using Microsoft.EntityFrameworkCore;
using SVSim.Database.Enums;
using SVSim.Database.Models;
using SVSim.Database.Repositories.Card;
using SVSim.Database.Repositories.Globals;

namespace SVSim.Database.Repositories.Viewer;

public class ViewerRepository : IViewerRepository
{
    protected readonly SVSimDbContext _dbContext;

    private const int MaxFriends = 20;

    public ViewerRepository(SVSimDbContext dbContext)
    {
        _dbContext = dbContext;
    }

    public async Task<Models.Viewer?> GetViewerBySocialConnection(SocialAccountType accountType, ulong socialId)
    {
        // SocialAccountConnection is [Owned]-by-Viewer — can't be queried as a top-level Set<T>.
        // Look up the Viewer that has a matching owned connection instead.
        return await _dbContext.Set<Models.Viewer>()
            .AsNoTracking()
            .FirstOrDefaultAsync(v => v.SocialAccountConnections.Any(sac =>
                sac.AccountType == accountType && sac.AccountId == socialId));
    }

    public async Task<Models.Viewer?> GetViewerWithSocials(long id)
    {
        return await _dbContext.Set<Models.Viewer>().AsNoTracking().Include(viewer => viewer.SocialAccountConnections)
            .FirstOrDefaultAsync(viewer => viewer.Id == id);
    }

    /// <summary>
    /// Loads a viewer with every navigation property needed to render the home-screen
    /// (/load/index). Heavy query — only call from LoadController.Index.
    /// </summary>
    public async Task<Models.Viewer?> GetViewerByShortUdid(long shortUdid)
    {
        return await _dbContext.Set<Models.Viewer>()
            .AsNoTracking()
            .Include(v => v.MissionData)
            .Include(v => v.Info).ThenInclude(i => i.SelectedEmblem)
            .Include(v => v.Info).ThenInclude(i => i.SelectedDegree)
            .Include(v => v.Currency)
            .Include(v => v.Classes).ThenInclude(c => c.Class).ThenInclude(c => c.LeaderSkins)
            .Include(v => v.Classes).ThenInclude(c => c.LeaderSkin)
            .Include(v => v.Decks).ThenInclude(d => d.Class)
            .Include(v => v.Decks).ThenInclude(d => d.Sleeve)
            .Include(v => v.Decks).ThenInclude(d => d.LeaderSkin)
            .Include(v => v.Cards).ThenInclude(c => c.Card)
            .Include(v => v.Items).ThenInclude(i => i.Item)
            .Include(v => v.Sleeves)
            .Include(v => v.Emblems)
            .Include(v => v.Degrees)
            .Include(v => v.LeaderSkins).ThenInclude(ls => ls.Class)
            .Include(v => v.MyPageBackgrounds)
            .FirstOrDefaultAsync(viewer => viewer.ShortUdid == shortUdid);
    }

    public async Task<Models.Viewer> RegisterViewer(string displayName, SocialAccountType socialType,
        ulong socialAccountIdentifier, ulong? shortUdid = null)
    {
        Models.Viewer viewer = new Models.Viewer
        {
            DisplayName = displayName
        };
        GameConfiguration gameConfig = await new GlobalsRepository(_dbContext).GetGameConfiguration("default");

        viewer.SocialAccountConnections.Add(new SocialAccountConnection
        {
            AccountId = socialAccountIdentifier,
            AccountType = socialType
        });

        viewer.Info.MaxFriends = gameConfig.MaxFriends;
        viewer.Info.CountryCode = "KOR";
        viewer.Info.BirthDate = DateTime.UtcNow;
        viewer.Currency.Crystals = gameConfig.DefaultCrystals;
        viewer.Currency.Rupees = gameConfig.DefaultRupees;
        viewer.Currency.RedEther = gameConfig.DefaultEther;
        viewer.MissionData.TutorialState = 100; // finishes tutorial for now

        // Load classes WITH their LeaderSkins — DefaultLeaderSkin iterates the nav collection
        // and would otherwise be null (audit §6 #3 latent NRE — this is the one).
        List<ClassEntry> classes = await _dbContext.Set<ClassEntry>()
            .Include(c => c.LeaderSkins)
            .ToListAsync();

        viewer.Classes = classes.Select(ce =>
        {
            var skin = ce.DefaultLeaderSkin ?? ce.LeaderSkins.FirstOrDefault();
            return new ViewerClassData
            {
                Class = ce,
                Exp = 0,
                Level = 0,
                LeaderSkin = skin ?? new LeaderSkinEntry { Id = 0, Name = "<missing>", ClassId = ce.Id }
            };
        }).ToList();

        if (gameConfig.DefaultSleeve is not null) viewer.Sleeves.Add(gameConfig.DefaultSleeve);
        if (gameConfig.DefaultDegree is not null) viewer.Degrees.Add(gameConfig.DefaultDegree);
        if (gameConfig.DefaultEmblem is not null) viewer.Emblems.Add(gameConfig.DefaultEmblem);
        if (gameConfig.DefaultMyPageBackground is not null) viewer.MyPageBackgrounds.Add(gameConfig.DefaultMyPageBackground);

        // Grant one of each class's default leader skin. Filter out the synthetic placeholders
        // (Id=0) and dedupe — skins are many-to-many via SleeveEntryViewer-style join.
        var grantedSkins = viewer.Classes
            .Select(vcd => vcd.LeaderSkin)
            .Where(s => s.Id != 0)
            .DistinctBy(s => s.Id)
            .ToList();
        viewer.LeaderSkins.AddRange(grantedSkins);

        _dbContext.Set<Models.Viewer>().Add(viewer);
        await _dbContext.SaveChangesAsync();
        return viewer;
    }
}