package eu.eudat.service.lock;

import eu.eudat.authorization.AffiliatedResource;
import eu.eudat.authorization.AuthorizationFlags;
import eu.eudat.authorization.Permission;
import eu.eudat.authorization.authorizationcontentresolver.AuthorizationContentResolver;
import eu.eudat.commons.scope.user.UserScope;
import eu.eudat.convention.ConventionService;
import eu.eudat.data.LockEntity;
import eu.eudat.errorcode.ErrorThesaurusProperties;
import eu.eudat.model.Lock;
import eu.eudat.model.builder.LockBuilder;
import eu.eudat.model.deleter.LockDeleter;
import eu.eudat.model.persist.LockPersist;
import eu.eudat.query.LockQuery;
import gr.cite.commons.web.authz.service.AuthorizationService;
import gr.cite.tools.data.builder.BuilderFactory;
import gr.cite.tools.data.deleter.DeleterFactory;
import gr.cite.tools.data.query.QueryFactory;
import gr.cite.tools.exception.MyApplicationException;
import gr.cite.tools.exception.MyForbiddenException;
import gr.cite.tools.exception.MyNotFoundException;
import gr.cite.tools.exception.MyValidationException;
import gr.cite.tools.fieldset.BaseFieldSet;
import gr.cite.tools.fieldset.FieldSet;
import gr.cite.tools.logging.LoggerService;
import gr.cite.tools.logging.MapLogEntry;
import jakarta.persistence.EntityManager;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.MessageSource;
import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.stereotype.Service;

import javax.management.InvalidApplicationException;
import java.time.Instant;
import java.util.Comparator;
import java.util.Date;
import java.util.List;
import java.util.UUID;

@Service
public class LockServiceImpl implements LockService {

    private static final LoggerService logger = new LoggerService(LoggerFactory.getLogger(LockServiceImpl.class));
    private final Comparator<LockEntity> compareByTouchedAt = Comparator.comparing(o ->  o.getTouchedAt());
    private final EntityManager entityManager;
    private final UserScope userScope;
    private final AuthorizationService authorizationService;
    private final DeleterFactory deleterFactory;
    private final BuilderFactory builderFactory;
    private final QueryFactory queryFactory;
    private final ConventionService conventionService;
    private final MessageSource messageSource;
    private final ErrorThesaurusProperties errors;
    private final AuthorizationContentResolver authorizationContentResolver;

    @Autowired
    public LockServiceImpl(
		    EntityManager entityManager,
		    UserScope userScope,
		    AuthorizationService authorizationService,
		    DeleterFactory deleterFactory,
		    BuilderFactory builderFactory,
		    QueryFactory queryFactory,
		    ConventionService conventionService,
		    MessageSource messageSource,
		    ErrorThesaurusProperties errors, AuthorizationContentResolver authorizationContentResolver) {
        this.entityManager = entityManager;
        this.userScope = userScope;
        this.authorizationService = authorizationService;
        this.deleterFactory = deleterFactory;
        this.builderFactory = builderFactory;
        this.queryFactory = queryFactory;
        this.conventionService = conventionService;
        this.messageSource = messageSource;
        this.errors = errors;
	    this.authorizationContentResolver = authorizationContentResolver;
    }

    public Lock persist(LockPersist model, FieldSet fields) throws MyForbiddenException, MyValidationException, MyApplicationException, MyNotFoundException, InvalidApplicationException {
        logger.debug(new MapLogEntry("persisting data").And("model", model).And("fields", fields));

        AffiliatedResource affiliatedResourceDmp = this.authorizationContentResolver.dmpAffiliation(model.getTarget());
        AffiliatedResource affiliatedResourceDescription = this.authorizationContentResolver.descriptionAffiliation(model.getTarget());
        this.authorizationService.authorizeAtLeastOneForce(List.of(affiliatedResourceDmp, affiliatedResourceDescription), Permission.EditLock);

        Boolean isUpdate = this.conventionService.isValidGuid(model.getId());

        LockEntity data;
        if (isUpdate) {
            data = this.entityManager.find(LockEntity.class, model.getId());
            if (data == null) throw new MyNotFoundException(messageSource.getMessage("General_ItemNotFound", new Object[]{model.getId(), Lock.class.getSimpleName()}, LocaleContextHolder.getLocale()));
            if (!data.getLockedBy().equals(this.userScope.getUserId())) throw new MyApplicationException("Is not locked by that user");
            if (!this.conventionService.hashValue(data.getTouchedAt()).equals(model.getHash())) throw new MyValidationException(this.errors.getHashConflict().getCode(), this.errors.getHashConflict().getMessage());
        } else {
            data = new LockEntity();
            data.setId(UUID.randomUUID());
            data.setLockedAt(Instant.now());
            data.setLockedBy(this.userScope.getUserId());
        }

        data.setTarget(model.getTarget());
        data.setTargetType(model.getTargetType());
        data.setTouchedAt(Instant.now());

        if (isUpdate) this.entityManager.merge(data);
        else  this.entityManager.persist(data);

        this.entityManager.flush();

        return this.builderFactory.builder(LockBuilder.class).authorize(AuthorizationFlags.OwnerOrDmpAssociatedOrPermission).build(BaseFieldSet.build(fields, Lock._id), data);
    }

    public boolean isLocked(UUID target) throws InvalidApplicationException {
        LockQuery query = this.queryFactory.query(LockQuery.class).authorize(AuthorizationFlags.OwnerOrDmpAssociatedOrPermission).targetIds(target);
        if (query.count() == 1) {
            LockEntity lock = query.first();
            if (lock.getLockedBy().equals(this.userScope.getUserId())) {
                lock.setTouchedAt(Instant.now());
                this.entityManager.merge(lock);
                this.entityManager.flush();
                return false;
            }
            return this.forceUnlock(target) > 0;
        } else if (query.count() > 1) {
            this.forceUnlock(target);
            return this.isLocked(target);
        }
        return false;

    }

    private Long forceUnlock(UUID target) throws InvalidApplicationException {

        LockQuery query = this.queryFactory.query(LockQuery.class).authorize(AuthorizationFlags.OwnerOrDmpAssociatedOrPermission).targetIds(target);
        Long availableLocks = query.count();
        long deletedLocks = 0L;
        if (availableLocks > 0) {
            List<LockEntity> locks = query.collect();
            for (LockEntity lock : locks) {
                if (new Date().getTime() - Date.from(lock.getTouchedAt()).getTime() > 120000) {
                    this.deleteAndSave(lock.getId());
                    deletedLocks++;
                }
            }
            if (deletedLocks == 0) {
                LockEntity recentLock = locks.stream().max(compareByTouchedAt).get();
                for (LockEntity lock : locks) {
                    if (lock != recentLock) {
                        this.deleteAndSave(lock.getId());
                        deletedLocks++;
                    }
                }
            }
        }
        return availableLocks - deletedLocks;
    }

    public void unlock(UUID target) throws InvalidApplicationException {

        LockQuery query = this.queryFactory.query(LockQuery.class).authorize(AuthorizationFlags.OwnerOrDmpAssociatedOrPermission).targetIds(target);
        if (query.count() == 1) {
            LockEntity lock = query.first();
            if (!lock.getLockedBy().equals(this.userScope.getUserId())) {
                throw new InvalidApplicationException("Only the user who created that lock can delete it");
            }
            this.deleteAndSave(lock.getId());
        } else if (query.count() > 1) {
            List<LockEntity> locks = query.collect();
            locks.stream().filter(lock -> lock.getLockedBy().equals(this.userScope.getUserIdSafe())).forEach(lock -> {
                try {
                    this.deleteAndSave(lock.getId());
                } catch (InvalidApplicationException e) {
                    throw new RuntimeException(e);
                }
            });

        }
    }

    public void deleteAndSave(UUID id) throws MyForbiddenException, InvalidApplicationException {
        logger.debug("deleting : {}", id);

        AffiliatedResource affiliatedResourceDmp = this.authorizationContentResolver.dmpAffiliation(id);
        AffiliatedResource affiliatedResourceDescription = this.authorizationContentResolver.descriptionAffiliation(id);
        this.authorizationService.authorizeAtLeastOneForce(List.of(affiliatedResourceDmp, affiliatedResourceDescription), Permission.DeleteLock);

        this.deleterFactory.deleter(LockDeleter.class).deleteAndSaveByIds(List.of(id));
    }
}