using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Domain.Entities.Feed;
using Microsoft.EntityFrameworkCore;
using SharedKernel.Results;

namespace Application.Features.Api.Feed.ToggleCommentLike;

public sealed class Handler(IAppDbContext db) : ICommandHandler<Command, Result<Response>>
{
    public async Task<Result<Response>> Handle(Command request, CancellationToken ct)
    {
        var comment = await db.FeedComment.FirstOrDefaultAsync(c => c.ID == request.CommentID && !c.IsDeleted, ct);
        if (comment is null)
        {
            return Result.Failure<Response>(Error.NotFound("Feed.CommentNotFound", "댓글을 찾을 수 없습니다."));
        }

        var existing = await db.FeedCommentLike.FirstOrDefaultAsync(l => l.FeedCommentID == request.CommentID && l.MemberID == request.MemberID, ct);

        bool hasLike;

        if (existing is null)
        {
            await db.FeedCommentLike.AddAsync(new FeedCommentLike
            {
                FeedPostID = comment.FeedPostID,
                FeedCommentID = request.CommentID,
                MemberID = request.MemberID
            }, ct);
            comment.Likes++;
            comment.Score = comment.Likes;
            hasLike = true;
        }
        else
        {
            db.FeedCommentLike.Remove(existing);
            comment.Likes = comment.Likes > 0 ? comment.Likes - 1 : 0;
            comment.Score = comment.Likes;
            hasLike = false;
        }

        await db.SaveChangesAsync(ct);

        return new Response(hasLike, comment.Likes);
    }
}