using decePubClient.E2E.Support;

using Microsoft.Playwright;

namespace decePubClient.E2E.Actions
{
	// Coming back to the feed from a thread shows it as it was left, with its older pages, without reading it again
	// (Services/FeedMemory.cs).
	public sealed class FeedMemoryTests(Browser browser)
	{
		[Fact]
		public async Task The_feed_comes_back_from_a_thread_as_it_was_left()
		{
			var persona = Pasture.Personas().First();
			await using var session = await SignIn.As(browser, persona);
			var page = session.Page;
			// a deletion the stream tells (late federated Deletes from the tests before) takes its post out at once
			var deletions = 0;
			page.WebSocket += (_, socket) => socket.FrameReceived += (_, frame) =>
			{
				if (frame.Text?.Contains("\"event\":\"delete\"") == true)
					Interlocked.Increment(ref deletions);
			};
			await Results.Cell("client.action.feed-memory", "privapub", persona.UserName, async () =>
			{
				await page.GotoAsync($"{Pasture.Site}/");
				await page.EvaluateAsync("() => localStorage.removeItem('FeedFilter')");
				await page.GotoAsync($"{Pasture.Site}/");
				var feed = page.Locator("[data-feed-count]");
				await page.Locator("article[data-uri]").First.WaitForAsync(new() { Timeout = 30000 });
				// an older page too when there is one, so there is more to keep than the first
				await page.EvalOnSelectorAsync("#feed-scroll", "root => root.scrollTop = root.scrollHeight");
				await Pasture.Eventually(async () => int.Parse(await feed.GetAttributeAsync("data-feed-count") ?? "0") > 20, 10);
				var count = int.Parse(await feed.GetAttributeAsync("data-feed-count") ?? "0");
				var deletedBefore = Volatile.Read(ref deletions);

				var homeReads = 0;
				page.Request += (_, request) =>
				{
					if (request.Url.Contains("/api/v1/timelines/home") && !request.Url.Contains("min_id"))
						homeReads++;
				};
				await page.EvalOnSelectorAsync("#feed-scroll", "root => root.scrollTop = 0");
				await page.Locator("article[data-uri] footer a[title='Expand']").First.ClickAsync();
				await page.WaitForURLAsync("**/expand/**");
				await page.GoBackAsync();
				await page.Locator("article[data-uri]").First.WaitForAsync(new() { Timeout = 10000 });

				var back = int.Parse(await feed.GetAttributeAsync("data-feed-count") ?? "0");
				var deleted = Volatile.Read(ref deletions) - deletedBefore;
				Assert.True(back >= count - deleted, $"the feed came back with {back} posts, left with {count} ({deleted} deleted meanwhile)");
				Assert.Equal(0, homeReads);
				await session.AssertGuards();
			}, page);
		}
	}
}