package eu.dnetlib.uoamonitorservice.service;

import eu.dnetlib.uoaadmintoolslibrary.handlers.ForbiddenException;
import eu.dnetlib.uoamonitorservice.dao.StakeholderDAO;
import eu.dnetlib.uoamonitorservice.dao.TopicDAO;
import eu.dnetlib.uoamonitorservice.dto.TopicFull;
import eu.dnetlib.uoamonitorservice.entities.Stakeholder;
import eu.dnetlib.uoamonitorservice.entities.Topic;
import eu.dnetlib.uoamonitorservice.generics.Common;
import eu.dnetlib.uoamonitorservice.handlers.EntityNotFoundException;
import eu.dnetlib.uoamonitorservice.handlers.PathNotValidException;
import eu.dnetlib.uoamonitorservice.primitives.Visibility;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Date;
import java.util.HashSet;
import java.util.List;
import java.util.stream.Collectors;

@Service
public class TopicService {

    private final StakeholderDAO stakeholderDAO;
    private final TopicDAO dao;

    private final CategoryService categoryService;
    private final CommonService commonService;

    @Autowired
    public TopicService(StakeholderDAO stakeholderDAO, TopicDAO dao, CategoryService categoryService, CommonService commonService) {
        this.stakeholderDAO = stakeholderDAO;
        this.dao = dao;
        this.categoryService = categoryService;
        this.commonService = commonService;
    }

    public Topic find(String id) {
        return dao.findById(id).orElseThrow(() -> new EntityNotFoundException("Topic with id: " + id + " not found"));
    }

    public Topic findByPath(Stakeholder stakeholder, String topicId) {
        if (!stakeholder.getTopics().contains(topicId)) {
            throw new PathNotValidException("Topic with id: " + topicId + " not found in Stakeholder: " + stakeholder.getId());
        }
        return this.dao.findById(topicId).orElseThrow(() -> new EntityNotFoundException("Topic with id: " + topicId + " not found"));
    }

    public TopicFull getFullTopic(String type, String alias, Topic topic) {
        if (commonService.hasVisibilityAuthority(type, alias, topic)) {
            return new TopicFull(topic, topic.getCategories().stream()
                    .map(categoryId -> this.categoryService.getFullCategory(type, alias, categoryId))
                    .collect(Collectors.toList()));
        } else {
            return null;
        }
    }

    public TopicFull getFullTopic(String type, String alias, String id) {
        Topic topic = this.find(id);
        return this.getFullTopic(type, alias, topic);
    }

    public TopicFull buildTopic(TopicFull topicFull) {
        topicFull.setCategories(topicFull.getCategories().stream().map(this.categoryService::buildCategory).collect(Collectors.toList()));
        topicFull.update(this.save(new Topic(topicFull)));
        return topicFull;
    }

    public Topic save(Topic topic) {
        if(topic.getId() != null) {
            topic.setCategories(this.find(topic.getId()).getCategories());
        } else {
            topic.setCreationDate(new Date());
        }
        topic.setUpdateDate(new Date());
        topic.getCategories().forEach(this.categoryService::find);
        return this.dao.save(topic);
    }

    public TopicFull save(Stakeholder stakeholder, Topic topic) {
        if(topic.getId() != null) {
            if(this.commonService.hasEditAuthority(stakeholder.getType(), stakeholder.getAlias())) {
                topic.setCategories(this.find(topic.getId()).getCategories());
                this.updateChildren(topic);
                topic = this.save(topic);
            } else {
                throw new ForbiddenException("You are not authorized to update stakeholder with id: " + stakeholder.getId());
            }
        } else {
            if(this.commonService.hasCreateAuthority(stakeholder.getType())) {
                topic = this.save(topic);
                this.createChildren(stakeholder, topic);
                this.addTopic(stakeholder, topic.getId());
            } else {
                throw new ForbiddenException("You are not authorized to create a topic in stakeholder with id: " + stakeholder.getId());
            }
        }
        return this.getFullTopic(stakeholder.getType(), stakeholder.getAlias(), topic);
    }

    public void createChildren(Stakeholder defaultStakeholder, Topic topic) {
       this.stakeholderDAO.findByDefaultId(defaultStakeholder.getId()).forEach(stakeholder -> {
           this.save(stakeholder, topic.copy());
       });
    }

    public void updateChildren(Topic topic) {
        this.dao.findByDefaultId(topic.getId()).forEach(child -> {
            this.save(topic.override(child, this.find(topic.getId())));
        });
    }

    public TopicFull reorderCategories(Stakeholder stakeholder, Topic topic, List<String> categories) {
        if(this.commonService.hasEditAuthority(stakeholder.getType(), stakeholder.getAlias())) {
            categories.forEach(this.categoryService::find);
            if (topic.getCategories().size() == categories.size() && new HashSet<>(topic.getCategories()).containsAll(categories)) {
                topic.setCategories(categories);
                this.reorderChildren(stakeholder, topic, categories);
                topic.setUpdateDate(new Date());
                return this.getFullTopic(stakeholder.getType(), stakeholder.getAlias(), this.dao.save(topic));
            } else {
                throw new EntityNotFoundException("Some categories dont exist in the topic with id " + topic.getId());
            }
        } else {
            throw new ForbiddenException("You are not authorized to reorder categories in topic with id: " + topic.getId());
        }
    }

    public void reorderChildren(Stakeholder defaultStakeholder, Topic defaultTopic, List<String> defaultCategories) {
        this.stakeholderDAO.findByDefaultId(defaultStakeholder.getId()).forEach(stakeholder -> {
            this.dao.findByDefaultId(defaultTopic.getId()).stream().map(topic -> this.getFullTopic(stakeholder.getType(), stakeholder.getAlias(), topic)).forEach(topic -> {
                this.reorderCategories(stakeholder, new Topic(topic),
                        this.commonService.reorder(defaultCategories, topic.getCategories().stream().map(category -> (Common) category).collect(Collectors.toList())));
            });
        });
    }

    public void delete(String type, Topic topic, boolean remove) {
        if (this.commonService.hasDeleteAuthority(type)) {
            this.dao.findByDefaultId(topic.getId()).forEach(child -> {
                this.delete(type, child.getId(), remove);
            });
            topic.getCategories().forEach(categoryId -> {
                this.categoryService.delete(type, categoryId, false);
            });
            if (remove) {
                this.removeTopic(topic.getId());
            }
            this.dao.delete(topic);
        } else {
            throw new ForbiddenException("Delete topic: You are not authorized to delete topic with id: " + topic.getId());
        }
    }

    public void delete(String type, String id, boolean remove) {
        Topic topic = this.find(id);
        this.delete(type, topic, remove);
    }

    public void addTopic(Stakeholder stakeholder, String id) {
        stakeholder.addTopic(id);
        stakeholder.setUpdateDate(new Date());
        this.stakeholderDAO.save(stakeholder);
    }

    public void removeTopic(String id) {
        this.stakeholderDAO.findByTopicsContaining(id).forEach(stakeholder -> {
            stakeholder.removeTopic(id);
            stakeholder.setUpdateDate(new Date());
            this.stakeholderDAO.save(stakeholder);
        });
    }

    public TopicFull changeVisibility(String type, String alias, TopicFull topic, Visibility visibility, Boolean propagate) {
        if (this.commonService.hasEditAuthority(type, alias)) {
            topic.setVisibility(visibility);
            if (propagate) {
                topic.setCategories(topic.getCategories().stream()
                        .map(category -> this.categoryService.changeVisibility(type, alias, category, visibility, true))
                        .collect(Collectors.toList()));
            }
            topic.update(this.save(new Topic(topic)));
            return topic;
        } else {
            throw new ForbiddenException("Change topic visibility: You are not authorized to update topic with id: " + topic.getId());
        }
    }

    public TopicFull changeVisibility(String type, String alias, Topic topic, Visibility visibility, Boolean propagate) {
        TopicFull topicFull = this.getFullTopic(type, alias, topic);
        return this.changeVisibility(type, alias, topicFull, visibility, propagate);
    }
}