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

namespace Application.Features.Api.Paper.GetLedger;

internal sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Response>
{
    public async Task<Response> Handle(Query request, CancellationToken ct)
    {
        var accountID = await db.PaperAccount.AsNoTracking().Where(c => c.MemberID == request.MemberID).Select(c => (int?)c.ID).FirstOrDefaultAsync(ct);

        if (accountID is null)
        {
            return new Response(0, []);
        }

        var query = db.PaperLedger.AsNoTracking().Where(c => c.AccountID == accountID.Value);

        var total = await query.CountAsync(ct);

        var rows = await query
            .OrderByDescending(c => c.ID)
            .Skip((request.Page - 1) * request.PerPage)
            .Take(request.PerPage)
            .Select(c => new
            {
                c.ID,
                c.Type,
                c.TokenAmount,
                c.UnitsDelta,
                c.BalanceAfter,
                c.CreatedAt
            })
            .ToListAsync(ct);

        var list = rows.Select(c => new Response.Row(
            c.ID,
            c.Type.ToString(),
            c.TokenAmount,
            c.UnitsDelta,
            c.BalanceAfter,
            c.CreatedAt
        )).ToList();

        return new Response(total, list);
    }
}