using Kruzya.TelegramBot.Core.Data;
using Kruzya.TelegramBot.Core.Extensions;
using Kruzya.TelegramBot.Core.Service;
using Microsoft.EntityFrameworkCore;
using Telegram.Bot.Types;
using West.TelegramBot.Reputation.Data;

namespace West.TelegramBot.Reputation.Service;

public class ReputationService : IReputation
{
    private readonly ReputationContext _reputationContext;

    public ReputationService(ReputationContext reputationContext)
    {
        _reputationContext = reputationContext;
    }

    public async Task<double> GetUserReputationAsync(Chat chat, User user)
    {
        var rep = await FindUserReputation(chat, user);

        return rep?.Value ?? 0;
    }

    public async Task<double> SetUserReputationAsync(Chat chat, User user, double value)
    {
        var rep = await FindUserReputation(chat, user) ?? new UserReputation
        {
            ChatId = chat.Id,
            UserId = user.Id
        };

        rep.Value = Math.Round(value, 2);
        _reputationContext.AddOrUpdate(rep);

        return rep.Value;
    }

    public async Task IncrementReputationAsync(Chat chat, User user, double diff)
    {
        await SetUserReputationAsync(chat, user, await GetUserReputationAsync(chat, user) + diff);
    }

    public async Task<double> GetReputationDiffAsync(Chat chat, User sender, User receiver)
    {
        var senderRep = await FindUserReputation(chat, sender);
        
        if (senderRep == null)
        {
            return 1;
        }

        var senderValue = senderRep.Value;
        return Math.Round(senderValue == 0 ? 1 : Math.Sqrt(senderValue), 2);
    }

    public async Task<IEnumerable<IReputationEntity>> GetChatRatingAsync(Chat chat, int limit = 10, int offset = 0)
    {
        return await _reputationContext.UserReputation
            .Where(r => r.ChatId == chat.Id && r.Value > 0D)
            .OrderByDescending(r => r.Value)
            .Skip(offset)
            .Take(limit)
            .ToListAsync();
    }

    private async Task<UserReputation?> FindUserReputation(Chat chat, User user)
    {
        return await _reputationContext.UserReputation.SingleOrDefaultAsync(
            e => e.ChatId == chat.Id && e.UserId == user.Id);
    }
}