using System.Collections.Generic;
using UIWidgetsSample;
using Unity.UIWidgets.foundation;

namespace ChatComponents
{
    public enum Role
    {
        admin,
        agent,
        moderator,
        user
    }

    /// Extension with one [toShortString] method
    /// RoleToShortString
    public  class RoleToShortString
    {
        /// Converts enum to the string equal to enum's name
        public  Role role;

        public string toShortString()
        {
            return ToString().Split('.').last();
        }
    }

    /// A class that represents user.
    public class User : Equatable
    {
        /// Created user timestamp, in ms
        public readonly int? createdAt;

        /// First name of the user
        public readonly string firstName;

        /// Unique ID of the user
        public readonly string id;

        /// Remote image URL representing user's avatar
        public readonly string imageUrl;

        /// Last name of the user
        public readonly string lastName;

        /// Timestamp when user was last visible, in ms
        public readonly int? lastSeen;

        /// Additional custom metadata or attributes related to the user
        public readonly Dictionary<string, object> metadata;

        /// User [Role]
        public Role? role;

        /// Creates a user.
        public User(
            string id,
            int? createdAt = null,
            string firstName = null,
            string imageUrl = null,
            string lastName = null,
            int? lastSeen = null,
            Dictionary<string, object> metadata = null,
            Role? role = null
        )
        {
            this.createdAt = createdAt;
            this.firstName = firstName;
            this.id = id;
            this.imageUrl = imageUrl;
            this.lastName = lastName;
            this.lastSeen = lastSeen;
            this.metadata = metadata;
            this.role = role;
        }

        /// Equatable props
        public override List<object> props => new List<object>
            {createdAt, firstName, id, imageUrl, lastName, lastSeen, metadata, role};

        /// Creates user from a map (decoded JSON).
        public static User fromJson(Dictionary<string, object> json)
        {
            return new User(
                createdAt: json["createdAt"] as int?,
                firstName: json["firstName"] as string,
                id: json["id"] as string,
                imageUrl: json["imageUrl"] as string,
                lastName: json["lastName"] as string,
                lastSeen: json["lastSeen"] as int?,
                metadata: json["metadata"] as Dictionary<string, object>,
                role: ChatRoomUtils.getRoleFromString(json["role"] as string)
            );
            /// Converts user to the map representation, encodable to JSON.
        }

        public Dictionary<string, object> toJson()
        {
            return new Dictionary<string, object>
            {
                {"createdAt", createdAt},
                {"firstName", firstName},
                {"id", id},
                {"imageUrl", imageUrl},
                {"lastName", lastName},
                {"lastSeen", lastSeen},
                {"metadata", metadata},
                {"role", ChatRoomUtils.toShortString(role == null ? null : role)}
            };
        }

        /// Creates a copy of the user with an updated data.
        /// [firstName], [imageUrl], [lastName], [lastSeen] and [role] with
        /// null values will nullify existing values.
        /// [metadata] with null value will nullify existing metadata, otherwise
        /// both metadatas will be merged into one Map, where keys from a passed
        /// metadata will overwite keys from the previous one.
        private User copyWith(
            string firstName = null,
            string imageUrl = null,
            string lastName = null,
            int? lastSeen = null,
            Dictionary<string, object> metadata = null,
            Role? role = null
        )
        {
            var result = new Dictionary<string, object>();
            if (this.metadata != null)
                foreach (var metaItem in this.metadata)
                    result.Add(metaItem.Key, metaItem.Value);
            foreach (var metaItem in metadata) result.Add(metaItem.Key, metaItem.Value);


            return new User(
                firstName: firstName,
                id: id,
                imageUrl: imageUrl,
                lastName: lastName,
                lastSeen: lastSeen,
                metadata: metadata == null
                    ? null
                    : result,
                role: role
            );
        }
    }
}