using System;
using Paca.App.Browser.Features;
using Xunit;

namespace Paca.Tests.App;

public class ChromeDownloadManagerParityTests
{
    private class FakeDownloadOperation : IDownloadOperation
    {
        public string Uri { get; set; } = "https://example.com/file.zip";
        public string FileName { get; set; } = "file.zip";
        public long TotalBytesToReceive { get; set; } = 100 * 1024 * 1024; // 100MB
        public long BytesReceived { get; set; } = 0;
        public string State { get; set; } = "InProgress";
        public event Action? Changed;

        public void Pause() { State = "Paused"; Changed?.Invoke(); }
        public void Resume() { State = "InProgress"; Changed?.Invoke(); }
        public void Cancel() { State = "Cancelled"; Changed?.Invoke(); }
        public void Notify(long received, string state)
        {
            BytesReceived = received;
            State = state;
            Changed?.Invoke();
        }
    }

    [Fact]
    public void PageDownloadItem_SizeProgressText_Formats_Correctly()
    {
        var fake = new FakeDownloadOperation { TotalBytesToReceive = 100 * 1024 * 1024, BytesReceived = 25 * 1024 * 1024 };
        var item = new PageDownloadItem(fake, "file.zip");

        Assert.Equal("25.0 MB / 100.0 MB", item.SizeProgressText);

        var unknownTotal = new FakeDownloadOperation { TotalBytesToReceive = 0, BytesReceived = 10 * 1024 * 1024 };
        var item2 = new PageDownloadItem(unknownTotal, "stream.bin");
        Assert.Equal("10.0 MB", item2.SizeProgressText);
    }

    [Fact]
    public void PageDownloadItem_EtaText_Calculations()
    {
        var fake = new FakeDownloadOperation { TotalBytesToReceive = 100 * 1024 * 1024, BytesReceived = 50 * 1024 * 1024 };
        var item = new PageDownloadItem(fake, "file.zip");

        // When bps is 0
        Assert.Equal("—", item.EtaText);

        // 50MB remaining. Speed = 5MB/s -> 10 seconds remaining
        item.UpdateSpeed(50 * 1024 * 1024, TimeSpan.FromSeconds(1));
        item.UpdateSpeed(55 * 1024 * 1024, TimeSpan.FromSeconds(1)); // 5 MB/s
        Assert.Contains("초 남음", item.EtaText);

        // When completed
        fake.Notify(100 * 1024 * 1024, "Completed");
        Assert.Equal("완료됨", item.EtaText);
    }
}