using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Xunit;
using XWorld.Framework;
using XWorld.Framework.Protocol;
using XWorld.Server.Gateway;

namespace XWorld.Server.Gateway.Tests
{
    public class RpsEndToEndTests
    {
        // RPS ChoiceOpcode = 1 (same as SnapshotOpcode from RpsServerRoom)
        private const ushort RpsChoiceOpcode = 1;

        private static Frame RpsJoinFrame()
            => new Frame(Channel.Framework, (ushort)FrameworkOpcode.MatchRequest,
                new MatchRequestMsg { GameId = "rps", Version = 1 }.Encode());

        private static Frame RpsChoiceFrame(byte choice)
        {
            var w = new PacketWriter();
            w.WriteByte(choice);
            return new Frame(Channel.Game, RpsChoiceOpcode, w.ToArray());
        }

        /// <summary>
        /// Two real clients match → both receive MatchFound → play choices → both receive RoomEnd
        /// Uses large logicalDt so 60s RPS finishes in ~6 ticks (≈120ms wall-clock with 20ms interval)
        /// </summary>
        [Fact]
        public async Task TwoHumans_MatchAndPlayToRoomEnd()
        {
            var host = new GameServerHost();
            // matchTimeoutTicks=200 (generous, will fill by count=2)
            // logicalDt=11f: each tick advances 11 logical seconds → ~6 ticks > 60s
            await host.StartAsync(TestGames.Root, tickIntervalMs: 20,
                reconnectWindowTicks: 100, matchTimeoutTicks: 200, logicalDt: 11f);
            try
            {
                using var client1 = new WsTestClient();
                using var client2 = new WsTestClient();

                await client1.ConnectAsync(host.WsBaseUrl, pid: 1);
                await client2.ConnectAsync(host.WsBaseUrl, pid: 2);

                await client1.SendFrameAsync(RpsJoinFrame());
                await client2.SendFrameAsync(RpsJoinFrame());

                // Both clients need to collect frames until MatchFound, then send choices, then wait for RoomEnd
                bool c1MatchFound = false, c2MatchFound = false;
                bool c1RoomEnd = false, c2RoomEnd = false;
                string c1RoomId = null, c2RoomId = null;
                RoomEndMsg c1End = null, c2End = null;

                // Receive frames from both clients concurrently
                var t1 = Task.Run(async () =>
                {
                    for (int i = 0; i < 60 && !c1RoomEnd; i++)
                    {
                        Frame f;
                        try { f = await client1.ReceiveFrameAsync(3000); }
                        catch (TimeoutException) { break; }
                        catch (Exception) { break; }

                        if (f.Channel == Channel.Framework && f.Opcode == (ushort)FrameworkOpcode.MatchFound)
                        {
                            c1MatchFound = true;
                            var mf = MatchFoundMsg.Decode(f.Payload);
                            c1RoomId = mf.RoomId;
                            // Send Rock choice after matched
                            await client1.SendFrameAsync(RpsChoiceFrame(1));
                        }
                        else if (f.Channel == Channel.Game)
                        {
                            // Got a snapshot; keep sending Rock in case we're in Choosing phase
                            await client1.SendFrameAsync(RpsChoiceFrame(1));
                        }
                        else if (f.Channel == Channel.Framework && f.Opcode == (ushort)FrameworkOpcode.RoomEnd)
                        {
                            c1End = RoomEndMsg.Decode(f.Payload);
                            c1RoomEnd = true;
                        }
                    }
                });

                var t2 = Task.Run(async () =>
                {
                    for (int i = 0; i < 60 && !c2RoomEnd; i++)
                    {
                        Frame f;
                        try { f = await client2.ReceiveFrameAsync(3000); }
                        catch (TimeoutException) { break; }
                        catch (Exception) { break; }

                        if (f.Channel == Channel.Framework && f.Opcode == (ushort)FrameworkOpcode.MatchFound)
                        {
                            c2MatchFound = true;
                            var mf = MatchFoundMsg.Decode(f.Payload);
                            c2RoomId = mf.RoomId;
                            await client2.SendFrameAsync(RpsChoiceFrame(2)); // Paper
                        }
                        else if (f.Channel == Channel.Game)
                        {
                            await client2.SendFrameAsync(RpsChoiceFrame(2)); // Paper
                        }
                        else if (f.Channel == Channel.Framework && f.Opcode == (ushort)FrameworkOpcode.RoomEnd)
                        {
                            c2End = RoomEndMsg.Decode(f.Payload);
                            c2RoomEnd = true;
                        }
                    }
                });

                await Task.WhenAll(t1, t2);

                Assert.True(c1MatchFound, "client1 should receive MatchFound");
                Assert.True(c2MatchFound, "client2 should receive MatchFound");
                Assert.NotNull(c1RoomId);
                Assert.Equal(c1RoomId, c2RoomId); // Both in same room
                Assert.True(c1RoomEnd, "client1 should receive RoomEnd");
                Assert.True(c2RoomEnd, "client2 should receive RoomEnd");

                // 结算结果：blob 非占位（RPS 填入 UTF-8 比分文本），双端一致
                Assert.NotNull(c1End);
                Assert.NotNull(c2End);
                Assert.True(c1End.ResultBlob != null && c1End.ResultBlob.Length > 0, "RoomEnd 应携带结算 blob");
                Assert.Equal(c1End.WinnerPlayerId, c2End.WinnerPlayerId);
                Assert.Equal(c1End.ResultBlob, c2End.ResultBlob); // 网关按房间统一下发同一结算
                Assert.Contains(":", System.Text.Encoding.UTF8.GetString(c1End.ResultBlob)); // 比分/平局文本

                await client1.CloseAsync();
                await client2.CloseAsync();
            }
            finally { await host.StopAsync(); }
        }

        /// <summary>
        /// Single client + small matchTimeoutTicks → AI fill → client receives MatchFound with AI player → RoomEnd
        /// </summary>
        [Fact]
        public async Task SingleClient_AiFill_MatchAndPlayToRoomEnd()
        {
            var host = new GameServerHost();
            // matchTimeoutTicks=3: after ~3 ticks (60ms at 20ms interval), AI fills in
            // logicalDt=11f: large logical time step to finish RPS in ~6 ticks
            await host.StartAsync(TestGames.Root, tickIntervalMs: 20,
                reconnectWindowTicks: 100, matchTimeoutTicks: 3, logicalDt: 11f);
            try
            {
                using var client = new WsTestClient();
                await client.ConnectAsync(host.WsBaseUrl, pid: 7);
                await client.SendFrameAsync(RpsJoinFrame());

                bool matchFound = false;
                bool hasAiPlayer = false;
                bool roomEnd = false;
                RoomEndMsg end = null;

                for (int i = 0; i < 60 && !roomEnd; i++)
                {
                    Frame f;
                    try { f = await client.ReceiveFrameAsync(3000); }
                    catch (TimeoutException) { break; }
                    catch (Exception) { break; }

                    if (f.Channel == Channel.Framework && f.Opcode == (ushort)FrameworkOpcode.MatchFound)
                    {
                        matchFound = true;
                        var mf = MatchFoundMsg.Decode(f.Payload);
                        Assert.Equal(2, mf.Players.Count);
                        foreach (var p in mf.Players)
                            if (p.IsAI) { hasAiPlayer = true; Assert.True(p.PlayerId < 0); }
                        // Send Rock choice after matched
                        await client.SendFrameAsync(RpsChoiceFrame(1));
                    }
                    else if (f.Channel == Channel.Game)
                    {
                        // Keep sending Rock on each snapshot
                        await client.SendFrameAsync(RpsChoiceFrame(1));
                    }
                    else if (f.Channel == Channel.Framework && f.Opcode == (ushort)FrameworkOpcode.RoomEnd)
                    {
                        end = RoomEndMsg.Decode(f.Payload);
                        roomEnd = true;
                    }
                }

                Assert.True(matchFound, "Should receive MatchFound (with AI fill)");
                Assert.True(hasAiPlayer, "MatchFound should include an AI player");
                Assert.True(roomEnd, "Should receive RoomEnd after AI-fill game settles");
                Assert.NotNull(end);
                Assert.True(end.ResultBlob != null && end.ResultBlob.Length > 0, "AI 对局的 RoomEnd 也应携带结算 blob");

                await client.CloseAsync();
            }
            finally { await host.StopAsync(); }
        }
    }
}