using System;
using System.IO;
using System.Threading;
using Aging.Infrastructure.Core;
using Aging.Infrastructure.Contracts;
using Xunit;

namespace Aging.MvpTests
{
    public class LayeredResourceManagerTests : IDisposable
    {
        private readonly string _dbPath;
        private readonly LayeredResourceManager _rm;

        public LayeredResourceManagerTests()
        {
            _dbPath = Path.Combine(Path.GetTempPath(),
                "arb_" + Guid.NewGuid().ToString("N") + ".db");
            _rm = new LayeredResourceManager(new DbLeaseStore(_dbPath, "local-main"));
        }

        public void Dispose() { try { File.Delete(_dbPath); File.Delete(_dbPath + "-wal"); File.Delete(_dbPath + "-shm"); } catch { } }

        [Fact]
        public void ReserveAsync_Then_ValidateOwner_True()
        {
            var owner = new ResourceOwnerToken(OwnerType.Maintenance, "W01");
            var key = new ResourceKey("CAN-002", "CAN");
            var res = _rm.ReserveAsync(owner, key, CancellationToken.None)
                         .GetAwaiter().GetResult();
            Assert.Equal(ReservationState.Active, res.State);
            Assert.True(_rm.ValidateOwner(owner, key));
        }

        [Fact]
        public void ReserveAsync_Conflict_ExceptionCarriesHolder()
        {
            var a = new ResourceOwnerToken(OwnerType.Maintenance, "holder-A");
            var b = new ResourceOwnerToken(OwnerType.Production, "requester-B");
            var key = new ResourceKey("CAN-002", "CAN");
            _rm.ReserveAsync(a, key, CancellationToken.None).GetAwaiter().GetResult();
            var ex = Assert.Throws<ResourceConflictException>(() =>
                _rm.ReserveAsync(b, key, CancellationToken.None).GetAwaiter().GetResult());
            Assert.Contains("holder-A", ex.Message);
        }

        [Fact]
        public void ValidateOwner_DoesNotShrinkLease_KeepsFullTtl()
        {
            // 回归：ValidateOwner 曾以 Renew(grant,1) 校验，会把租约到期砍到 now+1s，
            // 导致作用域租约心跳 Renew 因“已过期”失败≥2 → 误报“租约已失效”。
            var owner = new ResourceOwnerToken(OwnerType.Production, "auto_x");
            var key = new ResourceKey("CAN-001", "Generic");
            _rm.ReserveAsync(owner, key, CancellationToken.None).GetAwaiter().GetResult();

            // 模拟 DeviceService 每次操作前的栅栏校验
            Assert.True(_rm.ValidateOwner(owner, key));

            var holder = _rm.Coordinator.ProbeConflict(key.ToString());
            Assert.NotNull(holder);
            long nowMs = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
            Assert.True(holder!.ExpiresUtcMs - nowMs > 60_000,
                $"ValidateOwner 不应砍短租约，剩余应≈TTL，实际剩余 {(holder.ExpiresUtcMs - nowMs) / 1000}s");

            // 校验后心跳式续期仍应成功（租约未过期）
            Assert.True(_rm.TryGetGrants(owner.TokenId, out var grants));
            Assert.True(_rm.Coordinator.Renew(grants![0], 30));
        }

        [Fact]
        public void ReleaseReservationAsync_Then_OtherCanReserve()
        {
            var a = new ResourceOwnerToken(OwnerType.Maintenance, "A");
            var b = new ResourceOwnerToken(OwnerType.Production, "B");
            var key = new ResourceKey("CAN-002", "CAN");
            _rm.ReserveAsync(a, key, CancellationToken.None).GetAwaiter().GetResult();
            _rm.ReleaseReservationAsync(a, key, CancellationToken.None).GetAwaiter().GetResult();
            var ok = _rm.ReserveAsync(b, key, CancellationToken.None).GetAwaiter().GetResult();
            Assert.Equal(ReservationState.Active, ok.State);
        }
    }
}