using GmRelay.Web.Services;

namespace GmRelay.Bot.Tests.Web;

public sealed class AuthorizedSessionServiceTests
{
    [Fact]
    public async Task GetUpcomingSessionsForGmAsync_ReturnsSessions_WhenGroupBelongsToGm()
    {
        var gmId = 1001L;
        var groupId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", gmId)
            ],
            sessions:
            [
                new(Guid.NewGuid(), groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", Guid.NewGuid(), 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        var sessions = await service.GetUpcomingSessionsForGmAsync(groupId, gmId);

        Assert.NotNull(sessions);
        Assert.Single(sessions);
        Assert.Equal("Session A", sessions[0].Title);
    }

    [Fact]
    public async Task GetUpcomingSessionsForGmAsync_ReturnsNull_WhenGroupBelongsToAnotherGm()
    {
        var groupId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", 2002L)
            ]);
        var service = new AuthorizedSessionService(store);

        var sessions = await service.GetUpcomingSessionsForGmAsync(groupId, 1001L);

        Assert.Null(sessions);
    }

    [Fact]
    public async Task GetSessionForGmAsync_ReturnsSession_WhenSessionBelongsToOwnedGroup()
    {
        var gmId = 1001L;
        var groupId = Guid.NewGuid();
        var sessionId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", gmId)
            ],
            sessions:
            [
                new(sessionId, groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", Guid.NewGuid(), 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        var session = await service.GetSessionForGmAsync(sessionId, gmId);

        Assert.NotNull(session);
        Assert.Equal(sessionId, session.Id);
    }

    [Fact]
    public async Task GetSessionForGmAsync_ReturnsNull_WhenSessionBelongsToAnotherGm()
    {
        var groupId = Guid.NewGuid();
        var sessionId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", 2002L)
            ],
            sessions:
            [
                new(sessionId, groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", Guid.NewGuid(), 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        var session = await service.GetSessionForGmAsync(sessionId, 1001L);

        Assert.Null(session);
    }

    [Fact]
    public async Task UpdateSessionForGmAsync_Throws_WhenSessionBelongsToAnotherGm()
    {
        var groupId = Guid.NewGuid();
        var sessionId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", 2002L)
            ],
            sessions:
            [
                new(sessionId, groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", Guid.NewGuid(), 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        var action = () => service.UpdateSessionForGmAsync(sessionId, 1001L, "Updated", DateTime.UtcNow.AddDays(1), "https://example.test/b", 5);

        await Assert.ThrowsAsync<SessionAccessDeniedException>(action);
        Assert.False(store.UpdateCalled);
    }

    [Fact]
    public async Task UpdateSessionForGmAsync_UpdatesOwnedSession()
    {
        var gmId = 1001L;
        var groupId = Guid.NewGuid();
        var sessionId = Guid.NewGuid();
        var scheduledAt = DateTime.UtcNow.AddDays(1);
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", gmId)
            ],
            sessions:
            [
                new(sessionId, groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", Guid.NewGuid(), 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        await service.UpdateSessionForGmAsync(sessionId, gmId, "Updated", scheduledAt, "https://example.test/b", 5);

        Assert.True(store.UpdateCalled);
        Assert.Equal(groupId, store.LastUpdatedGroupId);
        Assert.Equal(sessionId, store.LastUpdatedSessionId);
        Assert.Equal("Updated", store.LastUpdatedTitle);
        Assert.Equal(scheduledAt, store.LastUpdatedScheduledAt);
        Assert.Equal("https://example.test/b", store.LastUpdatedJoinLink);
        Assert.Equal(5, store.LastUpdatedMaxPlayers);
    }

    [Fact]
    public async Task PromoteWaitlistedPlayerForGmAsync_PromotesOwnedSession()
    {
        var gmId = 1001L;
        var groupId = Guid.NewGuid();
        var sessionId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", gmId)
            ],
            sessions:
            [
                new(sessionId, groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", Guid.NewGuid(), 10, 42, 4, 3, 1)
            ]);
        var service = new AuthorizedSessionService(store);

        await service.PromoteWaitlistedPlayerForGmAsync(sessionId, gmId);

        Assert.True(store.PromoteCalled);
        Assert.Equal(groupId, store.LastPromotedGroupId);
        Assert.Equal(sessionId, store.LastPromotedSessionId);
    }

    [Fact]
    public async Task UpdateBatchDetailsForGmAsync_Throws_WhenBatchBelongsToAnotherGm()
    {
        var batchId = Guid.NewGuid();
        var groupId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", 2002L)
            ],
            sessions:
            [
                new(Guid.NewGuid(), groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", batchId, 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        var action = () => service.UpdateBatchDetailsForGmAsync(batchId, 1001L, "Updated", "https://example.test/b");

        await Assert.ThrowsAsync<SessionAccessDeniedException>(action);
        Assert.False(store.UpdateBatchDetailsCalled);
    }

    [Fact]
    public async Task UpdateBatchDetailsForGmAsync_UpdatesOwnedBatch()
    {
        var gmId = 1001L;
        var groupId = Guid.NewGuid();
        var batchId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", gmId)
            ],
            sessions:
            [
                new(Guid.NewGuid(), groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", batchId, 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        await service.UpdateBatchDetailsForGmAsync(batchId, gmId, "Updated", "https://example.test/b");

        Assert.True(store.UpdateBatchDetailsCalled);
        Assert.Equal(batchId, store.LastUpdatedBatchId);
        Assert.Equal(groupId, store.LastUpdatedBatchGroupId);
        Assert.Equal("Updated", store.LastUpdatedBatchTitle);
        Assert.Equal("https://example.test/b", store.LastUpdatedBatchJoinLink);
    }

    [Fact]
    public async Task RescheduleBatchForGmAsync_RejectsNonPositiveInterval()
    {
        var gmId = 1001L;
        var groupId = Guid.NewGuid();
        var batchId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", gmId)
            ],
            sessions:
            [
                new(Guid.NewGuid(), groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", batchId, 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        var action = () => service.RescheduleBatchForGmAsync(batchId, gmId, DateTime.UtcNow.AddDays(7), intervalDays: 0);

        await Assert.ThrowsAsync<ArgumentOutOfRangeException>(action);
        Assert.False(store.RescheduleBatchCalled);
    }

    [Fact]
    public async Task RescheduleBatchForGmAsync_ReschedulesOwnedBatch()
    {
        var gmId = 1001L;
        var groupId = Guid.NewGuid();
        var batchId = Guid.NewGuid();
        var firstScheduledAt = DateTime.UtcNow.AddDays(7);
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", gmId)
            ],
            sessions:
            [
                new(Guid.NewGuid(), groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", batchId, 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        await service.RescheduleBatchForGmAsync(batchId, gmId, firstScheduledAt, intervalDays: 14);

        Assert.True(store.RescheduleBatchCalled);
        Assert.Equal(batchId, store.LastRescheduledBatchId);
        Assert.Equal(groupId, store.LastRescheduledBatchGroupId);
        Assert.Equal(firstScheduledAt, store.LastRescheduledFirstScheduledAt);
        Assert.Equal(14, store.LastRescheduledIntervalDays);
    }

    [Fact]
    public async Task CloneBatchForGmAsync_ClonesOwnedBatch()
    {
        var gmId = 1001L;
        var groupId = Guid.NewGuid();
        var batchId = Guid.NewGuid();
        var store = new FakeSessionStore(
            groups:
            [
                new(groupId, 42, "Alpha", gmId)
            ],
            sessions:
            [
                new(Guid.NewGuid(), groupId, "Session A", DateTime.UtcNow, "Planned", "https://example.test/a", batchId, 10, 42, 4, 1, 0)
            ]);
        var service = new AuthorizedSessionService(store);

        await service.CloneBatchForGmAsync(batchId, gmId, BatchCloneInterval.NextWeek);

        Assert.True(store.CloneBatchCalled);
        Assert.Equal(batchId, store.LastClonedBatchId);
        Assert.Equal(groupId, store.LastClonedBatchGroupId);
        Assert.Equal(BatchCloneInterval.NextWeek, store.LastCloneInterval);
    }

    private sealed class FakeSessionStore(
        IEnumerable<WebGameGroup>? groups = null,
        IEnumerable<WebSession>? sessions = null) : ISessionStore
    {
        private readonly Dictionary<Guid, WebGameGroup> groupsById = groups?.ToDictionary(group => group.Id) ?? [];
        private readonly Dictionary<Guid, WebSession> sessionsById = sessions?.ToDictionary(session => session.Id) ?? [];

        public bool UpdateCalled { get; private set; }
        public bool PromoteCalled { get; private set; }
        public bool UpdateBatchDetailsCalled { get; private set; }
        public bool RescheduleBatchCalled { get; private set; }
        public bool CloneBatchCalled { get; private set; }
        public Guid? LastUpdatedSessionId { get; private set; }
        public Guid? LastUpdatedGroupId { get; private set; }
        public string? LastUpdatedTitle { get; private set; }
        public DateTime? LastUpdatedScheduledAt { get; private set; }
        public string? LastUpdatedJoinLink { get; private set; }
        public int? LastUpdatedMaxPlayers { get; private set; }
        public Guid? LastPromotedSessionId { get; private set; }
        public Guid? LastPromotedGroupId { get; private set; }
        public Guid? LastUpdatedBatchId { get; private set; }
        public Guid? LastUpdatedBatchGroupId { get; private set; }
        public string? LastUpdatedBatchTitle { get; private set; }
        public string? LastUpdatedBatchJoinLink { get; private set; }
        public Guid? LastRescheduledBatchId { get; private set; }
        public Guid? LastRescheduledBatchGroupId { get; private set; }
        public DateTime? LastRescheduledFirstScheduledAt { get; private set; }
        public int? LastRescheduledIntervalDays { get; private set; }
        public Guid? LastClonedBatchId { get; private set; }
        public Guid? LastClonedBatchGroupId { get; private set; }
        public BatchCloneInterval? LastCloneInterval { get; private set; }

        public Task<List<WebGameGroup>> GetGroupsForGmAsync(long gmId) =>
            Task.FromResult(groupsById.Values.Where(group => group.GmTelegramId == gmId).ToList());

        public Task<WebGameGroup?> GetGroupAsync(Guid groupId)
        {
            groupsById.TryGetValue(groupId, out var group);
            return Task.FromResult(group);
        }

        public Task<List<WebSession>> GetUpcomingSessionsAsync(Guid groupId) =>
            Task.FromResult(sessionsById.Values.Where(session => session.GroupId == groupId).ToList());

        public Task<WebSession?> GetSessionAsync(Guid sessionId)
        {
            sessionsById.TryGetValue(sessionId, out var session);
            return Task.FromResult(session);
        }

        public Task<WebSessionBatch?> GetBatchAsync(Guid batchId)
        {
            var batchSessions = sessionsById.Values
                .Where(session => session.BatchId == batchId)
                .OrderBy(session => session.ScheduledAt)
                .ToList();

            if (batchSessions.Count == 0)
            {
                return Task.FromResult<WebSessionBatch?>(null);
            }

            var firstSession = batchSessions[0];
            return Task.FromResult<WebSessionBatch?>(new(
                batchId,
                firstSession.GroupId,
                firstSession.Title,
                firstSession.JoinLink,
                firstSession.ScheduledAt,
                batchSessions[^1].ScheduledAt,
                batchSessions.Count));
        }

        public Task UpdateSessionAsync(Guid sessionId, Guid groupId, string title, DateTime scheduledAt, string joinLink, int? maxPlayers)
        {
            UpdateCalled = true;
            LastUpdatedSessionId = sessionId;
            LastUpdatedGroupId = groupId;
            LastUpdatedTitle = title;
            LastUpdatedScheduledAt = scheduledAt;
            LastUpdatedJoinLink = joinLink;
            LastUpdatedMaxPlayers = maxPlayers;
            return Task.CompletedTask;
        }

        public Task PromoteWaitlistedPlayerAsync(Guid sessionId, Guid groupId)
        {
            PromoteCalled = true;
            LastPromotedSessionId = sessionId;
            LastPromotedGroupId = groupId;
            return Task.CompletedTask;
        }

        public Task UpdateBatchDetailsAsync(Guid batchId, Guid groupId, string title, string joinLink)
        {
            UpdateBatchDetailsCalled = true;
            LastUpdatedBatchId = batchId;
            LastUpdatedBatchGroupId = groupId;
            LastUpdatedBatchTitle = title;
            LastUpdatedBatchJoinLink = joinLink;
            return Task.CompletedTask;
        }

        public Task RescheduleBatchAsync(Guid batchId, Guid groupId, DateTime firstScheduledAt, int intervalDays)
        {
            RescheduleBatchCalled = true;
            LastRescheduledBatchId = batchId;
            LastRescheduledBatchGroupId = groupId;
            LastRescheduledFirstScheduledAt = firstScheduledAt;
            LastRescheduledIntervalDays = intervalDays;
            return Task.CompletedTask;
        }

        public Task<WebSessionBatch> CloneBatchAsync(Guid batchId, Guid groupId, BatchCloneInterval interval)
        {
            CloneBatchCalled = true;
            LastClonedBatchId = batchId;
            LastClonedBatchGroupId = groupId;
            LastCloneInterval = interval;
            return Task.FromResult(new WebSessionBatch(
                Guid.NewGuid(),
                groupId,
                "Session A",
                "https://example.test/a",
                DateTime.UtcNow.AddDays(7),
                DateTime.UtcNow.AddDays(7),
                1));
        }
    }
}