using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Threading.Tasks;
using Timeline.Entities;
using Timeline.Models;

namespace Timeline.Services
{

    [Serializable]
    public class TimelineMemberOperationException : Exception
    {
        public TimelineMemberOperationException() : base(Resources.Services.Exception.TimelineMemberOperationException) { }
        public TimelineMemberOperationException(string message) : base(message) { }
        public TimelineMemberOperationException(string message, Exception inner) : base(message, inner) { }
        protected TimelineMemberOperationException(
          System.Runtime.Serialization.SerializationInfo info,
          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

        public TimelineMemberOperationException(int index, Exception inner) : base(MakeIndexMessage(index), inner) { Index = index; }

        private static string MakeIndexMessage(int index) => string.Format(CultureInfo.CurrentCulture,
            Resources.Services.Exception.TimelineMemberOperationExceptionIndex, index);

        public int? Index { get; set; }
    }

    /// <summary>
    /// This define the common interface of both personal timeline
    /// and normal timeline.
    /// </summary>
    /// <remarks>
    /// The "name" parameter in method means name of timeline in
    /// <see cref="ITimelineService"/> while username of the owner
    /// of the personal timeline in <see cref="IPersonalTimelineService"/>.
    /// </remarks>
    public interface IBaseTimelineService
    {
        /// <summary>
        /// Get all the posts in the timeline.
        /// </summary>
        /// <param name="name">Username or the timeline name. See remarks of <see cref="IBaseTimelineService"/>.</param>
        /// <returns>A list of all posts.</returns>
        /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/> is null.</exception>
        /// <exception cref="TimelineNameBadFormatException">
        /// Thrown when timeline name is of bad format.
        /// For normal timeline, it means name is an empty string.
        /// For personal timeline, it means the username is of bad format,
        /// the inner exception should be a <see cref="UsernameBadFormatException"/>.
        /// </exception>
        /// <exception cref="TimelineNotExistException">
        /// Thrown when timeline does not exist.
        /// For normal timeline, it means the name does not exist.
        /// For personal timeline, it means the user of that username does not exist
        /// and the inner exception should be a <see cref="UserNotExistException"/>.
        /// </exception>
        Task<List<TimelinePostInfo>> GetPosts(string name);

        /// <summary>
        /// Create a new post in timeline.
        /// </summary>
        /// <param name="name">Username or the timeline name. See remarks of <ssee cref="IBaseTimelineService"/>.</param>
        /// <param name="author">The author's username.</param>
        /// <param name="content">The content.</param>
        /// <param name="time">The time of the post. If null, then use current time.</param>
        /// <returns></returns>
        /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/> or <paramref name="author"/> or <paramref name="content"/> is null.</exception>
        /// <exception cref="TimelineNameBadFormatException">
        /// Thrown when timeline name is of bad format.
        /// For normal timeline, it means name is an empty string.
        /// For personal timeline, it means the username is of bad format,
        /// the inner exception should be a <see cref="UsernameBadFormatException"/>.
        /// </exception>
        /// <exception cref="TimelineNotExistException">
        /// Thrown when timeline does not exist.
        /// For normal timeline, it means the name does not exist.
        /// For personal timeline, it means the user of that username does not exist
        /// and the inner exception should be a <see cref="UserNotExistException"/>.
        /// </exception>
        /// <exception cref="UsernameBadFormatException">Thrown if <paramref name="author"/> is of bad format.</exception>
        /// <exception cref="UserNotExistException">Thrown if <paramref name="author"/> does not exist.</exception>
        Task<long> Post(string name, string author, string content, DateTime? time);

        /// <summary>
        /// Set the visibility permission of a timeline. 
        /// </summary>
        /// <param name="name">Username or the timeline name. See remarks of <see cref="IBaseTimelineService"/>.</param>
        /// <param name="visibility">The new visibility.</param>
        /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/> is null.</exception>
        /// <exception cref="TimelineNameBadFormatException">
        /// Thrown when timeline name is of bad format.
        /// For normal timeline, it means name is an empty string.
        /// For personal timeline, it means the username is of bad format,
        /// the inner exception should be a <see cref="UsernameBadFormatException"/>.
        /// </exception>
        /// <exception cref="TimelineNotExistException">
        /// Thrown when timeline does not exist.
        /// For normal timeline, it means the name does not exist.
        /// For personal timeline, it means the user of that username does not exist
        /// and the inner exception should be a <see cref="UserNotExistException"/>.
        /// </exception>
        Task SetVisibility(string name, TimelineVisibility visibility);

        /// <summary>
        /// Set the description of a timeline.
        /// </summary>
        /// <param name="name">Username or the timeline name. See remarks of <see cref="IBaseTimelineService"/>.</param>
        /// <param name="description">The new description.</param>
        /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/> or <paramref name="description"/> is null.</exception>
        /// <exception cref="TimelineNameBadFormatException">
        /// Thrown when timeline name is of bad format.
        /// For normal timeline, it means name is an empty string.
        /// For personal timeline, it means the username is of bad format,
        /// the inner exception should be a <see cref="UsernameBadFormatException"/>.
        /// </exception>
        /// <exception cref="TimelineNotExistException">
        /// Thrown when timeline does not exist.
        /// For normal timeline, it means the name does not exist.
        /// For personal timeline, it means the user of that username does not exist
        /// and the inner exception should be a <see cref="UserNotExistException"/>.
        /// </exception>
        Task SetDescription(string name, string description);

        /// <summary>
        /// Add members to a timeline.
        /// </summary>
        /// <param name="name">Username or the timeline name. See remarks of <see cref="IBaseTimelineService"/>.</param>
        /// <param name="usernames">A list of new members' usernames</param>
        /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/> or <paramref name="usernames"/> is null.</exception>
        /// <exception cref="TimelineNameBadFormatException">
        /// Thrown when timeline name is of bad format.
        /// For normal timeline, it means name is an empty string.
        /// For personal timeline, it means the username is of bad format,
        /// the inner exception should be a <see cref="UsernameBadFormatException"/>.
        /// </exception>
        /// <exception cref="TimelineNotExistException">
        /// Thrown when timeline does not exist.
        /// For normal timeline, it means the name does not exist.
        /// For personal timeline, it means the user of that username does not exist
        /// and the inner exception should be a <see cref="UserNotExistException"/>.
        /// </exception>
        /// <exception cref="TimelineMemberOperationException">
        /// TODO! complete this documents.
        /// </exception>
        Task AddMember(string name, IList<string> usernames);

        /// <summary>
        /// Remove members to a timeline.
        /// </summary>
        /// <param name="name">Username or the timeline name. See remarks of <see cref="IBaseTimelineService"/>.</param>
        /// <param name="usernames">A list of members' usernames</param>
        /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/> is null.</exception>
        /// <exception cref="TimelineNameBadFormatException">
        /// Thrown when timeline name is of bad format.
        /// For normal timeline, it means name is an empty string.
        /// For personal timeline, it means the username is of bad format,
        /// the inner exception should be a <see cref="UsernameBadFormatException"/>.
        /// </exception>
        /// <exception cref="TimelineNotExistException">
        /// Thrown when timeline does not exist.
        /// For normal timeline, it means the name does not exist.
        /// For personal timeline, it means the user of that username does not exist
        /// and the inner exception should be a <see cref="UserNotExistException"/>.
        /// </exception>
        Task RemoveMember(string name, IList<string> usernames);
    }

    /// <summary>
    /// Service for normal timeline.
    /// </summary>
    public interface ITimelineService : IBaseTimelineService
    {
        /// <summary>
        /// Get the timeline info.
        /// </summary>
        /// <param name="name">The name of the timeline.</param>
        /// <returns>The timeline info.</returns>
        Task<TimelineInfo> GetTimeline(string name);

        /// <summary>
        /// Create a timeline.
        /// </summary>
        /// <param name="name">The name of the timeline.</param>
        /// <param name="owner">The owner of the timeline.</param>
        Task CreateTimeline(string name, string owner);
    }

    public interface IPersonalTimelineService : IBaseTimelineService
    {
        /// <summary>
        /// Get the timeline info.
        /// </summary>
        /// <param name="username">The username of the owner of the personal timeline.</param>
        /// <returns>The timeline info.</returns>
        Task<BaseTimelineInfo> GetTimeline(string username);
    }
}