using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Microsoft.EntityFrameworkCore;
using SharedKernel.Results;

namespace Application.Features.Api.Member.GetPosts;

public sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Result<Response>>
{
    private const string FeedBoardCode = "feed";

    public async Task<Result<Response>> Handle(Query request, CancellationToken ct)
    {
        var member = await db.Member.AsNoTracking().Where(m => m.SID == request.MemberSID && !m.IsWithdraw).Select(m => new { m.ID }).FirstOrDefaultAsync(ct);
        if (member is null)
        {
            return Result.Failure<Response>(Error.NotFound("Member.NotFound", "회원을 찾을 수 없습니다."));
        }

        var feedBoardID = await db.Board.AsNoTracking().Where(b => b.Code == FeedBoardCode).Select(b => (int?)b.ID).FirstOrDefaultAsync(ct);
        var viewerID = request.ViewerMemberID ?? 0;
        var isSelf = viewerID > 0 && viewerID == member.ID;

        var query = db.Post.AsNoTracking()
            .Where(p => p.MemberID == member.ID && !p.IsDeleted && p.BoardID != (feedBoardID ?? -1));

        if (!isSelf)
        {
            query = query.Where(p => !p.IsSecret && !p.IsAnonymous);
        }

        var total = await query.LongCountAsync(ct);
        var skip = (request.Page - 1) * request.PerPage;

        var list = await query
            .OrderByDescending(p => p.CreatedAt)
            .Skip(skip)
            .Take(request.PerPage)
            .Select(p => new Response.Row
            {
                PostID = p.ID,
                BoardID = p.BoardID,
                BoardCode = p.Board.Code,
                BoardName = p.Board.Name,
                Subject = p.Subject,
                Thumbnail = p.Thumbnail,
                Views = p.Views,
                Likes = p.Likes,
                Comments = p.Comments,
                CreatedAt = p.CreatedAt
            })
            .ToListAsync(ct);

        return new Response
        {
            Total = total,
            List = list
        };
    }
}