using System.Security.Claims;
using System.Text;
using System.Text.Json;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Storage;
using RadicadeServer;
using RadicadeServer.DB;
using RadicadeServer.RecNet.Auth;
using RadicadeServer.RecNet.Enums;
using RadicadeServer.RecNet.Enums.Rooms;
using RadicadeServer.RecNet.Rooms;
using RadicadeServer.RoomServer;
using RadicadeServer.Utils;
using Xunit;

namespace RadicadeServer.Tests;

/// <summary>
/// A player's room role is what decides everything they may do in that room, and the client
/// reads it out of the room payload. These pin the ways that went wrong: the role list being
/// served empty (which silently removed every co-owner's and moderator's permissions), the
/// owner missing from it, an invite matching the target's role in a DIFFERENT room, and the
/// Creator tier being grantable through the role route.
/// </summary>
[Collection(DbFactoryCollection.Name)]
public class RoomRolesTests
{
    private const long CreatorId = 11;
    private const long RoomId = 5;
    private const long MemberId = 22;
    private const long StrangerId = 999;

    private static readonly JsonSerializerOptions ServerJson = new()
    {
        PropertyNamingPolicy = null,
        WriteIndented = true,
    };

    private static string Serialize(object? value) => JsonSerializer.Serialize(value, ServerJson);

    private sealed class TestDbContextFactory : IDbContextFactory<RecDBContext>
    {
        private readonly DbContextOptions<RecDBContext> options;

        public TestDbContextFactory()
        {
            // A unique database name isolates each test; the store is NOT given its own
            // InMemoryDatabaseRoot, because a distinct root makes Entity Framework build a
            // distinct internal service provider every time and it throws once the process
            // has more than twenty of them.
            options = TestDbOptions.Create()
                .UseInMemoryDatabase(Guid.NewGuid().ToString())
                .Options;
        }

        public RecDBContext CreateDbContext() => new(options);
    }

    private static (TestDbContextFactory Factory, RecDBContext Db) CreateContext()
    {
        var factory = new TestDbContextFactory();
        RoomUtils.DbFactory = factory;
        MatchmakingUtils.DbFactory = factory;
        return (factory, factory.CreateDbContext());
    }

    private static void SetUser(Controller controller, long accountId)
    {
        var identity = new ClaimsIdentity("TestAuth");
        identity.AddClaim(new Claim(ClaimTypes.NameIdentifier, accountId.ToString()));
        controller.ControllerContext = new ControllerContext
        {
            HttpContext = new DefaultHttpContext { User = new ClaimsPrincipal(identity) }
        };
    }

    private static void SetFormBody(Controller controller, string body)
    {
        var request = controller.ControllerContext.HttpContext.Request;
        request.ContentType = "application/x-www-form-urlencoded";
        request.Body = new MemoryStream(Encoding.UTF8.GetBytes(body));
    }

    private static void SetQuery(Controller controller, string query)
        => controller.ControllerContext.HttpContext.Request.QueryString = new QueryString(query);

    private static async Task SeedRoomAsync(RecDBContext db, long roomId = RoomId, long creatorId = CreatorId)
    {
        var creator = await db.Players.FirstOrDefaultAsync(x => x.AccountId == creatorId);
        if (creator == null)
            db.Players.Add(new PlayerData { AccountId = creatorId, Hashword = "x" });

        var member = await db.Players.FirstOrDefaultAsync(x => x.AccountId == MemberId);
        if (member == null)
            db.Players.Add(new PlayerData { AccountId = MemberId, Hashword = "x" });

        db.Rooms.Add(new RoomData
        {
            RoomId = roomId,
            Name = $"Room {roomId}",
            CreatorAccountId = creatorId,
            Accessibility = Accessibility.Public,
            MaxPlayers = 8,
            CreatedAt = DateTime.UtcNow,
        });

        await db.SaveChangesAsync();
    }

    private static async Task<RoomRole?> ReadPersistedRoleAsync(TestDbContextFactory factory, long roomId, long accountId)
    {
        await using var db = factory.CreateDbContext();
        return await db.RoomRoles.AsNoTracking().FirstOrDefaultAsync(x => x.RoomId == roomId && x.AccountId == accountId);
    }

    [Fact]
    public async Task RolesAreServedEvenWhenTheHighRanksConfigIsMissing()
    {
        var (_, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db);
        db.RoomRoles.Add(new RoomRole { RoomId = RoomId, AccountId = MemberId, Role = RoleType.CoOwner, InvitedRole = RoleType.None });
        await db.SaveChangesAsync();

        // No ServerConfig "HighRanks" row: the role list used to come back empty here, which
        // took every co-owner's and moderator's permissions with it.
        var roles = await RoomUtils.GetRoles(RoomId);

        Assert.Contains(roles, x => x.AccountId == MemberId && x.Role == RoleType.CoOwner);
        Assert.True(await MatchmakingUtils.IsAtLeastRole(MemberId, RoomId, RoleType.CoOwner));
    }

    [Fact]
    public async Task TheRoomsCreatorAlwaysAppearsAsCreator()
    {
        var (_, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db);

        var roles = await RoomUtils.GetRoles(RoomId);
        var row = Assert.Single(roles);
        Assert.Equal(CreatorId, row.AccountId);
        Assert.Equal(RoleType.Creator, row.Role);

        // ...and the room the client loads carries the same entry, so the owner's own watch
        // shows them as the owner.
        var room = await RoomUtils.GetRoom(RoomId);
        Assert.Contains(room!.Roles, x => x.AccountId == CreatorId && x.Role == RoleType.Creator);
    }

    [Fact]
    public async Task RoleLookupUsesTheHighestRoleAnAccountHolds()
    {
        var (_, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db);
        db.RoomRoles.AddRange(
            new RoomRole { RoomId = RoomId, AccountId = MemberId, Role = RoleType.Moderator, InvitedRole = RoleType.None },
            new RoomRole { RoomId = RoomId, AccountId = MemberId, Role = RoleType.Creator, InvitedRole = RoleType.None });
        await db.SaveChangesAsync();

        var role = await RoomUtils.GetRoleForPlayer(MemberId, RoomId);

        Assert.NotNull(role);
        Assert.Equal(RoleType.Creator, role!.Role);
        Assert.True(await MatchmakingUtils.IsAtLeastRole(MemberId, RoomId, RoleType.CoOwner));
    }

    [Fact]
    public async Task InvitingAPlayerOnlyTouchesThisRoomsRole()
    {
        var (factory, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db, RoomId, CreatorId);
        await SeedRoomAsync(db, 6, CreatorId);
        db.RoomRoles.Add(new RoomRole { RoomId = 6, AccountId = MemberId, Role = RoleType.CoOwner, InvitedRole = RoleType.None });
        await db.SaveChangesAsync();

        var api = new RoomServerAPI(db);
        SetUser(api, CreatorId);
        SetFormBody(api, "role=30");

        var result = await api.InvitePlayerToRole(RoomId, MemberId);
        using var doc = JsonDocument.Parse(Serialize(result));
        Assert.True(doc.RootElement.GetProperty("success").GetBoolean());

        // The other room's role is untouched...
        var other = await ReadPersistedRoleAsync(factory, 6, MemberId);
        Assert.NotNull(other);
        Assert.Equal(RoleType.CoOwner, other!.Role);
        Assert.Null(other.LastChangedByAccountId);

        // ...and this room has its own pending invite.
        var invited = await ReadPersistedRoleAsync(factory, RoomId, MemberId);
        Assert.NotNull(invited);
        Assert.Equal(RoleType.None, invited!.Role);
        Assert.Equal(RoleType.CoOwner, invited.InvitedRole);
        Assert.Equal(CreatorId, invited.LastChangedByAccountId);
    }

    [Fact]
    public async Task SettingARoleRecordsWhoChangedItAndReturnsTheRoom()
    {
        var (factory, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db);

        var api = new RoomServerAPI(db);
        SetUser(api, CreatorId);
        SetQuery(api, "?role=20");

        var result = await api.SetPlayerRole(RoomId, MemberId);
        using var doc = JsonDocument.Parse(Serialize(result));

        Assert.True(doc.RootElement.GetProperty("success").GetBoolean());
        Assert.Equal(RoomId, doc.RootElement.GetProperty("value").GetProperty("RoomId").GetInt64());

        var granted = await ReadPersistedRoleAsync(factory, RoomId, MemberId);
        Assert.Equal(RoleType.Moderator, granted!.Role);
        Assert.Equal(RoleType.None, granted.InvitedRole);
        Assert.Equal(CreatorId, granted.LastChangedByAccountId);
    }

    [Fact]
    public async Task RoleEntriesCarryLastChangedByAccountIdOnTheWire()
    {
        var (_, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db);
        db.RoomRoles.Add(new RoomRole
        {
            RoomId = RoomId,
            AccountId = MemberId,
            Role = RoleType.CoOwner,
            InvitedRole = RoleType.None,
            LastChangedByAccountId = CreatorId,
        });
        await db.SaveChangesAsync();

        var room = await RoomUtils.GetRoom(RoomId);
        using var doc = JsonDocument.Parse(Serialize(room!.Roles));
        var entry = doc.RootElement.EnumerateArray()
            .Single(x => x.GetProperty("AccountId").GetInt64() == MemberId);

        Assert.Equal(CreatorId, entry.GetProperty("LastChangedByAccountId").GetInt64());
        Assert.True(entry.TryGetProperty("InvitedRole", out _));
    }

    [Fact]
    public async Task TheCreatorTierCannotBeGrantedThroughTheRoleRoute()
    {
        var (factory, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db);

        var api = new RoomServerAPI(db);
        SetUser(api, CreatorId);
        SetFormBody(api, "role=255");

        var result = await api.SetPlayerRole(RoomId, MemberId);
        using var doc = JsonDocument.Parse(Serialize(result));

        Assert.False(doc.RootElement.GetProperty("success").GetBoolean());
        Assert.Null(await ReadPersistedRoleAsync(factory, RoomId, MemberId));
    }

    [Fact]
    public async Task ARequestWithNoRoleIsRejectedInsteadOfDemotingThePlayer()
    {
        var (factory, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db);
        db.RoomRoles.Add(new RoomRole { RoomId = RoomId, AccountId = MemberId, Role = RoleType.CoOwner, InvitedRole = RoleType.None });
        await db.SaveChangesAsync();

        var api = new RoomServerAPI(db);
        SetUser(api, CreatorId);
        SetFormBody(api, ""); // no role field at all

        var result = await api.SetPlayerRole(RoomId, MemberId);
        using var doc = JsonDocument.Parse(Serialize(result));

        Assert.False(doc.RootElement.GetProperty("success").GetBoolean());
        Assert.Contains("valid role", doc.RootElement.GetProperty("error").GetString()!);

        // An unbound role must never read as None, which would strip the co-owner.
        var unchanged = await ReadPersistedRoleAsync(factory, RoomId, MemberId);
        Assert.Equal(RoleType.CoOwner, unchanged!.Role);
    }

    [Fact]
    public async Task DemotingAPlayerRemovesTheirRoleEntry()
    {
        var (factory, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db);
        db.RoomRoles.Add(new RoomRole { RoomId = RoomId, AccountId = MemberId, Role = RoleType.CoOwner, InvitedRole = RoleType.None });
        await db.SaveChangesAsync();

        var api = new RoomServerAPI(db);
        SetUser(api, CreatorId);
        SetFormBody(api, "role=0");

        var result = await api.SetPlayerRole(RoomId, MemberId);
        using var doc = JsonDocument.Parse(Serialize(result));

        Assert.True(doc.RootElement.GetProperty("success").GetBoolean());
        Assert.Null(await ReadPersistedRoleAsync(factory, RoomId, MemberId));
    }

    [Fact]
    public async Task SettingARoleRequiresCoOwnerRights()
    {
        var (factory, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db, RoomId, StrangerId);

        var api = new RoomServerAPI(db);
        SetUser(api, CreatorId);
        SetFormBody(api, "role=30");

        var result = await api.SetPlayerRole(RoomId, MemberId);
        using var doc = JsonDocument.Parse(Serialize(result));

        Assert.False(doc.RootElement.GetProperty("success").GetBoolean());
        Assert.Null(await ReadPersistedRoleAsync(factory, RoomId, MemberId));
    }

    [Fact]
    public async Task TheRoomsCreatorCannotBeGivenAnotherRole()
    {
        var (_, db) = CreateContext();
        await using var _db = db;

        await SeedRoomAsync(db);

        var api = new RoomServerAPI(db);
        SetUser(api, CreatorId);
        SetFormBody(api, "role=20");

        var result = await api.SetPlayerRole(RoomId, CreatorId);
        using var doc = JsonDocument.Parse(Serialize(result));

        Assert.False(doc.RootElement.GetProperty("success").GetBoolean());
    }
}