bitforum-backend/Application/Features/Api/Crypto/Ticker/GetAll/Handler.cs

using Application.Abstractions.Messaging;
using Application.Abstractions.Data;
using Application.Abstractions.Cache;
using Application.Abstractions.Crypto;
using Microsoft.EntityFrameworkCore;

namespace Application.Features.Api.Crypto.Ticker.GetAll;

public sealed class Handler(IAppDbContext db, ICacheService cache) : IQueryHandler<Query, Response>
{
    public async Task<Response> Handle(Query request, CancellationToken ct)
    {
        // Redis에서 Ticker 목록 가져오기
        var tickers = await cache.GetAsync<List<UpbitTicker>>(CacheKeys.CryptoTickers, ct) ?? [];
        var tickerMap = tickers.ToDictionary(t => t.Market, t => t);

        // DB에서 코인 정보 가져오기
        var coinsQuery = db.Coin
            .AsNoTracking()
            .Where(c => c.IsActive && !c.IsDelisted);

        if (request.FeaturedOnly)
        {
            coinsQuery = coinsQuery.Where(c => c.IsFeatured);
        }

        var coins = await coinsQuery
            .OrderByDescending(c => c.IsFeatured)
            .ThenBy(c => c.DisplayOrder)
            .ThenBy(c => c.Symbol)
            .Select(c => new
            {
                c.Symbol,
                c.KorName,
                c.EngName,
                c.LogoImage,
                c.IsFeatured,
                c.DisplayOrder
            })
            .ToListAsync(ct);

        var rows = new List<Response.Row>();

        foreach (var coin in coins)
        {
            var market = $"KRW-{coin.Symbol.ToUpper()}";
            tickerMap.TryGetValue(market, out var ticker);

            rows.Add(new Response.Row(
                coin.Symbol,
                coin.KorName,
                coin.EngName,
                coin.LogoImage,
                ticker?.TradePrice ?? 0m,
                ticker?.Change ?? "",
                ticker?.SignedChangePrice ?? 0m,
                ticker?.SignedChangeRate ?? 0m,
                ticker?.AccTradePrice24h ?? 0m,
                coin.IsFeatured,
                coin.DisplayOrder
            ));
        }

        return new Response(rows);
    }
}