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)
            ]);
        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)
            ]);
        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)
            ]);
        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)
            ]);
        var service = new AuthorizedSessionService(store);

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

        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)
            ]);
        var service = new AuthorizedSessionService(store);

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

        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);
    }

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