using System.Security.Claims;
using System.Text.Json;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using RadicadeServer.API.Keepsakes;
using RadicadeServer.DB;
using RadicadeServer.RecNet.Keepsakes;
using Xunit;

namespace RadicadeServer.Tests;

/// <summary>
/// Keepsake rooms: which rooms the server tells the client it may place keepsakes in.
///
/// The client's room-role permissions have no keepsake entry and its room DTO carries no keepsake
/// field, so the room's <c>KeepsakeRoomListId</c> - the thing it reports as missing with
/// "This room does not have keepsake permissions." - can only arrive with
/// <c>GET /api/keepsakes/rooms/{id}</c>. A configured room therefore answers with the room fields
/// even while it holds nothing, and an unconfigured one keeps the old NO CONTENT.
/// </summary>
public class KeepsakeRoomConfigTests
{
    private const long Room = 25;

    private static RecDBContext NewDb()
        => new RecDBContext(TestDbOptions.Create()
            .UseInMemoryDatabase(Guid.NewGuid().ToString()).Options);

    private static KeepsakesAPI CreateApi(RecDBContext? db)
    {
        var identity = new ClaimsIdentity("TestAuth");
        identity.AddClaim(new Claim(ClaimTypes.NameIdentifier, "2"));
        var context = new DefaultHttpContext { User = new ClaimsPrincipal(identity) };
        return new KeepsakesAPI(db!) { ControllerContext = new ControllerContext { HttpContext = context } };
    }

    /// <summary>
    /// Runs one endpoint call against a config. The seam is process-wide and the endpoint reads it
    /// per call, so the override only has to be in place for the call itself.
    /// </summary>
    private static async Task<T> WithConfigAsync<T>(KeepsakeRoomConfig config, Func<Task<T>> call)
    {
        var previous = KeepsakeRoomConfig.Override;
        KeepsakeRoomConfig.Override = config;
        try
        {
            return await call();
        }
        finally
        {
            KeepsakeRoomConfig.Override = previous;
        }
    }

    [Fact]
    public void NothingConfiguredIsNothingConfigured()
    {
        var config = KeepsakeRoomConfig.Parse(null);

        Assert.False(config.Any);
        Assert.False(config.IsKeepsakeRoom(Room));
        Assert.Equal(KeepsakeRoomConfig.DefaultRoomListId, config.RoomListId);
        Assert.Equal(KeepsakeRoomConfig.DefaultRoomLimit, config.RoomLimit);
    }

    [Fact]
    public void ExplicitEnvironmentRoomsReplaceAllRoomsFromFile()
    {
        var config = KeepsakeRoomConfig.Parse("""{"AllRooms":true}""", rooms: "25");
        Assert.True(config.IsKeepsakeRoom(25));
        Assert.False(config.IsKeepsakeRoom(26));
    }

    [Theory]
    [InlineData(0)]
    [InlineData(-1)]
    [InlineData(4294967297L)]
    public void InvalidRoomLimitsUseDefault(long limit)
    {
        var config = KeepsakeRoomConfig.Parse($$"""{"RoomLimit":{{limit}}}""");
        Assert.Equal(KeepsakeRoomConfig.DefaultRoomLimit, config.RoomLimit);
    }

    [Fact]
    public void AllRoomsFlagMakesEveryRoomAKeepsakeRoom()
    {
        var config = KeepsakeRoomConfig.Parse("""{ "AllRooms": true }""");

        Assert.True(config.Any);
        Assert.True(config.IsKeepsakeRoom(1));
        Assert.True(config.IsKeepsakeRoom(Room));

        // No useful list of "every room" exists, so the payload advertises the room asked about.
        Assert.Equal(new[] { Room }, config.AdvertisedRooms(Room));
    }

    [Fact]
    public void RoomIdsAcceptNumbersAndStrings()
    {
        var config = KeepsakeRoomConfig.Parse("""{ "RoomIds": [3, "25"], "RoomListId": 7, "RoomLimit": 5 }""");

        Assert.True(config.IsKeepsakeRoom(3));
        Assert.True(config.IsKeepsakeRoom(Room));
        Assert.False(config.IsKeepsakeRoom(26));
        Assert.Equal(7, config.RoomListId);
        Assert.Equal(5, config.RoomLimit);
        Assert.Equal(new long[] { 3, Room }, config.AdvertisedRooms(Room));
    }

    [Fact]
    public void ABareArrayIsAListOfRooms()
    {
        var config = KeepsakeRoomConfig.Parse("[3, 25]");

        Assert.True(config.IsKeepsakeRoom(3));
        Assert.True(config.IsKeepsakeRoom(Room));
    }

    /// <summary>
    /// A half-written file is "nothing configured", not a crash and not an enabled server: this
    /// switch decides whether rooms may hold keepsakes, so a typo must not turn it on.
    /// </summary>
    [Fact]
    public void AMalformedFileConfiguresNothing()
    {
        var config = KeepsakeRoomConfig.Parse("{ \"RoomIds\": [3,");

        Assert.False(config.Any);
        Assert.False(config.IsKeepsakeRoom(3));
    }

    /// <summary>
    /// The environment names the rooms INSTEAD of the file: an operator reaching for
    /// <c>RADICADE_KEEPSAKE_ROOMS=*</c> means "all of them", not "all of them plus this list".
    /// </summary>
    [Fact]
    public void TheEnvironmentReplacesTheFilesRooms()
    {
        var replaced = KeepsakeRoomConfig.Parse("""{ "RoomIds": [3] }""", rooms: "25;26");
        Assert.False(replaced.IsKeepsakeRoom(3));
        Assert.True(replaced.IsKeepsakeRoom(25));
        Assert.True(replaced.IsKeepsakeRoom(26));

        var all = KeepsakeRoomConfig.Parse("""{ "RoomIds": [3] }""", rooms: "*");
        Assert.True(all.AllRooms);
        Assert.True(all.IsKeepsakeRoom(9999));
    }

    [Fact]
    public void TheEnvironmentCarriesTheListIdAndLimit()
    {
        var config = KeepsakeRoomConfig.Parse(null, rooms: "25", roomListId: "9", roomLimit: "12");

        Assert.Equal(9, config.RoomListId);
        Assert.Equal(12, config.RoomLimit);
    }

    /// <summary>
    /// A keepsake room answers with the room fields even while it holds nothing, and the answer
    /// still carries the three instance lists the client parses.
    /// </summary>
    [Fact]
    public async Task AConfiguredRoomAnswersTheRoomFields()
    {
        await using var db = NewDb();
        var api = CreateApi(db);

        var result = await WithConfigAsync(
            KeepsakeRoomConfig.Parse("""{ "RoomIds": [25], "RoomListId": 7, "RoomLimit": 5 }"""),
            () => api.Room(Room));

        var ok = Assert.IsType<OkObjectResult>(result);
        var json = JsonSerializer.SerializeToElement(ok.Value);

        Assert.Equal(Room, json.GetProperty("KeepsakeRoomId").GetInt64());
        Assert.Equal(7, json.GetProperty("KeepsakeRoomListId").GetInt64());
        Assert.Equal(5, json.GetProperty("KeepsakeRoomLimit").GetInt32());
        Assert.Equal(new long[] { Room }, json.GetProperty("KeepsakeRooms").EnumerateArray().Select(e => e.GetInt64()).ToArray());

        // The list the client resolves has to contain the room it is loading.
        var list = Assert.Single(json.GetProperty("KeepsakeRoomLists").EnumerateArray());
        Assert.Equal(7, list.GetProperty("KeepsakeRoomListId").GetInt64());
        Assert.Equal(new long[] { Room }, list.GetProperty("KeepsakeRooms").EnumerateArray().Select(e => e.GetProperty("RoomId").GetInt64()).ToArray());

        // Nothing is placed, so there is nothing for the keepsake loader to resolve - which is
        // what keeps this answer from being the body the client null-references over.
        Assert.Empty(json.GetProperty("KeepsakeInstances").EnumerateArray());
        Assert.Empty(json.GetProperty("KeepsakeCollectionRecords").EnumerateArray());
        // The room names the progression event its keepsakes belong to: that id is what the client
        // looks up among the active events before it offers a keepsake to place at all.
        Assert.Equal(
            new[] { KeepsakeRoomConfig.DefaultEventId },
            json.GetProperty("KeepsakeProgressionEventIds").EnumerateArray().Select(e => e.GetInt64()).ToArray());
    }

    [Fact]
    public async Task AnUnconfiguredRoomStillAnswersNoContent()
    {
        await using var db = NewDb();
        var api = CreateApi(db);

        var result = await WithConfigAsync(KeepsakeRoomConfig.Parse("""{ "RoomIds": [999] }"""), () => api.Room(Room));

        Assert.IsType<NoContentResult>(result);
    }

    /// <summary>A room that already holds a keepsake keeps its body whether or not it is listed -
    /// while the feature itself is on, which is forced here because a server with no keepsake room
    /// configured is a server with keepsakes disabled.</summary>
    [Fact]
    public async Task ARoomWithAPlacedKeepsakeKeepsItsBody()
    {
        await using var db = NewDb();
        await db.KeepsakeInstances.AddAsync(new KeepsakeInstance
        {
            KeepsakeInstanceId = Guid.Parse("a75f7547-79eb-47c6-8986-6767abcb4f92"),
            RoomId = Room,
            KeepsakeCategoryId = 0,
            PlacedByAccountId = 2,
            PlacedAt = DateTime.UtcNow
        });
        await db.SaveChangesAsync();

        var api = CreateApi(db);
        var previousFeature = KeepsakeFeature.Override;
        KeepsakeFeature.Override = true;
        try
        {
            var result = await WithConfigAsync(KeepsakeRoomConfig.Parse(null), () => api.Room(Room));

            var ok = Assert.IsType<OkObjectResult>(result);
            var json = JsonSerializer.SerializeToElement(ok.Value);

            Assert.Single(json.GetProperty("KeepsakeInstances").EnumerateArray());
            Assert.False(json.TryGetProperty("KeepsakeRoomListId", out _));
        }
        finally
        {
            KeepsakeFeature.Override = previousFeature;
        }
    }

    /// <summary>
    /// ...and with the feature OFF the same room answers NO CONTENT, keepsake and all. That is the
    /// point of the switch: a disabled server does not describe keepsakes to a client at all, so a
    /// room holding a placed keepsake is not the exception that still talks about one.
    /// </summary>
    [Fact]
    public async Task TheFeatureSwitchHidesEvenPlacedKeepsakes()
    {
        await using var db = NewDb();
        await db.KeepsakeInstances.AddAsync(new KeepsakeInstance
        {
            KeepsakeInstanceId = Guid.NewGuid(),
            RoomId = Room,
            KeepsakeCategoryId = 0,
            PlacedByAccountId = 2,
            PlacedAt = DateTime.UtcNow
        });
        await db.SaveChangesAsync();

        var previousFeature = KeepsakeFeature.Override;
        KeepsakeFeature.Override = false;
        try
        {
            var result = await WithConfigAsync(KeepsakeRoomConfig.Parse("""{ "AllRooms": true }"""),
                () => CreateApi(db).Room(Room));

            Assert.IsType<NoContentResult>(result);
        }
        finally
        {
            KeepsakeFeature.Override = previousFeature;
        }
    }

    /// <summary>
    /// The file this repository ships gives every room the permission. That answer is the one the
    /// client reads off `GET /api/keepsakes/rooms/{id}` as "this room can hold keepsakes", so a
    /// checkout that shipped it switched off would keep the MakerPen banner the feature exists to
    /// clear. Narrowing it is an operator edit - `AllRooms: false` plus the ids in `RoomIds`.
    /// </summary>
    [Fact]
    public void TheShippedConfigEnablesKeepsakesAsRequested()
    {
        var path = ShippedConfigPath();
        Assert.NotNull(path);

        var config = KeepsakeRoomConfig.Parse(File.ReadAllText(path!));

        Assert.True(config.Any);
        Assert.True(config.AllRooms);
        Assert.True(config.IsKeepsakeRoom(25));
        Assert.True(config.RoomLimit > 0);
        Assert.True(config.EventId > 0);
    }

    /// <summary>
    /// The feature switch follows that config: no keepsake room configured means the whole feature
    /// is off, which is the state the room, the catalog, the event and the client's own feature flag
    /// all read - see <see cref="KeepsakeFeature"/>. RADICADE_KEEPSAKES is the operator's override of
    /// exactly that inference.
    /// </summary>
    [Fact]
    public void NoKeepsakeRoomMeansTheFeatureIsOff()
    {
        Assert.False(KeepsakeFeature.EnabledFor(KeepsakeRoomConfig.Parse(null), environment: null));
        Assert.False(KeepsakeFeature.EnabledFor(KeepsakeRoomConfig.Parse(null), environment: "off"));
        Assert.True(KeepsakeFeature.EnabledFor(KeepsakeRoomConfig.Parse("""{ "AllRooms": true }"""), environment: null));
        Assert.True(KeepsakeFeature.EnabledFor(KeepsakeRoomConfig.Parse("""{ "RoomIds": [25] }"""), environment: null));
        Assert.False(KeepsakeFeature.EnabledFor(KeepsakeRoomConfig.Parse("""{ "AllRooms": true }"""), environment: "off"));
        Assert.True(KeepsakeFeature.EnabledFor(KeepsakeRoomConfig.Parse(null), environment: "on"));
    }

    /// <summary>
    /// The checked-in config, found from the test binaries rather than from the working directory:
    /// the test host's cwd is a bin folder, so the file the repository ships would otherwise go
    /// unread and this guard would silently pass.
    /// </summary>
    private static string? ShippedConfigPath()
    {
        var directory = new DirectoryInfo(AppContext.BaseDirectory);
        for (var depth = 0; depth < 6 && directory != null; depth++, directory = directory.Parent)
        {
            var candidate = Path.Join(directory.FullName, "Server", "RadicadeServer-Config", KeepsakeRoomConfig.FileName);
            if (File.Exists(candidate)) return candidate;
        }

        return null;
    }
}