/*
 *  Copyright 2012 Anyware Services
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.ametys.core.user;

import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.time.ZonedDateTime;
import java.util.List;
import java.util.TimeZone;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;

import org.ametys.core.user.dataprovider.UserDataProvider;
import org.ametys.core.user.directory.StoredUser;
import org.ametys.core.user.directory.UserDirectory;
import org.ametys.core.util.SizeUtils.ExcludeFromSizeCalculation;

/**
 * Implementation of the principal abstraction to represent an user with a login and a {@link StoredUser}
 * @param <T> The type of the factory
 */
public class User <T extends UserFactory> implements java.security.Principal
{
    /** The id of the last name data. This data is of type {@link String} */
    public static final String LAST_NAME_DATA_ID = "lastname";
    /** The id of the first name data. This data is of type {@link String} */
    public static final String FIRST_NAME_DATA_ID = "firstname";
    /** The id of the email data. This data is of type {@link String} */
    public static final String EMAIL_DATA_ID = "email";
    /** The id of the image data. This data is of type {@link UserImage} */
    public static final String IMAGE_DATA_ID = "image";
    /** The id of the language data. This data is of type String */
    public static final String LANGUAGE_DATA_ID = "language";
    /** The id of the timezone data. This data is of type {@link TimeZone} or is a TimeZoneId of type {@link String} */
    public static final String TIMEZONE_DATA_ID = "timezone";
    /** The id of the creation date data. This data is of type {@link ZonedDateTime} */
    public static final String CREATION_DATE_DATA_ID = "creation-date";
    /** The id of the creation origin data. This data is of type {@link UserCreationOrigin} */
    public static final String CREATION_ORIGIN_DATA_ID = "creation-origin";

    /**
     * The identity of this principal.
     */
    protected UserIdentity _identity;
    /**
     * The user directory this user belongs to.
     */
    @ExcludeFromSizeCalculation
    protected UserDirectory _userDirectory;
    
    /** The factory */
    @ExcludeFromSizeCalculation
    protected T _factory;
    
    @ExcludeFromSizeCalculation
    private Logger _logger;

    private StoredUser _storedUser;
    
    /**
     * Enumeration for the user creation origin
     *
     */
    public enum UserCreationOrigin
    {
        /** User created by system */
        SYSTEM,
        /** User created by an administrator */
        ADMIN,
        /** User created by user signup */
        USER_SIGNUP,
        /** When user creation is unknown or not available */
        NOT_AVAILABLE
    }
    
    /**
     * Basic structure holding necessary data representing an user profile image
     */
    public static class UserImage implements Closeable
    {
        private final InputStream _inputstream;
        private final String _filename;
        private final Long _length;
        private final Long _lastModified;
        private final String _type;
        
        /**
         * Constructor
         * @param inputstream The image input stream
         * @param filename The file name or null if unknown
         * @param length The file length if known
         * @param lastModified The last modified date
         * @param type The type name of the source of the image to compute a cache key
         */
        public UserImage(InputStream inputstream, String filename, Long length, Long lastModified, String type)
        {
            _inputstream = inputstream;
            _filename = filename;
            _length = length;
            _lastModified = lastModified;
            _type = type;
        }
        
        /**
         * Retrieve the type name of the source of the image to compute a cache key
         * @return the type
         */
        public String getType()
        {
            return _type;
        }
        
        /**
         * Retrieves the input stream
         * @return the input stream
         */
        public InputStream getInputstream()
        {
            return _inputstream;
        }

        /**
         * Retrieves the filename
         * @return the filename or null if not defined
         */
        public String getFilename()
        {
            return _filename;
        }

        /**
         * Retrieves the length
         * @return the length or null or -1 if unknown
         */
        public Long getLength()
        {
            return _length;
        }
        
        /**
         * Retrieve the last modified date.
         * @return The last modified date. Can be null if unknown.
         */
        public Long getLastModified()
        {
            return _lastModified;
        }
        
        /**
         * Close input stream
         * @implNote Close the input stream of the image.
         */
        public void close() throws IOException
        {
            _inputstream.close();
        }
    }
    
    /**
     * Construct a new UserPrincipal, associated with a last name, a first name,
     * an email and identified by a login.
     * @param storedUser The storedUser. Cannot be null
     * @param userDirectory The user directory the user belongs to. Cannot be null.
     * @param factory The factory
     */
    User(StoredUser storedUser, UserDirectory userDirectory, T factory, Logger logger)
    {
        _identity = new UserIdentity(storedUser.getIdentifier(), userDirectory.getPopulationId());
        _storedUser = storedUser;
        _userDirectory = userDirectory;
        _factory = factory;
        _logger = logger;
    }

    /**
     * The identity of the user.
     * 
     * @return The identity.
     */
    public UserIdentity getIdentity()
    {
        return _identity;
    }
    
    /**
     * Get the StoredUser of the User
     * @return The {@link StoredUser}
     */
    public StoredUser getStoredUser()
    {
        return _storedUser;
    }
    
    @Override
    public String getName()
    {
        return UserIdentity.userIdentityToString(_identity);
    }
    
    /**
     * The user directory this user belongs to.
     * @return The user directory
     */
    public UserDirectory getUserDirectory()
    {
        return _userDirectory;
    }
    
    /**
     * The last name of the user
     * @return The last name.
     */
    public String getLastName()
    {
        return (String) getValue(LAST_NAME_DATA_ID);
    }
    
    /**
     * The first name of the user
     * @return The first name.
     */
    public String getFirstName()
    {
        return (String) getValue(FIRST_NAME_DATA_ID);
    }
    
    /**
     * The email of the user represented by this Principal.
     * 
     * @return The email.
     */
    public String getEmail()
    {
        return (String) getValue(EMAIL_DATA_ID);
    }
    
    /**
     * The fullname of this user.
     * @return The full name
     */
    public String getFullName()
    {
        return _getFullName(true);
    }
    
    /**
     * The fullname to use to display if sort is needed.
     * Ensure the sort will be on
     * @return The sortable name
     */
    public String getSortableName()
    {
        return _getFullName(false);
    }
    
    /**
     * Get user's avatar from the {@link UserDataProvider} with the biggest priority
     * @param size The size
     * @param maxSize The maxSize
     * @return A {@link UserImage} the user's avatar or default image if an error occurs
     */
    public UserImage getImage(int size, int maxSize)
    {
        UserImageAccessor imageAccessor = (UserImageAccessor) getValue(IMAGE_DATA_ID);
        
        try
        {
            return imageAccessor != null ? imageAccessor.getImage(size, maxSize) : null;
        }
        catch (Exception e)
        {
            _logger.error("An error occurred while retrieving the profile image for user '" + getIdentity() + "'. Returning default image.", e);
            return _factory.getDefaultUserImageHelper().getDefaultImage();
        }
    }
    
    /**
     * Get user's language from the {@link UserDataProvider} with the biggest priority
     * @return The user's language
     */
    public String getLanguage()
    {
        return (String) getValue(LANGUAGE_DATA_ID);
    }
    
    /**
     * Get user's TimeZone from the {@link UserDataProvider} with the biggest priority
     * @return The user's timezone
     */
    public TimeZone getTimeZone()
    {
        Object timezoneFound = getValue(TIMEZONE_DATA_ID);
        if (timezoneFound instanceof TimeZone timeZone)
        {
            return timeZone;
        }
        else if (timezoneFound instanceof String timeZoneId && List.of(TimeZone.getAvailableIDs()).contains(timeZoneId))
        {
            return TimeZone.getTimeZone(timeZoneId);
        }
        
        return null;
    }
    
    /**
     * Get the last connection date of the user
     * @return the last connection date or null if the user never logged in
     */
    public ZonedDateTime getLastConnectionDate()
    {
        return _factory.getUserStatusManager().getLastConnectionDate(this.getIdentity()).orElse(null);
    }
    
    /**
     * Get the user's creation date
     * @return the creation date
     */
    public ZonedDateTime getCreationDate()
    {
        return (ZonedDateTime) getValue(CREATION_DATE_DATA_ID);
    }
    
    /**
     * Get the user's creation origin
     * @return the creation origin
     */
    public UserCreationOrigin getCreationOrigin()
    {
        return (UserCreationOrigin) getValue(CREATION_ORIGIN_DATA_ID);
    }
    
    /**
     * Get a user's data from the {@link UserDataProvider} with the biggest priority
     * @param dataId The data id
     * @return A user's data
     */
    public Object getValue(String dataId)
    {
        return _factory.getUserDataProviderEP().getValue(this, dataId);
    }
    
    /**
     * Get the {@link UserDataProvider} with the biggest priority and a value not null for the data requested
     * @param dataId The data id
     * @return A {@link UserDataProvider} the user data provider which is going to provide the data requested
     */
    public UserDataProvider getProviderFor(String dataId)
    {
        return _factory.getUserDataProviderEP().getProviderFor(this, dataId);
    }
    
    /**
     * The full name of the user represented by this Principal.
     * @param firstnameThenLastname Define the name order in the full name. Set to <code>true</code> to retrieve the fullname with firstname first and lastname second. Set to <code>false</code> to retrieve the fullname with lastname first and firstname second.
     * @return The full name.
     */
    protected String _getFullName(boolean firstnameThenLastname)
    {
        Stream<String> stream = firstnameThenLastname
                ? Stream.of(getFirstName(), getLastName())
                : Stream.of(getLastName(), getFirstName());
        
        String sortableName = stream.filter(StringUtils::isNotEmpty)
            .collect(Collectors.joining(" "));
        
        return StringUtils.defaultIfEmpty(sortableName, _identity.getLogin());
    }
    
    /**
     * Return a String representation of this object, which exposes only
     * information that should be public.
     * 
     * @return A string representing the user.
     */
    @Override
    public String toString()
    {
        StringBuilder sb = new StringBuilder("Principal[");
        sb.append(_userDirectory.getPopulationId());
        sb.append(", ");
        sb.append(_storedUser.toString());
        sb.append("]");
        return sb.toString();
    }

    /**
     * Test if two principal are equals.
     * @return true if the given Object represents the same Principal.
     */
    @Override
    public boolean equals(Object another)
    {
        if (another == null || !(another instanceof User))
        {
            return false;
        }
        
        User otherUser = (User) another;
        
        return _identity != null  && _identity.equals(otherUser.getIdentity());
    }
    
    @Override
    public int hashCode()
    {
        return _identity.hashCode();
    }
}