found
                throw new EntityNotFoundException("Delete category: Topic with id: " + topicId + " not found");
            }
        } else {
            // EXCEPTION - Stakeholder not found
            throw new EntityNotFoundException("Delete category: Stakeholder with id: " + stakeholderId + " not found");
        }
        return true;
    }


    public boolean onDeleteDefaultCategory(String defaultCategoryId, String defaultTopicId, String children) {
        if (children.equals("delete")) {
            List<Topic> topics = topicDAO.findByDefaultId(defaultTopicId);
            List<Category> categories = categoryDAO.findByDefaultId(defaultCategoryId);

            for (Topic topic : topics) {
                Iterator<Category> categoriesIterator = categories.iterator();
                while (categoriesIterator.hasNext()) {
                    Category category = categoriesIterator.next();

                    String categoryId = category.getId();

                    if (topic.getCategories() != null && topic.getCategories().contains(categoryId)) {
                        categoriesIterator.remove();

                        topic.getCategories().remove(categoryId);
                        topicDAO.save(topic);

                        subCategoryController.deleteTree(category);

                        categoryDAO.delete(categoryId);
                        log.debug("Category with id: " + categoryId + " deleted!");

                        break;
                    }
                }
            }
        } else if (children.equals("disconnect")) {
            List<Category> categories = categoryDAO.findByDefaultId(defaultCategoryId);
            for (Category category : categories) {
                subCategoryController.disConnectTree(category);

                category.setDefaultId(null);
                categoryDAO.save(category);

                log.debug("DefaultId for Category with id: " + category.getId() + " empty!");
            }
        }
        return true;
    }

    @PreAuthorize("isAuthenticated()")
    @RequestMapping(value = "/{stakeholderId}/{topicId}/reorder", method = RequestMethod.POST)
    public List<Category> reorderCategories(@PathVariable("stakeholderId") String stakeholderId,
                                            @PathVariable("topicId") String topicId,
                                            @RequestBody List<String> categories) {
        log.debug("reorder categories");
        log.debug("Stakeholder: " + stakeholderId + " - Topic: " + topicId);

        Topic<String> topic = checkForExceptions(stakeholderId, topicId);

        List<String> oldCategories = topic.getCategories();
        for (String categoryId : oldCategories) {
            if (!categories.contains(categoryId)) {
                categories.add(categoryId);
            }
        }
        topic.setCategories(categories);

        List<Category> categoriesFull = new ArrayList<>();
        for (String categoryId : categories) {
            Category category = categoryDAO.findById(categoryId);
            if (category == null) {
                // EXCEPTION - Category not found
                throw new EntityNotFoundException("Reorder Categories: Category with id: " + categoryId + " not found");
            }
            categoriesFull.add(category);
        }

        topicDAO.save(topic);
        log.debug("Categories reordered!");

        return categoriesFull;
    }

    @PreAuthorize("isAuthenticated()")
    @RequestMapping(value = "/{stakeholderId}/{topicId}/{categoryId}/change-visibility", method = RequestMethod.POST)
    public Category changeCategoryVisibility(@PathVariable("stakeholderId") String stakeholderId,
                                             @PathVariable("topicId") String topicId,
                                             @PathVariable("categoryId") String categoryId,
                                             @RequestParam("visibility") Visibility visibility, @RequestParam(required = false) Boolean propagate) {
        log.debug("change category visibility: " + visibility + " - toggle propagate: " + ((propagate != null && propagate) ? "true" : "false"));
        log.debug("Stakeholder: " + stakeholderId + " - Topic: " + topicId + " - Category: " + categoryId);

        Stakeholder<String> stakeholder = stakeholderDAO.findById(stakeholderId);

        if (stakeholder != null) {
            if (!rolesUtils.hasUpdateAuthority(stakeholder.getType(), stakeholder.getAlias())) {
                // EXCEPTION - Access denied
                throw new ForbiddenException("Toggle category: You are not authorized to update stakeholder with id: " + stakeholderId);
            }

            Topic<String> topic = topicDAO.findById(topicId);
            if (topic != null) {
                if (stakeholder.getTopics().contains(topicId)) {
                    if (topic.getCategories().contains(categoryId)) {
                        return changeVisibilityTree(categoryId, visibility, propagate);
                    } else {
                        // EXCEPTION - Category not found in Stakeholder: stakeholder.getAlias(); -> Topic: topic.getAlias();
                        throw new PathNotValidException("Toggle category: Category with id: " + categoryId + " not found in Topic: " + topicId);
                    }
                } else {
                    // EXCEPTION - Topic not found in Stakeholder: stakeholder.getAlias();
                    throw new PathNotValidException("Toggle category: Topic with id: " + topicId + " not found in Stakeholder: " + stakeholderId);
                }
            } else {
                // EXCEPTION - Topic not found
                throw new EntityNotFoundException("Toggle category: Topic with id: " + topicId + " not found");
            }
        } else {
            // EXCEPTION - Stakeholder not found
            throw new EntityNotFoundException("Toggle category: Stakeholder with id: " + stakeholderId + " not found");
        }
    }

    public Category changeVisibilityTree(String categoryId, Visibility visibility, Boolean propagate) {
        Category<String> category = categoryDAO.findById(categoryId);
        if (category == null) {
            // EXCEPTION - Category not found
            throw new EntityNotFoundException("Change category visibility: Category with id: " + categoryId + " not found");
        }

        Category<SubCategory> categoryFull = new Category(category);
        List<SubCategory> subCategoriesFull = new ArrayList<>();

        if (propagate != null && propagate) {
            for (String subCategoryId : category.getSubCategories()) {
                subCategoriesFull.add(subCategoryController.changeVisibilityTree(subCategoryId, visibility, propagate));
            }
        }

        category.setVisibility(visibility);
        categoryDAO.save(category);
        log.debug("Category toggled!");

        categoryFull.setVisibility(visibility);
        categoryFull.setSubCategories(subCategoriesFull);

        return categoryFull;
    }


    private Topic checkForExceptions(String stakeholderId, String topicId) {

        Stakeholder<String> stakeholder = stakeholderDAO.findById(stakeholderId);

        if (stakeholder == null) {
            // EXCEPTION - Stakeholder not found
            throw new EntityNotFoundException("checkForExceptions category: Stakeholder with id: " + stakeholderId + " not found");
        }
        if (!rolesUtils.hasUpdateAuthority(stakeholder.getType(), stakeholder.getAlias())) {
            // EXCEPTION - Access denied
            throw new ForbiddenException("checkForExceptions category: You are not authorized to update stakeholder with id: " + stakeholderId);
        }

        Topic<String> topic = topicDAO.findById(topicId);
        if (topic == null) {
            // EXCEPTION - Topic not found
            throw new EntityNotFoundException("checkForExceptions category: Topic with id: " + topicId + " not found");
        }

        if (!stakeholder.getTopics().contains(topicId)) {
            // EXCEPTION - Topic not found in Stakeholder: stakeholder.getAlias();
            throw new PathNotValidException("checkForExceptions category: Topic with id: " + topicId + " not found in Stakeholder: " + stakeholderId);
        }

        return topic;
    }

    public void deleteTree(Topic topic) {
        List<String> categories = topic.getCategories();
        for (String categoryId : categories) {
            Category category = categoryDAO.findById(categoryId);
            if (category == null) {
                // EXCEPTION - Category not found
                throw new EntityNotFoundException("Category delete tree: Category with id: " + categoryId + " not found (category exists in topic: " + topic.getId() + ")");
            }

            subCategoryController.deleteTree(category);

            categoryDAO.delete(categoryId);
        }
    }

    public void disConnectTree(Topic topic) {
        List<String> categories = topic.getCategories();
        for (String categoryId : categories) {
            Category category = categoryDAO.findById(categoryId);
            if (category == null) {
                // EXCEPTION - Category not found
                throw new EntityNotFoundException("Category disconnect tree: Category with id: " + categoryId + " not found (category exists in topic: " + topic.getId() + ")");
            }

            subCategoryController.disConnectTree(category);

            category.setDefaultId(null);
            categoryDAO.save(category);
        }
    }
}