From 5e5e51102f020a4f399097ca3e7f374fe7e9cf76 Mon Sep 17 00:00:00 2001
From: Wizou <11647984+wiz0u@users.noreply.github.com>
Date: Wed, 9 Feb 2022 22:17:19 +0100
Subject: [PATCH] renamed Channels_GetAllParticipantsSlow. use clever alphabet
 and detect lying subcounts to fetch more entries. (WIP)

---
 src/Client.cs | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/src/Client.cs b/src/Client.cs
index f19d306..00164ac 100644
--- a/src/Client.cs
+++ b/src/Client.cs
@@ -1630,13 +1630,18 @@ namespace WTelegram
 		/// <summary>Helper method that tries to fetch all participants from a Channel (beyond Telegram server-side limitations)</summary>
 		/// <param name="channel">The channel to query</param>
 		/// <param name="includeKickBan">Also fetch the kicked/banned members?</param>
+		/// <param name="alphabet1">first letters used to search for in participants names<br/>(default values crafted with ♥ to find most latin and cyrillic names)</param>
+		/// <param name="alphabet2">second (and further) letters used to search for in participants names</param>
 		/// <returns>Field count indicates the total count of members. Field participants contains those that were successfully fetched</returns>
-		/// <remarks>This method can take a few minutes to complete on big channels. It likely won't be able to obtain the full total count of members</remarks>
-		public async Task<Channels_ChannelParticipants> Channels_GetAllParticipants(InputChannelBase channel, bool includeKickBan = false)
+		/// <remarks>⚠ This method can take a few minutes to complete on big broadcast channels. It likely won't be able to obtain the full total count of members</remarks>
+		public async Task<Channels_ChannelParticipants> Channels_GetAllParticipantsSlow(InputChannelBase channel, bool includeKickBan = false, string alphabet1 = "АБCДЕЄЖФГHИІJКЛМНОПQРСТУВWХЦЧШЩЫЮЯЗ", string alphabet2 = "АCЕHИJЛМНОРСТУВWЫ")
 		{
+			alphabet2 ??= alphabet1;
+			File.AppendAllText("AllPart.txt", alphabet1 + "\n");
+			var sw = System.Diagnostics.Stopwatch.StartNew();
 			var result = new Channels_ChannelParticipants { chats = new(), users = new() };
 
-			var sem = new SemaphoreSlim(10); // prevents flooding Telegram with requests
+			var sem = new SemaphoreSlim(1); // prevents flooding Telegram with requests
 			var user_ids = new HashSet<long>();
 			var participants = new List<ChannelParticipantBase>();
 
@@ -1644,30 +1649,33 @@ namespace WTelegram
 			{
 				GetWithFilter(new ChannelParticipantsAdmins()),
 				GetWithFilter(new ChannelParticipantsBots()),
-				GetWithFilter(new ChannelParticipantsSearch { q = "" }, (f, c) => new ChannelParticipantsSearch { q = f.q + c }),
+				GetWithFilter(new ChannelParticipantsSearch { q = "" }, (f, c) => new ChannelParticipantsSearch { q = f.q + c }, alphabet1),
 			};
 			var mcf = this.Channels_GetFullChannel(channel);
 			tasks.Add(mcf);
 			if (includeKickBan)
 			{
-				tasks.Add(GetWithFilter(new ChannelParticipantsKicked { q = "" }, (f, c) => new ChannelParticipantsKicked { q = f.q + c }));
-				tasks.Add(GetWithFilter(new ChannelParticipantsBanned { q = "" }, (f, c) => new ChannelParticipantsBanned { q = f.q + c }));
+				tasks.Add(GetWithFilter(new ChannelParticipantsKicked { q = "" }, (f, c) => new ChannelParticipantsKicked { q = f.q + c }, alphabet1));
+				tasks.Add(GetWithFilter(new ChannelParticipantsBanned { q = "" }, (f, c) => new ChannelParticipantsBanned { q = f.q + c }, alphabet1));
 			}
 			await Task.WhenAll(tasks);
 
 			result.count = ((ChannelFull)mcf.Result.full_chat).participants_count;
 			result.participants = participants.ToArray();
+			File.AppendAllText("AllPart.txt", $"{alphabet1} {participants.Count}/{result.count} in {sw.Elapsed}\n");
 			return result;
 
-			async Task GetWithFilter<T>(T filter, Func<T, char, T> recurse = null) where T : ChannelParticipantsFilter
+			async Task GetWithFilter<T>(T filter, Func<T, char, T> recurse = null, string alphabet = null) where T : ChannelParticipantsFilter
 			{
 				Channels_ChannelParticipants ccp;
+				int maxCount = 0;
 				for (int offset = 0; ;)
 				{
 					await sem.WaitAsync();
 					try
 					{
 						ccp = await this.Channels_GetParticipants(channel, filter, offset, 1024, 0);
+						if (ccp.count > maxCount) maxCount = ccp.count;
 					}
 					finally
 					{
@@ -1682,8 +1690,10 @@ namespace WTelegram
 					offset += ccp.participants.Length;
 					if (offset >= ccp.count || ccp.participants.Length == 0) break;
 				}
-				if (recurse != null && (ccp.count == 200 || ccp.count == 1000))
-					await Task.WhenAll(Enumerable.Range('a', 26).Select(c => GetWithFilter(recurse(filter, (char)c), recurse)));
+				Console.WriteLine($"{participants.Count} {(filter as ChannelParticipantsSearch)?.q} {ccp.count} {maxCount}");
+				File.AppendAllText("AllPart.txt", $"{(filter as ChannelParticipantsSearch)?.q}\t{participants.Count,4}\t{ccp.count}/{maxCount}\n");
+				if (recurse != null && (ccp.count < maxCount - 100 || ccp.count == 200 || ccp.count == 1000))
+					await Task.WhenAll(alphabet.Select(c => GetWithFilter(recurse(filter, (char)c), recurse, c == 'А' ? alphabet : alphabet2)));
 			}
 		}