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

namespace Application.Features.Api.Developers.Stats.UsageStats;

internal sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Result<Response>>
{
    private const int DefaultDays = 7;
    private const int MaxDays = 90;

    public async Task<Result<Response>> Handle(Query request, CancellationToken ct)
    {
        var days = Math.Clamp(request.Days <= 0 ? DefaultDays : request.Days, 1, MaxDays);
        var since = DateTime.UtcNow.AddDays(-days);

        // 본인 소유 앱 + 본인 PAT 만 집계
        var ownedAppIDs = await db.ApiApplication
            .Where(c => c.OwnerMemberID == request.OwnerMemberID)
            .Select(c => c.ID)
            .ToListAsync(ct);

        var ownedPatIDs = await db.ApiPersonalAccessToken
            .Where(c => c.OwnerMemberID == request.OwnerMemberID)
            .Select(c => c.ID)
            .ToListAsync(ct);

        var raw = await db.ApiRequestLog
            .Where(c => c.RequestedAt >= since &&
                ((c.ApplicationID != null && ownedAppIDs.Contains(c.ApplicationID.Value)) ||
                 (c.PatID != null && ownedPatIDs.Contains(c.PatID.Value))))
            .GroupBy(c => new { Date = DateOnly.FromDateTime(c.RequestedAt) })
            .Select(g => new DailyUsage(
                g.Key.Date,
                g.Count(),
                g.Count(c => c.StatusCode >= 400),
                (int)g.Average(c => (double)c.ResponseMs)
            ))
            .OrderBy(c => c.Date)
            .ToListAsync(ct);

        return Result.Success(new Response(raw));
    }
}