using System.Diagnostics;
using Application.Abstractions.Cache;
using Application.Abstractions.Messaging;
using Application.Abstractions.YouTube;
using SharedKernel.Results;

namespace Application.Features.Admin.Channel.YouTubePubSub.TestApiKey;

internal sealed class Handler(
    IYouTubeApiConnectionTester tester,
    IYouTubeApiKeyProvider keyProvider,
    ICacheService cache
) : ICommandHandler<Command, Result<Response>>
{
    // Google Developers 공식 샘플 채널 — 퍼블릭/안정/삭제되지 않을 채널
    private const string TestChannelId = "UC_x5XG1OV2P6uZZ5FSM9Ttw";
    private static readonly TimeSpan Cooldown = TimeSpan.FromSeconds(30);

    public async Task<Result<Response>> Handle(Command request, CancellationToken ct)
    {
        // 30초 쿨다운 (quota 낭비 방지)
        var locked = await cache.TryLockAsync(CacheKeys.YouTubeApiTestKeyCooldown, Cooldown, ct);
        if (!locked)
        {
            return Result.Failure<Response>(Error.Problem(
                "YouTube.TestApiKey.Cooldown",
                "30초 쿨다운 중입니다. 잠시 후 다시 시도하세요."
            ));
        }

        // 방금 저장된 API Key가 캐시에 묻히는 문제 회피 — 테스트 직전 무효화
        keyProvider.Invalidate();

        var sw = Stopwatch.StartNew();
        var result = await tester.TestAsync(TestChannelId, ct);
        sw.Stop();

        return Result.Success(new Response(
            Ok: result.Ok,
            ElapsedMs: sw.ElapsedMilliseconds,
            TestedChannelName: result.ChannelTitle,
            TestedChannelId: result.ChannelId,
            ErrorMessage: result.ErrorMessage
        ));
    }
}