using Nuuru.Server.DTOs.Forum;
using Nuuru.Server.DTOs.Reaction;
using Nuuru.Server.Models.Forum;
using Nuuru.Server.Services;

namespace Nuuru.Server.Extensions
{
    /// <summary>
    /// Extension methods for mapping between Forum entities and DTOs
    /// </summary>
    public static class ForumMappingExtensions
    {
        /// <summary>
        /// Maps a ForumCategory entity to ForumCategoryDto
        /// </summary>
        public static ForumCategoryDto ToDto(this ForumCategory category, int threadCount = 0, int postCount = 0, ForumThread? latestThread = null, Dictionary<Guid, UserDisplayInfo>? displayInfoMap = null)
        {
            if (category == null) return null!;

            return new ForumCategoryDto
            {
                Id = category.Id,
                Slug = category.Slug.StartsWith("clan-") ? "clan" : category.Slug,
                Name = category.Name,
                Description = category.Description,
                DisplayOrder = category.DisplayOrder,
                Color = category.Color,
                ThreadCount = threadCount,
                PostCount = postCount,
                LatestThread = latestThread?.ToSummaryDto(displayInfoMap)
            };
        }

        /// <summary>
        /// Maps a ForumCategory entity to ForumCategorySummaryDto
        /// </summary>
        public static ForumCategorySummaryDto ToSummaryDto(this ForumCategory category)
        {
            if (category == null) return null!;

            return new ForumCategorySummaryDto
            {
                Id = category.Id,
                Slug = category.Slug.StartsWith("clan-") ? "clan" : category.Slug,
                Name = category.Name,
                Color = category.Color
            };
        }

        /// <summary>
        /// Maps a ForumThread entity to ForumThreadDto
        /// </summary>
        public static ForumThreadDto ToDto(this ForumThread thread, bool includeFirstPost = false, Guid? requestingUserId = null, Dictionary<Guid, UserDisplayInfo>? displayInfoMap = null)
        {
            if (thread == null) return null!;

            UserDisplayInfo? authorDisplayInfo = null;
            if (thread.Author != null && displayInfoMap != null)
            {
                displayInfoMap.TryGetValue(thread.Author.Id, out authorDisplayInfo);
            }

            UserDisplayInfo? lastPostAuthorDisplayInfo = null;
            if (thread.LastPost?.Author != null && displayInfoMap != null)
            {
                displayInfoMap.TryGetValue(thread.LastPost.Author.Id, out lastPostAuthorDisplayInfo);
            }

            var threadBansEnabled = !string.Equals(thread.Category?.Slug, "gen", StringComparison.OrdinalIgnoreCase);
            var canManageBans = threadBansEnabled && requestingUserId.HasValue && thread.AuthorId == requestingUserId.Value;
            var currentUserIsBanned = requestingUserId.HasValue
                && threadBansEnabled
                && thread.UserBans.Any(b => b.UserId == requestingUserId.Value);

            return new ForumThreadDto
            {
                Id = thread.Id,
                Title = thread.Title,
                IsPinned = thread.IsPinned,
                IsLocked = thread.IsLocked,
                CurrentUserCanManageBans = canManageBans,
                CurrentUserIsBanned = currentUserIsBanned,
                CreatedAt = thread.CreatedAt,
                LastPostAt = thread.LastPostAt,
                ReplyCount = thread.ReplyCount,
                ViewCount = thread.ViewCount,
                Author = thread.Author?.ToUploaderDto(authorDisplayInfo)!,
                LastPostId = thread.LastPostId,
                LastPostAuthor = thread.LastPost?.Author?.ToUploaderDto(lastPostAuthorDisplayInfo),
                Category = thread.Category?.ToSummaryDto()!,
                FirstPost = includeFirstPost ? thread.FirstPost?.ToDto(requestingUserId, displayInfoMap) : null,
                BannedUsers = canManageBans
                    ? thread.UserBans
                        .Where(b => b.User != null)
                        .OrderBy(b => b.User.UserName)
                        .Select(b =>
                        {
                            UserDisplayInfo? bannedUserDisplayInfo = null;
                            displayInfoMap?.TryGetValue(b.UserId, out bannedUserDisplayInfo);
                            return new ForumThreadBannedUserDto
                            {
                                User = b.User.ToUploaderDto(bannedUserDisplayInfo),
                                BannedAt = b.CreatedAt
                            };
                        })
                        .ToList()
                    : []
            };
        }

        /// <summary>
        /// Maps a ForumThread entity to ForumThreadSummaryDto
        /// </summary>
        public static ForumThreadSummaryDto ToSummaryDto(this ForumThread thread, Dictionary<Guid, UserDisplayInfo>? displayInfoMap = null)
        {
            if (thread == null) return null!;

            UserDisplayInfo? authorDisplayInfo = null;
            if (thread.Author != null && displayInfoMap != null)
            {
                displayInfoMap.TryGetValue(thread.Author.Id, out authorDisplayInfo);
            }

            UserDisplayInfo? lastPostAuthorDisplayInfo = null;
            if (thread.LastPost?.Author != null && displayInfoMap != null)
            {
                displayInfoMap.TryGetValue(thread.LastPost.Author.Id, out lastPostAuthorDisplayInfo);
            }

            return new ForumThreadSummaryDto
            {
                Id = thread.Id,
                Title = thread.Title,
                LastPostAt = thread.LastPostAt,
                ReplyCount = thread.ReplyCount,
                Author = thread.Author?.ToUploaderDto(authorDisplayInfo)!,
                LastPostId = thread.LastPostId,
                LastPostAuthor = thread.LastPost?.Author?.ToUploaderDto(lastPostAuthorDisplayInfo)
            };
        }

        /// <summary>
        /// Maps a collection of ForumThreads to ForumThreadDtos
        /// </summary>
        public static List<ForumThreadDto> ToDto(this IEnumerable<ForumThread> threads, bool includeFirstPost = false, Guid? requestingUserId = null, Dictionary<Guid, UserDisplayInfo>? displayInfoMap = null)
        {
            return threads?.Select(t => t.ToDto(includeFirstPost, requestingUserId, displayInfoMap)).ToList() ?? new List<ForumThreadDto>();
        }

        /// <summary>
        /// Maps a ForumPost entity to ForumPostDto
        /// </summary>
        /// <param name="post">The post to map</param>
        /// <param name="requestingUserId">If provided, includes raw content only if this user is the author</param>
        /// <param name="displayInfoMap">Optional display info map for badge/color lookup</param>
        /// <param name="reactionsMap">Optional reactions map for reaction data</param>
        public static ForumPostDto ToDto(
            this ForumPost post,
            Guid? requestingUserId = null,
            Dictionary<Guid, UserDisplayInfo>? displayInfoMap = null,
            Dictionary<int, ReactionDTO>? reactionsMap = null)
        {
            if (post == null) return null!;

            UserDisplayInfo? authorDisplayInfo = null;
            if (post.Author != null && displayInfoMap != null)
            {
                displayInfoMap.TryGetValue(post.Author.Id, out authorDisplayInfo);
            }

            ReactionDTO? reactions = null;
            reactionsMap?.TryGetValue(post.Id, out reactions);

            return new ForumPostDto
            {
                Id = post.Id,
                ContentHtml = post.ContentHtml,
                // Only include raw content for the author (so they can edit)
                ContentRaw = requestingUserId.HasValue && post.AuthorId == requestingUserId.Value
                    ? post.ContentRaw
                    : null,
                CreatedAt = post.CreatedAt,
                EditedAt = post.EditedAt,
                Author = post.Author?.ToUploaderDto(authorDisplayInfo)!,
                ThreadId = post.ThreadId,
                Thread = post.Thread != null ? new ForumPostThreadDto
                {
                    Id = post.Thread.Id,
                    Title = post.Thread.Title,
                    Category = post.Thread.Category?.ToSummaryDto()
                } : null,
                Reactions = reactions
            };
        }

        /// <summary>
        /// Maps a collection of ForumPosts to ForumPostDtos
        /// </summary>
        public static List<ForumPostDto> ToDto(
            this IEnumerable<ForumPost> posts,
            Guid? requestingUserId = null,
            Dictionary<Guid, UserDisplayInfo>? displayInfoMap = null,
            Dictionary<int, ReactionDTO>? reactionsMap = null)
        {
            return posts?.Select(p => p.ToDto(requestingUserId, displayInfoMap, reactionsMap)).ToList() ?? new List<ForumPostDto>();
        }
    }
}