using Microsoft.EntityFrameworkCore;
using NSubstitute;
using UniVerse.Application.DTOs.Lectures;
using UniVerse.Application.DTOs.Notifications;
using UniVerse.Application.Interfaces;
using UniVerse.Domain.Entities;
using UniVerse.Infrastructure.Data;
using UniVerse.Infrastructure.Services;
using Xunit;

namespace UniVerse.Api.Tests.Lectures;

public class LectureServiceTests
{
    [Fact]
    public async Task GetAllAsync_MarksLecturesEnrolledByCurrentUser()
    {
        await using var db = CreateDbContext();
        var service = new LectureService(db, Substitute.For<IGamificationService>(), Substitute.For<INotificationScheduler>());
        var startsAt = DateTime.UtcNow.AddDays(1);

        db.Users.Add(new User { Id = 1, Email = "student@test.local" });
        db.Courses.Add(new Course { Id = 1, Name = "Course" });
        db.Lectures.AddRange(
            Lecture(1, startsAt),
            Lecture(2, startsAt.AddDays(1)));
        db.LectureEnrollments.Add(new LectureEnrollment { LectureId = 1, UserId = 1 });
        await db.SaveChangesAsync();

        var result = await service.GetAllAsync(new LectureFilterRequest(null, null, null, null, null, null, null, null), 1);

        Assert.True(result.Items.Single(item => item.Id == 1).IsEnrolled);
        Assert.False(result.Items.Single(item => item.Id == 2).IsEnrolled);
    }

    [Fact]
    public async Task EnrollAsync_SchedulesLectureReminders()
    {
        await using var db = CreateDbContext();
        var scheduler = Substitute.For<INotificationScheduler>();
        var service = new LectureService(db, Substitute.For<IGamificationService>(), scheduler);
        var startsAt = DateTime.UtcNow.AddHours(4);

        db.Users.Add(new User { Id = 1, Email = "student@test.local", DisplayName = "Student" });
        db.Courses.Add(new Course { Id = 1, Name = "Course" });
        db.Lectures.Add(Lecture(1, startsAt));
        await db.SaveChangesAsync();

        await service.EnrollAsync(1, 1);

        await scheduler.Received(1).ScheduleAsync(
            Arg.Is<NotificationMessage>(m => m.Recipient == "student@test.local" && m.Subject.Contains("через 3 часа")),
            Arg.Is<DateTimeOffset>(d => d == new DateTimeOffset(startsAt.AddHours(-3))),
            "lecture-1-user-1-starts-in-3-hours",
            Arg.Any<CancellationToken>());
        await scheduler.Received(1).ScheduleAsync(
            Arg.Is<NotificationMessage>(m => m.Recipient == "student@test.local" && m.Subject.Contains("через 1 час")),
            Arg.Is<DateTimeOffset>(d => d == new DateTimeOffset(startsAt.AddHours(-1))),
            "lecture-1-user-1-starts-in-1-hour",
            Arg.Any<CancellationToken>());
        await scheduler.Received(1).ScheduleAsync(
            Arg.Is<NotificationMessage>(m => m.Recipient == "student@test.local" && m.Subject.Contains("Оцените")),
            Arg.Is<DateTimeOffset>(d => d == new DateTimeOffset(startsAt.AddHours(2))),
            "lecture-1-user-1-ended",
            Arg.Any<CancellationToken>());
    }

    [Fact]
    public async Task EnrollAsync_SkipsPastLectureReminders()
    {
        await using var db = CreateDbContext();
        var scheduler = Substitute.For<INotificationScheduler>();
        var service = new LectureService(db, Substitute.For<IGamificationService>(), scheduler);
        var startsAt = DateTime.UtcNow.AddMinutes(90);

        db.Users.Add(new User { Id = 1, Email = "student@test.local" });
        db.Courses.Add(new Course { Id = 1, Name = "Course" });
        db.Lectures.Add(Lecture(1, startsAt));
        await db.SaveChangesAsync();

        await service.EnrollAsync(1, 1);

        await scheduler.DidNotReceive().ScheduleAsync(
            Arg.Any<NotificationMessage>(),
            Arg.Any<DateTimeOffset>(),
            "lecture-1-user-1-starts-in-3-hours",
            Arg.Any<CancellationToken>());
        await scheduler.Received(2).ScheduleAsync(
            Arg.Any<NotificationMessage>(),
            Arg.Any<DateTimeOffset>(),
            Arg.Any<string>(),
            Arg.Any<CancellationToken>());
    }

    [Fact]
    public async Task UnenrollAsync_CancelsLectureReminders()
    {
        await using var db = CreateDbContext();
        var scheduler = Substitute.For<INotificationScheduler>();
        var service = new LectureService(db, Substitute.For<IGamificationService>(), scheduler);
        var startsAt = DateTime.UtcNow.AddHours(4);

        db.Users.Add(new User { Id = 1, Email = "student@test.local" });
        db.Courses.Add(new Course { Id = 1, Name = "Course" });
        db.Lectures.Add(Lecture(1, startsAt));
        db.LectureEnrollments.Add(new LectureEnrollment { LectureId = 1, UserId = 1 });
        await db.SaveChangesAsync();

        await service.UnenrollAsync(1, 1);

        await scheduler.Received(1).CancelAsync("lecture-1-user-1-starts-in-3-hours", Arg.Any<CancellationToken>());
        await scheduler.Received(1).CancelAsync("lecture-1-user-1-starts-in-1-hour", Arg.Any<CancellationToken>());
        await scheduler.Received(1).CancelAsync("lecture-1-user-1-ended", Arg.Any<CancellationToken>());
    }

    private static AppDbContext CreateDbContext()
    {
        var options = new DbContextOptionsBuilder<AppDbContext>()
            .UseInMemoryDatabase($"LectureServiceTests_{Guid.NewGuid()}")
            .Options;
        return new AppDbContext(options);
    }

    private static Lecture Lecture(int id, DateTime startsAt) => new()
    {
        Id = id,
        CourseId = 1,
        Title = $"Lecture {id}",
        StartsAt = startsAt,
        EndsAt = startsAt.AddHours(2),
        IsOpen = true,
        MaxEnrollments = 30
    };
}