using Xunit;
using XWorld.Server.Gateway;

namespace XWorld.Server.Gateway.Tests
{
    public class MatchmakerTests
    {
        [Fact]
        public void TwoEnqueues_SameBucket_PlayerCount2_Poll_ReturnsTwoHumanMatch()
        {
            var mm = new Matchmaker(timeoutTicks: 100);
            mm.Enqueue(pid: 1, gameId: "rps", version: 1, playerCount: 2, tick: 0);
            mm.Enqueue(pid: 2, gameId: "rps", version: 1, playerCount: 2, tick: 0);

            var matches = mm.Poll(currentTick: 0);

            Assert.Single(matches);
            var m = matches[0];
            Assert.Equal("rps", m.GameId);
            Assert.Equal(1, m.Version);
            Assert.Equal(2, m.Seats.Count);
            Assert.False(m.Seats[0].IsAi);
            Assert.False(m.Seats[1].IsAi);
            Assert.Equal(1, m.Seats[0].PlayerId);
            Assert.Equal(2, m.Seats[1].PlayerId);
        }

        [Fact]
        public void SingleEnqueue_PollAfterTimeout_Returns1Human1AiMatch()
        {
            var mm = new Matchmaker(timeoutTicks: 10);
            mm.Enqueue(pid: 7, gameId: "rps", version: 1, playerCount: 2, tick: 0);

            // Not timed out yet
            var early = mm.Poll(currentTick: 9);
            Assert.Empty(early);

            // Now timed out (currentTick - enqueuedTick > timeoutTicks → 11 - 0 = 11 > 10)
            var matches = mm.Poll(currentTick: 10);

            Assert.Single(matches);
            var m = matches[0];
            Assert.Equal(2, m.Seats.Count);
            // First seat is the real player
            Assert.False(m.Seats[0].IsAi);
            Assert.Equal(7, m.Seats[0].PlayerId);
            // Second seat is AI with negative pid
            Assert.True(m.Seats[1].IsAi);
            Assert.True(m.Seats[1].PlayerId < 0);
        }

        [Fact]
        public void NotFull_NotTimedOut_Poll_ReturnsEmpty()
        {
            var mm = new Matchmaker(timeoutTicks: 100);
            mm.Enqueue(pid: 3, gameId: "rps", version: 1, playerCount: 2, tick: 5);

            var matches = mm.Poll(currentTick: 50); // 50-5=45 <= 100, not timed out, not full

            Assert.Empty(matches);
        }

        [Fact]
        public void PlayerCount1_SingleEnqueue_PollImmediately_ReturnsMatch()
        {
            // playerCount=1 应立即成团（Matchmaker 仅按 playerCount 分桶，不加载具体游戏）
            var mm = new Matchmaker(timeoutTicks: 100);
            mm.Enqueue(pid: 5, gameId: "solo1p", version: 1, playerCount: 1, tick: 0);

            var matches = mm.Poll(currentTick: 0);

            Assert.Single(matches);
            Assert.Single(matches[0].Seats);
            Assert.False(matches[0].Seats[0].IsAi);
        }

        [Fact]
        public void Remove_DequeuesWaiter_SoNoMatchForms()
        {
            var mm = new Matchmaker(timeoutTicks: 100);
            mm.Enqueue(1, "rps", 1, 2, tick: 0);
            Assert.True(mm.Remove(1));
            mm.Enqueue(2, "rps", 1, 2, tick: 0); // 只剩玩家2，凑不齐2人
            Assert.Empty(mm.Poll(1));            // 未满未超时 → 无对局
            Assert.False(mm.Remove(999));        // 不存在的 pid
        }
    }
}