using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Storage;
using RadicadeServer.DB;
using RadicadeServer.Leaderboard;
using RadicadeServer.RecNet.Auth;
using RadicadeServer.RecNet.Leaderboards;
using Xunit;

namespace RadicadeServer.Tests;

/// <summary>
/// The room scoreboard / watch leaderboard path: the client posts a stat with
/// CheckAndSetStat (SetStatRequestDTO: StatChannel + RoomId + StatValue, with identity
/// coming from the auth token rather than the body), then reads it back with GetRanks,
/// GetNearbyScores or GetPlayerRank. These tests drive the store end to end, because the
/// conformance suite only ever exercised an empty board.
/// </summary>
public class LeaderboardTests
{
    private const long RoomA = 25;
    private const long RoomB = 32;

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

        public TestDbContextFactory()
        {
            var root = new InMemoryDatabaseRoot();
            options = TestDbOptions.Create()
                .UseInMemoryDatabase(Guid.NewGuid().ToString(), root)
                .Options;
        }

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

    private static async Task SeedProfilesAsync(IDbContextFactory<RecDBContext> factory, params long[] ids)
    {
        await using var db = factory.CreateDbContext();
        foreach (var id in ids)
            db.Profiles.Add(new Profile
            {
                accountId = id,
                profileImage = "default.png",
                username = $"user{id}",
                displayName = $"User {id}",
            });
        await db.SaveChangesAsync();
    }

    private static string Stat(long roomId, int channel, int value) =>
        $"{{\"StatChannel\":{channel},\"RoomId\":{roomId},\"StatValue\":{value}}}";

    [Fact]
    public async Task SubmitScore_RanksPlayersAndKeepsRoomsSeparate()
    {
        var factory = new TestDbContextFactory();
        await SeedProfilesAsync(factory, 2, 3);

        await LeaderboardStore.SubmitScoreAsync(factory, Stat(RoomA, 1, 10), 2, 0);
        await LeaderboardStore.SubmitScoreAsync(factory, Stat(RoomA, 1, 40), 3, 0);
        // A different room's board on the same channel number must not leak into RoomA.
        await LeaderboardStore.SubmitScoreAsync(factory, Stat(RoomB, 1, 999), 2, 0);

        var board = await LeaderboardStore.GetRanksAsync(factory, new GetRanksRequest
        {
            RoomId = RoomA,
            StatChannel = 1,
            RankStart = 1,
            RankEnd = 10,
        });

        Assert.Equal(2, board.Total);
        Assert.Equal(2, board.Rows.Count);
        Assert.Equal(3, board.Rows[0].PlayerId);
        Assert.Equal(40, board.Rows[0].Score);
        Assert.Equal(1, board.Rows[0].Rank);
        Assert.Equal(2, board.Rows[1].PlayerId);
        Assert.Equal(2, board.Rows[1].Rank);
        Assert.Equal("User 3", board.Rows[0].PlayerName);
    }

    [Fact]
    public async Task SubmitScore_KeepsEachPlayersBestRatherThanTheirLast()
    {
        var factory = new TestDbContextFactory();
        await SeedProfilesAsync(factory, 2);

        await LeaderboardStore.SubmitScoreAsync(factory, Stat(RoomA, 1, 50), 2, 0);
        await LeaderboardStore.SubmitScoreAsync(factory, Stat(RoomA, 1, 10), 2, 0);

        var board = await LeaderboardStore.GetRanksAsync(factory, new GetRanksRequest
        {
            RoomId = RoomA,
            StatChannel = 1,
            RankStart = 1,
            RankEnd = 10,
        });

        Assert.Equal(1, board.Total);
        Assert.Equal(50, board.Rows[0].Score);
    }

    [Fact]
    public async Task SubmitScore_AscendingBoardRanksTheLowerTimeFirst()
    {
        var factory = new TestDbContextFactory();
        await SeedProfilesAsync(factory, 2, 3);

        // A race board: lower is better, and the client marks it with SortAscending.
        await LeaderboardStore.SubmitScoreAsync(factory, "{\"StatChannel\":2,\"RoomId\":25,\"Time\":9000}", 2, 0);
        await LeaderboardStore.SubmitScoreAsync(factory, "{\"StatChannel\":2,\"RoomId\":25,\"Time\":4000}", 3, 0);

        var board = await LeaderboardStore.GetRanksAsync(factory, new GetRanksRequest
        {
            RoomId = RoomA,
            StatChannel = 2,
            SortAscending = true,
            RankStart = 1,
            RankEnd = 10,
        });

        Assert.Equal(2, board.Total);
        Assert.Equal(3, board.Rows[0].PlayerId);
        Assert.Equal(1, board.Rows[0].Rank);
    }

    [Fact]
    public async Task SubmitScore_FallsBackToTheAuthenticatedPlayerWhenTheBodyHasNoPlayerId()
    {
        // The client's SetStatRequestDTO has no player field at all; identity is the token.
        var factory = new TestDbContextFactory();
        await SeedProfilesAsync(factory, 2);

        var result = await LeaderboardStore.SubmitScoreAsync(factory, Stat(RoomA, 3, 7), 2, 0);
        Assert.NotNull(result);

        await using var db = factory.CreateDbContext();
        var stored = await db.LeaderboardScores.SingleAsync();
        Assert.Equal(2, stored.PlayerId);
        Assert.Equal(7, stored.Score);
    }

    [Fact]
    public async Task GetNearbyScores_CentresTheWindowOnTheAskingPlayer()
    {
        var factory = new TestDbContextFactory();
        await SeedProfilesAsync(factory, 2, 3, 4, 5, 6);

        for (var i = 0; i < 5; i++)
            await LeaderboardStore.SubmitScoreAsync(factory, Stat(RoomA, 1, 10 * (i + 1)), 2 + i, 0);

        // Player 4 scored 30, so they sit third of five.
        var nearby = await LeaderboardStore.GetNearbyScoresAsync(factory, new GetNearbyScoresRequest
        {
            RoomId = RoomA,
            StatChannel = 1,
            PlayerId = 4,
            WindowSize = 3,
        });

        Assert.Equal(5, nearby.Total);
        Assert.Equal(3, nearby.MyRank);
        Assert.Contains(nearby.Rows, r => r.PlayerId == 4 && r.Rank == 3);
    }

    [Fact]
    public async Task EmptyBoard_StillNamesTheAskingPlayer()
    {
        // The scoreboard renders the row the server hands back, so the synthetic row for
        // a player who has not scored yet must still carry their name rather than an
        // empty string. Names were loaded only for players already on the board, which on
        // an empty board is nobody.
        var factory = new TestDbContextFactory();
        await SeedProfilesAsync(factory, 2);

        var ranks = await LeaderboardStore.GetRanksAsync(factory, new GetRanksRequest
        {
            RoomId = RoomA,
            StatChannel = 1,
            PlayerId = 2,
            RankStart = 1,
            RankEnd = 10,
        });
        Assert.Equal("User 2", ranks.Rows[0].PlayerName);

        var nearby = await LeaderboardStore.GetNearbyScoresAsync(factory, new GetNearbyScoresRequest
        {
            RoomId = RoomA,
            StatChannel = 1,
            PlayerId = 2,
            WindowSize = 10,
        });
        Assert.Equal("User 2", nearby.Rows[0].PlayerName);
    }

    [Fact]
    public async Task GetPlayerRank_NamesTheAskingPlayerWhenTheyHaveNotScored()
    {
        var factory = new TestDbContextFactory();
        await SeedProfilesAsync(factory, 2);

        var rank = await LeaderboardStore.GetPlayerRankAsync(factory, new GetRankRequest
        {
            RoomId = RoomA,
            StatChannel = 1,
            PlayerId = 2,
        });

        var name = rank.GetType().GetProperty("PlayerName")?.GetValue(rank) as string;
        Assert.Equal("User 2", name);
    }

    [Fact]
    public async Task GetPlayerRank_ReportsZeroForAPlayerWhoHasNotScored()
    {
        var factory = new TestDbContextFactory();
        await SeedProfilesAsync(factory, 2, 3);
        await LeaderboardStore.SubmitScoreAsync(factory, Stat(RoomA, 1, 10), 3, 0);

        var rank = await LeaderboardStore.GetPlayerRankAsync(factory, new GetRankRequest
        {
            RoomId = RoomA,
            StatChannel = 1,
            PlayerId = 2,
        });

        Assert.NotNull(rank);
    }
}