using Microsoft.EntityFrameworkCore;
using Novelly.Api.Chapters;
using Novelly.Api.Common;
using Novelly.Api.Novels;
using Novelly.Api.Users;

namespace Novelly.Api.Tests;

[TestFixture]
public class NovelAccessTests : ServiceTestFixture
{
    private Guid AsNewUser(GlobalRole globalRole)
    {
        var user = new NovellyUser
        {
            Id = Guid.NewGuid(),
            UserName = $"{Guid.NewGuid()}@novelly.test",
            Email = $"{Guid.NewGuid()}@novelly.test",
            DisplayName = "Test User",
            GlobalRole = globalRole
        };
        Db.Context.Users.Add(user);
        Db.Context.SaveChanges();

        UserContext.UserId = user.Id;
        UserContext.GlobalRole = globalRole;
        return user.Id;
    }

    private void GrantNovelRole(Guid novelId, Guid userId, NovelRole role)
    {
        Db.Context.NovelMembers.Add(new NovelMember { NovelId = novelId, UserId = userId, NovelRole = role, GrantedByUserId = userId });
        Db.Context.SaveChanges();
    }

    private void AsAdmin()
    {
        UserContext.UserId = Db.Context.Users.Single(u => u.GlobalRole == GlobalRole.Admin).Id;
        UserContext.GlobalRole = GlobalRole.Admin;
    }

    [Test]
    public async Task A_writer_sees_only_novels_they_own_or_have_been_granted()
    {
        var writerId = AsNewUser(GlobalRole.Writer);
        var ownedNovel = await Novels.CreateAsync(new CreateNovelRequest("Owned by writer"));

        AsAdmin();
        var otherNovel = await Novels.CreateAsync(new CreateNovelRequest("Owned by someone else"));

        UserContext.UserId = writerId;
        UserContext.GlobalRole = GlobalRole.Writer;

        var visibleBeforeGrant = await Novels.ListAsync();
        Assert.That(visibleBeforeGrant.Select(p => p.Id), Is.EquivalentTo(new[] { ownedNovel.Id }));

        GrantNovelRole(otherNovel.Id, writerId, NovelRole.Reviewer);

        var visibleAfterGrant = await Novels.ListAsync();
        Assert.That(visibleAfterGrant.Select(p => p.Id), Is.EquivalentTo(new[] { ownedNovel.Id, otherNovel.Id }));
    }

    [Test]
    public async Task An_editor_can_rewrite_a_chapter_but_cannot_delete_it()
    {
        var novel = await Novels.CreateAsync(new CreateNovelRequest("Editable Novel"));
        var chapter = await Chapters.CreateAsync(novel.Id, new CreateChapterRequest("Chapter One"));

        var editorId = AsNewUser(GlobalRole.Reviewer);
        GrantNovelRole(novel.Id, editorId, NovelRole.Editor);

        var updated = await Chapters.UpdateAsync(chapter!.Id, new UpdateChapterRequest(Title: "Renamed"));
        Assert.That(updated!.Title, Is.EqualTo("Renamed"));

        Assert.That(() => Chapters.DeleteAsync(chapter.Id), Throws.TypeOf<NotAuthorizedException>());
    }

    [Test]
    public void An_editor_cannot_create_a_new_novel()
    {
        AsNewUser(GlobalRole.Editor);

        Assert.That(() => Novels.CreateAsync(new CreateNovelRequest("Should not exist")), Throws.TypeOf<NotAuthorizedException>());
    }

    [Test]
    public async Task A_reviewer_can_read_a_chapter_but_not_change_it()
    {
        var novel = await Novels.CreateAsync(new CreateNovelRequest("Reviewed Novel"));
        var chapter = await Chapters.CreateAsync(novel.Id, new CreateChapterRequest("Chapter One"));

        var reviewerId = AsNewUser(GlobalRole.Reviewer);
        GrantNovelRole(novel.Id, reviewerId, NovelRole.Reviewer);

        var read = await Chapters.GetAsync(chapter!.Id);
        Assert.That(read, Is.Not.Null);

        Assert.That(
            () => Chapters.UpdateAsync(chapter.Id, new UpdateChapterRequest(Title: "Nope")),
            Throws.TypeOf<NotAuthorizedException>());
    }

    [Test]
    public async Task A_writer_granted_access_to_someone_elses_novel_still_cannot_grant_access_to_others()
    {
        var novel = await Novels.CreateAsync(new CreateNovelRequest("Someone Else's Novel"));

        var grantedWriterId = AsNewUser(GlobalRole.Writer);
        GrantNovelRole(novel.Id, grantedWriterId, NovelRole.Writer);

        Assert.That(
            () => Access.RequireAsync(novel.Id, NovelPermission.ManageAccess),
            Throws.TypeOf<NotAuthorizedException>());
    }

    [Test]
    public async Task An_admin_reaches_every_novel()
    {
        AsNewUser(GlobalRole.Writer);
        await Novels.CreateAsync(new CreateNovelRequest("Writer's Novel"));

        AsAdmin();
        await Novels.CreateAsync(new CreateNovelRequest("Admin's Novel"));

        var visible = await Novels.ListAsync();
        Assert.That(visible, Has.Count.EqualTo(2));
    }

    [Test]
    public void Deleting_a_user_does_not_cascade_to_their_novels()
    {
        var ownerNavigation = Db.Context.Model.FindEntityType(typeof(Novel))!.FindNavigation(nameof(Novel.Owner))!;
        Assert.That(ownerNavigation.ForeignKey.DeleteBehavior, Is.EqualTo(DeleteBehavior.Restrict));
    }

    [Test]
    public async Task The_creator_of_a_novel_sees_their_role_as_owner()
    {
        var writerId = AsNewUser(GlobalRole.Writer);
        var novel = await Novels.CreateAsync(new CreateNovelRequest("Owned by writer"));

        UserContext.UserId = writerId;
        var role = await Access.GetMyRoleAsync(novel);

        Assert.That(role, Is.EqualTo("Owner"));
    }

    [Test]
    public async Task An_admin_sees_their_role_as_admin_even_on_a_novel_they_do_not_own()
    {
        AsNewUser(GlobalRole.Writer);
        var novel = await Novels.CreateAsync(new CreateNovelRequest("Owned by someone else"));

        AsAdmin();
        var role = await Access.GetMyRoleAsync(novel);

        Assert.That(role, Is.EqualTo("Admin"));
    }

    [Test]
    public async Task A_user_granted_editor_sees_their_role_as_editor()
    {
        var novel = await Novels.CreateAsync(new CreateNovelRequest("Granted Novel"));
        var editorId = AsNewUser(GlobalRole.Reviewer);
        GrantNovelRole(novel.Id, editorId, NovelRole.Editor);

        var role = await Access.GetMyRoleAsync(novel);

        Assert.That(role, Is.EqualTo("Editor"));
    }

    [Test]
    public async Task A_user_with_no_access_sees_a_null_role()
    {
        var novel = await Novels.CreateAsync(new CreateNovelRequest("Someone Else's Novel"));
        AsNewUser(GlobalRole.Writer);

        var role = await Access.GetMyRoleAsync(novel);

        Assert.That(role, Is.Null);
    }
}